Tips

Myth: Sunscreens cause cancer

Regular sunscreen use is recommended by the American Academy of Dermatology as a primary method of sun protection to reduce the risk of melanoma and other nonmelanoma skin cancers. However, due to reports in the media, patients often inquire if sunscreen ingredients, specifically oxybenzone and retinyl palmitate as well as nanoparticles, are toxic and actually cause malignant melanoma and other skin cancers rather than prevent them.

Overall, the known benefits of sunscreen use to minimize short-term and long-term damage to the skin from UV radiation outweigh any unproven claims of toxicity or human health hazard. Active ingredients in sunscreens, such as oxybenzone and retinyl palmitate, are regulated as over-the-counter drugs by the US Food and Drug Administration and have a long-standing history of providing effective broad-spectrum protection from UV radiation. Despite concerns that oxybenzone can penetrate the skin and effect hormone levels, there is no evidence supporting this claim. Although oxybenzone is absorbed by the body, it is subsequently excreted and has no potential for harmful buildup. It also has been suggested that retinyl palmitate generates free radicals that can lead to cancer formation; however, the risk has only been linked to UV exposure in isolation, and antioxidants in the body can theoretically neutralize these free radicals before they lead to cancer development.

Sunscreens containing nanoparticles of inorganic filters such as zinc oxide and titanium dioxide also have been scrutinized. These formulations have largely proven effective in protecting against UVA and UVB radiation, and claims that nanoparticles are small enough to penetrate the epidermis and be absorbed in the human bloodstream have been refuted.

The positive association between sunscreen use and risk of developing malignant melanoma may be due to selection bias and uncontrolled confounding in studies rather than proven toxicity of sunscreen ingredients. Results from a meta-analysis of 11 case-control studies indicated that there is no association and the researchers discussed the role of selection bias in contributing to the positive association between sunscreen use and melanoma development. For instance, some studies failed to control for factors that commonly are linked with increased melanoma risk (eg, red or fair hair color, blue eye color, presence of nevi, freckling). Also, increased sun exposure among patients who use sunscreens may have impacted study results.

Dermatologists should emphasize to concerned patients that long-term sunscreen use has been proven to reduce the incidence of melanoma. A 2011 Australian study evaluated the effects of long-term application of sunscreen on the risk of cutaneous melanoma in 1621 randomly selected participants who applied sunscreen in combination with 30 mg of beta-carotene or placebo supplements for 4 years and were observed for 10 more years. They observed a reduction in primary melanomas and invasive melanomas in the sunscreen group, concluding that melanoma may be preventable with regular sunscreen use in adults.

For patients who are still concerned, dermatologists can recommend sunscreens containing organic UV filters only. Education about factors that contribute to the increased rate of melanoma also is necessary. Longer lifespans, the thinning ozone layer, increased popularity of outdoor activities, exposed skin due to clothing style, use of tanning beds, earlier detection of skin cancer, and other factors may be responsible. Greater exposure to UV radiation rather than commercial sunscreens is the likely cause of skin cancer.

Myth: Sunscreens cause cancer

Regular sunscreen use is recommended by the American Academy of Dermatology as a primary method of sun protection to reduce the risk of melanoma and other nonmelanoma skin cancers. However, due to reports in the media, patients often inquire if sunscreen ingredients, specifically oxybenzone and retinyl palmitate as well as nanoparticles, are toxic and actually cause malignant melanoma and other skin cancers rather than prevent them.

Overall, the known benefits of sunscreen use to minimize short-term and long-term damage to the skin from UV radiation outweigh any unproven claims of toxicity or human health hazard. Active ingredients in sunscreens, such as oxybenzone and retinyl palmitate, are regulated as over-the-counter drugs by the US Food and Drug Administration and have a long-standing history of providing effective broad-spectrum protection from UV radiation. Despite concerns that oxybenzone can penetrate the skin and effect hormone levels, there is no evidence supporting this claim. Although oxybenzone is absorbed by the body, it is subsequently excreted and has no potential for harmful buildup. It also has been suggested that retinyl palmitate generates free radicals that can lead to cancer formation; however, the risk has only been linked to UV exposure in isolation, and antioxidants in the body can theoretically neutralize these free radicals before they lead to cancer development.

Sunscreens containing nanoparticles of inorganic filters such as zinc oxide and titanium dioxide also have been scrutinized. These formulations have largely proven effective in protecting against UVA and UVB radiation, and claims that nanoparticles are small enough to penetrate the epidermis and be absorbed in the human bloodstream have been refuted.

The positive association between sunscreen use and risk of developing malignant melanoma may be due to selection bias and uncontrolled confounding in studies rather than proven toxicity of sunscreen ingredients. Results from a meta-analysis of 11 case-control studies indicated that there is no association and the researchers discussed the role of selection bias in contributing to the positive association between sunscreen use and melanoma development. For instance, some studies failed to control for factors that commonly are linked with increased melanoma risk (eg, red or fair hair color, blue eye color, presence of nevi, freckling). Also, increased sun exposure among patients who use sunscreens may have impacted study results.

Dermatologists should emphasize to concerned patients that long-term sunscreen use has been proven to reduce the incidence of melanoma. A 2011 Australian study evaluated the effects of long-term application of sunscreen on the risk of cutaneous melanoma in 1621 randomly selected participants who applied sunscreen in combination with 30 mg of beta-carotene or placebo supplements for 4 years and were observed for 10 more years. They observed a reduction in primary melanomas and invasive melanomas in the sunscreen group, concluding that melanoma may be preventable with regular sunscreen use in adults.

For patients who are still concerned, dermatologists can recommend sunscreens containing organic UV filters only. Education about factors that contribute to the increased rate of melanoma also is necessary. Longer lifespans, the thinning ozone layer, increased popularity of outdoor activities, exposed skin due to clothing style, use of tanning beds, earlier detection of skin cancer, and other factors may be responsible. Greater exposure to UV radiation rather than commercial sunscreens is the likely cause of skin cancer.

Myth: Sunscreens cause cancer

Regular sunscreen use is recommended by the American Academy of Dermatology as a primary method of sun protection to reduce the risk of melanoma and other nonmelanoma skin cancers. However, due to reports in the media, patients often inquire if sunscreen ingredients, specifically oxybenzone and retinyl palmitate as well as nanoparticles, are toxic and actually cause malignant melanoma and other skin cancers rather than prevent them.

Overall, the known benefits of sunscreen use to minimize short-term and long-term damage to the skin from UV radiation outweigh any unproven claims of toxicity or human health hazard. Active ingredients in sunscreens, such as oxybenzone and retinyl palmitate, are regulated as over-the-counter drugs by the US Food and Drug Administration and have a long-standing history of providing effective broad-spectrum protection from UV radiation. Despite concerns that oxybenzone can penetrate the skin and effect hormone levels, there is no evidence supporting this claim. Although oxybenzone is absorbed by the body, it is subsequently excreted and has no potential for harmful buildup. It also has been suggested that retinyl palmitate generates free radicals that can lead to cancer formation; however, the risk has only been linked to UV exposure in isolation, and antioxidants in the body can theoretically neutralize these free radicals before they lead to cancer development.

Sunscreens containing nanoparticles of inorganic filters such as zinc oxide and titanium dioxide also have been scrutinized. These formulations have largely proven effective in protecting against UVA and UVB radiation, and claims that nanoparticles are small enough to penetrate the epidermis and be absorbed in the human bloodstream have been refuted.

The positive association between sunscreen use and risk of developing malignant melanoma may be due to selection bias and uncontrolled confounding in studies rather than proven toxicity of sunscreen ingredients. Results from a meta-analysis of 11 case-control studies indicated that there is no association and the researchers discussed the role of selection bias in contributing to the positive association between sunscreen use and melanoma development. For instance, some studies failed to control for factors that commonly are linked with increased melanoma risk (eg, red or fair hair color, blue eye color, presence of nevi, freckling). Also, increased sun exposure among patients who use sunscreens may have impacted study results.

Dermatologists should emphasize to concerned patients that long-term sunscreen use has been proven to reduce the incidence of melanoma. A 2011 Australian study evaluated the effects of long-term application of sunscreen on the risk of cutaneous melanoma in 1621 randomly selected participants who applied sunscreen in combination with 30 mg of beta-carotene or placebo supplements for 4 years and were observed for 10 more years. They observed a reduction in primary melanomas and invasive melanomas in the sunscreen group, concluding that melanoma may be preventable with regular sunscreen use in adults.

For patients who are still concerned, dermatologists can recommend sunscreens containing organic UV filters only. Education about factors that contribute to the increased rate of melanoma also is necessary. Longer lifespans, the thinning ozone layer, increased popularity of outdoor activities, exposed skin due to clothing style, use of tanning beds, earlier detection of skin cancer, and other factors may be responsible. Greater exposure to UV radiation rather than commercial sunscreens is the likely cause of skin cancer.

Myth: Psoriasis treatments may cause depression

It has been well documented that patients with inflammatory diseases such as psoriasis have an increased risk for depression. One population-based cohort study in the United Kingdom reported the risk of depression was greater in patients with severe psoriasis versus mild psoriasis. Younger psoriasis patients also had a higher risk compared to older patients. A US population-based study also reported that psoriasis was associated with major depression, but the severity of psoriasis and patient's age were unrelated. Therefore, all psoriasis patients may be at risk.

But are some therapies associated with an increased risk of depression? Increased concentrations of proinflammatory cytokines such as tumor necrosis factor α have been associated with depression apart from psoriasis. Administering immunomodulating agents has been shown to increase the risk of depression.

Depression has been cited as an adverse effect of apremilast in the drug's package insert, which states, "Before using [apremilast] in patients with a history of depression and/or suicidal thoughts or behavior prescribers should carefully weigh the risks and benefits of treatment." In clinical trials, 1.3% (12/920) of participants treated with apremilast reported depression compared to 0.4% (2/506) treated with placebo. Dermatologists should remain vigilant about monitoring for symptoms of depression in patients treated with apremilast.

However, depression in the context of autoimmune disorders or any disorder with increased inflammation has responded to treatment with tumor necrosis factor α antagonists. The relationship between depression and inflammation suggests that there is an inflammatory subtype of depression and use of anti-inflammatory agents may treat both inflammation and depression.

Disease control has been shown to improve symptoms of depression in psoriasis patients. A study of 618 patients with moderate to severe psoriasis who were treated with etanercept or placebo for 12 weeks revealed that more patients receiving etanercept experienced 50% improvement in 2 rating scales of depression compared to placebo.

Excessive worrying, a form of psychological distress, can impact treatment outcomes in patients with psoriasis. A 2003 study found that patients with psoriasis who are classified as high-level worriers may benefit from adjunctive psychological intervention before and during treatment. In this cohort of psoriasis patients receiving psoralen plus UVA (PUVA) therapy, high-level worry was the only significant predictor of time taken for PUVA to clear psoriasis (P=.01). Patients in the high-level worry group cleared with PUVA treatment at a rate of 1.8 times slower than the low-level worry group.

In conclusion, psoriasis patients should follow the treatment plan outlined by dermatologists, as improving psoriasis symptoms may help alleviate depression or prevent it from occurring. Patients with a history of depression should be monitored carefully by dermatologists or referred to another health care professional, and patients as well as family and friends should be encouraged to report any depression symptoms.

Expert Commentary

The prescribing information for apremilast lists a warning (but not a black-box warning) for depression. Long-term registries will determine if there is truly an increased risk of depression when taking apremilast. When I counsel patients before prescribing apremilast, I mention this potential increased risk of depression as noted in the prescribing information, but I tell them that the risk is very low and that a true risk has not yet been determined in long-term registries. I mention to patients that if they really do feel depressed after starting apremilast, they should stop taking apremilast and contact me.

Long-term registries for etanercept, adalimumab, infliximab, and ustekinumab do not indicate an increased risk for depression. Intuitively, if a patient with severe psoriasis has depression worsened by their psoriasis, it stands to reason that improving their skin will likely improve their mood, which clinical trials have shown using patient-related outcomes.

—Jashin J. Wu, MD (Los Angeles, California)

Myth: Psoriasis treatments may cause depression

It has been well documented that patients with inflammatory diseases such as psoriasis have an increased risk for depression. One population-based cohort study in the United Kingdom reported the risk of depression was greater in patients with severe psoriasis versus mild psoriasis. Younger psoriasis patients also had a higher risk compared to older patients. A US population-based study also reported that psoriasis was associated with major depression, but the severity of psoriasis and patient's age were unrelated. Therefore, all psoriasis patients may be at risk.

But are some therapies associated with an increased risk of depression? Increased concentrations of proinflammatory cytokines such as tumor necrosis factor α have been associated with depression apart from psoriasis. Administering immunomodulating agents has been shown to increase the risk of depression.

Depression has been cited as an adverse effect of apremilast in the drug's package insert, which states, "Before using [apremilast] in patients with a history of depression and/or suicidal thoughts or behavior prescribers should carefully weigh the risks and benefits of treatment." In clinical trials, 1.3% (12/920) of participants treated with apremilast reported depression compared to 0.4% (2/506) treated with placebo. Dermatologists should remain vigilant about monitoring for symptoms of depression in patients treated with apremilast.

However, depression in the context of autoimmune disorders or any disorder with increased inflammation has responded to treatment with tumor necrosis factor α antagonists. The relationship between depression and inflammation suggests that there is an inflammatory subtype of depression and use of anti-inflammatory agents may treat both inflammation and depression.

Disease control has been shown to improve symptoms of depression in psoriasis patients. A study of 618 patients with moderate to severe psoriasis who were treated with etanercept or placebo for 12 weeks revealed that more patients receiving etanercept experienced 50% improvement in 2 rating scales of depression compared to placebo.

Excessive worrying, a form of psychological distress, can impact treatment outcomes in patients with psoriasis. A 2003 study found that patients with psoriasis who are classified as high-level worriers may benefit from adjunctive psychological intervention before and during treatment. In this cohort of psoriasis patients receiving psoralen plus UVA (PUVA) therapy, high-level worry was the only significant predictor of time taken for PUVA to clear psoriasis (P=.01). Patients in the high-level worry group cleared with PUVA treatment at a rate of 1.8 times slower than the low-level worry group.

In conclusion, psoriasis patients should follow the treatment plan outlined by dermatologists, as improving psoriasis symptoms may help alleviate depression or prevent it from occurring. Patients with a history of depression should be monitored carefully by dermatologists or referred to another health care professional, and patients as well as family and friends should be encouraged to report any depression symptoms.

Expert Commentary

The prescribing information for apremilast lists a warning (but not a black-box warning) for depression. Long-term registries will determine if there is truly an increased risk of depression when taking apremilast. When I counsel patients before prescribing apremilast, I mention this potential increased risk of depression as noted in the prescribing information, but I tell them that the risk is very low and that a true risk has not yet been determined in long-term registries. I mention to patients that if they really do feel depressed after starting apremilast, they should stop taking apremilast and contact me.

Long-term registries for etanercept, adalimumab, infliximab, and ustekinumab do not indicate an increased risk for depression. Intuitively, if a patient with severe psoriasis has depression worsened by their psoriasis, it stands to reason that improving their skin will likely improve their mood, which clinical trials have shown using patient-related outcomes.

—Jashin J. Wu, MD (Los Angeles, California)

Myth: Psoriasis treatments may cause depression

It has been well documented that patients with inflammatory diseases such as psoriasis have an increased risk for depression. One population-based cohort study in the United Kingdom reported the risk of depression was greater in patients with severe psoriasis versus mild psoriasis. Younger psoriasis patients also had a higher risk compared to older patients. A US population-based study also reported that psoriasis was associated with major depression, but the severity of psoriasis and patient's age were unrelated. Therefore, all psoriasis patients may be at risk.

But are some therapies associated with an increased risk of depression? Increased concentrations of proinflammatory cytokines such as tumor necrosis factor α have been associated with depression apart from psoriasis. Administering immunomodulating agents has been shown to increase the risk of depression.

Depression has been cited as an adverse effect of apremilast in the drug's package insert, which states, "Before using [apremilast] in patients with a history of depression and/or suicidal thoughts or behavior prescribers should carefully weigh the risks and benefits of treatment." In clinical trials, 1.3% (12/920) of participants treated with apremilast reported depression compared to 0.4% (2/506) treated with placebo. Dermatologists should remain vigilant about monitoring for symptoms of depression in patients treated with apremilast.

However, depression in the context of autoimmune disorders or any disorder with increased inflammation has responded to treatment with tumor necrosis factor α antagonists. The relationship between depression and inflammation suggests that there is an inflammatory subtype of depression and use of anti-inflammatory agents may treat both inflammation and depression.

Disease control has been shown to improve symptoms of depression in psoriasis patients. A study of 618 patients with moderate to severe psoriasis who were treated with etanercept or placebo for 12 weeks revealed that more patients receiving etanercept experienced 50% improvement in 2 rating scales of depression compared to placebo.

Excessive worrying, a form of psychological distress, can impact treatment outcomes in patients with psoriasis. A 2003 study found that patients with psoriasis who are classified as high-level worriers may benefit from adjunctive psychological intervention before and during treatment. In this cohort of psoriasis patients receiving psoralen plus UVA (PUVA) therapy, high-level worry was the only significant predictor of time taken for PUVA to clear psoriasis (P=.01). Patients in the high-level worry group cleared with PUVA treatment at a rate of 1.8 times slower than the low-level worry group.

In conclusion, psoriasis patients should follow the treatment plan outlined by dermatologists, as improving psoriasis symptoms may help alleviate depression or prevent it from occurring. Patients with a history of depression should be monitored carefully by dermatologists or referred to another health care professional, and patients as well as family and friends should be encouraged to report any depression symptoms.

Expert Commentary

The prescribing information for apremilast lists a warning (but not a black-box warning) for depression. Long-term registries will determine if there is truly an increased risk of depression when taking apremilast. When I counsel patients before prescribing apremilast, I mention this potential increased risk of depression as noted in the prescribing information, but I tell them that the risk is very low and that a true risk has not yet been determined in long-term registries. I mention to patients that if they really do feel depressed after starting apremilast, they should stop taking apremilast and contact me.

Long-term registries for etanercept, adalimumab, infliximab, and ustekinumab do not indicate an increased risk for depression. Intuitively, if a patient with severe psoriasis has depression worsened by their psoriasis, it stands to reason that improving their skin will likely improve their mood, which clinical trials have shown using patient-related outcomes.

—Jashin J. Wu, MD (Los Angeles, California)

Injury of the anterior cruciate ligament (ACL) is very common with over 200,000 annual injuries in the United Status.^1,2 There is a general consensus that these injuries should not be treated conservatively in patients that are younger, or who wish to remain active.^3,4 Reconstructive surgery is currently the preferred treatment in these patients, and anatomic single-bundle reconstruction with autografts is considered the gold standard.^5,6

Reconstruction of the ACL is, however, not a perfect treatment. Following single-bundle autograft reconstruction, revision rates of 3% to 8%,^6-9 contralateral injury rates of 3% to 8%,^10,11 and infection rates of 0.5% to 3%^7,12,13 have been reported. Furthermore, due to the invasive nature of graft harvesting and the surgical procedure, 10% to 25% of the patients are not satisfied following ACL reconstruction.^14,15 This can often be explained by common complaints, such as anterior knee pain (13%-43%), kneeling pain (12%-54%), quadriceps muscle atrophy (20%-30%),^16,17 and loss of range of motion (ROM) (12%-23%).^7,9,18,19 Furthermore, as a result of the invasive nature of reconstructive surgery, revisions can be difficult due to complications, such as tunnel widening, tunnel malpositioning, and preexisting hardware.^20-22 This can lead to inferior outcomes and higher rates (13%) of revision surgery compared to primary reconstruction.^23-26 Finally, reconstructive surgery does not restore native kinematics of the ACL,^27-29 which may partially explain why reconstructive surgery has not been shown to prevent osteoarthritis.^28-31

Over the past decades, there has been an increasing interest in the preservation of the ACL in an attempt to ameliorate these issues.^32-37 Ligament preservation focuses on preserving the native tissues and biology, while minimizing the surgical morbidity to the patients.

Some authors have recently reported on arthroscopic primary repair of proximal ACL tears in which the ligament is reattached onto the femoral wall using modern-day suture anchor technology.^32,38 Others have augmented this repair technique with an internal brace^39,40 or with a synthetic device.^33,41 When performing primary repair, it is believed that proprioception is maintained,^42-44 while experimental studies have suggested that primary repair also restores the native kinematics,⁴⁵ and may prevent osteoarthritis.⁴⁶ Furthermore, primary repair is a conservative approach in that no grafts need to be harvested, no tunnels need to be drilled, and revision surgery, if necessary, is more analogous to primary reconstructions.³²In patients with partial tears, some surgeons have advocated preserving the anteromedial (AM) or posterolateral (PL) bundle and performing selective single-bundle augmentation.^34,35 In addition, several authors have used remnant tensioning^36,47 or remnant preservation^37,48 in combination with reconstructive surgery in order to benefit from the biological characteristics of the remnant. These techniques lead to better proprioceptive function,^44,49,50 vascularization and ligamentization of the graft,^50-52 provide an optical guide for anatomic tunnel placement,⁵³ and decrease the incidence of tunnel widening.^54,55The feasibility and applicability of these surgical techniques mainly depends on the tear type and tissue quality of the torn ligament. In this article we (I) discuss the history of ACL preservation, (II) discuss how modern advances alter the risk-benefit ratio for ACL preservation, and (III) propose a treatment algorithm for ACL injuries that is based on tear location and tissue quality.

History of ACL Preservation

The history of the surgical treatment of ACL injuries started in 1895 when Robson⁵⁶ treated a 41-year-old male who tore both cruciate ligaments from the femoral wall. Performing primary repair with catgut ligatures, both cruciate ligaments were preserved and the patients had resolution of pain symptoms and full function at 6-year follow-up. Over the following decades, Palmer^57,58 and O’Donoghue^59,60 further popularized open primary repair for the treatment of ACL injuries, and this technique was the most commonly performed treatment in the 1970s and early 1980s.^61-65 The initial short-term results of primary repair were excellent,^61,62 but Feagin and Curl⁶⁶ were the first to note that the results deteriorated at mid-term follow-up. Despite improvements in the surgical technique of repairing the ACL, such as the usage of nonabsorbable sutures and directly tying the sutures over bone,^63,67 the results remained disappointing at longer-term follow-up.^68-70

In response to these disappointing results, surgeons sought to improve the surgical treatment by either augmenting the primary repair with a semitendinosus, a patella tendon graft or an augmentation device,^71-74 or by performing primary reconstruction.^75-77 At the end of the 1980s and early 1990s, several randomized and prospective clinical trials were performed in order to compare the outcomes of these techniques.^74,78-82 Many studies showed that results of augmented repair were more reliable when compared to primary repair, which led to the abandonment of primary repair in favor of augmented repair, and eventually primary reconstruction.⁶⁵

The Important Role of Tear Location in Ligament Preservation

When taking a closer look at the outcomes of primary repair and augmented repair, it seems that the results of these preservation techniques were not as disappointing as was suggested. This can be explained, in large part, by the fact that the important roles of tear location and tissue quality were not widely recognized.

Sherman and colleagues⁷⁰ reported in 1991 their mid-term results of open primary repair. Similar to others, they noted a deterioration of their results at mid-term follow-up. However, they uniquely performed an extensive subgroup analysis in order to find an explanation for this. In their study, considered a landmark paper on primary repair,^65,70 they concluded that, “poor tissue quality is typical for midsubstance tears and that a repair of these injuries will predictably fail while type I tears (proximal), with better tissue quality, show a definite trend towards better results.”⁷⁰ With these findings, they confirmed the findings of others that had recognized a trend of better outcomes with proximal tears.^64,67,83-85

A majority of the historical studies that were published before 1991 had not considered the role of tear location and tissue quality on outcomes of open primary repair. This was also true for the aforementioned randomized studies that compared primary repair with augmented repair and primary reconstruction. Because these studies randomized patients and did not take tear location into account, it can be expected that patients with midsubstance tears were included in the cohorts of primary repair and the outcomes of these studies were therefore confounded.^74,78-82 If these studies would have been aware of the role that tear location plays on primary repair outcomes, different outcomes may have been found and different conclusions on the optimal treatment for different tear types may have been drawn.⁸⁶

Open Primary ACL Repair Outcomes Stratified by Tear Location

When reviewing the literature of open primary repair outcomes stratified by tear location, it is noted that multiple studies reported excellent outcomes following primary repair of proximal ACL tears.^{73,83,84,87-90} Weaver and colleagues⁶⁴ were among the first to stratify their results by tear location, and they found that more patients with proximal tears (52 of 66; 79%) were satisfied after the procedure when compared to patients with midsubstance tears (3 of 13; 23%) at 3.5-year follow-up. They concluded that, “selection can be made with some predictability of the type of injury to the ligament as to which patients will do better.”⁶⁴ Kühne and colleagues⁸⁹ reported the outcomes of 75 patients with proximal tears treated with open primary repair and noted no failures, negative pivot shift in 88% of patients, stable or nearly stable Lachman test in 87% of patients, and 89% return to sports rate at 4-year follow-up. Raunest and colleagues⁹¹ reported a negative pivot shift and negative anterior drawer test in 84%, return to sports in 71%, and satisfaction in 75% of 51 patients that underwent open primary repair of proximal tears at 3.5-year follow-up.

Interestingly, and in contrast to the findings of Feagin and Curl,⁶⁶ no deterioration of the outcomes at mid-term follow-up was noted in patients with proximal tears. Genelin and colleagues⁸⁸ reported their results of 42 patients with proximal tears treated with open primary repair at 5- to 7-year follow-up. They found a negative pivot shift in 81%, stable or nearly stable Lachman test in 81%, and patient satisfaction in 86% of patients. Similarly, Bräm and colleagues⁸⁷ found good results at mid-term follow-up with a good-excellent Lysholm score in 79%, return to a similar level of sports in 76%, stable or nearly stable Lachman test in 91%, and anterior drawer test in 94% of patients, along with an 88% satisfaction rate and 7% failure rate in patients who underwent open primary repair of proximal tears.

On the contrary, when the outcomes of studies that performed open primary repair in mainly, or only, patients with midsubstance tears are reviewed, significantly inferior results are found. Frank and colleagues⁹² reported outcomes in 42 patients with midsubstance tears at 4-year follow-up. They reported that 56% had a stable or nearly stable anterior drawer test, 78% had a positive pivot shift, and that only 61% were satisfied with the procedure. Odensten and colleagues⁷⁸ reported outcomes of open primary repair in a subgroup of 22 patients with midsubstance tears at 1.5-year follow-up, and noted a 14% failure rate.

When reviewing the mid-term results in patients with midsubstance tears, it seems that there was more deterioration in outcomes.^69,70 Firstly, the aforementioned study by Sherman and colleagues⁷⁰ showed poor results in the patients with (type IV) midsubstance tears at mid-term follow-up. Furthermore, Kaplan and colleagues⁶⁹ reported the mid-term outcomes of 70 patients, of which 56 patients had midsubstance tears. After having reported good outcomes at short-term follow-up,^63,67 they noted that 42% of patients had >3 mm anteroposterior stability when compared to the contralateral leg, only a 62% return to sport rate, and a 17% failure rate. They concluded that, “Although … primary repair of the anterior cruciate may work in some patients, it is an unpredictable operative procedure.”

These studies showed that the outcomes of open primary repair were significantly better in patients with proximal ACL tears and sufficient tissue quality when compared to midsubstance tears. This suggests that open primary ACL repair may have been prematurely abandoned as a treatment option for patients with proximal tears.

Augmented ACL Repair

There were several reasons why augmented repair became the preferred treatment in the early and mid 1990s. First of all, the results of augmented repair were more consistent compared to primary repair in the aforementioned randomized and prospective studies,^74,78-82 which is not surprising given the fact that the role of tear location was not widely recognized at the time. Secondly, in the 1970s and early 1980s, patients were treated postoperatively in a cast for 6 weeks, which led to problems, such as loss of ROM, pain, and decreased function.^93,94 At the end of the1980s and 1990s, the focus shifted from prolonged joint immobilization towards early postoperative ROM.^95-97 Since many authors believed that primary repair of the ACL was not strong enough to tolerate early mobilization, an augmentation was added to the technique in order to fortify the repair and enable early ROM.⁹⁸

Interestingly, augmented repair, which is essentially a combination of primary ACL repair and ACL reconstruction, was mainly performed in the 1990s and many surgeons did recognize the role of tear location in this treatment at this point.^73,98-103 In these years, the treatment algorithm consisted of augmented ACL repair in patients with proximal tears in the acute setting and ACL reconstruction in patients with midsubstance or chronic tears. Several different augmentation techniques were used to reinforce the primary repair in these years including autograft tissues (semitendinosus tendon,^102-104 patellar tendon,¹⁰⁰ or iliotibial band [ITB]¹⁰⁵) synthetic materials (polydioxanone [PDS],^101,102,106 carbon fibre,⁷⁴ and polyester [Trevira]⁹⁷), augmentation devices (Kennedy Ligament Augmentation Device [LAD]^98-100) and extra-articular augmentations.⁷³

When reviewing the outcomes of augmented repair of the ACL, good to excellent results can be found in studies that used this technique in patients with proximal tears.^73,98-106 Kdolsky and colleagues⁹⁸ were in one of the first groups that reported their results of augmented repair in only patients with proximal tears. In 1993, they reported their mid-term outcomes (5 to 8 years) in 66 patients who underwent primary repair and augmentation with the Kennedy LAD and found that 97% of patients had stable knees (<3 mm on KT-1000 examination), 98% had a negative pivot shift, and 76% returned to previous level of sports. However, often-reported problems with the augmentation devices were found in this study with rupture of the device (12%) and decreased ROM (14%).⁹⁸ In 1995, Grøntvedt and Engebretsen¹⁰⁰ compared augmentation with the Kennedy LAD to patellar tendon augmentation in a randomized study of patients with acute proximal tears. They noted that 50% of the patients in the Kennedy LAD group had a positive pivot shift compared to 23% in the patellar tendon group. Furthermore, they found KT-1000 leg differences of <3 mm in 92% of the patellar tendon group and 54% of the Kennedy LAD group. Because the authors found significant differences between both groups at 1- and 2-year follow-up, they stopped the clinical trial.

Several authors in the following years reported good results of augmented repair using autograft tissues. Natri and colleagues¹⁰⁵ reported the outcomes of 72 patients treated with primary repair of proximal tears augmented with the ITB at 3.5-year follow-up. They found 89% negative pivot shift rate, 93% stable or nearly stable Lachman test, 99% stable or nearly stable anterior drawer test, 79% satisfaction rate, and 91% return to previous level of sports rate. Krueger-Franke and colleagues¹⁰⁴ reported the outcomes of primary repair of proximal tears with augmentation using the semitendinosus tendon. In a retrospective study of 76 patients, they noted that 96% of patients had a negative pivot shift, 75% of patients had stable or nearly stable Lachman test, 93% were satisfied with the procedure, a mean Lysholm score of 92, a Tegner score that only decreased from 7.2 to 7.1, and KT-1000 testing with 78% <4 mm leg difference with the contralateral leg. The authors concluded that patients with femoral ruptures could be treated with augmented repair when performed in the acute setting. As this study was published in 1998, they stated that magnetic resonance imaging and arthroscopy could be helpful in identifying the tear location.

Final Abandonment of ACL Preservation

Reviewing these outcomes raises the question as to why these techniques were ultimately abandoned in the treatment algorithm of proximal ACL injuries, especially given the aforementioned advantages of ACL preservation. One of the possible answers can be found in a landmark study on ACL reconstruction and rehabilitation published by Shelbourne and colleagues¹⁰⁷ in 1991. At that time, arthrofibrosis and knee stiffness were frequently reported problems following ACL surgery, which could partially be explained by the standard conservative rehabilitation using postoperative joint immobilization.^67,70,80,88

Shelbourne and colleagues¹⁰⁷ aimed to assess the cause of arthrofibrosis and knee stiffness, and divided the patients into groups by number of days between injury and surgery (<7, 7 to 21 days, and >21 days between injury and surgery). Furthermore, patients within these groups underwent either a conventional or accelerated rehabilitation program. The authors not only found that patients undergoing accelerated rehabilitation had less arthrofibrosis, but they also noted that less arthrofibrosis was seen when surgery was delayed. These findings, however, contrasted with the general perception that the ACL should be repaired in the first 3 weeks postinjury to ensure optimal tissue quality with an augmented approach. As a result, the treatment of ACL injuries shifted towards ACL reconstruction after these findings. Krueger-Franke and colleagues¹⁰⁴ commented on the trend after the study of Shelbourne and colleagues:¹⁰⁷ “Less consideration has been given to the importance of the proprioceptive receptors in the tibial remnants of the torn ACL and the value of their preservation as part of a primary reconstruction.”

In addition to the trend away from an augmented repair approach due to the novel understanding of the importance of early mobilization, some discussion should focus on the technical limitations of arthroscopy at that time. While arthroscopy had been around for several decades, fluid management and arthroscopic instrumentation was slow to develop. All of the repair and augmentation techniques previously discussed had been performed via an open arthrotomy. Arthroscopic technologies of the time were not refined enough to enable surgeons to perform such complex, intra-articular techniques that would enable suturing of the ligament remnant. In this regard, arthroscopic ACL reconstruction was a much simpler technique to accomplish, and this also likely contributed to the final abandonment of the ligament preservation approach.

Role for ACL Preservation with Modern Advances

As stated in the introduction, there has been a recent resurgence of interest in preservation of the native ligament.^32-37 With the passage of time, many technologic advances have been made, which has allowed surgeons to reconsider the concept of ligament preservation.

First of all, appropriate patient selection was not applied historically, as the critical factors of tear location and tissue quality were not recognized in the era of open primary repair. In modern days, however, advances such as MRI have been developed, which can give the surgeon an idea of the status, and tear type of the ACL pre-operatively.¹⁰⁸ This may help the orthopaedic surgeon to plan the surgery and make an assessment as to whether ACL preservation is possible. Secondly, in the historic literature the postoperative regimen consisted of casting for 5 or 6 weeks,^67,70,80,88 while the focus later shifted towards early ROM.^95-97Modern day ACL rehabilitation focuses on immediate ROM to avoid the complications stiffness, pain and decreased function that plagued the outcomes when immobilization was used.^93,94 Thirdly, historically small tunnels were drilled with primary repair and sutures had to be tied over bone,^57,67 whereas currently suture anchors are available that prevent the need for tunnel drilling and enable direct suture tensioning.^32,38 Finally, and most importantly, in the historic literature patients were treated with an invasive arthrotomy technique, while modern day arthroscopic techniques readily enable the surgeon to effectively suture the remnant arthroscopically. Interestingly, in 2005, in their 20-year follow-up of primary repair surgeries, Strand and colleagues¹⁰⁹ stated, “if the same results could be accomplished by a smaller, arthroscopic procedure, primary repair might reduce the number of patients needing later reconstructions with small ‘costs’ in the way of risk and inconvenience for the patients. We therefore believe that further research and development of methods for closed (arthroscopic) repair are justified.”

Altered Risk-Benefit Ratio

Historically, the treatments of open primary repair and open ACL reconstruction were both invasive surgeries with an arthrotomy, drilling of bone tunnels, and postoperative joint immobilization for 4 to 6 weeks. However, with the modern-day advances, the risk-benefit ratio of both treatments has changed, as Strand and colleagues¹⁰⁹ had already suggested. Although ACL reconstruction can be performed arthroscopically, it remains an invasive procedure, in which tunnels are drilled, patellar tendons or hamstring tendons are harvested, and complications, such as knee pain and quadriceps atrophy, are common. The surgery of primary ACL repair, however, has benefited significantly from the modern developments.^32,38 Primary ACL repair can now be performed arthroscopically, and by using suture anchors no tunnels need to be drilled and the remnant can be tensioned directly. An additional benefit of the use of suture anchors is that revision surgery of a failed primary repair is analogous to primary reconstruction, whereas revision surgery of a failed ACL reconstruction can be problematic due to tunnel widening, tunnel malpositioning, and preexisting hardware.^20-22

Reviewing the differences between arthroscopic primary ACL repair and ACL reconstruction, it becomes clear that primary repair has benefited significantly from the modern advances and that the risk-benefit ratio for primary repair has been altered. This means that patients with proximal tears can be treated with a relatively straight forward, minimally invasive surgery, which has been shown to be effective in 85% to 90% of patients.^32,38

Treatment Algorithm Based on Tear Location

Since 2008, in the practice of the senior author (GSD), the surgical treatment algorithm for ACL injuries is completely based on the tear location and tissue quality of the ligament.^110,111 To describe the different tear types, we use the modified Sherman classification in which we extended his classification towards the tibial side whereas Sherman and colleagues⁷⁰ only described the femoral side of the tears (Figures A-F, Table).

Type I Tears: Primary Repair

Type I tears are soft tissue avulsion type tears that can be easily treated with arthroscopic primary repair.¹⁰⁷ The length of the distal remnant has to be at least 90% and the tissue quality has to be good to excellent in order to approximate the remnant towards the femoral wall (Table).¹¹² The incidence of type I tears was 26% in the study of Sherman and colleagues,⁷⁰ although recent studies showed a lower incidence (6% to 10%) in a larger population.^32,38 Certainly, individual practices will see different percentages of type I tears based upon the mix of injury mechanisms they see most frequently. Over the last 2 years, with the recognition of the importance of tear type and tissue quality, there has been a renewed interest in arthroscopic primary ACL repair.^32,38

DiFelice and colleagues³² were the first to arthroscopically perform primary repair of the ACL in proximal tears using suture anchors. They reported the outcomes of the first 11 consecutive patients that underwent primary repair in a previously described technique.¹¹³ At mean 3.5-year follow-up, they noted only 1 failure (9%) due to re-injury; mean Lysholm score of 93.2; mean modified Cincinnati score of 91.5; pre- and postoperative Tegner score of 7.3 and 6.9, respectively; SANE score of 91.8; and subjective International Knee Documentation Committee (IKDC) score of 86.4. Of the patients with an intact repair, 9 patients had an objective IKDC rating A and 1 patient had B and all patients had KT-1000 leg differences of <3 mm with the contralateral side (three patients were not available for KT-1000 testing). The authors concluded that arthroscopic primary ACL repair could achieve short-term clinical success in a selected group of patients with proximal avulsion tears and excellent tissue quality. They further noted that mid-term outcomes are necessary given that the results of open primary repair deteriorated at longer-term follow-up in the historical literature. Recently, the senior author (GSD) has added an Internal Brace (Arthrex) to the primary repair with the goal of protecting the ligament in the first weeks to further promote healing of the ligament.^39,40,114

More recently, Achtnich and colleagues³⁸ compared the treatment of arthroscopic primary ACL repair with primary ACL reconstruction in 41 patients with type I tears at 2.3-years follow-up. Twenty-one patients consented for primary repair while 20 patients declined this procedure and underwent primary reconstruction. They noted no significant differences in Lachman test, pivot shift test, objective IKDC score, and KT-1000 scores. Although not significant, the clinical failure rate in the primary repair group (15%) was higher than the reconstruction group (0%). Interestingly, despite the higher failure rate in the repair group, the authors concluded that primary ACL repair is recommended in a carefully selected group of patients with type I tears and excellent tissue quality, which can likely be explained by the differences in the risk-benefit ratio between both procedures.

Over the last decade, the research group led by Murray^46,115,116 has performed experimental research on primary repair with a biological scaffold and reported many interesting findings that could be extrapolated to primary ACL repair. First of all, they compared bioenhanced primary repair with bioenhanced primary reconstruction in 64 Yucutan pigs and noted that there was significantly less macroscopic cartilage damage in the primary repair group at 1-year follow-up.⁴⁶ They concluded that bioenhanced ACL repair may provide a new, less invasive treatment option that reduces cartilage damage following joint injury. This may suggest that primary repair may have a lower incidence of osteoarthritis when compared to ACL reconstruction, which is interesting as osteoarthritis is very common after ACL reconstruction. Further research in this area is certainly warranted.

In another study they compared bioenhanced primary repair in juvenile, adolescent and mature Yucutan pigs and noted that functional healing depended on the level of skeletal maturity with immature animals having a more productive healing response.¹¹⁶ This indicates that primary repair might be a good treatment option in skeletally immature patients, especially since reconstruction increases the risk of premature closure of the epiphysis^117,118 and delaying treatment increases the risk of meniscus injury.¹¹⁹ Interestingly, a recent meta-analysis showed indeed that the risk of epiphysis closure was lower in primary repair when compared to ACL reconstruction and the rupture rate was also lower.¹¹⁸ Primary repair may be a good treatment option in children as the procedure has all the attributes that should be applicable to children: it is minimally morbid, tissue sparing, and it is a conservative approach that does not burn any surgical bridges for future reconstructive surgery if necessary.

Finally, the research group of Murray¹¹⁵ assessed the effect of surgical delay of primary repair following injury in Yucutan pigs and noted that better biomechanical outcomes were noted after delaying surgery for 2 weeks when compared to 6 weeks. This suggests that primary repair should preferably be performed in the acute setting, which has also been shown in historical studies since the ligament in the acute setting has optimal tissue quality and the ligament is less likely to be retracted or reabsorbed.^59,60,115

One Bundle Type I Tears: Single Bundle Augmented Repair

In some cases, the tear locations of the AM and PL bundle are not at the same location and Zantop and colleagues¹²⁰ reported in an arthroscopic study that this could be as frequent as in 30% of all complete tears. In some of these tears, one of the bundles can be avulsed of the femoral wall (type I tear) while the other bundle is not directly repairable (non-type I tear). In these cases, the senior author (GSD) will repair the type I tear bundle, whereas a hamstring augmentation is placed at the location of the other bundle. When reviewing the literature, a combination of primary repair of one bundle and reconstruction of the second bundle has not been described before. However, over the last decade several surgeons have performed augmentation of one bundle in the setting of partial tears.^{34,35,121-124}

Buda and colleagues³⁴ were the first to perform selective AM or PL bundle reconstruction in the setting of partial tears.³⁴ At 5-year follow-up, they reported no reruptures and only 1 patient with an IKDC C-score, although reoperation was necessary in 4 out of 47 patients (9%). Following this publication, many others reported on selective bundle reconstruction.^35,121-124 However, with partial tears, the knee is often stable and a selective augmentation technique is utilized to prevent complete rupture of the ligament. The application of this technique is essentially different from reconstruction for complete ACL tears in which the knee is unstable, there is a giving way sensation and patients have problems participating in sports.

Type II Tears: Augmented Repair

Type II tears often have good or excellent tissue quality and can be pulled up towards the femoral footprint, but are too short to be firmly attached. Sherman and colleagues⁷⁰ reported that approximately 22% patients had a type II tear, which corresponds to a tear located in the proximal part of the ligament. With this technique, multiple suture passes are used to stitch the remnant and, in addition, a smaller hamstring autograft or allograft is passed through the middle of the tibial remnant. A suture button is used proximally for the graft, and the tensioning repair sutures through the remnant are also passed through the suture button. The suture button is passed through the femoral tunnel and flipped so that the graft is proximally fixed. Then, the repair sutures of the remnant are tensioned, and the ligament is pulled towards the femoral wall as a sleeve around the graft. When the ligament is approximated to the femoral wall, the sutures are tied over the suture button. The graft is then tensioned distally to complete the augmented repair.

In the recent literature, the technique of augmentation of a primary repair using autograft tissue has not been reported. However, augmented repair using an internal brace^39,40 or augmentation devices^33,41 have been recently performed. MacKay and colleagues³⁹ reported good outcomes of arthroscopic primary repair of proximal tears using an internal brace. Eggli and colleagues³³ reported the results of the first 10 patients treated with ACL preservation using primary repair of the ligament with the addition of a dynamic screw-spring mechanism. The authors reported good preliminary results with one failure (10%) and good objective and subjective outcomes. In a next study, they reported the outcomes of 278 patients and although they reported good clinical outcomes and a revision rate of 4%, the reoperation rate for removal of the screw-spring mechanism was high (24%).⁴¹ This is not surprising when reviewing the historical literature in which high complication rates of the augmentation devices were reported.^99,100 We were unable to identify any other studies reporting surgical techniques of augmenting primary repair in the literature.

Type III Tears: Reconstruction With Remnant Tensioning

In patients with type III tears, the ligament cannot be approximated to the wall and reconstruction is necessary in order to restore knee stability. However, in these cases the ligament has sufficient length (25%-75%) and can be tensioned along or around the graft. Preservation of the ligament remnant has several (theoretical) advantages, such as better proprioceptive function,^42,49,50 vascularization and ligamentization of the graft,^50-52 an optical guide for anatomic tunnel placement,⁵³ and a decreased incidence of tunnel widening.^54,55 Furthermore, tensioning of the remnant is thought to lower the risk of cyclops lesions when compared to remnant preservation.¹²⁵ Although the difference between augmented repair and remnant tensioning seems small, the purpose of surgery is different. With augmented repair, the ligament can be approximated close to the femoral wall and the goal of surgery is to use the healing capacity that the ACL has in the proximal part of the ligament,¹²⁶ while with remnant tensioning the goal is only to benefit from some of the aforementioned advantages. Ahn and colleagues³⁶ were the first to perform this technique and stated, “Our concept is that the remnant tissue has only an additive effect.” Furthermore, with augmented repair multiple sutures are passed through the AM and PL bundle in order to sufficiently approximate the ligament to the femoral wall, while with the remnant tensioning technique generally one or a few sutures or lasso loop are passed through the proximal part to tension the ligament, prevent sagging of the remnant, and decrease the risk of cyclops lesions.^127,128

Several authors have recently performed remnant tensioning during ACL.^{36,47,125-127} Ahn and colleagues⁴⁷ reported excellent objective and subjective outcomes following this procedure and found that with re-arthroscopy nearly all patients had fair synovialization of the graft. Others have reported similarly good outcomes of these techniques.^125,129,130 However, studies comparing this treatment with normal ACL reconstruction and assessing outcomes, failure rates and proprioception are lacking.

Type IV Tears: Reconstruction With Remnant Preservation

Finally, in some patients the ligament is torn distally or the tissue quality is not optimal. In these patients, the remnant can be debrided to the part of good tissue quality in order to preserve the biology and minimize the risk for cyclops lesions. A standard reconstruction needs to be performed to restore the instability, but by preserving the remnant, advantages, such as proprioception,^44,49,50 graft vascularization,^50-52 an optical guide for tibial tunnel placement,⁵³ and a decreased incidence of tunnel widening^54,55 can be expected.

Lee and colleagues³⁷ presented the tibial remnant technique in which standard reconstruction was performed, and the tibial tunnel was drilled through the center of the remnant. In a later study, they compared remnant preservation with a remnant of <20% of the total ACL length with >20% of the length and found that proprioception was better with more remnant volume.⁴⁸ Similarly, Muneta and colleagues¹³¹ assessed the role of remnant length and found that remnant length is positively correlated with better stability measured on KT-1000 anteroposterior stability.

Several studies compared ACL reconstruction with remnant preservation vs conventional ACL reconstruction.^52,54,129 Takazawa and colleagues⁵² performed a retrospective study of 183 patients and found that patients in the remnant preservation group had significantly better KT-2000 stability, while they also reported a significantly lower graft rupture rate in this group (1.1% vs 7.1%) at 2-year follow-up. Hong and colleagues¹²⁹ performed a randomized clinical trial of 80 patients and did not find these differences, although there was a trend towards higher Lysholm scores in the remnant preservation group. Finally, Zhang and colleagues⁵⁴ performed a randomized clinical trial and found a lower incidence and amount of tibial tunnel widening in the preserving-remnant group when compared to the removing-remnant group. These studies show that there is likely a role for remnant preservation.

Type V Tears: Primary Repair

In some patients, the ligament is torn in the distal 10% of the ligament, which can occur as a distal avulsion tear or as a distal bony avulsion fracture.¹³² Bony avulsion fractures are most commonly seen in children whereas true distal soft tissue avulsion tears are very rare.¹³²

Treatments of these tear types include antegrade screw fixation, pullout sutures or the use of suture anchors in case of bony avulsion fractures and pullout sutures with tying over a bony bridge or ligament button in case of soft tissue avulsions. Leeberg and colleagues¹³² recently performed a systematic review of all studies reporting on treatment of distal avulsion fractures.They noted that most treatments were currently performed arthroscopically and that outcomes were generally good. Another recent biomechanical study compared antegrade screw fixation with suture anchor fixation and pullout suture fixation.¹³³ The authors noted that suture anchor fixation has slightly less displacement of the bony fragment when compared to screw fixation and pull-out sutures, and that the strength to failure was higher in the suture anchor fixation when compared to the pullout suture fixation. The outcomes of this study suggest that screw fixation and suture anchor fixation might be superior to pullout suture fixation, which might be interesting as with pullout suture fixation the ligament cannot be directly tensioned to the tibial footprint, which can lead to anteroposterior laxity.¹³² Clinical studies are necessary to assess the preferred treatment in these tear types but it seems that screw fixation is preferred in large bony avulsion fractures, while suture anchor fixation or pullout suture fixation can be used for soft tissue avulsion tears.

Complex Tears or Poor Tissue Quality: Reconstruction

If the tear is complex, multiple tears are present, or the tissue quality is poor, then preservation of the ligament is not possible, and in these cases a standard reconstruction should be performed.

Conclusion

When reviewing the literature of ACL preservation, it becomes clear that the evolution of surgical treatment of ACL injuries was biased. Preservation of the native ligament has many advantages, such as better proprioception, graft vascularization, an optical guide for tibial tunnel placement, and a decreased incidence of tunnel widening that can be expected. Furthermore, arthroscopic primary ACL repair is minimally invasive and does not burn any bridges for future reconstructions, if necessary. This is in addition to the other (theoretical) advantages of primary repair, such as restoration of native kinematics and a decreased risk of osteoarthritis. Modern advances have significantly changed the risk-benefit ratio that should make us reconsider ACL preservation approaches. Certainly, further research in this area is warranted. In this article we have presented a treatment algorithm for ACL preservation, which is based on tear location and remnant tissue quality.

Am J Orthop. 2016;45(7):E393-E405. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Injury of the anterior cruciate ligament (ACL) is very common with over 200,000 annual injuries in the United Status.^1,2 There is a general consensus that these injuries should not be treated conservatively in patients that are younger, or who wish to remain active.^3,4 Reconstructive surgery is currently the preferred treatment in these patients, and anatomic single-bundle reconstruction with autografts is considered the gold standard.^5,6

Reconstruction of the ACL is, however, not a perfect treatment. Following single-bundle autograft reconstruction, revision rates of 3% to 8%,^6-9 contralateral injury rates of 3% to 8%,^10,11 and infection rates of 0.5% to 3%^7,12,13 have been reported. Furthermore, due to the invasive nature of graft harvesting and the surgical procedure, 10% to 25% of the patients are not satisfied following ACL reconstruction.^14,15 This can often be explained by common complaints, such as anterior knee pain (13%-43%), kneeling pain (12%-54%), quadriceps muscle atrophy (20%-30%),^16,17 and loss of range of motion (ROM) (12%-23%).^7,9,18,19 Furthermore, as a result of the invasive nature of reconstructive surgery, revisions can be difficult due to complications, such as tunnel widening, tunnel malpositioning, and preexisting hardware.^20-22 This can lead to inferior outcomes and higher rates (13%) of revision surgery compared to primary reconstruction.^23-26 Finally, reconstructive surgery does not restore native kinematics of the ACL,^27-29 which may partially explain why reconstructive surgery has not been shown to prevent osteoarthritis.^28-31

Over the past decades, there has been an increasing interest in the preservation of the ACL in an attempt to ameliorate these issues.^32-37 Ligament preservation focuses on preserving the native tissues and biology, while minimizing the surgical morbidity to the patients.

Some authors have recently reported on arthroscopic primary repair of proximal ACL tears in which the ligament is reattached onto the femoral wall using modern-day suture anchor technology.^32,38 Others have augmented this repair technique with an internal brace^39,40 or with a synthetic device.^33,41 When performing primary repair, it is believed that proprioception is maintained,^42-44 while experimental studies have suggested that primary repair also restores the native kinematics,⁴⁵ and may prevent osteoarthritis.⁴⁶ Furthermore, primary repair is a conservative approach in that no grafts need to be harvested, no tunnels need to be drilled, and revision surgery, if necessary, is more analogous to primary reconstructions.³²In patients with partial tears, some surgeons have advocated preserving the anteromedial (AM) or posterolateral (PL) bundle and performing selective single-bundle augmentation.^34,35 In addition, several authors have used remnant tensioning^36,47 or remnant preservation^37,48 in combination with reconstructive surgery in order to benefit from the biological characteristics of the remnant. These techniques lead to better proprioceptive function,^44,49,50 vascularization and ligamentization of the graft,^50-52 provide an optical guide for anatomic tunnel placement,⁵³ and decrease the incidence of tunnel widening.^54,55The feasibility and applicability of these surgical techniques mainly depends on the tear type and tissue quality of the torn ligament. In this article we (I) discuss the history of ACL preservation, (II) discuss how modern advances alter the risk-benefit ratio for ACL preservation, and (III) propose a treatment algorithm for ACL injuries that is based on tear location and tissue quality.

History of ACL Preservation

The history of the surgical treatment of ACL injuries started in 1895 when Robson⁵⁶ treated a 41-year-old male who tore both cruciate ligaments from the femoral wall. Performing primary repair with catgut ligatures, both cruciate ligaments were preserved and the patients had resolution of pain symptoms and full function at 6-year follow-up. Over the following decades, Palmer^57,58 and O’Donoghue^59,60 further popularized open primary repair for the treatment of ACL injuries, and this technique was the most commonly performed treatment in the 1970s and early 1980s.^61-65 The initial short-term results of primary repair were excellent,^61,62 but Feagin and Curl⁶⁶ were the first to note that the results deteriorated at mid-term follow-up. Despite improvements in the surgical technique of repairing the ACL, such as the usage of nonabsorbable sutures and directly tying the sutures over bone,^63,67 the results remained disappointing at longer-term follow-up.^68-70

In response to these disappointing results, surgeons sought to improve the surgical treatment by either augmenting the primary repair with a semitendinosus, a patella tendon graft or an augmentation device,^71-74 or by performing primary reconstruction.^75-77 At the end of the 1980s and early 1990s, several randomized and prospective clinical trials were performed in order to compare the outcomes of these techniques.^74,78-82 Many studies showed that results of augmented repair were more reliable when compared to primary repair, which led to the abandonment of primary repair in favor of augmented repair, and eventually primary reconstruction.⁶⁵

The Important Role of Tear Location in Ligament Preservation

When taking a closer look at the outcomes of primary repair and augmented repair, it seems that the results of these preservation techniques were not as disappointing as was suggested. This can be explained, in large part, by the fact that the important roles of tear location and tissue quality were not widely recognized.

Sherman and colleagues⁷⁰ reported in 1991 their mid-term results of open primary repair. Similar to others, they noted a deterioration of their results at mid-term follow-up. However, they uniquely performed an extensive subgroup analysis in order to find an explanation for this. In their study, considered a landmark paper on primary repair,^65,70 they concluded that, “poor tissue quality is typical for midsubstance tears and that a repair of these injuries will predictably fail while type I tears (proximal), with better tissue quality, show a definite trend towards better results.”⁷⁰ With these findings, they confirmed the findings of others that had recognized a trend of better outcomes with proximal tears.^64,67,83-85

A majority of the historical studies that were published before 1991 had not considered the role of tear location and tissue quality on outcomes of open primary repair. This was also true for the aforementioned randomized studies that compared primary repair with augmented repair and primary reconstruction. Because these studies randomized patients and did not take tear location into account, it can be expected that patients with midsubstance tears were included in the cohorts of primary repair and the outcomes of these studies were therefore confounded.^74,78-82 If these studies would have been aware of the role that tear location plays on primary repair outcomes, different outcomes may have been found and different conclusions on the optimal treatment for different tear types may have been drawn.⁸⁶

Open Primary ACL Repair Outcomes Stratified by Tear Location

When reviewing the literature of open primary repair outcomes stratified by tear location, it is noted that multiple studies reported excellent outcomes following primary repair of proximal ACL tears.^{73,83,84,87-90} Weaver and colleagues⁶⁴ were among the first to stratify their results by tear location, and they found that more patients with proximal tears (52 of 66; 79%) were satisfied after the procedure when compared to patients with midsubstance tears (3 of 13; 23%) at 3.5-year follow-up. They concluded that, “selection can be made with some predictability of the type of injury to the ligament as to which patients will do better.”⁶⁴ Kühne and colleagues⁸⁹ reported the outcomes of 75 patients with proximal tears treated with open primary repair and noted no failures, negative pivot shift in 88% of patients, stable or nearly stable Lachman test in 87% of patients, and 89% return to sports rate at 4-year follow-up. Raunest and colleagues⁹¹ reported a negative pivot shift and negative anterior drawer test in 84%, return to sports in 71%, and satisfaction in 75% of 51 patients that underwent open primary repair of proximal tears at 3.5-year follow-up.

Interestingly, and in contrast to the findings of Feagin and Curl,⁶⁶ no deterioration of the outcomes at mid-term follow-up was noted in patients with proximal tears. Genelin and colleagues⁸⁸ reported their results of 42 patients with proximal tears treated with open primary repair at 5- to 7-year follow-up. They found a negative pivot shift in 81%, stable or nearly stable Lachman test in 81%, and patient satisfaction in 86% of patients. Similarly, Bräm and colleagues⁸⁷ found good results at mid-term follow-up with a good-excellent Lysholm score in 79%, return to a similar level of sports in 76%, stable or nearly stable Lachman test in 91%, and anterior drawer test in 94% of patients, along with an 88% satisfaction rate and 7% failure rate in patients who underwent open primary repair of proximal tears.

On the contrary, when the outcomes of studies that performed open primary repair in mainly, or only, patients with midsubstance tears are reviewed, significantly inferior results are found. Frank and colleagues⁹² reported outcomes in 42 patients with midsubstance tears at 4-year follow-up. They reported that 56% had a stable or nearly stable anterior drawer test, 78% had a positive pivot shift, and that only 61% were satisfied with the procedure. Odensten and colleagues⁷⁸ reported outcomes of open primary repair in a subgroup of 22 patients with midsubstance tears at 1.5-year follow-up, and noted a 14% failure rate.

When reviewing the mid-term results in patients with midsubstance tears, it seems that there was more deterioration in outcomes.^69,70 Firstly, the aforementioned study by Sherman and colleagues⁷⁰ showed poor results in the patients with (type IV) midsubstance tears at mid-term follow-up. Furthermore, Kaplan and colleagues⁶⁹ reported the mid-term outcomes of 70 patients, of which 56 patients had midsubstance tears. After having reported good outcomes at short-term follow-up,^63,67 they noted that 42% of patients had >3 mm anteroposterior stability when compared to the contralateral leg, only a 62% return to sport rate, and a 17% failure rate. They concluded that, “Although … primary repair of the anterior cruciate may work in some patients, it is an unpredictable operative procedure.”

These studies showed that the outcomes of open primary repair were significantly better in patients with proximal ACL tears and sufficient tissue quality when compared to midsubstance tears. This suggests that open primary ACL repair may have been prematurely abandoned as a treatment option for patients with proximal tears.

Augmented ACL Repair

There were several reasons why augmented repair became the preferred treatment in the early and mid 1990s. First of all, the results of augmented repair were more consistent compared to primary repair in the aforementioned randomized and prospective studies,^74,78-82 which is not surprising given the fact that the role of tear location was not widely recognized at the time. Secondly, in the 1970s and early 1980s, patients were treated postoperatively in a cast for 6 weeks, which led to problems, such as loss of ROM, pain, and decreased function.^93,94 At the end of the1980s and 1990s, the focus shifted from prolonged joint immobilization towards early postoperative ROM.^95-97 Since many authors believed that primary repair of the ACL was not strong enough to tolerate early mobilization, an augmentation was added to the technique in order to fortify the repair and enable early ROM.⁹⁸

Interestingly, augmented repair, which is essentially a combination of primary ACL repair and ACL reconstruction, was mainly performed in the 1990s and many surgeons did recognize the role of tear location in this treatment at this point.^73,98-103 In these years, the treatment algorithm consisted of augmented ACL repair in patients with proximal tears in the acute setting and ACL reconstruction in patients with midsubstance or chronic tears. Several different augmentation techniques were used to reinforce the primary repair in these years including autograft tissues (semitendinosus tendon,^102-104 patellar tendon,¹⁰⁰ or iliotibial band [ITB]¹⁰⁵) synthetic materials (polydioxanone [PDS],^101,102,106 carbon fibre,⁷⁴ and polyester [Trevira]⁹⁷), augmentation devices (Kennedy Ligament Augmentation Device [LAD]^98-100) and extra-articular augmentations.⁷³

When reviewing the outcomes of augmented repair of the ACL, good to excellent results can be found in studies that used this technique in patients with proximal tears.^73,98-106 Kdolsky and colleagues⁹⁸ were in one of the first groups that reported their results of augmented repair in only patients with proximal tears. In 1993, they reported their mid-term outcomes (5 to 8 years) in 66 patients who underwent primary repair and augmentation with the Kennedy LAD and found that 97% of patients had stable knees (<3 mm on KT-1000 examination), 98% had a negative pivot shift, and 76% returned to previous level of sports. However, often-reported problems with the augmentation devices were found in this study with rupture of the device (12%) and decreased ROM (14%).⁹⁸ In 1995, Grøntvedt and Engebretsen¹⁰⁰ compared augmentation with the Kennedy LAD to patellar tendon augmentation in a randomized study of patients with acute proximal tears. They noted that 50% of the patients in the Kennedy LAD group had a positive pivot shift compared to 23% in the patellar tendon group. Furthermore, they found KT-1000 leg differences of <3 mm in 92% of the patellar tendon group and 54% of the Kennedy LAD group. Because the authors found significant differences between both groups at 1- and 2-year follow-up, they stopped the clinical trial.

Several authors in the following years reported good results of augmented repair using autograft tissues. Natri and colleagues¹⁰⁵ reported the outcomes of 72 patients treated with primary repair of proximal tears augmented with the ITB at 3.5-year follow-up. They found 89% negative pivot shift rate, 93% stable or nearly stable Lachman test, 99% stable or nearly stable anterior drawer test, 79% satisfaction rate, and 91% return to previous level of sports rate. Krueger-Franke and colleagues¹⁰⁴ reported the outcomes of primary repair of proximal tears with augmentation using the semitendinosus tendon. In a retrospective study of 76 patients, they noted that 96% of patients had a negative pivot shift, 75% of patients had stable or nearly stable Lachman test, 93% were satisfied with the procedure, a mean Lysholm score of 92, a Tegner score that only decreased from 7.2 to 7.1, and KT-1000 testing with 78% <4 mm leg difference with the contralateral leg. The authors concluded that patients with femoral ruptures could be treated with augmented repair when performed in the acute setting. As this study was published in 1998, they stated that magnetic resonance imaging and arthroscopy could be helpful in identifying the tear location.

Final Abandonment of ACL Preservation

Reviewing these outcomes raises the question as to why these techniques were ultimately abandoned in the treatment algorithm of proximal ACL injuries, especially given the aforementioned advantages of ACL preservation. One of the possible answers can be found in a landmark study on ACL reconstruction and rehabilitation published by Shelbourne and colleagues¹⁰⁷ in 1991. At that time, arthrofibrosis and knee stiffness were frequently reported problems following ACL surgery, which could partially be explained by the standard conservative rehabilitation using postoperative joint immobilization.^67,70,80,88

Shelbourne and colleagues¹⁰⁷ aimed to assess the cause of arthrofibrosis and knee stiffness, and divided the patients into groups by number of days between injury and surgery (<7, 7 to 21 days, and >21 days between injury and surgery). Furthermore, patients within these groups underwent either a conventional or accelerated rehabilitation program. The authors not only found that patients undergoing accelerated rehabilitation had less arthrofibrosis, but they also noted that less arthrofibrosis was seen when surgery was delayed. These findings, however, contrasted with the general perception that the ACL should be repaired in the first 3 weeks postinjury to ensure optimal tissue quality with an augmented approach. As a result, the treatment of ACL injuries shifted towards ACL reconstruction after these findings. Krueger-Franke and colleagues¹⁰⁴ commented on the trend after the study of Shelbourne and colleagues:¹⁰⁷ “Less consideration has been given to the importance of the proprioceptive receptors in the tibial remnants of the torn ACL and the value of their preservation as part of a primary reconstruction.”

In addition to the trend away from an augmented repair approach due to the novel understanding of the importance of early mobilization, some discussion should focus on the technical limitations of arthroscopy at that time. While arthroscopy had been around for several decades, fluid management and arthroscopic instrumentation was slow to develop. All of the repair and augmentation techniques previously discussed had been performed via an open arthrotomy. Arthroscopic technologies of the time were not refined enough to enable surgeons to perform such complex, intra-articular techniques that would enable suturing of the ligament remnant. In this regard, arthroscopic ACL reconstruction was a much simpler technique to accomplish, and this also likely contributed to the final abandonment of the ligament preservation approach.

Role for ACL Preservation with Modern Advances

As stated in the introduction, there has been a recent resurgence of interest in preservation of the native ligament.^32-37 With the passage of time, many technologic advances have been made, which has allowed surgeons to reconsider the concept of ligament preservation.

First of all, appropriate patient selection was not applied historically, as the critical factors of tear location and tissue quality were not recognized in the era of open primary repair. In modern days, however, advances such as MRI have been developed, which can give the surgeon an idea of the status, and tear type of the ACL pre-operatively.¹⁰⁸ This may help the orthopaedic surgeon to plan the surgery and make an assessment as to whether ACL preservation is possible. Secondly, in the historic literature the postoperative regimen consisted of casting for 5 or 6 weeks,^67,70,80,88 while the focus later shifted towards early ROM.^95-97Modern day ACL rehabilitation focuses on immediate ROM to avoid the complications stiffness, pain and decreased function that plagued the outcomes when immobilization was used.^93,94 Thirdly, historically small tunnels were drilled with primary repair and sutures had to be tied over bone,^57,67 whereas currently suture anchors are available that prevent the need for tunnel drilling and enable direct suture tensioning.^32,38 Finally, and most importantly, in the historic literature patients were treated with an invasive arthrotomy technique, while modern day arthroscopic techniques readily enable the surgeon to effectively suture the remnant arthroscopically. Interestingly, in 2005, in their 20-year follow-up of primary repair surgeries, Strand and colleagues¹⁰⁹ stated, “if the same results could be accomplished by a smaller, arthroscopic procedure, primary repair might reduce the number of patients needing later reconstructions with small ‘costs’ in the way of risk and inconvenience for the patients. We therefore believe that further research and development of methods for closed (arthroscopic) repair are justified.”

Altered Risk-Benefit Ratio

Historically, the treatments of open primary repair and open ACL reconstruction were both invasive surgeries with an arthrotomy, drilling of bone tunnels, and postoperative joint immobilization for 4 to 6 weeks. However, with the modern-day advances, the risk-benefit ratio of both treatments has changed, as Strand and colleagues¹⁰⁹ had already suggested. Although ACL reconstruction can be performed arthroscopically, it remains an invasive procedure, in which tunnels are drilled, patellar tendons or hamstring tendons are harvested, and complications, such as knee pain and quadriceps atrophy, are common. The surgery of primary ACL repair, however, has benefited significantly from the modern developments.^32,38 Primary ACL repair can now be performed arthroscopically, and by using suture anchors no tunnels need to be drilled and the remnant can be tensioned directly. An additional benefit of the use of suture anchors is that revision surgery of a failed primary repair is analogous to primary reconstruction, whereas revision surgery of a failed ACL reconstruction can be problematic due to tunnel widening, tunnel malpositioning, and preexisting hardware.^20-22

Reviewing the differences between arthroscopic primary ACL repair and ACL reconstruction, it becomes clear that primary repair has benefited significantly from the modern advances and that the risk-benefit ratio for primary repair has been altered. This means that patients with proximal tears can be treated with a relatively straight forward, minimally invasive surgery, which has been shown to be effective in 85% to 90% of patients.^32,38

Treatment Algorithm Based on Tear Location

Since 2008, in the practice of the senior author (GSD), the surgical treatment algorithm for ACL injuries is completely based on the tear location and tissue quality of the ligament.^110,111 To describe the different tear types, we use the modified Sherman classification in which we extended his classification towards the tibial side whereas Sherman and colleagues⁷⁰ only described the femoral side of the tears (Figures A-F, Table).

Type I Tears: Primary Repair

Type I tears are soft tissue avulsion type tears that can be easily treated with arthroscopic primary repair.¹⁰⁷ The length of the distal remnant has to be at least 90% and the tissue quality has to be good to excellent in order to approximate the remnant towards the femoral wall (Table).¹¹² The incidence of type I tears was 26% in the study of Sherman and colleagues,⁷⁰ although recent studies showed a lower incidence (6% to 10%) in a larger population.^32,38 Certainly, individual practices will see different percentages of type I tears based upon the mix of injury mechanisms they see most frequently. Over the last 2 years, with the recognition of the importance of tear type and tissue quality, there has been a renewed interest in arthroscopic primary ACL repair.^32,38

DiFelice and colleagues³² were the first to arthroscopically perform primary repair of the ACL in proximal tears using suture anchors. They reported the outcomes of the first 11 consecutive patients that underwent primary repair in a previously described technique.¹¹³ At mean 3.5-year follow-up, they noted only 1 failure (9%) due to re-injury; mean Lysholm score of 93.2; mean modified Cincinnati score of 91.5; pre- and postoperative Tegner score of 7.3 and 6.9, respectively; SANE score of 91.8; and subjective International Knee Documentation Committee (IKDC) score of 86.4. Of the patients with an intact repair, 9 patients had an objective IKDC rating A and 1 patient had B and all patients had KT-1000 leg differences of <3 mm with the contralateral side (three patients were not available for KT-1000 testing). The authors concluded that arthroscopic primary ACL repair could achieve short-term clinical success in a selected group of patients with proximal avulsion tears and excellent tissue quality. They further noted that mid-term outcomes are necessary given that the results of open primary repair deteriorated at longer-term follow-up in the historical literature. Recently, the senior author (GSD) has added an Internal Brace (Arthrex) to the primary repair with the goal of protecting the ligament in the first weeks to further promote healing of the ligament.^39,40,114

More recently, Achtnich and colleagues³⁸ compared the treatment of arthroscopic primary ACL repair with primary ACL reconstruction in 41 patients with type I tears at 2.3-years follow-up. Twenty-one patients consented for primary repair while 20 patients declined this procedure and underwent primary reconstruction. They noted no significant differences in Lachman test, pivot shift test, objective IKDC score, and KT-1000 scores. Although not significant, the clinical failure rate in the primary repair group (15%) was higher than the reconstruction group (0%). Interestingly, despite the higher failure rate in the repair group, the authors concluded that primary ACL repair is recommended in a carefully selected group of patients with type I tears and excellent tissue quality, which can likely be explained by the differences in the risk-benefit ratio between both procedures.

Over the last decade, the research group led by Murray^46,115,116 has performed experimental research on primary repair with a biological scaffold and reported many interesting findings that could be extrapolated to primary ACL repair. First of all, they compared bioenhanced primary repair with bioenhanced primary reconstruction in 64 Yucutan pigs and noted that there was significantly less macroscopic cartilage damage in the primary repair group at 1-year follow-up.⁴⁶ They concluded that bioenhanced ACL repair may provide a new, less invasive treatment option that reduces cartilage damage following joint injury. This may suggest that primary repair may have a lower incidence of osteoarthritis when compared to ACL reconstruction, which is interesting as osteoarthritis is very common after ACL reconstruction. Further research in this area is certainly warranted.

In another study they compared bioenhanced primary repair in juvenile, adolescent and mature Yucutan pigs and noted that functional healing depended on the level of skeletal maturity with immature animals having a more productive healing response.¹¹⁶ This indicates that primary repair might be a good treatment option in skeletally immature patients, especially since reconstruction increases the risk of premature closure of the epiphysis^117,118 and delaying treatment increases the risk of meniscus injury.¹¹⁹ Interestingly, a recent meta-analysis showed indeed that the risk of epiphysis closure was lower in primary repair when compared to ACL reconstruction and the rupture rate was also lower.¹¹⁸ Primary repair may be a good treatment option in children as the procedure has all the attributes that should be applicable to children: it is minimally morbid, tissue sparing, and it is a conservative approach that does not burn any surgical bridges for future reconstructive surgery if necessary.

Finally, the research group of Murray¹¹⁵ assessed the effect of surgical delay of primary repair following injury in Yucutan pigs and noted that better biomechanical outcomes were noted after delaying surgery for 2 weeks when compared to 6 weeks. This suggests that primary repair should preferably be performed in the acute setting, which has also been shown in historical studies since the ligament in the acute setting has optimal tissue quality and the ligament is less likely to be retracted or reabsorbed.^59,60,115

One Bundle Type I Tears: Single Bundle Augmented Repair

In some cases, the tear locations of the AM and PL bundle are not at the same location and Zantop and colleagues¹²⁰ reported in an arthroscopic study that this could be as frequent as in 30% of all complete tears. In some of these tears, one of the bundles can be avulsed of the femoral wall (type I tear) while the other bundle is not directly repairable (non-type I tear). In these cases, the senior author (GSD) will repair the type I tear bundle, whereas a hamstring augmentation is placed at the location of the other bundle. When reviewing the literature, a combination of primary repair of one bundle and reconstruction of the second bundle has not been described before. However, over the last decade several surgeons have performed augmentation of one bundle in the setting of partial tears.^{34,35,121-124}

Buda and colleagues³⁴ were the first to perform selective AM or PL bundle reconstruction in the setting of partial tears.³⁴ At 5-year follow-up, they reported no reruptures and only 1 patient with an IKDC C-score, although reoperation was necessary in 4 out of 47 patients (9%). Following this publication, many others reported on selective bundle reconstruction.^35,121-124 However, with partial tears, the knee is often stable and a selective augmentation technique is utilized to prevent complete rupture of the ligament. The application of this technique is essentially different from reconstruction for complete ACL tears in which the knee is unstable, there is a giving way sensation and patients have problems participating in sports.

Type II Tears: Augmented Repair

Type II tears often have good or excellent tissue quality and can be pulled up towards the femoral footprint, but are too short to be firmly attached. Sherman and colleagues⁷⁰ reported that approximately 22% patients had a type II tear, which corresponds to a tear located in the proximal part of the ligament. With this technique, multiple suture passes are used to stitch the remnant and, in addition, a smaller hamstring autograft or allograft is passed through the middle of the tibial remnant. A suture button is used proximally for the graft, and the tensioning repair sutures through the remnant are also passed through the suture button. The suture button is passed through the femoral tunnel and flipped so that the graft is proximally fixed. Then, the repair sutures of the remnant are tensioned, and the ligament is pulled towards the femoral wall as a sleeve around the graft. When the ligament is approximated to the femoral wall, the sutures are tied over the suture button. The graft is then tensioned distally to complete the augmented repair.

In the recent literature, the technique of augmentation of a primary repair using autograft tissue has not been reported. However, augmented repair using an internal brace^39,40 or augmentation devices^33,41 have been recently performed. MacKay and colleagues³⁹ reported good outcomes of arthroscopic primary repair of proximal tears using an internal brace. Eggli and colleagues³³ reported the results of the first 10 patients treated with ACL preservation using primary repair of the ligament with the addition of a dynamic screw-spring mechanism. The authors reported good preliminary results with one failure (10%) and good objective and subjective outcomes. In a next study, they reported the outcomes of 278 patients and although they reported good clinical outcomes and a revision rate of 4%, the reoperation rate for removal of the screw-spring mechanism was high (24%).⁴¹ This is not surprising when reviewing the historical literature in which high complication rates of the augmentation devices were reported.^99,100 We were unable to identify any other studies reporting surgical techniques of augmenting primary repair in the literature.

Type III Tears: Reconstruction With Remnant Tensioning

In patients with type III tears, the ligament cannot be approximated to the wall and reconstruction is necessary in order to restore knee stability. However, in these cases the ligament has sufficient length (25%-75%) and can be tensioned along or around the graft. Preservation of the ligament remnant has several (theoretical) advantages, such as better proprioceptive function,^42,49,50 vascularization and ligamentization of the graft,^50-52 an optical guide for anatomic tunnel placement,⁵³ and a decreased incidence of tunnel widening.^54,55 Furthermore, tensioning of the remnant is thought to lower the risk of cyclops lesions when compared to remnant preservation.¹²⁵ Although the difference between augmented repair and remnant tensioning seems small, the purpose of surgery is different. With augmented repair, the ligament can be approximated close to the femoral wall and the goal of surgery is to use the healing capacity that the ACL has in the proximal part of the ligament,¹²⁶ while with remnant tensioning the goal is only to benefit from some of the aforementioned advantages. Ahn and colleagues³⁶ were the first to perform this technique and stated, “Our concept is that the remnant tissue has only an additive effect.” Furthermore, with augmented repair multiple sutures are passed through the AM and PL bundle in order to sufficiently approximate the ligament to the femoral wall, while with the remnant tensioning technique generally one or a few sutures or lasso loop are passed through the proximal part to tension the ligament, prevent sagging of the remnant, and decrease the risk of cyclops lesions.^127,128

Several authors have recently performed remnant tensioning during ACL.^{36,47,125-127} Ahn and colleagues⁴⁷ reported excellent objective and subjective outcomes following this procedure and found that with re-arthroscopy nearly all patients had fair synovialization of the graft. Others have reported similarly good outcomes of these techniques.^125,129,130 However, studies comparing this treatment with normal ACL reconstruction and assessing outcomes, failure rates and proprioception are lacking.

Type IV Tears: Reconstruction With Remnant Preservation

Finally, in some patients the ligament is torn distally or the tissue quality is not optimal. In these patients, the remnant can be debrided to the part of good tissue quality in order to preserve the biology and minimize the risk for cyclops lesions. A standard reconstruction needs to be performed to restore the instability, but by preserving the remnant, advantages, such as proprioception,^44,49,50 graft vascularization,^50-52 an optical guide for tibial tunnel placement,⁵³ and a decreased incidence of tunnel widening^54,55 can be expected.

Lee and colleagues³⁷ presented the tibial remnant technique in which standard reconstruction was performed, and the tibial tunnel was drilled through the center of the remnant. In a later study, they compared remnant preservation with a remnant of <20% of the total ACL length with >20% of the length and found that proprioception was better with more remnant volume.⁴⁸ Similarly, Muneta and colleagues¹³¹ assessed the role of remnant length and found that remnant length is positively correlated with better stability measured on KT-1000 anteroposterior stability.

Several studies compared ACL reconstruction with remnant preservation vs conventional ACL reconstruction.^52,54,129 Takazawa and colleagues⁵² performed a retrospective study of 183 patients and found that patients in the remnant preservation group had significantly better KT-2000 stability, while they also reported a significantly lower graft rupture rate in this group (1.1% vs 7.1%) at 2-year follow-up. Hong and colleagues¹²⁹ performed a randomized clinical trial of 80 patients and did not find these differences, although there was a trend towards higher Lysholm scores in the remnant preservation group. Finally, Zhang and colleagues⁵⁴ performed a randomized clinical trial and found a lower incidence and amount of tibial tunnel widening in the preserving-remnant group when compared to the removing-remnant group. These studies show that there is likely a role for remnant preservation.

Type V Tears: Primary Repair

In some patients, the ligament is torn in the distal 10% of the ligament, which can occur as a distal avulsion tear or as a distal bony avulsion fracture.¹³² Bony avulsion fractures are most commonly seen in children whereas true distal soft tissue avulsion tears are very rare.¹³²

Treatments of these tear types include antegrade screw fixation, pullout sutures or the use of suture anchors in case of bony avulsion fractures and pullout sutures with tying over a bony bridge or ligament button in case of soft tissue avulsions. Leeberg and colleagues¹³² recently performed a systematic review of all studies reporting on treatment of distal avulsion fractures.They noted that most treatments were currently performed arthroscopically and that outcomes were generally good. Another recent biomechanical study compared antegrade screw fixation with suture anchor fixation and pullout suture fixation.¹³³ The authors noted that suture anchor fixation has slightly less displacement of the bony fragment when compared to screw fixation and pull-out sutures, and that the strength to failure was higher in the suture anchor fixation when compared to the pullout suture fixation. The outcomes of this study suggest that screw fixation and suture anchor fixation might be superior to pullout suture fixation, which might be interesting as with pullout suture fixation the ligament cannot be directly tensioned to the tibial footprint, which can lead to anteroposterior laxity.¹³² Clinical studies are necessary to assess the preferred treatment in these tear types but it seems that screw fixation is preferred in large bony avulsion fractures, while suture anchor fixation or pullout suture fixation can be used for soft tissue avulsion tears.

Complex Tears or Poor Tissue Quality: Reconstruction

If the tear is complex, multiple tears are present, or the tissue quality is poor, then preservation of the ligament is not possible, and in these cases a standard reconstruction should be performed.

Conclusion

When reviewing the literature of ACL preservation, it becomes clear that the evolution of surgical treatment of ACL injuries was biased. Preservation of the native ligament has many advantages, such as better proprioception, graft vascularization, an optical guide for tibial tunnel placement, and a decreased incidence of tunnel widening that can be expected. Furthermore, arthroscopic primary ACL repair is minimally invasive and does not burn any bridges for future reconstructions, if necessary. This is in addition to the other (theoretical) advantages of primary repair, such as restoration of native kinematics and a decreased risk of osteoarthritis. Modern advances have significantly changed the risk-benefit ratio that should make us reconsider ACL preservation approaches. Certainly, further research in this area is warranted. In this article we have presented a treatment algorithm for ACL preservation, which is based on tear location and remnant tissue quality.

Am J Orthop. 2016;45(7):E393-E405. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Injury of the anterior cruciate ligament (ACL) is very common with over 200,000 annual injuries in the United Status.^1,2 There is a general consensus that these injuries should not be treated conservatively in patients that are younger, or who wish to remain active.^3,4 Reconstructive surgery is currently the preferred treatment in these patients, and anatomic single-bundle reconstruction with autografts is considered the gold standard.^5,6

Reconstruction of the ACL is, however, not a perfect treatment. Following single-bundle autograft reconstruction, revision rates of 3% to 8%,^6-9 contralateral injury rates of 3% to 8%,^10,11 and infection rates of 0.5% to 3%^7,12,13 have been reported. Furthermore, due to the invasive nature of graft harvesting and the surgical procedure, 10% to 25% of the patients are not satisfied following ACL reconstruction.^14,15 This can often be explained by common complaints, such as anterior knee pain (13%-43%), kneeling pain (12%-54%), quadriceps muscle atrophy (20%-30%),^16,17 and loss of range of motion (ROM) (12%-23%).^7,9,18,19 Furthermore, as a result of the invasive nature of reconstructive surgery, revisions can be difficult due to complications, such as tunnel widening, tunnel malpositioning, and preexisting hardware.^20-22 This can lead to inferior outcomes and higher rates (13%) of revision surgery compared to primary reconstruction.^23-26 Finally, reconstructive surgery does not restore native kinematics of the ACL,^27-29 which may partially explain why reconstructive surgery has not been shown to prevent osteoarthritis.^28-31

Over the past decades, there has been an increasing interest in the preservation of the ACL in an attempt to ameliorate these issues.^32-37 Ligament preservation focuses on preserving the native tissues and biology, while minimizing the surgical morbidity to the patients.

Some authors have recently reported on arthroscopic primary repair of proximal ACL tears in which the ligament is reattached onto the femoral wall using modern-day suture anchor technology.^32,38 Others have augmented this repair technique with an internal brace^39,40 or with a synthetic device.^33,41 When performing primary repair, it is believed that proprioception is maintained,^42-44 while experimental studies have suggested that primary repair also restores the native kinematics,⁴⁵ and may prevent osteoarthritis.⁴⁶ Furthermore, primary repair is a conservative approach in that no grafts need to be harvested, no tunnels need to be drilled, and revision surgery, if necessary, is more analogous to primary reconstructions.³²In patients with partial tears, some surgeons have advocated preserving the anteromedial (AM) or posterolateral (PL) bundle and performing selective single-bundle augmentation.^34,35 In addition, several authors have used remnant tensioning^36,47 or remnant preservation^37,48 in combination with reconstructive surgery in order to benefit from the biological characteristics of the remnant. These techniques lead to better proprioceptive function,^44,49,50 vascularization and ligamentization of the graft,^50-52 provide an optical guide for anatomic tunnel placement,⁵³ and decrease the incidence of tunnel widening.^54,55The feasibility and applicability of these surgical techniques mainly depends on the tear type and tissue quality of the torn ligament. In this article we (I) discuss the history of ACL preservation, (II) discuss how modern advances alter the risk-benefit ratio for ACL preservation, and (III) propose a treatment algorithm for ACL injuries that is based on tear location and tissue quality.

History of ACL Preservation

The history of the surgical treatment of ACL injuries started in 1895 when Robson⁵⁶ treated a 41-year-old male who tore both cruciate ligaments from the femoral wall. Performing primary repair with catgut ligatures, both cruciate ligaments were preserved and the patients had resolution of pain symptoms and full function at 6-year follow-up. Over the following decades, Palmer^57,58 and O’Donoghue^59,60 further popularized open primary repair for the treatment of ACL injuries, and this technique was the most commonly performed treatment in the 1970s and early 1980s.^61-65 The initial short-term results of primary repair were excellent,^61,62 but Feagin and Curl⁶⁶ were the first to note that the results deteriorated at mid-term follow-up. Despite improvements in the surgical technique of repairing the ACL, such as the usage of nonabsorbable sutures and directly tying the sutures over bone,^63,67 the results remained disappointing at longer-term follow-up.^68-70

In response to these disappointing results, surgeons sought to improve the surgical treatment by either augmenting the primary repair with a semitendinosus, a patella tendon graft or an augmentation device,^71-74 or by performing primary reconstruction.^75-77 At the end of the 1980s and early 1990s, several randomized and prospective clinical trials were performed in order to compare the outcomes of these techniques.^74,78-82 Many studies showed that results of augmented repair were more reliable when compared to primary repair, which led to the abandonment of primary repair in favor of augmented repair, and eventually primary reconstruction.⁶⁵

The Important Role of Tear Location in Ligament Preservation

When taking a closer look at the outcomes of primary repair and augmented repair, it seems that the results of these preservation techniques were not as disappointing as was suggested. This can be explained, in large part, by the fact that the important roles of tear location and tissue quality were not widely recognized.

Sherman and colleagues⁷⁰ reported in 1991 their mid-term results of open primary repair. Similar to others, they noted a deterioration of their results at mid-term follow-up. However, they uniquely performed an extensive subgroup analysis in order to find an explanation for this. In their study, considered a landmark paper on primary repair,^65,70 they concluded that, “poor tissue quality is typical for midsubstance tears and that a repair of these injuries will predictably fail while type I tears (proximal), with better tissue quality, show a definite trend towards better results.”⁷⁰ With these findings, they confirmed the findings of others that had recognized a trend of better outcomes with proximal tears.^64,67,83-85

A majority of the historical studies that were published before 1991 had not considered the role of tear location and tissue quality on outcomes of open primary repair. This was also true for the aforementioned randomized studies that compared primary repair with augmented repair and primary reconstruction. Because these studies randomized patients and did not take tear location into account, it can be expected that patients with midsubstance tears were included in the cohorts of primary repair and the outcomes of these studies were therefore confounded.^74,78-82 If these studies would have been aware of the role that tear location plays on primary repair outcomes, different outcomes may have been found and different conclusions on the optimal treatment for different tear types may have been drawn.⁸⁶

Open Primary ACL Repair Outcomes Stratified by Tear Location

When reviewing the literature of open primary repair outcomes stratified by tear location, it is noted that multiple studies reported excellent outcomes following primary repair of proximal ACL tears.^{73,83,84,87-90} Weaver and colleagues⁶⁴ were among the first to stratify their results by tear location, and they found that more patients with proximal tears (52 of 66; 79%) were satisfied after the procedure when compared to patients with midsubstance tears (3 of 13; 23%) at 3.5-year follow-up. They concluded that, “selection can be made with some predictability of the type of injury to the ligament as to which patients will do better.”⁶⁴ Kühne and colleagues⁸⁹ reported the outcomes of 75 patients with proximal tears treated with open primary repair and noted no failures, negative pivot shift in 88% of patients, stable or nearly stable Lachman test in 87% of patients, and 89% return to sports rate at 4-year follow-up. Raunest and colleagues⁹¹ reported a negative pivot shift and negative anterior drawer test in 84%, return to sports in 71%, and satisfaction in 75% of 51 patients that underwent open primary repair of proximal tears at 3.5-year follow-up.

Interestingly, and in contrast to the findings of Feagin and Curl,⁶⁶ no deterioration of the outcomes at mid-term follow-up was noted in patients with proximal tears. Genelin and colleagues⁸⁸ reported their results of 42 patients with proximal tears treated with open primary repair at 5- to 7-year follow-up. They found a negative pivot shift in 81%, stable or nearly stable Lachman test in 81%, and patient satisfaction in 86% of patients. Similarly, Bräm and colleagues⁸⁷ found good results at mid-term follow-up with a good-excellent Lysholm score in 79%, return to a similar level of sports in 76%, stable or nearly stable Lachman test in 91%, and anterior drawer test in 94% of patients, along with an 88% satisfaction rate and 7% failure rate in patients who underwent open primary repair of proximal tears.

On the contrary, when the outcomes of studies that performed open primary repair in mainly, or only, patients with midsubstance tears are reviewed, significantly inferior results are found. Frank and colleagues⁹² reported outcomes in 42 patients with midsubstance tears at 4-year follow-up. They reported that 56% had a stable or nearly stable anterior drawer test, 78% had a positive pivot shift, and that only 61% were satisfied with the procedure. Odensten and colleagues⁷⁸ reported outcomes of open primary repair in a subgroup of 22 patients with midsubstance tears at 1.5-year follow-up, and noted a 14% failure rate.

When reviewing the mid-term results in patients with midsubstance tears, it seems that there was more deterioration in outcomes.^69,70 Firstly, the aforementioned study by Sherman and colleagues⁷⁰ showed poor results in the patients with (type IV) midsubstance tears at mid-term follow-up. Furthermore, Kaplan and colleagues⁶⁹ reported the mid-term outcomes of 70 patients, of which 56 patients had midsubstance tears. After having reported good outcomes at short-term follow-up,^63,67 they noted that 42% of patients had >3 mm anteroposterior stability when compared to the contralateral leg, only a 62% return to sport rate, and a 17% failure rate. They concluded that, “Although … primary repair of the anterior cruciate may work in some patients, it is an unpredictable operative procedure.”

These studies showed that the outcomes of open primary repair were significantly better in patients with proximal ACL tears and sufficient tissue quality when compared to midsubstance tears. This suggests that open primary ACL repair may have been prematurely abandoned as a treatment option for patients with proximal tears.

Augmented ACL Repair

There were several reasons why augmented repair became the preferred treatment in the early and mid 1990s. First of all, the results of augmented repair were more consistent compared to primary repair in the aforementioned randomized and prospective studies,^74,78-82 which is not surprising given the fact that the role of tear location was not widely recognized at the time. Secondly, in the 1970s and early 1980s, patients were treated postoperatively in a cast for 6 weeks, which led to problems, such as loss of ROM, pain, and decreased function.^93,94 At the end of the1980s and 1990s, the focus shifted from prolonged joint immobilization towards early postoperative ROM.^95-97 Since many authors believed that primary repair of the ACL was not strong enough to tolerate early mobilization, an augmentation was added to the technique in order to fortify the repair and enable early ROM.⁹⁸

Interestingly, augmented repair, which is essentially a combination of primary ACL repair and ACL reconstruction, was mainly performed in the 1990s and many surgeons did recognize the role of tear location in this treatment at this point.^73,98-103 In these years, the treatment algorithm consisted of augmented ACL repair in patients with proximal tears in the acute setting and ACL reconstruction in patients with midsubstance or chronic tears. Several different augmentation techniques were used to reinforce the primary repair in these years including autograft tissues (semitendinosus tendon,^102-104 patellar tendon,¹⁰⁰ or iliotibial band [ITB]¹⁰⁵) synthetic materials (polydioxanone [PDS],^101,102,106 carbon fibre,⁷⁴ and polyester [Trevira]⁹⁷), augmentation devices (Kennedy Ligament Augmentation Device [LAD]^98-100) and extra-articular augmentations.⁷³

When reviewing the outcomes of augmented repair of the ACL, good to excellent results can be found in studies that used this technique in patients with proximal tears.^73,98-106 Kdolsky and colleagues⁹⁸ were in one of the first groups that reported their results of augmented repair in only patients with proximal tears. In 1993, they reported their mid-term outcomes (5 to 8 years) in 66 patients who underwent primary repair and augmentation with the Kennedy LAD and found that 97% of patients had stable knees (<3 mm on KT-1000 examination), 98% had a negative pivot shift, and 76% returned to previous level of sports. However, often-reported problems with the augmentation devices were found in this study with rupture of the device (12%) and decreased ROM (14%).⁹⁸ In 1995, Grøntvedt and Engebretsen¹⁰⁰ compared augmentation with the Kennedy LAD to patellar tendon augmentation in a randomized study of patients with acute proximal tears. They noted that 50% of the patients in the Kennedy LAD group had a positive pivot shift compared to 23% in the patellar tendon group. Furthermore, they found KT-1000 leg differences of <3 mm in 92% of the patellar tendon group and 54% of the Kennedy LAD group. Because the authors found significant differences between both groups at 1- and 2-year follow-up, they stopped the clinical trial.

Several authors in the following years reported good results of augmented repair using autograft tissues. Natri and colleagues¹⁰⁵ reported the outcomes of 72 patients treated with primary repair of proximal tears augmented with the ITB at 3.5-year follow-up. They found 89% negative pivot shift rate, 93% stable or nearly stable Lachman test, 99% stable or nearly stable anterior drawer test, 79% satisfaction rate, and 91% return to previous level of sports rate. Krueger-Franke and colleagues¹⁰⁴ reported the outcomes of primary repair of proximal tears with augmentation using the semitendinosus tendon. In a retrospective study of 76 patients, they noted that 96% of patients had a negative pivot shift, 75% of patients had stable or nearly stable Lachman test, 93% were satisfied with the procedure, a mean Lysholm score of 92, a Tegner score that only decreased from 7.2 to 7.1, and KT-1000 testing with 78% <4 mm leg difference with the contralateral leg. The authors concluded that patients with femoral ruptures could be treated with augmented repair when performed in the acute setting. As this study was published in 1998, they stated that magnetic resonance imaging and arthroscopy could be helpful in identifying the tear location.

Final Abandonment of ACL Preservation

Reviewing these outcomes raises the question as to why these techniques were ultimately abandoned in the treatment algorithm of proximal ACL injuries, especially given the aforementioned advantages of ACL preservation. One of the possible answers can be found in a landmark study on ACL reconstruction and rehabilitation published by Shelbourne and colleagues¹⁰⁷ in 1991. At that time, arthrofibrosis and knee stiffness were frequently reported problems following ACL surgery, which could partially be explained by the standard conservative rehabilitation using postoperative joint immobilization.^67,70,80,88

Shelbourne and colleagues¹⁰⁷ aimed to assess the cause of arthrofibrosis and knee stiffness, and divided the patients into groups by number of days between injury and surgery (<7, 7 to 21 days, and >21 days between injury and surgery). Furthermore, patients within these groups underwent either a conventional or accelerated rehabilitation program. The authors not only found that patients undergoing accelerated rehabilitation had less arthrofibrosis, but they also noted that less arthrofibrosis was seen when surgery was delayed. These findings, however, contrasted with the general perception that the ACL should be repaired in the first 3 weeks postinjury to ensure optimal tissue quality with an augmented approach. As a result, the treatment of ACL injuries shifted towards ACL reconstruction after these findings. Krueger-Franke and colleagues¹⁰⁴ commented on the trend after the study of Shelbourne and colleagues:¹⁰⁷ “Less consideration has been given to the importance of the proprioceptive receptors in the tibial remnants of the torn ACL and the value of their preservation as part of a primary reconstruction.”

In addition to the trend away from an augmented repair approach due to the novel understanding of the importance of early mobilization, some discussion should focus on the technical limitations of arthroscopy at that time. While arthroscopy had been around for several decades, fluid management and arthroscopic instrumentation was slow to develop. All of the repair and augmentation techniques previously discussed had been performed via an open arthrotomy. Arthroscopic technologies of the time were not refined enough to enable surgeons to perform such complex, intra-articular techniques that would enable suturing of the ligament remnant. In this regard, arthroscopic ACL reconstruction was a much simpler technique to accomplish, and this also likely contributed to the final abandonment of the ligament preservation approach.

Role for ACL Preservation with Modern Advances

As stated in the introduction, there has been a recent resurgence of interest in preservation of the native ligament.^32-37 With the passage of time, many technologic advances have been made, which has allowed surgeons to reconsider the concept of ligament preservation.

First of all, appropriate patient selection was not applied historically, as the critical factors of tear location and tissue quality were not recognized in the era of open primary repair. In modern days, however, advances such as MRI have been developed, which can give the surgeon an idea of the status, and tear type of the ACL pre-operatively.¹⁰⁸ This may help the orthopaedic surgeon to plan the surgery and make an assessment as to whether ACL preservation is possible. Secondly, in the historic literature the postoperative regimen consisted of casting for 5 or 6 weeks,^67,70,80,88 while the focus later shifted towards early ROM.^95-97Modern day ACL rehabilitation focuses on immediate ROM to avoid the complications stiffness, pain and decreased function that plagued the outcomes when immobilization was used.^93,94 Thirdly, historically small tunnels were drilled with primary repair and sutures had to be tied over bone,^57,67 whereas currently suture anchors are available that prevent the need for tunnel drilling and enable direct suture tensioning.^32,38 Finally, and most importantly, in the historic literature patients were treated with an invasive arthrotomy technique, while modern day arthroscopic techniques readily enable the surgeon to effectively suture the remnant arthroscopically. Interestingly, in 2005, in their 20-year follow-up of primary repair surgeries, Strand and colleagues¹⁰⁹ stated, “if the same results could be accomplished by a smaller, arthroscopic procedure, primary repair might reduce the number of patients needing later reconstructions with small ‘costs’ in the way of risk and inconvenience for the patients. We therefore believe that further research and development of methods for closed (arthroscopic) repair are justified.”

Altered Risk-Benefit Ratio

Historically, the treatments of open primary repair and open ACL reconstruction were both invasive surgeries with an arthrotomy, drilling of bone tunnels, and postoperative joint immobilization for 4 to 6 weeks. However, with the modern-day advances, the risk-benefit ratio of both treatments has changed, as Strand and colleagues¹⁰⁹ had already suggested. Although ACL reconstruction can be performed arthroscopically, it remains an invasive procedure, in which tunnels are drilled, patellar tendons or hamstring tendons are harvested, and complications, such as knee pain and quadriceps atrophy, are common. The surgery of primary ACL repair, however, has benefited significantly from the modern developments.^32,38 Primary ACL repair can now be performed arthroscopically, and by using suture anchors no tunnels need to be drilled and the remnant can be tensioned directly. An additional benefit of the use of suture anchors is that revision surgery of a failed primary repair is analogous to primary reconstruction, whereas revision surgery of a failed ACL reconstruction can be problematic due to tunnel widening, tunnel malpositioning, and preexisting hardware.^20-22

Reviewing the differences between arthroscopic primary ACL repair and ACL reconstruction, it becomes clear that primary repair has benefited significantly from the modern advances and that the risk-benefit ratio for primary repair has been altered. This means that patients with proximal tears can be treated with a relatively straight forward, minimally invasive surgery, which has been shown to be effective in 85% to 90% of patients.^32,38

Treatment Algorithm Based on Tear Location

Since 2008, in the practice of the senior author (GSD), the surgical treatment algorithm for ACL injuries is completely based on the tear location and tissue quality of the ligament.^110,111 To describe the different tear types, we use the modified Sherman classification in which we extended his classification towards the tibial side whereas Sherman and colleagues⁷⁰ only described the femoral side of the tears (Figures A-F, Table).

Type I Tears: Primary Repair

Type I tears are soft tissue avulsion type tears that can be easily treated with arthroscopic primary repair.¹⁰⁷ The length of the distal remnant has to be at least 90% and the tissue quality has to be good to excellent in order to approximate the remnant towards the femoral wall (Table).¹¹² The incidence of type I tears was 26% in the study of Sherman and colleagues,⁷⁰ although recent studies showed a lower incidence (6% to 10%) in a larger population.^32,38 Certainly, individual practices will see different percentages of type I tears based upon the mix of injury mechanisms they see most frequently. Over the last 2 years, with the recognition of the importance of tear type and tissue quality, there has been a renewed interest in arthroscopic primary ACL repair.^32,38

DiFelice and colleagues³² were the first to arthroscopically perform primary repair of the ACL in proximal tears using suture anchors. They reported the outcomes of the first 11 consecutive patients that underwent primary repair in a previously described technique.¹¹³ At mean 3.5-year follow-up, they noted only 1 failure (9%) due to re-injury; mean Lysholm score of 93.2; mean modified Cincinnati score of 91.5; pre- and postoperative Tegner score of 7.3 and 6.9, respectively; SANE score of 91.8; and subjective International Knee Documentation Committee (IKDC) score of 86.4. Of the patients with an intact repair, 9 patients had an objective IKDC rating A and 1 patient had B and all patients had KT-1000 leg differences of <3 mm with the contralateral side (three patients were not available for KT-1000 testing). The authors concluded that arthroscopic primary ACL repair could achieve short-term clinical success in a selected group of patients with proximal avulsion tears and excellent tissue quality. They further noted that mid-term outcomes are necessary given that the results of open primary repair deteriorated at longer-term follow-up in the historical literature. Recently, the senior author (GSD) has added an Internal Brace (Arthrex) to the primary repair with the goal of protecting the ligament in the first weeks to further promote healing of the ligament.^39,40,114

More recently, Achtnich and colleagues³⁸ compared the treatment of arthroscopic primary ACL repair with primary ACL reconstruction in 41 patients with type I tears at 2.3-years follow-up. Twenty-one patients consented for primary repair while 20 patients declined this procedure and underwent primary reconstruction. They noted no significant differences in Lachman test, pivot shift test, objective IKDC score, and KT-1000 scores. Although not significant, the clinical failure rate in the primary repair group (15%) was higher than the reconstruction group (0%). Interestingly, despite the higher failure rate in the repair group, the authors concluded that primary ACL repair is recommended in a carefully selected group of patients with type I tears and excellent tissue quality, which can likely be explained by the differences in the risk-benefit ratio between both procedures.

Over the last decade, the research group led by Murray^46,115,116 has performed experimental research on primary repair with a biological scaffold and reported many interesting findings that could be extrapolated to primary ACL repair. First of all, they compared bioenhanced primary repair with bioenhanced primary reconstruction in 64 Yucutan pigs and noted that there was significantly less macroscopic cartilage damage in the primary repair group at 1-year follow-up.⁴⁶ They concluded that bioenhanced ACL repair may provide a new, less invasive treatment option that reduces cartilage damage following joint injury. This may suggest that primary repair may have a lower incidence of osteoarthritis when compared to ACL reconstruction, which is interesting as osteoarthritis is very common after ACL reconstruction. Further research in this area is certainly warranted.

In another study they compared bioenhanced primary repair in juvenile, adolescent and mature Yucutan pigs and noted that functional healing depended on the level of skeletal maturity with immature animals having a more productive healing response.¹¹⁶ This indicates that primary repair might be a good treatment option in skeletally immature patients, especially since reconstruction increases the risk of premature closure of the epiphysis^117,118 and delaying treatment increases the risk of meniscus injury.¹¹⁹ Interestingly, a recent meta-analysis showed indeed that the risk of epiphysis closure was lower in primary repair when compared to ACL reconstruction and the rupture rate was also lower.¹¹⁸ Primary repair may be a good treatment option in children as the procedure has all the attributes that should be applicable to children: it is minimally morbid, tissue sparing, and it is a conservative approach that does not burn any surgical bridges for future reconstructive surgery if necessary.

Finally, the research group of Murray¹¹⁵ assessed the effect of surgical delay of primary repair following injury in Yucutan pigs and noted that better biomechanical outcomes were noted after delaying surgery for 2 weeks when compared to 6 weeks. This suggests that primary repair should preferably be performed in the acute setting, which has also been shown in historical studies since the ligament in the acute setting has optimal tissue quality and the ligament is less likely to be retracted or reabsorbed.^59,60,115

One Bundle Type I Tears: Single Bundle Augmented Repair

In some cases, the tear locations of the AM and PL bundle are not at the same location and Zantop and colleagues¹²⁰ reported in an arthroscopic study that this could be as frequent as in 30% of all complete tears. In some of these tears, one of the bundles can be avulsed of the femoral wall (type I tear) while the other bundle is not directly repairable (non-type I tear). In these cases, the senior author (GSD) will repair the type I tear bundle, whereas a hamstring augmentation is placed at the location of the other bundle. When reviewing the literature, a combination of primary repair of one bundle and reconstruction of the second bundle has not been described before. However, over the last decade several surgeons have performed augmentation of one bundle in the setting of partial tears.^{34,35,121-124}

Buda and colleagues³⁴ were the first to perform selective AM or PL bundle reconstruction in the setting of partial tears.³⁴ At 5-year follow-up, they reported no reruptures and only 1 patient with an IKDC C-score, although reoperation was necessary in 4 out of 47 patients (9%). Following this publication, many others reported on selective bundle reconstruction.^35,121-124 However, with partial tears, the knee is often stable and a selective augmentation technique is utilized to prevent complete rupture of the ligament. The application of this technique is essentially different from reconstruction for complete ACL tears in which the knee is unstable, there is a giving way sensation and patients have problems participating in sports.

Type II Tears: Augmented Repair

Type II tears often have good or excellent tissue quality and can be pulled up towards the femoral footprint, but are too short to be firmly attached. Sherman and colleagues⁷⁰ reported that approximately 22% patients had a type II tear, which corresponds to a tear located in the proximal part of the ligament. With this technique, multiple suture passes are used to stitch the remnant and, in addition, a smaller hamstring autograft or allograft is passed through the middle of the tibial remnant. A suture button is used proximally for the graft, and the tensioning repair sutures through the remnant are also passed through the suture button. The suture button is passed through the femoral tunnel and flipped so that the graft is proximally fixed. Then, the repair sutures of the remnant are tensioned, and the ligament is pulled towards the femoral wall as a sleeve around the graft. When the ligament is approximated to the femoral wall, the sutures are tied over the suture button. The graft is then tensioned distally to complete the augmented repair.

In the recent literature, the technique of augmentation of a primary repair using autograft tissue has not been reported. However, augmented repair using an internal brace^39,40 or augmentation devices^33,41 have been recently performed. MacKay and colleagues³⁹ reported good outcomes of arthroscopic primary repair of proximal tears using an internal brace. Eggli and colleagues³³ reported the results of the first 10 patients treated with ACL preservation using primary repair of the ligament with the addition of a dynamic screw-spring mechanism. The authors reported good preliminary results with one failure (10%) and good objective and subjective outcomes. In a next study, they reported the outcomes of 278 patients and although they reported good clinical outcomes and a revision rate of 4%, the reoperation rate for removal of the screw-spring mechanism was high (24%).⁴¹ This is not surprising when reviewing the historical literature in which high complication rates of the augmentation devices were reported.^99,100 We were unable to identify any other studies reporting surgical techniques of augmenting primary repair in the literature.

Type III Tears: Reconstruction With Remnant Tensioning

In patients with type III tears, the ligament cannot be approximated to the wall and reconstruction is necessary in order to restore knee stability. However, in these cases the ligament has sufficient length (25%-75%) and can be tensioned along or around the graft. Preservation of the ligament remnant has several (theoretical) advantages, such as better proprioceptive function,^42,49,50 vascularization and ligamentization of the graft,^50-52 an optical guide for anatomic tunnel placement,⁵³ and a decreased incidence of tunnel widening.^54,55 Furthermore, tensioning of the remnant is thought to lower the risk of cyclops lesions when compared to remnant preservation.¹²⁵ Although the difference between augmented repair and remnant tensioning seems small, the purpose of surgery is different. With augmented repair, the ligament can be approximated close to the femoral wall and the goal of surgery is to use the healing capacity that the ACL has in the proximal part of the ligament,¹²⁶ while with remnant tensioning the goal is only to benefit from some of the aforementioned advantages. Ahn and colleagues³⁶ were the first to perform this technique and stated, “Our concept is that the remnant tissue has only an additive effect.” Furthermore, with augmented repair multiple sutures are passed through the AM and PL bundle in order to sufficiently approximate the ligament to the femoral wall, while with the remnant tensioning technique generally one or a few sutures or lasso loop are passed through the proximal part to tension the ligament, prevent sagging of the remnant, and decrease the risk of cyclops lesions.^127,128

Several authors have recently performed remnant tensioning during ACL.^{36,47,125-127} Ahn and colleagues⁴⁷ reported excellent objective and subjective outcomes following this procedure and found that with re-arthroscopy nearly all patients had fair synovialization of the graft. Others have reported similarly good outcomes of these techniques.^125,129,130 However, studies comparing this treatment with normal ACL reconstruction and assessing outcomes, failure rates and proprioception are lacking.

Type IV Tears: Reconstruction With Remnant Preservation

Finally, in some patients the ligament is torn distally or the tissue quality is not optimal. In these patients, the remnant can be debrided to the part of good tissue quality in order to preserve the biology and minimize the risk for cyclops lesions. A standard reconstruction needs to be performed to restore the instability, but by preserving the remnant, advantages, such as proprioception,^44,49,50 graft vascularization,^50-52 an optical guide for tibial tunnel placement,⁵³ and a decreased incidence of tunnel widening^54,55 can be expected.

Lee and colleagues³⁷ presented the tibial remnant technique in which standard reconstruction was performed, and the tibial tunnel was drilled through the center of the remnant. In a later study, they compared remnant preservation with a remnant of <20% of the total ACL length with >20% of the length and found that proprioception was better with more remnant volume.⁴⁸ Similarly, Muneta and colleagues¹³¹ assessed the role of remnant length and found that remnant length is positively correlated with better stability measured on KT-1000 anteroposterior stability.

Several studies compared ACL reconstruction with remnant preservation vs conventional ACL reconstruction.^52,54,129 Takazawa and colleagues⁵² performed a retrospective study of 183 patients and found that patients in the remnant preservation group had significantly better KT-2000 stability, while they also reported a significantly lower graft rupture rate in this group (1.1% vs 7.1%) at 2-year follow-up. Hong and colleagues¹²⁹ performed a randomized clinical trial of 80 patients and did not find these differences, although there was a trend towards higher Lysholm scores in the remnant preservation group. Finally, Zhang and colleagues⁵⁴ performed a randomized clinical trial and found a lower incidence and amount of tibial tunnel widening in the preserving-remnant group when compared to the removing-remnant group. These studies show that there is likely a role for remnant preservation.

Type V Tears: Primary Repair

In some patients, the ligament is torn in the distal 10% of the ligament, which can occur as a distal avulsion tear or as a distal bony avulsion fracture.¹³² Bony avulsion fractures are most commonly seen in children whereas true distal soft tissue avulsion tears are very rare.¹³²

Treatments of these tear types include antegrade screw fixation, pullout sutures or the use of suture anchors in case of bony avulsion fractures and pullout sutures with tying over a bony bridge or ligament button in case of soft tissue avulsions. Leeberg and colleagues¹³² recently performed a systematic review of all studies reporting on treatment of distal avulsion fractures.They noted that most treatments were currently performed arthroscopically and that outcomes were generally good. Another recent biomechanical study compared antegrade screw fixation with suture anchor fixation and pullout suture fixation.¹³³ The authors noted that suture anchor fixation has slightly less displacement of the bony fragment when compared to screw fixation and pull-out sutures, and that the strength to failure was higher in the suture anchor fixation when compared to the pullout suture fixation. The outcomes of this study suggest that screw fixation and suture anchor fixation might be superior to pullout suture fixation, which might be interesting as with pullout suture fixation the ligament cannot be directly tensioned to the tibial footprint, which can lead to anteroposterior laxity.¹³² Clinical studies are necessary to assess the preferred treatment in these tear types but it seems that screw fixation is preferred in large bony avulsion fractures, while suture anchor fixation or pullout suture fixation can be used for soft tissue avulsion tears.

Complex Tears or Poor Tissue Quality: Reconstruction

If the tear is complex, multiple tears are present, or the tissue quality is poor, then preservation of the ligament is not possible, and in these cases a standard reconstruction should be performed.

Conclusion

When reviewing the literature of ACL preservation, it becomes clear that the evolution of surgical treatment of ACL injuries was biased. Preservation of the native ligament has many advantages, such as better proprioception, graft vascularization, an optical guide for tibial tunnel placement, and a decreased incidence of tunnel widening that can be expected. Furthermore, arthroscopic primary ACL repair is minimally invasive and does not burn any bridges for future reconstructions, if necessary. This is in addition to the other (theoretical) advantages of primary repair, such as restoration of native kinematics and a decreased risk of osteoarthritis. Modern advances have significantly changed the risk-benefit ratio that should make us reconsider ACL preservation approaches. Certainly, further research in this area is warranted. In this article we have presented a treatment algorithm for ACL preservation, which is based on tear location and remnant tissue quality.

Am J Orthop. 2016;45(7):E393-E405. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

In the first part of this series, “Preservation of the Anterior Cruciate Ligament: A Treatment Algorithm Based on Tear Location and Tissue Quality” we discussed the history of anterior cruciate ligament (ACL) preservation, and the historical outcomes of both open primary repair and augmented repair. We also presented our surgical treatment algorithm for ACL preservation, which is based on the tear location and tissue quality of the ligament remnant. In this article, we propose a modification of the Sherman classification¹ to identify the different tear types, and we will discuss the different surgical techniques that can be used for each one. Furthermore, we aim to provide an overview of the variations of these techniques that are seen in the literature. It is important to emphasize that these tear types and corresponding surgical techniques are to be seen as guidelines, rather than strict criteria, and that significant overlap between these tear types and surgical indications exist.

Assessment of Tear Type and Tissue Quality

The first assessment of the tear location and tissue quality is made using magnetic resonance imaging (MRI). Although MRI can give you an idea of where the tear is located, the final assessment for eligibility of each specific preservation technique is made during arthroscopy. Therefore, the routine preoperative discussion and informed consent process with the patient should encompass the gamut of surgical possibilities ranging from repair to reconstruction.

The Table shows our tear type classification, along with the corresponding preservation surgical techniques.

Surgical Preparation

In the operating room, the patient is placed in supine position on a standard operative table, such that the knee can be moved freely through its range of motion (ROM). The operative leg is then prepped and draped in standard fashion for knee arthroscopy. Standard knee arthroscopy equipment and implants are used, although some instruments from the standard shoulder set are also utilized. Anteromedial and anterolateral portals are created, and a general inspection of the knee is performed. By pulling the remnant ligament proximally using a broad tissue gasper, the available length of the remnant can be assessed. It is important to reduce possible anterior tibial subluxation in the sagittal plane in order to prevent “false” shortening of the distal ligament remnant. Once the length of the remnant tissue is assessed and the tissue quality is determined, the surgical preservation technique can be chosen (Table).

Type I Tears: Primary Repair

In order to be a candidate for arthroscopic primary repair, sufficient tissue length and tissue quality are necessary (Figures 1A and 1B, Table).

Sutures are then passed through the anteromedial bundle using the Scorpion Suture Passer (Arthrex) with a No. 2 FiberWire suture (Arthrex) (Figure 1C). Suturing is commenced at the intact distal end of the anteromedial bundle and is advanced in an alternating, interlocking Bunnell-type pattern towards the avulsed proximal end with approximately 4 mm to 5 mm between each pass. In general, 3 to 4 passes can be made before the final pass exits via the avulsed end of the ligament towards the femur (Figure 1D). The same process is then repeated for the posterolateral bundle of the ACL remnant with a No. 2 TigerWire suture (Arthrex) to optimize suture management. With each subsequent pass of the sutures, it is important to assess tissue resistance to prevent perforation of a previous stitch. Mild resistance is normal, but the suture-passing device should be repositioned when notably increased resistance is encountered. In addition, placing all of the bites in the same plane should be avoided since this can allow the sutures to “cheese cut” along the collagen fibers of the ligament remnant rather than holding firm.

After passing the sutures through both bundles, the sutures are guided outside the knee using an accessory stab incision situated just above the medial portal. Using this portal, the ligament can be retracted away from the femoral footprint for optimal visibility. The femoral footprint is then roughed using a shaver or burr, and bleeding is induced to stimulate a local healing response,² while the sutures and the ACL are protected via the portal. With the knee in flexion, an accessory inferomedial portal is then created under direct visualization using a spinal needle for localization. Care should be taken to enable the appropriate trajectory for anchor placement to be achieved.

Many different techniques can be used to provide fixation of the ACL repair to the femoral footprint; the 2 most straightforward techniques are presented here. The first technique provides fixation with knotless suture anchors,^3,4 whereas in the second technique the sutures are transosseously passed, and tied over a bone bridge, as was performed in the 1970s and 1980s.

Suture Anchor Fixation

With the suture anchor fixation technique, the knee is flexed in 90°, the anteromedial bundle origin within the femoral footprint is identified, and a 4.5-mm x 20-mm hole is drilled, punched, or tapped, in the case of high bone density. The FiberWire sutures are then retrieved through the accessory portal and passed through a 4.75-mm Vented BioComposite SwiveLock suture anchor (Arthrex). The suture anchor for the anteromedial bundle is then deployed into the hole within the anteromedial footprint, while tensioning the ACL remnant to the wall with a visual gap of <1 mm (Figure 1E).⁵ The procedure is then repeated using another suture anchor with TigerWire sutures for the posterolateral bundle with the knee flexed at 110° to 115°. This ensures an optimal angle of approach and avoids perforating the posterior condyle with the anchor. The drill hole and anchor are placed into the origin of the posterolateral bundle within the femoral footprint. The order of bundle tensioning and repair may be varied depending on the particulars of each case.

Once the anchors are fully deployed and flush with the femoral footprint, the handle is removed and the additional core stitches are unloaded. Occasionally, the core stitches can be passed from lateral to medial through the proximal ligament remnant and tied down with an arthroscopic knot pusher to add extra compression of the remnant to the origin. The free ends of the repair sutures are cut with an Open Ended Suture Cutter (Arthrex) so that they are flush with the notch. The repair is now complete (Figure 1F). Using a probe, the ACL remnant is tested for tension and stiffness. Finally, cycling of the knee through the full ROM confirms anatomic positioning without impingement of the graft. Manual laxity testing should reveal minimal anteroposterior translation with a firm endpoint on Lachman examination intraoperatively.

Bone Bridge Fixation

With this technique, parallel drill holes are created exiting at each bundle origin. The repair stitches can then be retrieved and tensioned proximally. One way to accomplish this is by using an ACL femoral guide (Arthrex) that is placed via the anterolateral portal and is centered on the anteromedial bundle insertion. This device guides a cannulated RetroDrill (Arthrex) to drill through the lateral femoral condyle towards the anteromedial footprint. A passing wire can then be delivered through the cannulation and used to retrieve that anteromedial bundle repair stitches. This process can then be repeated for the posterolateral bundle and the associated repair stitches. Drill holes can also be made retrograde from a low anteromedial accessory portal using a slotted pit that can be used to shuttle the repair stitches. When all the repair sutures are passed, the ligament is tensioned while being visualized arthroscopically. The knee is held at 20° of flexion and a posterior drawer force can be applied, if necessary, to reduce the tibia to its anatomic position. The suture limbs are then tensioned and can be fixated using any of a multitude of techniques, including tying over a bony bridge, tying over a 4-hole ligament button, and tying to a post.

One disadvantage of the bone bridge fixation technique, however, is the suspensory fixation that is not as stiff as tensioning and fixating with suture anchors. Despite this disadvantage, however, the senior author (GSD) has achieved excellent results with this technique at longer-term follow-up in a small group of patients. One advantage of the bone bridge fixation technique is that the procedure has lower costs than fixation with suture anchors.

One Anchor Repair Fixation

Achtnich and colleagues⁶ recently published a slightly different technique for repairing type I tears. The authors passed a No. 2 FiberWire suture through the midsubstance of both bundles of the ACL remnant to create a modified Mason-Allen stitch configuration. Subsequently, they tensioned the remnant towards the middle of the ACL footprint (between the anteromedial and posterolateral footprint) using one PushLock suture anchor (Arthrex). They hypothesized that using 1 anchor would be enough fixation for tears amenable to repair, and that doing so would minimize the invasion of the bone.

The preference of the senior author (GSD) is, however, to use 2 suture anchors for each bundle in order to more anatomically and biomechanically repair the remnant, since both bundles have different biomechanical characteristics.⁷ Similarly, the preference of the senior author is to commence the suturing as distal as possible and pass multiple sutures towards the proximal end. This ensures that the last suture pass is exited very proximally, and ensures that the proximal end is approximated towards the femoral wall. One suture passed at the midsubstance portion of the remnant might cause a different tension pattern and prevent optimal re-approximation of the most proximal part towards the femoral wall. Future studies are necessary to assess the efficacy of different suture and fixation techniques as these are currently lacking.

Addition of Internal Brace

Over the last few years, the senior author has added an internal brace (FiberTape, Arthrex) to the repair technique, which was first performed by MacKay and colleagues.⁸ The added internal brace protects the repair and the healing process in the first few weeks and enables early ROM.

With this technique, the previously described arthroscopic primary repair technique is performed with suturing of both bundles. However, after punching, tapping, or drilling a hole in the anteromedial origin of the femoral footprint, the anteromedial anchor is first loaded with the FiberTape in addition to the repair stitches. After placing the anteromedial suture anchor in the femoral footprint, the internal brace is fixated proximally with the suture anchor into the femoral wall.

One Bundle Type I Tears: Single Bundle Augmented Repair

In some cases, the anteromedial or posterolateral bundle is a type I tear with good or excellent tissue quality, whereas the other bundle is not a type I tear or has poor tissue quality (Figure 3A). In these cases, a primary repair of one bundle is performed with a hamstring reconstruction of the other bundle.

First, a No. 2 FiberWire is used to make 4 to 5 passes from distal to proximal, as previously described. Then, the remnants of the irreparable bundle are debrided (Figure 3B). Subsequently, the semitendinosus tendon is harvested in standard fashion, or soft tissue allografts can be used.

Type II Tears: Augmented Repair

In patients with type II tears, primary repair is not possible as the length of the remnant is too short to firmly approximate the remnant towards the femoral wall (75%-90% of native tissue length) (Figure 4A). In these patients, an augmented repair of the entire ACL is performed using hamstring autograft or soft tissue allograft.

With this technique, repair stitches are passed into the anteromedial bundle of the remnant as previously described (Figure 4B). Keeping the repair stitches anteriorly in the anteromedial bundle tends to prevent entanglement during graft passage later in the case.

Type III Tears: Reconstruction With Remnant Tensioning

The previously discussed techniques have the goals of preserving as much native ligament remnant as possible, approximating the ligament remnant towards the femoral wall, and promoting healing of the ligament. In some cases, however, the ligament remnant is too short for healing (Figure 5A). Although the ligament cannot be approximated to the femoral wall in these cases, there is still an argument for ACL preservation, as was discussed in the first article of this series.

If the ligament length is between 25% and 75% of the native tissue length, the senior author performs a remnant tensioning technique.

Type IV Tears: Reconstruction With Remnant Preservation

Finally, in some cases, the distal remnant is small or the tissue quality in the largest part of the remnant is poor, and after debriding back to good tissue quality, only 10% to 25% of the native tissue length is left (Figure 6A). In these cases, the remnant is preserved, however, tensioning of the remnant with sutures is usually not necessary for the prevention of cyclops lesions. Nonetheless, it is important to debride the parts of the remnant ligament with poor tissue quality as mop-end patterns of the remnant may increase the chance of these lesions (Figure 6B).

In this situation, any of the standard ACL reconstruction techniques can be performed with simple attention being paid to preserving what is left of the tibial insertion site. At the very least, the small insertion remnant guides the anatomic placement of the graft, and prevents egress of joint fluid into the tibial tunnel and could minimize tunnel widening.

Type V Tears: Primary Repair

Finally, in some patients a soft tissue avulsion (Figure 7A) or bony avulsion of the distal attachment of the ACL can be seen. Both injuries are relatively rare, although bony avulsions are frequently seen in children, especially those younger than 12 years old. In these cases, the same techniques and theory that are applied to proximal avulsion type tears can be used and applied to distal avulsion type tears.

First, No. 2 FiberWire sutures are passed from proximal towards the distal end of the ligament in the anteromedial bundle, and the same process is then repeated for No. 2 TigerWire sutures for the posterolateral bundle. Then both sutures are exited at the distal avulsed end at the locations of the anteromedial and posterolateral footprints (Figure 7B). A 2.4-mm ACL guide wire and a Ninitol wire are used to drill 2 tunnels from the tibia towards the tibial footprint. The repair sutures are then retrieved through both tunnels (Figure 7C) and the sutures are tied distally over a ligament button after cycling of the knee (Figure 7D). This technique is very useful for soft tissue avulsions, or when there are only small flecks of bone or when the avulsed bone is significantly comminuted. If a large bony avulsion fragment is present, this technique can also be applied with some modification, although there have been multiple other techniques described in the literature that work well in this situation including fixation with screw and washer, or with suture anchors.

Complex Tear or Poor Tissue Quality: Reconstruction

In some cases, the tissue quality is poor, or the ligament has complex or multiple tears. Essentially, in these cases, there is nothing to preserve and a standard reconstruction approach is performed in these cases.

Conclusion

The uniform gold standard for all ACL tear types is currently primary reconstruction. However, several disadvantages of ACL reconstruction exist, while there are multiple advantages to the concept of ACL preservation. In this surgical technique article, we have discussed our tear type classification and the recommended surgical techniques for each. With this treatment algorithm, which is based on tear location and tissue quality, an optimal and minimally invasive treatment can be chosen for each individual patient. Future studies are needed to compare and contrast these treatments with the current gold standard of ACL reconstruction.

Am J Orthop. 2016;45(7):E406-E414. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

In the first part of this series, “Preservation of the Anterior Cruciate Ligament: A Treatment Algorithm Based on Tear Location and Tissue Quality” we discussed the history of anterior cruciate ligament (ACL) preservation, and the historical outcomes of both open primary repair and augmented repair. We also presented our surgical treatment algorithm for ACL preservation, which is based on the tear location and tissue quality of the ligament remnant. In this article, we propose a modification of the Sherman classification¹ to identify the different tear types, and we will discuss the different surgical techniques that can be used for each one. Furthermore, we aim to provide an overview of the variations of these techniques that are seen in the literature. It is important to emphasize that these tear types and corresponding surgical techniques are to be seen as guidelines, rather than strict criteria, and that significant overlap between these tear types and surgical indications exist.

Assessment of Tear Type and Tissue Quality

The first assessment of the tear location and tissue quality is made using magnetic resonance imaging (MRI). Although MRI can give you an idea of where the tear is located, the final assessment for eligibility of each specific preservation technique is made during arthroscopy. Therefore, the routine preoperative discussion and informed consent process with the patient should encompass the gamut of surgical possibilities ranging from repair to reconstruction.

The Table shows our tear type classification, along with the corresponding preservation surgical techniques.

Surgical Preparation

In the operating room, the patient is placed in supine position on a standard operative table, such that the knee can be moved freely through its range of motion (ROM). The operative leg is then prepped and draped in standard fashion for knee arthroscopy. Standard knee arthroscopy equipment and implants are used, although some instruments from the standard shoulder set are also utilized. Anteromedial and anterolateral portals are created, and a general inspection of the knee is performed. By pulling the remnant ligament proximally using a broad tissue gasper, the available length of the remnant can be assessed. It is important to reduce possible anterior tibial subluxation in the sagittal plane in order to prevent “false” shortening of the distal ligament remnant. Once the length of the remnant tissue is assessed and the tissue quality is determined, the surgical preservation technique can be chosen (Table).

Type I Tears: Primary Repair

In order to be a candidate for arthroscopic primary repair, sufficient tissue length and tissue quality are necessary (Figures 1A and 1B, Table).

Sutures are then passed through the anteromedial bundle using the Scorpion Suture Passer (Arthrex) with a No. 2 FiberWire suture (Arthrex) (Figure 1C). Suturing is commenced at the intact distal end of the anteromedial bundle and is advanced in an alternating, interlocking Bunnell-type pattern towards the avulsed proximal end with approximately 4 mm to 5 mm between each pass. In general, 3 to 4 passes can be made before the final pass exits via the avulsed end of the ligament towards the femur (Figure 1D). The same process is then repeated for the posterolateral bundle of the ACL remnant with a No. 2 TigerWire suture (Arthrex) to optimize suture management. With each subsequent pass of the sutures, it is important to assess tissue resistance to prevent perforation of a previous stitch. Mild resistance is normal, but the suture-passing device should be repositioned when notably increased resistance is encountered. In addition, placing all of the bites in the same plane should be avoided since this can allow the sutures to “cheese cut” along the collagen fibers of the ligament remnant rather than holding firm.

After passing the sutures through both bundles, the sutures are guided outside the knee using an accessory stab incision situated just above the medial portal. Using this portal, the ligament can be retracted away from the femoral footprint for optimal visibility. The femoral footprint is then roughed using a shaver or burr, and bleeding is induced to stimulate a local healing response,² while the sutures and the ACL are protected via the portal. With the knee in flexion, an accessory inferomedial portal is then created under direct visualization using a spinal needle for localization. Care should be taken to enable the appropriate trajectory for anchor placement to be achieved.

Many different techniques can be used to provide fixation of the ACL repair to the femoral footprint; the 2 most straightforward techniques are presented here. The first technique provides fixation with knotless suture anchors,^3,4 whereas in the second technique the sutures are transosseously passed, and tied over a bone bridge, as was performed in the 1970s and 1980s.

Suture Anchor Fixation

With the suture anchor fixation technique, the knee is flexed in 90°, the anteromedial bundle origin within the femoral footprint is identified, and a 4.5-mm x 20-mm hole is drilled, punched, or tapped, in the case of high bone density. The FiberWire sutures are then retrieved through the accessory portal and passed through a 4.75-mm Vented BioComposite SwiveLock suture anchor (Arthrex). The suture anchor for the anteromedial bundle is then deployed into the hole within the anteromedial footprint, while tensioning the ACL remnant to the wall with a visual gap of <1 mm (Figure 1E).⁵ The procedure is then repeated using another suture anchor with TigerWire sutures for the posterolateral bundle with the knee flexed at 110° to 115°. This ensures an optimal angle of approach and avoids perforating the posterior condyle with the anchor. The drill hole and anchor are placed into the origin of the posterolateral bundle within the femoral footprint. The order of bundle tensioning and repair may be varied depending on the particulars of each case.

Once the anchors are fully deployed and flush with the femoral footprint, the handle is removed and the additional core stitches are unloaded. Occasionally, the core stitches can be passed from lateral to medial through the proximal ligament remnant and tied down with an arthroscopic knot pusher to add extra compression of the remnant to the origin. The free ends of the repair sutures are cut with an Open Ended Suture Cutter (Arthrex) so that they are flush with the notch. The repair is now complete (Figure 1F). Using a probe, the ACL remnant is tested for tension and stiffness. Finally, cycling of the knee through the full ROM confirms anatomic positioning without impingement of the graft. Manual laxity testing should reveal minimal anteroposterior translation with a firm endpoint on Lachman examination intraoperatively.

Bone Bridge Fixation

With this technique, parallel drill holes are created exiting at each bundle origin. The repair stitches can then be retrieved and tensioned proximally. One way to accomplish this is by using an ACL femoral guide (Arthrex) that is placed via the anterolateral portal and is centered on the anteromedial bundle insertion. This device guides a cannulated RetroDrill (Arthrex) to drill through the lateral femoral condyle towards the anteromedial footprint. A passing wire can then be delivered through the cannulation and used to retrieve that anteromedial bundle repair stitches. This process can then be repeated for the posterolateral bundle and the associated repair stitches. Drill holes can also be made retrograde from a low anteromedial accessory portal using a slotted pit that can be used to shuttle the repair stitches. When all the repair sutures are passed, the ligament is tensioned while being visualized arthroscopically. The knee is held at 20° of flexion and a posterior drawer force can be applied, if necessary, to reduce the tibia to its anatomic position. The suture limbs are then tensioned and can be fixated using any of a multitude of techniques, including tying over a bony bridge, tying over a 4-hole ligament button, and tying to a post.

One disadvantage of the bone bridge fixation technique, however, is the suspensory fixation that is not as stiff as tensioning and fixating with suture anchors. Despite this disadvantage, however, the senior author (GSD) has achieved excellent results with this technique at longer-term follow-up in a small group of patients. One advantage of the bone bridge fixation technique is that the procedure has lower costs than fixation with suture anchors.

One Anchor Repair Fixation

Achtnich and colleagues⁶ recently published a slightly different technique for repairing type I tears. The authors passed a No. 2 FiberWire suture through the midsubstance of both bundles of the ACL remnant to create a modified Mason-Allen stitch configuration. Subsequently, they tensioned the remnant towards the middle of the ACL footprint (between the anteromedial and posterolateral footprint) using one PushLock suture anchor (Arthrex). They hypothesized that using 1 anchor would be enough fixation for tears amenable to repair, and that doing so would minimize the invasion of the bone.

The preference of the senior author (GSD) is, however, to use 2 suture anchors for each bundle in order to more anatomically and biomechanically repair the remnant, since both bundles have different biomechanical characteristics.⁷ Similarly, the preference of the senior author is to commence the suturing as distal as possible and pass multiple sutures towards the proximal end. This ensures that the last suture pass is exited very proximally, and ensures that the proximal end is approximated towards the femoral wall. One suture passed at the midsubstance portion of the remnant might cause a different tension pattern and prevent optimal re-approximation of the most proximal part towards the femoral wall. Future studies are necessary to assess the efficacy of different suture and fixation techniques as these are currently lacking.

Addition of Internal Brace

Over the last few years, the senior author has added an internal brace (FiberTape, Arthrex) to the repair technique, which was first performed by MacKay and colleagues.⁸ The added internal brace protects the repair and the healing process in the first few weeks and enables early ROM.

With this technique, the previously described arthroscopic primary repair technique is performed with suturing of both bundles. However, after punching, tapping, or drilling a hole in the anteromedial origin of the femoral footprint, the anteromedial anchor is first loaded with the FiberTape in addition to the repair stitches. After placing the anteromedial suture anchor in the femoral footprint, the internal brace is fixated proximally with the suture anchor into the femoral wall.

One Bundle Type I Tears: Single Bundle Augmented Repair

In some cases, the anteromedial or posterolateral bundle is a type I tear with good or excellent tissue quality, whereas the other bundle is not a type I tear or has poor tissue quality (Figure 3A). In these cases, a primary repair of one bundle is performed with a hamstring reconstruction of the other bundle.

First, a No. 2 FiberWire is used to make 4 to 5 passes from distal to proximal, as previously described. Then, the remnants of the irreparable bundle are debrided (Figure 3B). Subsequently, the semitendinosus tendon is harvested in standard fashion, or soft tissue allografts can be used.

Type II Tears: Augmented Repair

In patients with type II tears, primary repair is not possible as the length of the remnant is too short to firmly approximate the remnant towards the femoral wall (75%-90% of native tissue length) (Figure 4A). In these patients, an augmented repair of the entire ACL is performed using hamstring autograft or soft tissue allograft.

With this technique, repair stitches are passed into the anteromedial bundle of the remnant as previously described (Figure 4B). Keeping the repair stitches anteriorly in the anteromedial bundle tends to prevent entanglement during graft passage later in the case.

Type III Tears: Reconstruction With Remnant Tensioning

The previously discussed techniques have the goals of preserving as much native ligament remnant as possible, approximating the ligament remnant towards the femoral wall, and promoting healing of the ligament. In some cases, however, the ligament remnant is too short for healing (Figure 5A). Although the ligament cannot be approximated to the femoral wall in these cases, there is still an argument for ACL preservation, as was discussed in the first article of this series.

If the ligament length is between 25% and 75% of the native tissue length, the senior author performs a remnant tensioning technique.

Type IV Tears: Reconstruction With Remnant Preservation

Finally, in some cases, the distal remnant is small or the tissue quality in the largest part of the remnant is poor, and after debriding back to good tissue quality, only 10% to 25% of the native tissue length is left (Figure 6A). In these cases, the remnant is preserved, however, tensioning of the remnant with sutures is usually not necessary for the prevention of cyclops lesions. Nonetheless, it is important to debride the parts of the remnant ligament with poor tissue quality as mop-end patterns of the remnant may increase the chance of these lesions (Figure 6B).

In this situation, any of the standard ACL reconstruction techniques can be performed with simple attention being paid to preserving what is left of the tibial insertion site. At the very least, the small insertion remnant guides the anatomic placement of the graft, and prevents egress of joint fluid into the tibial tunnel and could minimize tunnel widening.

Type V Tears: Primary Repair

Finally, in some patients a soft tissue avulsion (Figure 7A) or bony avulsion of the distal attachment of the ACL can be seen. Both injuries are relatively rare, although bony avulsions are frequently seen in children, especially those younger than 12 years old. In these cases, the same techniques and theory that are applied to proximal avulsion type tears can be used and applied to distal avulsion type tears.

First, No. 2 FiberWire sutures are passed from proximal towards the distal end of the ligament in the anteromedial bundle, and the same process is then repeated for No. 2 TigerWire sutures for the posterolateral bundle. Then both sutures are exited at the distal avulsed end at the locations of the anteromedial and posterolateral footprints (Figure 7B). A 2.4-mm ACL guide wire and a Ninitol wire are used to drill 2 tunnels from the tibia towards the tibial footprint. The repair sutures are then retrieved through both tunnels (Figure 7C) and the sutures are tied distally over a ligament button after cycling of the knee (Figure 7D). This technique is very useful for soft tissue avulsions, or when there are only small flecks of bone or when the avulsed bone is significantly comminuted. If a large bony avulsion fragment is present, this technique can also be applied with some modification, although there have been multiple other techniques described in the literature that work well in this situation including fixation with screw and washer, or with suture anchors.

Complex Tear or Poor Tissue Quality: Reconstruction

In some cases, the tissue quality is poor, or the ligament has complex or multiple tears. Essentially, in these cases, there is nothing to preserve and a standard reconstruction approach is performed in these cases.

Conclusion

The uniform gold standard for all ACL tear types is currently primary reconstruction. However, several disadvantages of ACL reconstruction exist, while there are multiple advantages to the concept of ACL preservation. In this surgical technique article, we have discussed our tear type classification and the recommended surgical techniques for each. With this treatment algorithm, which is based on tear location and tissue quality, an optimal and minimally invasive treatment can be chosen for each individual patient. Future studies are needed to compare and contrast these treatments with the current gold standard of ACL reconstruction.

Am J Orthop. 2016;45(7):E406-E414. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

In the first part of this series, “Preservation of the Anterior Cruciate Ligament: A Treatment Algorithm Based on Tear Location and Tissue Quality” we discussed the history of anterior cruciate ligament (ACL) preservation, and the historical outcomes of both open primary repair and augmented repair. We also presented our surgical treatment algorithm for ACL preservation, which is based on the tear location and tissue quality of the ligament remnant. In this article, we propose a modification of the Sherman classification¹ to identify the different tear types, and we will discuss the different surgical techniques that can be used for each one. Furthermore, we aim to provide an overview of the variations of these techniques that are seen in the literature. It is important to emphasize that these tear types and corresponding surgical techniques are to be seen as guidelines, rather than strict criteria, and that significant overlap between these tear types and surgical indications exist.

Assessment of Tear Type and Tissue Quality

The first assessment of the tear location and tissue quality is made using magnetic resonance imaging (MRI). Although MRI can give you an idea of where the tear is located, the final assessment for eligibility of each specific preservation technique is made during arthroscopy. Therefore, the routine preoperative discussion and informed consent process with the patient should encompass the gamut of surgical possibilities ranging from repair to reconstruction.

The Table shows our tear type classification, along with the corresponding preservation surgical techniques.

Surgical Preparation

In the operating room, the patient is placed in supine position on a standard operative table, such that the knee can be moved freely through its range of motion (ROM). The operative leg is then prepped and draped in standard fashion for knee arthroscopy. Standard knee arthroscopy equipment and implants are used, although some instruments from the standard shoulder set are also utilized. Anteromedial and anterolateral portals are created, and a general inspection of the knee is performed. By pulling the remnant ligament proximally using a broad tissue gasper, the available length of the remnant can be assessed. It is important to reduce possible anterior tibial subluxation in the sagittal plane in order to prevent “false” shortening of the distal ligament remnant. Once the length of the remnant tissue is assessed and the tissue quality is determined, the surgical preservation technique can be chosen (Table).

Type I Tears: Primary Repair

In order to be a candidate for arthroscopic primary repair, sufficient tissue length and tissue quality are necessary (Figures 1A and 1B, Table).

Sutures are then passed through the anteromedial bundle using the Scorpion Suture Passer (Arthrex) with a No. 2 FiberWire suture (Arthrex) (Figure 1C). Suturing is commenced at the intact distal end of the anteromedial bundle and is advanced in an alternating, interlocking Bunnell-type pattern towards the avulsed proximal end with approximately 4 mm to 5 mm between each pass. In general, 3 to 4 passes can be made before the final pass exits via the avulsed end of the ligament towards the femur (Figure 1D). The same process is then repeated for the posterolateral bundle of the ACL remnant with a No. 2 TigerWire suture (Arthrex) to optimize suture management. With each subsequent pass of the sutures, it is important to assess tissue resistance to prevent perforation of a previous stitch. Mild resistance is normal, but the suture-passing device should be repositioned when notably increased resistance is encountered. In addition, placing all of the bites in the same plane should be avoided since this can allow the sutures to “cheese cut” along the collagen fibers of the ligament remnant rather than holding firm.

After passing the sutures through both bundles, the sutures are guided outside the knee using an accessory stab incision situated just above the medial portal. Using this portal, the ligament can be retracted away from the femoral footprint for optimal visibility. The femoral footprint is then roughed using a shaver or burr, and bleeding is induced to stimulate a local healing response,² while the sutures and the ACL are protected via the portal. With the knee in flexion, an accessory inferomedial portal is then created under direct visualization using a spinal needle for localization. Care should be taken to enable the appropriate trajectory for anchor placement to be achieved.

Many different techniques can be used to provide fixation of the ACL repair to the femoral footprint; the 2 most straightforward techniques are presented here. The first technique provides fixation with knotless suture anchors,^3,4 whereas in the second technique the sutures are transosseously passed, and tied over a bone bridge, as was performed in the 1970s and 1980s.

Suture Anchor Fixation

With the suture anchor fixation technique, the knee is flexed in 90°, the anteromedial bundle origin within the femoral footprint is identified, and a 4.5-mm x 20-mm hole is drilled, punched, or tapped, in the case of high bone density. The FiberWire sutures are then retrieved through the accessory portal and passed through a 4.75-mm Vented BioComposite SwiveLock suture anchor (Arthrex). The suture anchor for the anteromedial bundle is then deployed into the hole within the anteromedial footprint, while tensioning the ACL remnant to the wall with a visual gap of <1 mm (Figure 1E).⁵ The procedure is then repeated using another suture anchor with TigerWire sutures for the posterolateral bundle with the knee flexed at 110° to 115°. This ensures an optimal angle of approach and avoids perforating the posterior condyle with the anchor. The drill hole and anchor are placed into the origin of the posterolateral bundle within the femoral footprint. The order of bundle tensioning and repair may be varied depending on the particulars of each case.

Once the anchors are fully deployed and flush with the femoral footprint, the handle is removed and the additional core stitches are unloaded. Occasionally, the core stitches can be passed from lateral to medial through the proximal ligament remnant and tied down with an arthroscopic knot pusher to add extra compression of the remnant to the origin. The free ends of the repair sutures are cut with an Open Ended Suture Cutter (Arthrex) so that they are flush with the notch. The repair is now complete (Figure 1F). Using a probe, the ACL remnant is tested for tension and stiffness. Finally, cycling of the knee through the full ROM confirms anatomic positioning without impingement of the graft. Manual laxity testing should reveal minimal anteroposterior translation with a firm endpoint on Lachman examination intraoperatively.

Bone Bridge Fixation

With this technique, parallel drill holes are created exiting at each bundle origin. The repair stitches can then be retrieved and tensioned proximally. One way to accomplish this is by using an ACL femoral guide (Arthrex) that is placed via the anterolateral portal and is centered on the anteromedial bundle insertion. This device guides a cannulated RetroDrill (Arthrex) to drill through the lateral femoral condyle towards the anteromedial footprint. A passing wire can then be delivered through the cannulation and used to retrieve that anteromedial bundle repair stitches. This process can then be repeated for the posterolateral bundle and the associated repair stitches. Drill holes can also be made retrograde from a low anteromedial accessory portal using a slotted pit that can be used to shuttle the repair stitches. When all the repair sutures are passed, the ligament is tensioned while being visualized arthroscopically. The knee is held at 20° of flexion and a posterior drawer force can be applied, if necessary, to reduce the tibia to its anatomic position. The suture limbs are then tensioned and can be fixated using any of a multitude of techniques, including tying over a bony bridge, tying over a 4-hole ligament button, and tying to a post.

One disadvantage of the bone bridge fixation technique, however, is the suspensory fixation that is not as stiff as tensioning and fixating with suture anchors. Despite this disadvantage, however, the senior author (GSD) has achieved excellent results with this technique at longer-term follow-up in a small group of patients. One advantage of the bone bridge fixation technique is that the procedure has lower costs than fixation with suture anchors.

One Anchor Repair Fixation

Achtnich and colleagues⁶ recently published a slightly different technique for repairing type I tears. The authors passed a No. 2 FiberWire suture through the midsubstance of both bundles of the ACL remnant to create a modified Mason-Allen stitch configuration. Subsequently, they tensioned the remnant towards the middle of the ACL footprint (between the anteromedial and posterolateral footprint) using one PushLock suture anchor (Arthrex). They hypothesized that using 1 anchor would be enough fixation for tears amenable to repair, and that doing so would minimize the invasion of the bone.

The preference of the senior author (GSD) is, however, to use 2 suture anchors for each bundle in order to more anatomically and biomechanically repair the remnant, since both bundles have different biomechanical characteristics.⁷ Similarly, the preference of the senior author is to commence the suturing as distal as possible and pass multiple sutures towards the proximal end. This ensures that the last suture pass is exited very proximally, and ensures that the proximal end is approximated towards the femoral wall. One suture passed at the midsubstance portion of the remnant might cause a different tension pattern and prevent optimal re-approximation of the most proximal part towards the femoral wall. Future studies are necessary to assess the efficacy of different suture and fixation techniques as these are currently lacking.

Addition of Internal Brace

Over the last few years, the senior author has added an internal brace (FiberTape, Arthrex) to the repair technique, which was first performed by MacKay and colleagues.⁸ The added internal brace protects the repair and the healing process in the first few weeks and enables early ROM.

With this technique, the previously described arthroscopic primary repair technique is performed with suturing of both bundles. However, after punching, tapping, or drilling a hole in the anteromedial origin of the femoral footprint, the anteromedial anchor is first loaded with the FiberTape in addition to the repair stitches. After placing the anteromedial suture anchor in the femoral footprint, the internal brace is fixated proximally with the suture anchor into the femoral wall.

One Bundle Type I Tears: Single Bundle Augmented Repair

In some cases, the anteromedial or posterolateral bundle is a type I tear with good or excellent tissue quality, whereas the other bundle is not a type I tear or has poor tissue quality (Figure 3A). In these cases, a primary repair of one bundle is performed with a hamstring reconstruction of the other bundle.

First, a No. 2 FiberWire is used to make 4 to 5 passes from distal to proximal, as previously described. Then, the remnants of the irreparable bundle are debrided (Figure 3B). Subsequently, the semitendinosus tendon is harvested in standard fashion, or soft tissue allografts can be used.

Type II Tears: Augmented Repair

In patients with type II tears, primary repair is not possible as the length of the remnant is too short to firmly approximate the remnant towards the femoral wall (75%-90% of native tissue length) (Figure 4A). In these patients, an augmented repair of the entire ACL is performed using hamstring autograft or soft tissue allograft.

With this technique, repair stitches are passed into the anteromedial bundle of the remnant as previously described (Figure 4B). Keeping the repair stitches anteriorly in the anteromedial bundle tends to prevent entanglement during graft passage later in the case.

Type III Tears: Reconstruction With Remnant Tensioning

The previously discussed techniques have the goals of preserving as much native ligament remnant as possible, approximating the ligament remnant towards the femoral wall, and promoting healing of the ligament. In some cases, however, the ligament remnant is too short for healing (Figure 5A). Although the ligament cannot be approximated to the femoral wall in these cases, there is still an argument for ACL preservation, as was discussed in the first article of this series.

If the ligament length is between 25% and 75% of the native tissue length, the senior author performs a remnant tensioning technique.

Type IV Tears: Reconstruction With Remnant Preservation

Finally, in some cases, the distal remnant is small or the tissue quality in the largest part of the remnant is poor, and after debriding back to good tissue quality, only 10% to 25% of the native tissue length is left (Figure 6A). In these cases, the remnant is preserved, however, tensioning of the remnant with sutures is usually not necessary for the prevention of cyclops lesions. Nonetheless, it is important to debride the parts of the remnant ligament with poor tissue quality as mop-end patterns of the remnant may increase the chance of these lesions (Figure 6B).

In this situation, any of the standard ACL reconstruction techniques can be performed with simple attention being paid to preserving what is left of the tibial insertion site. At the very least, the small insertion remnant guides the anatomic placement of the graft, and prevents egress of joint fluid into the tibial tunnel and could minimize tunnel widening.

Type V Tears: Primary Repair

Finally, in some patients a soft tissue avulsion (Figure 7A) or bony avulsion of the distal attachment of the ACL can be seen. Both injuries are relatively rare, although bony avulsions are frequently seen in children, especially those younger than 12 years old. In these cases, the same techniques and theory that are applied to proximal avulsion type tears can be used and applied to distal avulsion type tears.

First, No. 2 FiberWire sutures are passed from proximal towards the distal end of the ligament in the anteromedial bundle, and the same process is then repeated for No. 2 TigerWire sutures for the posterolateral bundle. Then both sutures are exited at the distal avulsed end at the locations of the anteromedial and posterolateral footprints (Figure 7B). A 2.4-mm ACL guide wire and a Ninitol wire are used to drill 2 tunnels from the tibia towards the tibial footprint. The repair sutures are then retrieved through both tunnels (Figure 7C) and the sutures are tied distally over a ligament button after cycling of the knee (Figure 7D). This technique is very useful for soft tissue avulsions, or when there are only small flecks of bone or when the avulsed bone is significantly comminuted. If a large bony avulsion fragment is present, this technique can also be applied with some modification, although there have been multiple other techniques described in the literature that work well in this situation including fixation with screw and washer, or with suture anchors.

Complex Tear or Poor Tissue Quality: Reconstruction

In some cases, the tissue quality is poor, or the ligament has complex or multiple tears. Essentially, in these cases, there is nothing to preserve and a standard reconstruction approach is performed in these cases.

Conclusion

The uniform gold standard for all ACL tear types is currently primary reconstruction. However, several disadvantages of ACL reconstruction exist, while there are multiple advantages to the concept of ACL preservation. In this surgical technique article, we have discussed our tear type classification and the recommended surgical techniques for each. With this treatment algorithm, which is based on tear location and tissue quality, an optimal and minimally invasive treatment can be chosen for each individual patient. Future studies are needed to compare and contrast these treatments with the current gold standard of ACL reconstruction.

Am J Orthop. 2016;45(7):E406-E414. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Ultrasound has classically been marketed and used as a diagnostic tool. Radiologists, emergency physicians, and sports physicians used ultrasound units to rapidly and appropriately diagnose numerous injuries and disorders, in a timely and cost effective manner. Part 1¹ and Part 2² of this series showed how to use ultrasound in the shoulder for diagnosis and how to code and get reimbursed for its use.Ultrasound can also be used to help guide procedures and interventions performed to treat patients. Currently, more physicians are beginning to recognize the utility of this modality as an aid to interventional procedures.

First-generation procedures use ultrasound to improve accuracy of joint, bursal, tendon, and muscular injections.³ Recent studies have shown a significant improvement in accuracy, outcomes, and patient satisfaction using ultrasound guidance for injections.^3-12 Within the limitation of using a needle, second-generation procedures—hydrodissection of peripherally entrapped nerves, capsular distention, mechanical disruption of neovascularization, and needle fenestration or barbotage in chronic tendinopathy—try to simulate surgical objectives while minimizing tissue burden and other complications of surgery.³ More advanced procedures include needle fenestration/release of the carpal ligament in carpal tunnel syndrome and A1 pulley needle release in the setting of trigger finger.³ Innovative third-generation procedures involve the use of surgical tools such as hook blades under ultrasound guidance to perform surgical procedures. Surgeons are now improving already established percutaneous, arthroscopic, and open surgical procedures with ultrasound assistance.³ Aside from better guidance, reducing cost and improving surgeon comfort may be additional benefits of ultrasound assisted surgery.

Image-Guided Treatment Options

Prior to image guidance, palpation of surface anatomy helped physicians determine the anatomic placement of injections, incisions, or portals. Joints and bursas that do not have any inflammation or fluid can sometimes be difficult to identify or locate by palpation alone. Palpation-guided joint injections often miss their target and cause significant pain when the therapeutic agent is injected into a muscle, tendon, ligament, fat, or other tissue. Ultrasound-guided injections have proven to be more accurate and have better patient satisfaction when compared to blind injections.^3-12

X-ray fluoroscopy has been the primary option for surgeons to assist in surgery. This is a natural modality for orthopedic surgeons; their primary use is for bone to help with fracture reduction and fixation as the bone, instrumentation, and fixation methods are usually radio-opaque. With the advancement in technology, many orthopedic surgeons are regularly using radiolucent fixation devices and working with soft tissue as opposed to bone. Fixation of tendons, ligaments, and muscles would be done using a large incision, palpation of the anatomy, then fixation or repair. Many surgeons began looking for ways to minimize the incisions. Turning to fluoroscopy, a traditional and well-used modality, was a natural progression. Guides and methods were developed to isolate insertions and drill placements. However, fluoroscopy is limited by its difficulty in changing planes and the large equipment required. Also, it is limited in its ability to image soft tissue.

Computed tomography (CT) scans and magnetic resonance imaging (MRI) are far better at imaging soft tissue but cannot be taken for use into the office or surgical suite. These modalities are also far more expensive and take up significant space.

Ultrasound Procedural Basics

Appropriate use of ultrasound still remains highly technician-dependent. Unlike other imaging modalities, ultrasound requires a higher skill level by the physician to implement the use of ultrasound and identification of pathology to treat these disease processes. However, this is no different from the use of arthroscopy or fluoroscopy to treat patients. Training is required, as well as an understanding of the ultrasound machine, anatomy, and sono-anatomy—identification of anatomy and pathology as shown by the ultrasound machine.²

In ultrasound, the long axis refers to looking at a structure along its length, as in longitudinal. The short axis refers to evaluating a structure in cross-section, transverse, or along its shortest length. “In plane” refers to performing a procedure where the needle or object being used enters the ultrasound field along the plane of the transducer, allowing visualization of the majority of the needle as it crosses tissue planes. “Out of plane” has the needle entering perpendicular to the plane of the transducer, showing the needle on the monitor as a bright, hyperechoic dot. Some studies have suggested that novice ultrasonographers should start in a long axis view and use the in plane technique when injecting, as doing so may decrease time to identify the target and improve mean imaging quality during needle advancement.¹³

Anisotropy is the property of being directionally dependent. The ultrasound beam needs to be perpendicular to the structure being imaged to give the optimal image. When the beam hits a longitudinal structure like a needle at an angle <90°, the linear structure might reflect most of the beam away from the transducer. So when using a needle to localize or inject a specific area, maintaining the probe as close to perpendicular as possible with the needle will give a better image. New technology exists to better visualize needles even at high acuity angles by using a multi-beam processing algorithm, which can significantly aid the physician without the need for specialized needles.

Despite better technology, advance planning is key to a successful procedure. Positioning the patient and ultrasound machine in a manner that is comfortable and makes the desired target accessible while being able to visualize the ultrasound monitor comes first. Identifying the target, mapping the needle trajectory using depth markings, and scanning for nerves, vessels, and other structures that may be damaged along the needle path comes next. Using the in plane ultrasound technique with color Doppler and the nerve contrast setting can ensure that the physician has placed the therapeutic agent to the proper location while avoiding any nerves, arteries, or veins. Marking the borders of the ultrasound probe and needle entry site can be helpful to return to the same area after sterile preparation is done. As in any procedure, sterile technique is paramount. Sterile technique considerations may include using sterile gloves and a probe cover with sterile gel, cleaning the area thoroughly, planning the needle entry point 3 cm to 5 cm away from the probe, and maintaining a dry and gel-free needle entry.^14-15 The probe should be sterilized between patients to avoid cross-contamination; note that certain solutions like alcohol or ethyl chloride can damage the transducer.^14-15 However, simple injections do not require such stringent standards when simple sterile technique is observed by cleaning and then never touching the cleaned area again except with the needle to avoid contamination. Also, ethyl chloride has been found to not contaminate a sterile site and can be used safely to anesthetize the skin.

Ultrasound-Guided Procedures

Many injectable therapeutic options exist as interventions. Cortisone, hyaluronic acid, platelet-rich plasma (PRP), stem cells/bone marrow concentrate (BMC), amniotic fluid, prolotherapy, and saline are now commonly used.^16-17 A meta-analysis of the literature assessing the accuracy of ultrasound-guided shoulder girdle injections vs a landmark-guided injection was done in 2015.¹⁸ It showed that for the acromioclavicular joint, accuracy was 93.6% vs 68.2% (P < .0001), based on single studies. The accuracy of ultrasound vs a landmark-guided injection was 65% vs 70% for the subacromial space (P > .05); 86.7% vs 26.7% for the biceps tendon sheath (P < .05); and 92.5% vs 72.5% for the glenohumeral joint (P = .025).¹⁸ 

With cortisone, injecting into muscle, ligament, or tendons could potentially harm the tissue or cause worsening of the disease process.^19-20 With the advent of orthobiologics, injecting into these structures is now desirable, instead of a potential complication.^19-20 Ultrasound has become even more important to the accurate delivery of these therapies to the disease locations. Multiple studies using leukocyte-poor PRP for osteoarthritis show significant differences in pain scores.^21-23 Peerbooms and colleagues^24,25 also showed that PRP reduced pain and increased function compared to cortisone injections for lateral epicondylitis in 1- and 2-year double-blind randomized controlled trials. Centeno and colleagues²⁶ performed a prospective, multi-site registry study on 102 patients with symptomatic osteoarthritis and/or rotator cuff tears that were injected with bone marrow concentrate. There was a statistically significant improvement in Disabilities of the Arm, Shoulder and Hand (DASH) scores from 36.1 to 17.1 (P < .001) and numeric pain scores improved from 4.3 to 2.4 (P < .001).

By being able to see the pathology, like a hypoechoic region in a tendon, ligament, or muscle, the physician can reliably place the therapeutic agent into the precise location. Also, adjacent para-tendon or para-ligament injections allow for in-season athletes to get some relief from symptoms while allowing to return to play quickly; injections into muscle, ligament, or tendon can damage the structure and require days or weeks of rest, while para-tendon and para-ligament injections are far less painful.

Second-generation techniques have provided patients with great options that can help avoid surgery. Calcific tendonitis appears brightly hyperechoic on ultrasound and is easily identified. The physician can attempt to break up the calcium by fenestration or barbotage of the calcium. The same can be accomplished by injecting the density with PRP or stem cells. If the calcium is soft or “toothpaste-like,” the negative pressure will make it easy to aspirate it into the syringe. A 2-year, longitudinal prospective study of 121 patients demonstrated that visual analog score (VAS) pain scores and size of calcium significantly decreased with ultrasound-guided percutaneous needle lavage; 89% of patients were pain-free at 1-year follow-up.²⁷ Moreover, a randomized controlled trial of 48 patients comparing needle lavage vs subacromial steroid injection showed statistically significant radiographic and clinically better outcomes with the needle lavage group at the 1-year mark.²⁸

The Tenex procedure is a novel technique that uses ultrasonic energy to fenestrate diseased tendon tissue. It also can be used to break up calcific deposits. After the Tenex probe is guided to the diseased tendon/calcium, the TX-1 tip oscillates at the speed of sound, fenestrating/cutting through the tendon or calcium while lavaging the tendon with saline. Multiple prospective, noncontrolled studies done in common extensor, patellar, and rotator cuff tendinopathy have demonstrated good to excellent improvements in pain scores with the Tenex procedure.^29-31

Ultrasound is extremely useful in the treatment of adhesive capsulitis.³² The posterior glenohumeral capsule can be distended using a large volume (60 cc) of saline to loosen adhesions in preparation for manipulation. Because the manipulation can be an extremely painful procedure, ultrasound can be used to perform an inter-scalene block for regional anesthesia prior to the procedure. In 2014, Park and colleagues³³ performed a randomized prospective trial that showed that capsular distension followed by manipulation was more effective than cortisone injection alone for the treatment of adhesive capsulitis.Ultrasound guidance was found to be just as efficacious as fluoroscopy in a randomized controlled trial in 2014; the authors noted that ultrasound does not expose the patient or clinician to radiation and can be done in office.³⁴

Currently, techniques to perform ultrasound-guided percutaneous tenotomies of the long head of the biceps tendon using hook blades are being studied.³⁵

Ultrasound-Assisted Surgery

Ultrasound has been a boon to surgeons who perform minimally invasive procedures. It is far less cumbersome than classic fluoroscopy. Fluoroscopy requires the use of heavy lead aprons by the surgeons. Combining this with the impervious gowns and hot lights, the surgeons’ comfort level is severely sacrificed. When having to do many long surgeries in a row, this situation can take a toll on the surgeons’ endurance and strength. Improving the comfort of the surgeon is not the primary goal of surgery, but can significantly help our ability to do a better job.

Ultrasound allows the surgeon to localize any superficial foreign objects, especially with radiolucent objects like fragments of glass. Small glass fragments or pieces of wood have always been extremely difficult to remove. X-rays cannot localize these objects, so getting a proper orientation is difficult. MRI and CT scans easily identify these types of foreign objects, but cannot be used intraoperatively (Figure 1A). Often, these objects cannot be felt and therefore require a large dissection. The objects may encapsulate and be easily confused with other soft tissues.

Conclusion

Ultrasound is quickly becoming a popular imaging modality due to its simplicity, portability, and cost efficiency. Its use as a diagnostic tool is widely known. As an adjunct for procedures and interventions, its advantages over larger, more expensive modalities such as fluoroscopy, CT, or MRI make it stand out. Ultrasound is not the perfect solution to all problems, but it is clearly a technology that is gaining traction. Ultrasound is another imaging modality and tool that physicians and surgeons can use to improve their patients’ treatment.

Ultrasound has classically been marketed and used as a diagnostic tool. Radiologists, emergency physicians, and sports physicians used ultrasound units to rapidly and appropriately diagnose numerous injuries and disorders, in a timely and cost effective manner. Part 1¹ and Part 2² of this series showed how to use ultrasound in the shoulder for diagnosis and how to code and get reimbursed for its use.Ultrasound can also be used to help guide procedures and interventions performed to treat patients. Currently, more physicians are beginning to recognize the utility of this modality as an aid to interventional procedures.

First-generation procedures use ultrasound to improve accuracy of joint, bursal, tendon, and muscular injections.³ Recent studies have shown a significant improvement in accuracy, outcomes, and patient satisfaction using ultrasound guidance for injections.^3-12 Within the limitation of using a needle, second-generation procedures—hydrodissection of peripherally entrapped nerves, capsular distention, mechanical disruption of neovascularization, and needle fenestration or barbotage in chronic tendinopathy—try to simulate surgical objectives while minimizing tissue burden and other complications of surgery.³ More advanced procedures include needle fenestration/release of the carpal ligament in carpal tunnel syndrome and A1 pulley needle release in the setting of trigger finger.³ Innovative third-generation procedures involve the use of surgical tools such as hook blades under ultrasound guidance to perform surgical procedures. Surgeons are now improving already established percutaneous, arthroscopic, and open surgical procedures with ultrasound assistance.³ Aside from better guidance, reducing cost and improving surgeon comfort may be additional benefits of ultrasound assisted surgery.

Image-Guided Treatment Options

Prior to image guidance, palpation of surface anatomy helped physicians determine the anatomic placement of injections, incisions, or portals. Joints and bursas that do not have any inflammation or fluid can sometimes be difficult to identify or locate by palpation alone. Palpation-guided joint injections often miss their target and cause significant pain when the therapeutic agent is injected into a muscle, tendon, ligament, fat, or other tissue. Ultrasound-guided injections have proven to be more accurate and have better patient satisfaction when compared to blind injections.^3-12

X-ray fluoroscopy has been the primary option for surgeons to assist in surgery. This is a natural modality for orthopedic surgeons; their primary use is for bone to help with fracture reduction and fixation as the bone, instrumentation, and fixation methods are usually radio-opaque. With the advancement in technology, many orthopedic surgeons are regularly using radiolucent fixation devices and working with soft tissue as opposed to bone. Fixation of tendons, ligaments, and muscles would be done using a large incision, palpation of the anatomy, then fixation or repair. Many surgeons began looking for ways to minimize the incisions. Turning to fluoroscopy, a traditional and well-used modality, was a natural progression. Guides and methods were developed to isolate insertions and drill placements. However, fluoroscopy is limited by its difficulty in changing planes and the large equipment required. Also, it is limited in its ability to image soft tissue.

Computed tomography (CT) scans and magnetic resonance imaging (MRI) are far better at imaging soft tissue but cannot be taken for use into the office or surgical suite. These modalities are also far more expensive and take up significant space.

Ultrasound Procedural Basics

Appropriate use of ultrasound still remains highly technician-dependent. Unlike other imaging modalities, ultrasound requires a higher skill level by the physician to implement the use of ultrasound and identification of pathology to treat these disease processes. However, this is no different from the use of arthroscopy or fluoroscopy to treat patients. Training is required, as well as an understanding of the ultrasound machine, anatomy, and sono-anatomy—identification of anatomy and pathology as shown by the ultrasound machine.²

In ultrasound, the long axis refers to looking at a structure along its length, as in longitudinal. The short axis refers to evaluating a structure in cross-section, transverse, or along its shortest length. “In plane” refers to performing a procedure where the needle or object being used enters the ultrasound field along the plane of the transducer, allowing visualization of the majority of the needle as it crosses tissue planes. “Out of plane” has the needle entering perpendicular to the plane of the transducer, showing the needle on the monitor as a bright, hyperechoic dot. Some studies have suggested that novice ultrasonographers should start in a long axis view and use the in plane technique when injecting, as doing so may decrease time to identify the target and improve mean imaging quality during needle advancement.¹³

Anisotropy is the property of being directionally dependent. The ultrasound beam needs to be perpendicular to the structure being imaged to give the optimal image. When the beam hits a longitudinal structure like a needle at an angle <90°, the linear structure might reflect most of the beam away from the transducer. So when using a needle to localize or inject a specific area, maintaining the probe as close to perpendicular as possible with the needle will give a better image. New technology exists to better visualize needles even at high acuity angles by using a multi-beam processing algorithm, which can significantly aid the physician without the need for specialized needles.

Despite better technology, advance planning is key to a successful procedure. Positioning the patient and ultrasound machine in a manner that is comfortable and makes the desired target accessible while being able to visualize the ultrasound monitor comes first. Identifying the target, mapping the needle trajectory using depth markings, and scanning for nerves, vessels, and other structures that may be damaged along the needle path comes next. Using the in plane ultrasound technique with color Doppler and the nerve contrast setting can ensure that the physician has placed the therapeutic agent to the proper location while avoiding any nerves, arteries, or veins. Marking the borders of the ultrasound probe and needle entry site can be helpful to return to the same area after sterile preparation is done. As in any procedure, sterile technique is paramount. Sterile technique considerations may include using sterile gloves and a probe cover with sterile gel, cleaning the area thoroughly, planning the needle entry point 3 cm to 5 cm away from the probe, and maintaining a dry and gel-free needle entry.^14-15 The probe should be sterilized between patients to avoid cross-contamination; note that certain solutions like alcohol or ethyl chloride can damage the transducer.^14-15 However, simple injections do not require such stringent standards when simple sterile technique is observed by cleaning and then never touching the cleaned area again except with the needle to avoid contamination. Also, ethyl chloride has been found to not contaminate a sterile site and can be used safely to anesthetize the skin.

Ultrasound-Guided Procedures

Many injectable therapeutic options exist as interventions. Cortisone, hyaluronic acid, platelet-rich plasma (PRP), stem cells/bone marrow concentrate (BMC), amniotic fluid, prolotherapy, and saline are now commonly used.^16-17 A meta-analysis of the literature assessing the accuracy of ultrasound-guided shoulder girdle injections vs a landmark-guided injection was done in 2015.¹⁸ It showed that for the acromioclavicular joint, accuracy was 93.6% vs 68.2% (P < .0001), based on single studies. The accuracy of ultrasound vs a landmark-guided injection was 65% vs 70% for the subacromial space (P > .05); 86.7% vs 26.7% for the biceps tendon sheath (P < .05); and 92.5% vs 72.5% for the glenohumeral joint (P = .025).¹⁸ 

With cortisone, injecting into muscle, ligament, or tendons could potentially harm the tissue or cause worsening of the disease process.^19-20 With the advent of orthobiologics, injecting into these structures is now desirable, instead of a potential complication.^19-20 Ultrasound has become even more important to the accurate delivery of these therapies to the disease locations. Multiple studies using leukocyte-poor PRP for osteoarthritis show significant differences in pain scores.^21-23 Peerbooms and colleagues^24,25 also showed that PRP reduced pain and increased function compared to cortisone injections for lateral epicondylitis in 1- and 2-year double-blind randomized controlled trials. Centeno and colleagues²⁶ performed a prospective, multi-site registry study on 102 patients with symptomatic osteoarthritis and/or rotator cuff tears that were injected with bone marrow concentrate. There was a statistically significant improvement in Disabilities of the Arm, Shoulder and Hand (DASH) scores from 36.1 to 17.1 (P < .001) and numeric pain scores improved from 4.3 to 2.4 (P < .001).

By being able to see the pathology, like a hypoechoic region in a tendon, ligament, or muscle, the physician can reliably place the therapeutic agent into the precise location. Also, adjacent para-tendon or para-ligament injections allow for in-season athletes to get some relief from symptoms while allowing to return to play quickly; injections into muscle, ligament, or tendon can damage the structure and require days or weeks of rest, while para-tendon and para-ligament injections are far less painful.

Second-generation techniques have provided patients with great options that can help avoid surgery. Calcific tendonitis appears brightly hyperechoic on ultrasound and is easily identified. The physician can attempt to break up the calcium by fenestration or barbotage of the calcium. The same can be accomplished by injecting the density with PRP or stem cells. If the calcium is soft or “toothpaste-like,” the negative pressure will make it easy to aspirate it into the syringe. A 2-year, longitudinal prospective study of 121 patients demonstrated that visual analog score (VAS) pain scores and size of calcium significantly decreased with ultrasound-guided percutaneous needle lavage; 89% of patients were pain-free at 1-year follow-up.²⁷ Moreover, a randomized controlled trial of 48 patients comparing needle lavage vs subacromial steroid injection showed statistically significant radiographic and clinically better outcomes with the needle lavage group at the 1-year mark.²⁸

The Tenex procedure is a novel technique that uses ultrasonic energy to fenestrate diseased tendon tissue. It also can be used to break up calcific deposits. After the Tenex probe is guided to the diseased tendon/calcium, the TX-1 tip oscillates at the speed of sound, fenestrating/cutting through the tendon or calcium while lavaging the tendon with saline. Multiple prospective, noncontrolled studies done in common extensor, patellar, and rotator cuff tendinopathy have demonstrated good to excellent improvements in pain scores with the Tenex procedure.^29-31

Ultrasound is extremely useful in the treatment of adhesive capsulitis.³² The posterior glenohumeral capsule can be distended using a large volume (60 cc) of saline to loosen adhesions in preparation for manipulation. Because the manipulation can be an extremely painful procedure, ultrasound can be used to perform an inter-scalene block for regional anesthesia prior to the procedure. In 2014, Park and colleagues³³ performed a randomized prospective trial that showed that capsular distension followed by manipulation was more effective than cortisone injection alone for the treatment of adhesive capsulitis.Ultrasound guidance was found to be just as efficacious as fluoroscopy in a randomized controlled trial in 2014; the authors noted that ultrasound does not expose the patient or clinician to radiation and can be done in office.³⁴

Currently, techniques to perform ultrasound-guided percutaneous tenotomies of the long head of the biceps tendon using hook blades are being studied.³⁵

Ultrasound-Assisted Surgery

Ultrasound has been a boon to surgeons who perform minimally invasive procedures. It is far less cumbersome than classic fluoroscopy. Fluoroscopy requires the use of heavy lead aprons by the surgeons. Combining this with the impervious gowns and hot lights, the surgeons’ comfort level is severely sacrificed. When having to do many long surgeries in a row, this situation can take a toll on the surgeons’ endurance and strength. Improving the comfort of the surgeon is not the primary goal of surgery, but can significantly help our ability to do a better job.

Ultrasound allows the surgeon to localize any superficial foreign objects, especially with radiolucent objects like fragments of glass. Small glass fragments or pieces of wood have always been extremely difficult to remove. X-rays cannot localize these objects, so getting a proper orientation is difficult. MRI and CT scans easily identify these types of foreign objects, but cannot be used intraoperatively (Figure 1A). Often, these objects cannot be felt and therefore require a large dissection. The objects may encapsulate and be easily confused with other soft tissues.

Conclusion

Ultrasound is quickly becoming a popular imaging modality due to its simplicity, portability, and cost efficiency. Its use as a diagnostic tool is widely known. As an adjunct for procedures and interventions, its advantages over larger, more expensive modalities such as fluoroscopy, CT, or MRI make it stand out. Ultrasound is not the perfect solution to all problems, but it is clearly a technology that is gaining traction. Ultrasound is another imaging modality and tool that physicians and surgeons can use to improve their patients’ treatment.

Ultrasound has classically been marketed and used as a diagnostic tool. Radiologists, emergency physicians, and sports physicians used ultrasound units to rapidly and appropriately diagnose numerous injuries and disorders, in a timely and cost effective manner. Part 1¹ and Part 2² of this series showed how to use ultrasound in the shoulder for diagnosis and how to code and get reimbursed for its use.Ultrasound can also be used to help guide procedures and interventions performed to treat patients. Currently, more physicians are beginning to recognize the utility of this modality as an aid to interventional procedures.

First-generation procedures use ultrasound to improve accuracy of joint, bursal, tendon, and muscular injections.³ Recent studies have shown a significant improvement in accuracy, outcomes, and patient satisfaction using ultrasound guidance for injections.^3-12 Within the limitation of using a needle, second-generation procedures—hydrodissection of peripherally entrapped nerves, capsular distention, mechanical disruption of neovascularization, and needle fenestration or barbotage in chronic tendinopathy—try to simulate surgical objectives while minimizing tissue burden and other complications of surgery.³ More advanced procedures include needle fenestration/release of the carpal ligament in carpal tunnel syndrome and A1 pulley needle release in the setting of trigger finger.³ Innovative third-generation procedures involve the use of surgical tools such as hook blades under ultrasound guidance to perform surgical procedures. Surgeons are now improving already established percutaneous, arthroscopic, and open surgical procedures with ultrasound assistance.³ Aside from better guidance, reducing cost and improving surgeon comfort may be additional benefits of ultrasound assisted surgery.

Image-Guided Treatment Options

Prior to image guidance, palpation of surface anatomy helped physicians determine the anatomic placement of injections, incisions, or portals. Joints and bursas that do not have any inflammation or fluid can sometimes be difficult to identify or locate by palpation alone. Palpation-guided joint injections often miss their target and cause significant pain when the therapeutic agent is injected into a muscle, tendon, ligament, fat, or other tissue. Ultrasound-guided injections have proven to be more accurate and have better patient satisfaction when compared to blind injections.^3-12

X-ray fluoroscopy has been the primary option for surgeons to assist in surgery. This is a natural modality for orthopedic surgeons; their primary use is for bone to help with fracture reduction and fixation as the bone, instrumentation, and fixation methods are usually radio-opaque. With the advancement in technology, many orthopedic surgeons are regularly using radiolucent fixation devices and working with soft tissue as opposed to bone. Fixation of tendons, ligaments, and muscles would be done using a large incision, palpation of the anatomy, then fixation or repair. Many surgeons began looking for ways to minimize the incisions. Turning to fluoroscopy, a traditional and well-used modality, was a natural progression. Guides and methods were developed to isolate insertions and drill placements. However, fluoroscopy is limited by its difficulty in changing planes and the large equipment required. Also, it is limited in its ability to image soft tissue.

Computed tomography (CT) scans and magnetic resonance imaging (MRI) are far better at imaging soft tissue but cannot be taken for use into the office or surgical suite. These modalities are also far more expensive and take up significant space.

Ultrasound Procedural Basics

Appropriate use of ultrasound still remains highly technician-dependent. Unlike other imaging modalities, ultrasound requires a higher skill level by the physician to implement the use of ultrasound and identification of pathology to treat these disease processes. However, this is no different from the use of arthroscopy or fluoroscopy to treat patients. Training is required, as well as an understanding of the ultrasound machine, anatomy, and sono-anatomy—identification of anatomy and pathology as shown by the ultrasound machine.²

In ultrasound, the long axis refers to looking at a structure along its length, as in longitudinal. The short axis refers to evaluating a structure in cross-section, transverse, or along its shortest length. “In plane” refers to performing a procedure where the needle or object being used enters the ultrasound field along the plane of the transducer, allowing visualization of the majority of the needle as it crosses tissue planes. “Out of plane” has the needle entering perpendicular to the plane of the transducer, showing the needle on the monitor as a bright, hyperechoic dot. Some studies have suggested that novice ultrasonographers should start in a long axis view and use the in plane technique when injecting, as doing so may decrease time to identify the target and improve mean imaging quality during needle advancement.¹³

Anisotropy is the property of being directionally dependent. The ultrasound beam needs to be perpendicular to the structure being imaged to give the optimal image. When the beam hits a longitudinal structure like a needle at an angle <90°, the linear structure might reflect most of the beam away from the transducer. So when using a needle to localize or inject a specific area, maintaining the probe as close to perpendicular as possible with the needle will give a better image. New technology exists to better visualize needles even at high acuity angles by using a multi-beam processing algorithm, which can significantly aid the physician without the need for specialized needles.

Despite better technology, advance planning is key to a successful procedure. Positioning the patient and ultrasound machine in a manner that is comfortable and makes the desired target accessible while being able to visualize the ultrasound monitor comes first. Identifying the target, mapping the needle trajectory using depth markings, and scanning for nerves, vessels, and other structures that may be damaged along the needle path comes next. Using the in plane ultrasound technique with color Doppler and the nerve contrast setting can ensure that the physician has placed the therapeutic agent to the proper location while avoiding any nerves, arteries, or veins. Marking the borders of the ultrasound probe and needle entry site can be helpful to return to the same area after sterile preparation is done. As in any procedure, sterile technique is paramount. Sterile technique considerations may include using sterile gloves and a probe cover with sterile gel, cleaning the area thoroughly, planning the needle entry point 3 cm to 5 cm away from the probe, and maintaining a dry and gel-free needle entry.^14-15 The probe should be sterilized between patients to avoid cross-contamination; note that certain solutions like alcohol or ethyl chloride can damage the transducer.^14-15 However, simple injections do not require such stringent standards when simple sterile technique is observed by cleaning and then never touching the cleaned area again except with the needle to avoid contamination. Also, ethyl chloride has been found to not contaminate a sterile site and can be used safely to anesthetize the skin.

Ultrasound-Guided Procedures

Many injectable therapeutic options exist as interventions. Cortisone, hyaluronic acid, platelet-rich plasma (PRP), stem cells/bone marrow concentrate (BMC), amniotic fluid, prolotherapy, and saline are now commonly used.^16-17 A meta-analysis of the literature assessing the accuracy of ultrasound-guided shoulder girdle injections vs a landmark-guided injection was done in 2015.¹⁸ It showed that for the acromioclavicular joint, accuracy was 93.6% vs 68.2% (P < .0001), based on single studies. The accuracy of ultrasound vs a landmark-guided injection was 65% vs 70% for the subacromial space (P > .05); 86.7% vs 26.7% for the biceps tendon sheath (P < .05); and 92.5% vs 72.5% for the glenohumeral joint (P = .025).¹⁸ 

With cortisone, injecting into muscle, ligament, or tendons could potentially harm the tissue or cause worsening of the disease process.^19-20 With the advent of orthobiologics, injecting into these structures is now desirable, instead of a potential complication.^19-20 Ultrasound has become even more important to the accurate delivery of these therapies to the disease locations. Multiple studies using leukocyte-poor PRP for osteoarthritis show significant differences in pain scores.^21-23 Peerbooms and colleagues^24,25 also showed that PRP reduced pain and increased function compared to cortisone injections for lateral epicondylitis in 1- and 2-year double-blind randomized controlled trials. Centeno and colleagues²⁶ performed a prospective, multi-site registry study on 102 patients with symptomatic osteoarthritis and/or rotator cuff tears that were injected with bone marrow concentrate. There was a statistically significant improvement in Disabilities of the Arm, Shoulder and Hand (DASH) scores from 36.1 to 17.1 (P < .001) and numeric pain scores improved from 4.3 to 2.4 (P < .001).

By being able to see the pathology, like a hypoechoic region in a tendon, ligament, or muscle, the physician can reliably place the therapeutic agent into the precise location. Also, adjacent para-tendon or para-ligament injections allow for in-season athletes to get some relief from symptoms while allowing to return to play quickly; injections into muscle, ligament, or tendon can damage the structure and require days or weeks of rest, while para-tendon and para-ligament injections are far less painful.

Second-generation techniques have provided patients with great options that can help avoid surgery. Calcific tendonitis appears brightly hyperechoic on ultrasound and is easily identified. The physician can attempt to break up the calcium by fenestration or barbotage of the calcium. The same can be accomplished by injecting the density with PRP or stem cells. If the calcium is soft or “toothpaste-like,” the negative pressure will make it easy to aspirate it into the syringe. A 2-year, longitudinal prospective study of 121 patients demonstrated that visual analog score (VAS) pain scores and size of calcium significantly decreased with ultrasound-guided percutaneous needle lavage; 89% of patients were pain-free at 1-year follow-up.²⁷ Moreover, a randomized controlled trial of 48 patients comparing needle lavage vs subacromial steroid injection showed statistically significant radiographic and clinically better outcomes with the needle lavage group at the 1-year mark.²⁸

The Tenex procedure is a novel technique that uses ultrasonic energy to fenestrate diseased tendon tissue. It also can be used to break up calcific deposits. After the Tenex probe is guided to the diseased tendon/calcium, the TX-1 tip oscillates at the speed of sound, fenestrating/cutting through the tendon or calcium while lavaging the tendon with saline. Multiple prospective, noncontrolled studies done in common extensor, patellar, and rotator cuff tendinopathy have demonstrated good to excellent improvements in pain scores with the Tenex procedure.^29-31

Ultrasound is extremely useful in the treatment of adhesive capsulitis.³² The posterior glenohumeral capsule can be distended using a large volume (60 cc) of saline to loosen adhesions in preparation for manipulation. Because the manipulation can be an extremely painful procedure, ultrasound can be used to perform an inter-scalene block for regional anesthesia prior to the procedure. In 2014, Park and colleagues³³ performed a randomized prospective trial that showed that capsular distension followed by manipulation was more effective than cortisone injection alone for the treatment of adhesive capsulitis.Ultrasound guidance was found to be just as efficacious as fluoroscopy in a randomized controlled trial in 2014; the authors noted that ultrasound does not expose the patient or clinician to radiation and can be done in office.³⁴

Currently, techniques to perform ultrasound-guided percutaneous tenotomies of the long head of the biceps tendon using hook blades are being studied.³⁵

Ultrasound-Assisted Surgery

Ultrasound has been a boon to surgeons who perform minimally invasive procedures. It is far less cumbersome than classic fluoroscopy. Fluoroscopy requires the use of heavy lead aprons by the surgeons. Combining this with the impervious gowns and hot lights, the surgeons’ comfort level is severely sacrificed. When having to do many long surgeries in a row, this situation can take a toll on the surgeons’ endurance and strength. Improving the comfort of the surgeon is not the primary goal of surgery, but can significantly help our ability to do a better job.

Ultrasound allows the surgeon to localize any superficial foreign objects, especially with radiolucent objects like fragments of glass. Small glass fragments or pieces of wood have always been extremely difficult to remove. X-rays cannot localize these objects, so getting a proper orientation is difficult. MRI and CT scans easily identify these types of foreign objects, but cannot be used intraoperatively (Figure 1A). Often, these objects cannot be felt and therefore require a large dissection. The objects may encapsulate and be easily confused with other soft tissues.

Conclusion

Ultrasound is quickly becoming a popular imaging modality due to its simplicity, portability, and cost efficiency. Its use as a diagnostic tool is widely known. As an adjunct for procedures and interventions, its advantages over larger, more expensive modalities such as fluoroscopy, CT, or MRI make it stand out. Ultrasound is not the perfect solution to all problems, but it is clearly a technology that is gaining traction. Ultrasound is another imaging modality and tool that physicians and surgeons can use to improve their patients’ treatment.

Restoring native kinematics of the knee has been a primary goal of anterior cruciate ligament (ACL) procedures. Double-bundle ACL reconstruction, compared to single-bundle, has been hypothesized to more effectively re-establish rotational stability by re-creating the anatomic ACL, but has not yet proven to result in better clinical outcomes.¹

In 1879, Dr. Paul Segond described a “fibrous, pearly band” at the lateral aspect of the knee that avulsed off the anterolateral proximal tibia during many ACL injuries.² The role of the lateral tissues in knee stability and their relationship with ACL pathology has attracted noteworthy attention in recent time. There have been multiple studies presenting an anatomical description of a structure at the anterolateral portion of the knee with definitive femoral, meniscal, and tibial attachments, which helps control internal rotational forces.^3-7 Claes and colleagues⁴ later found that band of tissue to be the anterolateral ligament (ALL) and determined its injury to be pathognomonic with ACL ruptures.

The ALL is a vital static stabilizer of the tibio-femoral joint, especially during internal tibial rotation.^8-10 In their report on ALL and ACL reconstruction, Helito and colleagues¹¹ acknowledge the necessity of accurate assessment of the lateral structures through imaging to determine the presence of extra-articular injury. Musculoskeletal diagnostic ultrasound has been established as an appropriate means to identify the ALL.¹²

Ultrasound can accurately determine the exact anatomic location of the origin and insertion of the ALL. Reconstruction of the ALL could yield better patient outcomes for those who experience concurrent ACL/ALL injury. Here we present an innovative technique for an ultrasound-guided percutaneous method for reconstruction of the ALL and report on a patient who had underwent ALL reconstruction.

Surgical Indications

All patients undergo an ultrasound evaluation preoperatively to determine if the ALL is intact or injured. Our experience has shown that when ultrasound evaluation reveals an intact ALL, the pivot shift has never been a grade III.

Surgical Technique

For a demonstration of this technique, see the video that accompanies this article.

The pivot shift test is conducted under anesthesia to determine whether an ALL reconstruction is required. The patient is placed in a supine position with the knee flexed at 30^o, at neutral rotation, and without any varus or valgus stress.

Rehabilitation

Rehabilitation following an ALL procedure is similar to traditional ACL rehabilitation with an added emphasis on minimizing rotational torque of the tibia in the early stages.

Case Report

In January 2013, a 17-year-old male soccer player suffered an ACL rupture of his right knee. Later that spring, he had an ACL reconstruction with an allograft. Twelve months postoperatively, the patient returned, saying that he felt much better; however, anytime he tried to plant his foot and rotate over that fixed foot, his knee felt unstable. The physical examination revealed both negative Lachman and anterior drawer tests but a I+ pivot shift test. A magnetic resonance imaging (MRI) examination revealed an intact ACL graft. A diagnostic ultrasound evaluation revealed a distal ALL injury. After discussing the risks, benefits, and goals with the patient, we opted for a diagnostic arthroscopy and a percutaneous, ultrasound-guided reconstruction of the ALL.

Postoperatively, the patient did very well. One week after surgery, he returned, saying he felt completely stable and demonstrated by repeating the rotation of his knee. The patient continued to have no issues until he returned 13 months post-ALL surgery, complaining of a recent injury that had caused the return of his feelings of instability. An MRI evaluation showed an intact ACL graft and the possibility of a ruptured ALL. Fifteen months after the initial ALL reconstruction, we proceeded with surgery. At arthroscopy, the patient was found to have a pivot shift of I+ and an intact ACL graft. The ALL was reconstructed again using an allograft, internal brace, and bone marrow concentrate. At 13 months post-ALL reconstruction revision, the patient had no complaints.

Discussion

Reconstruction of the ALL is aimed to restore anatomic rotational kinematics. Sonnery-Cottet and colleagues¹⁴ have reported promising initial results in their 2-year follow-up study of combined ACL and ALL reconstruction outcomes. This surgical technique includes use of an internal brace, which negates the necessity for external support devices and allows for earlier mobilization of the joint. A reconstruction of the ALL, performed concurrently with the ACL, does not add recovery time, but could prevent postsurgical complications and improve rehabilitation by eliminating rotational instability that presents in some ACL-reconstructed patients.

Sonnery-Cottet and colleagues¹⁵ state that their arthroscopic identification of the ALL can help to cultivate a “less invasive and more anatomic” reconstruction. The use of musculoskeletal ultrasound allows our technique to utilize a completely noninvasive imaging tool that allows proper establishment of ALL anatomy prior to the procedure. The entirety of the ALL is easily identifiable,^4,12 which has proven to be shortcoming of MRI evaluation.^15-17 Accurate preoperative assessment of the lateral structures is necessary in ACL-deficient individuals.^11,15 Sonography also provides a means of accurate guidance and socket creation, without generating large incisions.

If the ALL is responsible for internal rotatory stability as asserted, the structure should exhibit biomechanical properties during movement. In their study on the function of the ligament, Parsons and colleagues⁹ established the inverse relationship between the ALL and ACL during internal rotation. As their cadaveric knees were subjected to an internal rotatory force through increasing angles of flexion, the contribution of the ALL towards stability significantly increased while the ACL declined. Helito and colleagues⁸ and Zens and colleagues¹⁰ have demonstrated length changes of the ligament through varying degrees of flexion and internal rotation. Their reports indicate greater tension during knee movements, coinciding with the description of increasing ALL stability contribution by Parsons and colleagues.⁹ Kennedy and colleagues⁷ conducted a pull-to-failure test on the ALL. The average failure load was 175 N with a stiffness of 20 N/mm, illustrating the structure is a candidate for most traditional soft tissue grafts. The biomechanical evidence of the structural properties of the ALL confirms its importance in knee function and the necessity for its reconstruction.

With the understanding that ACL contributes to rotatory stability to some extent, the notion begs the question of how a centrally located ligament is able to prevent excessive rotation in a structure with a large relative radius. Biomechanically, with such a small moment arm, the ACL would experience tremendous stress when a rotatory force is applied. The same torque applied to a more superficial structure, with a greater moment, would sustain a large reduction in the applied force. The concept of a wheel and an axle should be considered. The equation is F₁ × R₁ = F₂ × R₂. We measured on a cadaveric knee the distance from the center of rotation to the ACL and the ALL, finding the radii were 5 mm and 30 mm, respectively. Taking these measurements, we would then expect the force experienced on the axle (ACL) to be 6 times greater than what would be experienced on the periphery of the wheel (ALL). The ALL (wheel) has a significant biomechanical advantage over the ACL (axle) in controlling and enduring internal rotatory forces of the knee. This would imply that if the ALL were damaged and not re-established, the ACL would experience a 6 times greater force trying to control internal rotation, which would result in a significantly increased chance of failure and rupture.

While there is a degree of dissent on the presence of the ALL, a number of studies have classified the tissue as an independent ligamentous structure.^3-7 While there is disagreement on the precise location of the femoral attachment, there is a consensus on the location of the tibial and meniscal attachments. Claes and colleagues⁴ originally outlined the femoral attachment as anterior and distal to the origin of the fibular collateral ligament (FCL), which is the description this technique follows. Since Claes and colleagues’⁴ report, many have investigated the ligament’s femoral origin with delineations ranging from posterior and proximal^3,5,7 to anterior and distal.^6,16-18

The accurate, noninvasive nature of the musculoskeletal ultrasound prior to any incisions being made makes this technique innovative and superior to other open surgical techniques or those that require fluoroscopy.

Conclusion

The ALL has been determined to play an integral role in the rotational stability of the knee. In the setting of instability and insufficiency, reconstruction will lead to better patient outcomes for concurrent ACL/ALL injuries and postsurgical rotatory instability following ACL procedures. This innovative technique utilizes ultrasound to ascertain the precise anatomical attachments of the ALL prior to the operation. The novel nature of this ultrasound-guided reconstruction has the potential to be applicable in many other surgical procedures.

Restoring native kinematics of the knee has been a primary goal of anterior cruciate ligament (ACL) procedures. Double-bundle ACL reconstruction, compared to single-bundle, has been hypothesized to more effectively re-establish rotational stability by re-creating the anatomic ACL, but has not yet proven to result in better clinical outcomes.¹

In 1879, Dr. Paul Segond described a “fibrous, pearly band” at the lateral aspect of the knee that avulsed off the anterolateral proximal tibia during many ACL injuries.² The role of the lateral tissues in knee stability and their relationship with ACL pathology has attracted noteworthy attention in recent time. There have been multiple studies presenting an anatomical description of a structure at the anterolateral portion of the knee with definitive femoral, meniscal, and tibial attachments, which helps control internal rotational forces.^3-7 Claes and colleagues⁴ later found that band of tissue to be the anterolateral ligament (ALL) and determined its injury to be pathognomonic with ACL ruptures.

The ALL is a vital static stabilizer of the tibio-femoral joint, especially during internal tibial rotation.^8-10 In their report on ALL and ACL reconstruction, Helito and colleagues¹¹ acknowledge the necessity of accurate assessment of the lateral structures through imaging to determine the presence of extra-articular injury. Musculoskeletal diagnostic ultrasound has been established as an appropriate means to identify the ALL.¹²

Ultrasound can accurately determine the exact anatomic location of the origin and insertion of the ALL. Reconstruction of the ALL could yield better patient outcomes for those who experience concurrent ACL/ALL injury. Here we present an innovative technique for an ultrasound-guided percutaneous method for reconstruction of the ALL and report on a patient who had underwent ALL reconstruction.

Surgical Indications

All patients undergo an ultrasound evaluation preoperatively to determine if the ALL is intact or injured. Our experience has shown that when ultrasound evaluation reveals an intact ALL, the pivot shift has never been a grade III.

Surgical Technique

For a demonstration of this technique, see the video that accompanies this article.

The pivot shift test is conducted under anesthesia to determine whether an ALL reconstruction is required. The patient is placed in a supine position with the knee flexed at 30^o, at neutral rotation, and without any varus or valgus stress.

Rehabilitation

Rehabilitation following an ALL procedure is similar to traditional ACL rehabilitation with an added emphasis on minimizing rotational torque of the tibia in the early stages.

Case Report

In January 2013, a 17-year-old male soccer player suffered an ACL rupture of his right knee. Later that spring, he had an ACL reconstruction with an allograft. Twelve months postoperatively, the patient returned, saying that he felt much better; however, anytime he tried to plant his foot and rotate over that fixed foot, his knee felt unstable. The physical examination revealed both negative Lachman and anterior drawer tests but a I+ pivot shift test. A magnetic resonance imaging (MRI) examination revealed an intact ACL graft. A diagnostic ultrasound evaluation revealed a distal ALL injury. After discussing the risks, benefits, and goals with the patient, we opted for a diagnostic arthroscopy and a percutaneous, ultrasound-guided reconstruction of the ALL.

Postoperatively, the patient did very well. One week after surgery, he returned, saying he felt completely stable and demonstrated by repeating the rotation of his knee. The patient continued to have no issues until he returned 13 months post-ALL surgery, complaining of a recent injury that had caused the return of his feelings of instability. An MRI evaluation showed an intact ACL graft and the possibility of a ruptured ALL. Fifteen months after the initial ALL reconstruction, we proceeded with surgery. At arthroscopy, the patient was found to have a pivot shift of I+ and an intact ACL graft. The ALL was reconstructed again using an allograft, internal brace, and bone marrow concentrate. At 13 months post-ALL reconstruction revision, the patient had no complaints.

Discussion

Reconstruction of the ALL is aimed to restore anatomic rotational kinematics. Sonnery-Cottet and colleagues¹⁴ have reported promising initial results in their 2-year follow-up study of combined ACL and ALL reconstruction outcomes. This surgical technique includes use of an internal brace, which negates the necessity for external support devices and allows for earlier mobilization of the joint. A reconstruction of the ALL, performed concurrently with the ACL, does not add recovery time, but could prevent postsurgical complications and improve rehabilitation by eliminating rotational instability that presents in some ACL-reconstructed patients.

Sonnery-Cottet and colleagues¹⁵ state that their arthroscopic identification of the ALL can help to cultivate a “less invasive and more anatomic” reconstruction. The use of musculoskeletal ultrasound allows our technique to utilize a completely noninvasive imaging tool that allows proper establishment of ALL anatomy prior to the procedure. The entirety of the ALL is easily identifiable,^4,12 which has proven to be shortcoming of MRI evaluation.^15-17 Accurate preoperative assessment of the lateral structures is necessary in ACL-deficient individuals.^11,15 Sonography also provides a means of accurate guidance and socket creation, without generating large incisions.

If the ALL is responsible for internal rotatory stability as asserted, the structure should exhibit biomechanical properties during movement. In their study on the function of the ligament, Parsons and colleagues⁹ established the inverse relationship between the ALL and ACL during internal rotation. As their cadaveric knees were subjected to an internal rotatory force through increasing angles of flexion, the contribution of the ALL towards stability significantly increased while the ACL declined. Helito and colleagues⁸ and Zens and colleagues¹⁰ have demonstrated length changes of the ligament through varying degrees of flexion and internal rotation. Their reports indicate greater tension during knee movements, coinciding with the description of increasing ALL stability contribution by Parsons and colleagues.⁹ Kennedy and colleagues⁷ conducted a pull-to-failure test on the ALL. The average failure load was 175 N with a stiffness of 20 N/mm, illustrating the structure is a candidate for most traditional soft tissue grafts. The biomechanical evidence of the structural properties of the ALL confirms its importance in knee function and the necessity for its reconstruction.

With the understanding that ACL contributes to rotatory stability to some extent, the notion begs the question of how a centrally located ligament is able to prevent excessive rotation in a structure with a large relative radius. Biomechanically, with such a small moment arm, the ACL would experience tremendous stress when a rotatory force is applied. The same torque applied to a more superficial structure, with a greater moment, would sustain a large reduction in the applied force. The concept of a wheel and an axle should be considered. The equation is F₁ × R₁ = F₂ × R₂. We measured on a cadaveric knee the distance from the center of rotation to the ACL and the ALL, finding the radii were 5 mm and 30 mm, respectively. Taking these measurements, we would then expect the force experienced on the axle (ACL) to be 6 times greater than what would be experienced on the periphery of the wheel (ALL). The ALL (wheel) has a significant biomechanical advantage over the ACL (axle) in controlling and enduring internal rotatory forces of the knee. This would imply that if the ALL were damaged and not re-established, the ACL would experience a 6 times greater force trying to control internal rotation, which would result in a significantly increased chance of failure and rupture.

While there is a degree of dissent on the presence of the ALL, a number of studies have classified the tissue as an independent ligamentous structure.^3-7 While there is disagreement on the precise location of the femoral attachment, there is a consensus on the location of the tibial and meniscal attachments. Claes and colleagues⁴ originally outlined the femoral attachment as anterior and distal to the origin of the fibular collateral ligament (FCL), which is the description this technique follows. Since Claes and colleagues’⁴ report, many have investigated the ligament’s femoral origin with delineations ranging from posterior and proximal^3,5,7 to anterior and distal.^6,16-18

The accurate, noninvasive nature of the musculoskeletal ultrasound prior to any incisions being made makes this technique innovative and superior to other open surgical techniques or those that require fluoroscopy.

Conclusion

The ALL has been determined to play an integral role in the rotational stability of the knee. In the setting of instability and insufficiency, reconstruction will lead to better patient outcomes for concurrent ACL/ALL injuries and postsurgical rotatory instability following ACL procedures. This innovative technique utilizes ultrasound to ascertain the precise anatomical attachments of the ALL prior to the operation. The novel nature of this ultrasound-guided reconstruction has the potential to be applicable in many other surgical procedures.

Restoring native kinematics of the knee has been a primary goal of anterior cruciate ligament (ACL) procedures. Double-bundle ACL reconstruction, compared to single-bundle, has been hypothesized to more effectively re-establish rotational stability by re-creating the anatomic ACL, but has not yet proven to result in better clinical outcomes.¹

In 1879, Dr. Paul Segond described a “fibrous, pearly band” at the lateral aspect of the knee that avulsed off the anterolateral proximal tibia during many ACL injuries.² The role of the lateral tissues in knee stability and their relationship with ACL pathology has attracted noteworthy attention in recent time. There have been multiple studies presenting an anatomical description of a structure at the anterolateral portion of the knee with definitive femoral, meniscal, and tibial attachments, which helps control internal rotational forces.^3-7 Claes and colleagues⁴ later found that band of tissue to be the anterolateral ligament (ALL) and determined its injury to be pathognomonic with ACL ruptures.

The ALL is a vital static stabilizer of the tibio-femoral joint, especially during internal tibial rotation.^8-10 In their report on ALL and ACL reconstruction, Helito and colleagues¹¹ acknowledge the necessity of accurate assessment of the lateral structures through imaging to determine the presence of extra-articular injury. Musculoskeletal diagnostic ultrasound has been established as an appropriate means to identify the ALL.¹²

Ultrasound can accurately determine the exact anatomic location of the origin and insertion of the ALL. Reconstruction of the ALL could yield better patient outcomes for those who experience concurrent ACL/ALL injury. Here we present an innovative technique for an ultrasound-guided percutaneous method for reconstruction of the ALL and report on a patient who had underwent ALL reconstruction.

Surgical Indications

All patients undergo an ultrasound evaluation preoperatively to determine if the ALL is intact or injured. Our experience has shown that when ultrasound evaluation reveals an intact ALL, the pivot shift has never been a grade III.

Surgical Technique

For a demonstration of this technique, see the video that accompanies this article.

The pivot shift test is conducted under anesthesia to determine whether an ALL reconstruction is required. The patient is placed in a supine position with the knee flexed at 30^o, at neutral rotation, and without any varus or valgus stress.

Rehabilitation

Rehabilitation following an ALL procedure is similar to traditional ACL rehabilitation with an added emphasis on minimizing rotational torque of the tibia in the early stages.

Case Report

In January 2013, a 17-year-old male soccer player suffered an ACL rupture of his right knee. Later that spring, he had an ACL reconstruction with an allograft. Twelve months postoperatively, the patient returned, saying that he felt much better; however, anytime he tried to plant his foot and rotate over that fixed foot, his knee felt unstable. The physical examination revealed both negative Lachman and anterior drawer tests but a I+ pivot shift test. A magnetic resonance imaging (MRI) examination revealed an intact ACL graft. A diagnostic ultrasound evaluation revealed a distal ALL injury. After discussing the risks, benefits, and goals with the patient, we opted for a diagnostic arthroscopy and a percutaneous, ultrasound-guided reconstruction of the ALL.

Postoperatively, the patient did very well. One week after surgery, he returned, saying he felt completely stable and demonstrated by repeating the rotation of his knee. The patient continued to have no issues until he returned 13 months post-ALL surgery, complaining of a recent injury that had caused the return of his feelings of instability. An MRI evaluation showed an intact ACL graft and the possibility of a ruptured ALL. Fifteen months after the initial ALL reconstruction, we proceeded with surgery. At arthroscopy, the patient was found to have a pivot shift of I+ and an intact ACL graft. The ALL was reconstructed again using an allograft, internal brace, and bone marrow concentrate. At 13 months post-ALL reconstruction revision, the patient had no complaints.

Discussion

Reconstruction of the ALL is aimed to restore anatomic rotational kinematics. Sonnery-Cottet and colleagues¹⁴ have reported promising initial results in their 2-year follow-up study of combined ACL and ALL reconstruction outcomes. This surgical technique includes use of an internal brace, which negates the necessity for external support devices and allows for earlier mobilization of the joint. A reconstruction of the ALL, performed concurrently with the ACL, does not add recovery time, but could prevent postsurgical complications and improve rehabilitation by eliminating rotational instability that presents in some ACL-reconstructed patients.

Sonnery-Cottet and colleagues¹⁵ state that their arthroscopic identification of the ALL can help to cultivate a “less invasive and more anatomic” reconstruction. The use of musculoskeletal ultrasound allows our technique to utilize a completely noninvasive imaging tool that allows proper establishment of ALL anatomy prior to the procedure. The entirety of the ALL is easily identifiable,^4,12 which has proven to be shortcoming of MRI evaluation.^15-17 Accurate preoperative assessment of the lateral structures is necessary in ACL-deficient individuals.^11,15 Sonography also provides a means of accurate guidance and socket creation, without generating large incisions.

If the ALL is responsible for internal rotatory stability as asserted, the structure should exhibit biomechanical properties during movement. In their study on the function of the ligament, Parsons and colleagues⁹ established the inverse relationship between the ALL and ACL during internal rotation. As their cadaveric knees were subjected to an internal rotatory force through increasing angles of flexion, the contribution of the ALL towards stability significantly increased while the ACL declined. Helito and colleagues⁸ and Zens and colleagues¹⁰ have demonstrated length changes of the ligament through varying degrees of flexion and internal rotation. Their reports indicate greater tension during knee movements, coinciding with the description of increasing ALL stability contribution by Parsons and colleagues.⁹ Kennedy and colleagues⁷ conducted a pull-to-failure test on the ALL. The average failure load was 175 N with a stiffness of 20 N/mm, illustrating the structure is a candidate for most traditional soft tissue grafts. The biomechanical evidence of the structural properties of the ALL confirms its importance in knee function and the necessity for its reconstruction.

With the understanding that ACL contributes to rotatory stability to some extent, the notion begs the question of how a centrally located ligament is able to prevent excessive rotation in a structure with a large relative radius. Biomechanically, with such a small moment arm, the ACL would experience tremendous stress when a rotatory force is applied. The same torque applied to a more superficial structure, with a greater moment, would sustain a large reduction in the applied force. The concept of a wheel and an axle should be considered. The equation is F₁ × R₁ = F₂ × R₂. We measured on a cadaveric knee the distance from the center of rotation to the ACL and the ALL, finding the radii were 5 mm and 30 mm, respectively. Taking these measurements, we would then expect the force experienced on the axle (ACL) to be 6 times greater than what would be experienced on the periphery of the wheel (ALL). The ALL (wheel) has a significant biomechanical advantage over the ACL (axle) in controlling and enduring internal rotatory forces of the knee. This would imply that if the ALL were damaged and not re-established, the ACL would experience a 6 times greater force trying to control internal rotation, which would result in a significantly increased chance of failure and rupture.

While there is a degree of dissent on the presence of the ALL, a number of studies have classified the tissue as an independent ligamentous structure.^3-7 While there is disagreement on the precise location of the femoral attachment, there is a consensus on the location of the tibial and meniscal attachments. Claes and colleagues⁴ originally outlined the femoral attachment as anterior and distal to the origin of the fibular collateral ligament (FCL), which is the description this technique follows. Since Claes and colleagues’⁴ report, many have investigated the ligament’s femoral origin with delineations ranging from posterior and proximal^3,5,7 to anterior and distal.^6,16-18

The accurate, noninvasive nature of the musculoskeletal ultrasound prior to any incisions being made makes this technique innovative and superior to other open surgical techniques or those that require fluoroscopy.

Conclusion

The ALL has been determined to play an integral role in the rotational stability of the knee. In the setting of instability and insufficiency, reconstruction will lead to better patient outcomes for concurrent ACL/ALL injuries and postsurgical rotatory instability following ACL procedures. This innovative technique utilizes ultrasound to ascertain the precise anatomical attachments of the ALL prior to the operation. The novel nature of this ultrasound-guided reconstruction has the potential to be applicable in many other surgical procedures.

Rejuvenation of the periocular area is in high demand among patients who want to look and feel their best. Physicians should understand the complicated anatomy surrounding the eyes before attempting to inject this area with facial fillers, both to understand the aging process and to minimize treatment complications.

Basic Oculoplastic and Orbital Anatomy

The injector should understand the anatomy of the periocular muscles, the orbital osteology, and the secretory and lacrimal system, in addition to the fat, ligaments, and vascular anatomy in this area.¹

The eyes are surrounded by fat compartments that provide glide planes for the motion of the eyelids and globe. There are 2 upper eyelid fat-pads—nasal and central [preaponeurotic])—in the upper lid, leaving room for the lacrimal gland laterally. There are 3 fat compartments—nasal, central, and lateral—in the lower eyelid. The nasal and central compartments are separated by the inferior oblique muscle, which elevates and extorts the eye. The orbital septum holds the fat-pads in place in the orbit. The brow fat-pad is the retro-orbicularis oculi fat-pad (ROOF). There are fat compartments that lie in the subcutaneous space along the entire forehead and in the temple. The suborbicularis oculi fat-pad (SOOF) lies over the malar eminence. Superficial and deep submuscular fat compartments of the face have been described.² Deep fat compartments also have been examined on computed tomography.³

Orbital circulation comes from the internal carotid artery and anastomoses with the supply from the external carotid artery to supply the orbit. The first branch off of the carotid artery is the ophthalmic artery, and the first branch off of the ophthalmic artery is the central retinal artery that enters the optic nerve sheath 1 cm behind the globe to supply the retina. The supraorbital and supratrochlear arteries branch off of the ophthalmic artery and supply the forehead. The supraorbital artery runs through the supraorbital notch (foramen in 8%)¹ and can usually be palpated with one’s finger. There are 15 to 20 short posterior ciliary arteries leading to the choroid, 2 long posterior ciliary arteries to the iris circle, and 7 anterior ciliary arteries to the extraocular muscles. The superior and inferior venous systems drain into the cavernous sinus.⁴

The ligaments are important to signs of facial aging because tissue atrophy occurs along them. The main orbital ligaments are the lateral orbital thickening (known as the LOT) that adheres the eyelids to the lateral orbital rim and the orbitomalar ligament (orbicularis retaining ligament), which is a condensation fibrous tissue that attaches the skin to the inferior orbital rim and orbital septum along the arcus marginalis and defines the superior edge of the SOOF.⁵ The zygomatic ligament not only suspends the zygomaticus major and zygomaticus minor muscles to the malar eminence but there are osseocutaneous attachments that connect the skin over the zygoma’s malar eminence and demarcate the inferior edge of the SOOF.⁶

Periocular Aging

The skin, fat, muscles, and bones change and rotate with aging, and not all orbits age in the same manner. Older patients with dermatochalasis (excess skin fat and muscle) often undergo rejuvenation with blepharoplasty, a brow-lift, and a midface-lift, but many atrophic changes can be improved with facial fillers.^7,8

As adults age, the soft tissue along the ligaments begins to show atrophy, prime signs of aging that are often improved with fillers. Atrophy along the orbitomalar ligament along the infraorbital rim creates a depressed tear trough, which is an early sign of aging. A 3-point grading system reported by Hirmand⁸ describes the severity of progressive hallowing. There also is atrophy along the zygomatic cutaneous ligament that creates the malar hollow. The SOOF appears to be more prominent when these areas above and below show atrophy, which creates the look of an unwanted bag known as a festoon. Additionally, there is atrophy along the superior orbital notch where the ophthalmic branch of the trigeminal nerve (V1) and the supraorbital artery traverse. Soft-tissue atrophy along the supraorbital notch resembles the peak at the top of the letter A, giving the slang term A-frame deformity.

Periocular fat can atrophy, hypertrophy, herniate forward as the septum weakens, or become ptotic. Some patients develop hypertrophy and herniation of the superior and inferior orbital fat-pads, while others develop unwanted atrophy leaving a hollow superior orbit and loss of support to the levator muscle that contributes to eyelid ptosis. The frontalis fat deflates, leaving veins, arteries, and the hypertrophied corrugators unwantedly visible. Loss of subcutaneous fat in the glabella contributes to the formation of frown lines between the brows (also called number 11’s). The ROOF deflates in some patients adding to brow ptosis. Loss of the facial frame occurs when temple fat atrophies.

Skeletal rotation also occurs. Throughout a patient’s life, the skeleton remodels itself via activity of osteoclasts and osteoblasts. Pessa et al^9,10 has described the expansion of the anterior orbital aperture superomedially and inferolaterally as well as maxillary retrusion that results in angular changes of the midface in relation to the orbital rim. Lambros’ algorithm describes the rotational changes of the cranium where the superior orbit protrudes as the maxilla retreats posteriorly.^9-11 The equator of the globe does not change its distance from the ROOF of the orbit, presumably because of its suspension in the orbit by the optic nerve after it passes through the optic canal and trochlea via the superior oblique muscle, but the distance of the inferior equator of the globe to the floor of the orbit increases as the floor of the orbit descends.¹²

Dermal Fillers for Periocular Rejuvenation

Hyaluronic acid (HA) was first pioneered for use in humans in the late 1970s by ophthalmologists for anterior segment surgery.^13-15 Biocompatibility for orthopedic and dermal applications was explored in the early 1990s.¹⁶

At this time, no dermal filler is approved by the US Food and Drug Administration for use in the periorbital area. Some fillers are approved for subdermal areas extending to the preperiosteal plane and can be used in the midface such as HA fillers (eg, Restylane Lyft [Galderma Laboratories, LP]), Juvéderm Voluma XC [Allergan, Inc]), poly-L-lactic acid (PLLA), and calcium hydroxylapatite (CaHA). No dermal fillers are approved for use in the forehead, glabella, or temples. Their use is becoming increasingly popular but is considered off label. In addition, cannulas are not approved for use in these areas. Cannulas may be beneficial in that they are thought to create less bruising and have less chance of entering a vessel than needles, but some injectors prefer needles because they are stiffer and therefore more precise.

The ideal filler for the tear trough, superior sulcus, ROOF, over the orbitomalar ligament, forehead, and glabella is one that is somewhat moldable but does not migrate, is not hydrophilic, is smooth to inject, and is reversible should there be any complications. No single filler fits this ideal description, but HAs typically are the first choice.

In vitro studies to determine the stiffness (G') and the ability to flow (viscosity) have been performed.^17,18 Calcium hydroxylapatite has the most stiffness, while Belotero Balance (Merz Aesthetics) and Juvéderm Ultra XC (Allergan, Inc) are more soft¹⁷ (Table). These guidelines are important but may not correlate directly with how the fillers behave in vivo as demonstrated in animal models.¹⁸

Periocular Injection Considerations

An experienced injector is one who has developed not only an artistic eye for the face and excellent sense of anatomy but also has a sensitive ability to predict the filler-tissue interaction based on tactile feedback dependent on 3 main qualities: (1) stiffness and viscosity of the filler, (2) gauge of the needle or cannula, and (3) depth of the needle in the tissue. Periocular injections of dermal fillers can be delivered with needles or cannulas, diluted or undiluted. Smaller-gauge needles require more force than larger-gauge needles and cannulas that flow more freely. A needle in the dense dermis will require more force than one placed in the loose subcutaneous space.

The tear trough is generally preferable to fill with a mid-level G' HA filler that is less apt to migrate. A neutral gaze during the injection is preferred because closing or moving the eyes can distort the position of the inferior orbital fat-pads (Figure 1). A needle or cannula can be used, diluted or undiluted. The tear trough can be filled with the injection directed horizontally or vertically via a fanning technique. If needles are used, the skin should be stretched to view the 3 to 5 vertical veins and then the needle should be advanced beneath them to avoid bruising. Avoidance of hydrophilic fillers in the tear trough is important to avoid edema. The superior sulcus can be filled both anteriorly and posteriorly to the septum, which is a highly advanced injection for experienced injectors because of the proximity to the supratrochlear and supraorbital arteries as well as the superior ophthalmic vein (Figure 2). Sharp creases such as deep lateral periocular rhytides known as crow’s-feet are nicely filled with intradermal HAs with a low G'.

Image courtesy of Julie A. Woodward, MD.

Adding volume to the midface is important because it is the continuum of the lower eyelid. Fillers can be injected into multiple levels in this area: deep (to act as pillars to lift the malar eminence and replace bone that has rotated and soft tissue that has become atrophic or descended) and subcutaneous (to efface soft tissue along the zygomatic cutaneous ligament). Higher G' HA fillers and CaHA often are used in the midface along with PLLA. Facial framing of the temples, lateral cheeks, and preauricular area is often accomplished with PLLA but also can be done with mid to high G' HA fillers or CaHA. A cannula may be used to undermine and break apart the zygomatic cutaneous ligament’s cutaneous attachments prior to delivery of the filler in the subcutaneous plane.²⁶ If not done, filler may track away from the hollow area where the ligament is attached and instead move to adjacent areas that will accentuate the hollow and make it look worse.

The temples and lateral face often are filled with PLLA for framing. Mid or high G' HA fillers and CaHA also are used in the temples both beneath the temporalis muscle and also above the deep temporalis fascia or sometimes in the subcutaneous plane.²⁷

Prevention and Management of Periocular Complications

Blindness is the most devastating periocular complication of facial fillers, which is caused by retrograde arterial embolization followed by anterograde flow into the ophthalmic then central retinal arteries. Injectables that have caused blindness include (in descending order of frequency) fat, HA, collagen, paraffin, polymethyl methacrylate, silicone, PLLA, CaHA, polyacrylamide hydrogel, and micronized acellular dermal matrix. Of the 98 cases of blindness from periocular complications from dermal fillers reported in the world literature, the order of affected sites include the glabella (38 cases), nose (25), nasolabial folds (13), superior forehead (12), infraorbital rim (6), temples (1), malar area (1), lip (1), and chin (1). Prevention includes avoidance of danger zone arteries including the supratrochlear, supraorbital, dorsal nasal, angular, infraorbital, zygomaticofacial and zygomaticotemporal arteries.²⁸

Avoiding the average critical volume of 0.84 in any single aliquot dispensed is key to avoid filling of these periocular arteries to the critical bifurcation point that can result in anterograde flow into the eye (Freudenthal Nicolau syndrome). The smallest supratrochlear artery’s volume in this study was 0.04 cc, so aliquots that do not exceed 0.03 cc are ideal.^29,30

The injector should always be thinking about the anatomy of the danger zones (eg, infratrochlear and supratrochlear arteries, supraorbital artery, frontal branch of the superficial temporal artery, lacrimal artery, dorsal nasal artery, infraorbital artery, angular artery, zygomaticofacial artery, zygomaticotemporal artery)(Figure 3).

Image courtesy of Julie A. Woodward, MD.

Conclusion

In summary, periocular injections of facial fillers are useful tools for rejuvenation of the upper face when used with great caution and respect for anatomy.

Rejuvenation of the periocular area is in high demand among patients who want to look and feel their best. Physicians should understand the complicated anatomy surrounding the eyes before attempting to inject this area with facial fillers, both to understand the aging process and to minimize treatment complications.

Basic Oculoplastic and Orbital Anatomy

The injector should understand the anatomy of the periocular muscles, the orbital osteology, and the secretory and lacrimal system, in addition to the fat, ligaments, and vascular anatomy in this area.¹

The eyes are surrounded by fat compartments that provide glide planes for the motion of the eyelids and globe. There are 2 upper eyelid fat-pads—nasal and central [preaponeurotic])—in the upper lid, leaving room for the lacrimal gland laterally. There are 3 fat compartments—nasal, central, and lateral—in the lower eyelid. The nasal and central compartments are separated by the inferior oblique muscle, which elevates and extorts the eye. The orbital septum holds the fat-pads in place in the orbit. The brow fat-pad is the retro-orbicularis oculi fat-pad (ROOF). There are fat compartments that lie in the subcutaneous space along the entire forehead and in the temple. The suborbicularis oculi fat-pad (SOOF) lies over the malar eminence. Superficial and deep submuscular fat compartments of the face have been described.² Deep fat compartments also have been examined on computed tomography.³

Orbital circulation comes from the internal carotid artery and anastomoses with the supply from the external carotid artery to supply the orbit. The first branch off of the carotid artery is the ophthalmic artery, and the first branch off of the ophthalmic artery is the central retinal artery that enters the optic nerve sheath 1 cm behind the globe to supply the retina. The supraorbital and supratrochlear arteries branch off of the ophthalmic artery and supply the forehead. The supraorbital artery runs through the supraorbital notch (foramen in 8%)¹ and can usually be palpated with one’s finger. There are 15 to 20 short posterior ciliary arteries leading to the choroid, 2 long posterior ciliary arteries to the iris circle, and 7 anterior ciliary arteries to the extraocular muscles. The superior and inferior venous systems drain into the cavernous sinus.⁴

The ligaments are important to signs of facial aging because tissue atrophy occurs along them. The main orbital ligaments are the lateral orbital thickening (known as the LOT) that adheres the eyelids to the lateral orbital rim and the orbitomalar ligament (orbicularis retaining ligament), which is a condensation fibrous tissue that attaches the skin to the inferior orbital rim and orbital septum along the arcus marginalis and defines the superior edge of the SOOF.⁵ The zygomatic ligament not only suspends the zygomaticus major and zygomaticus minor muscles to the malar eminence but there are osseocutaneous attachments that connect the skin over the zygoma’s malar eminence and demarcate the inferior edge of the SOOF.⁶

Periocular Aging

The skin, fat, muscles, and bones change and rotate with aging, and not all orbits age in the same manner. Older patients with dermatochalasis (excess skin fat and muscle) often undergo rejuvenation with blepharoplasty, a brow-lift, and a midface-lift, but many atrophic changes can be improved with facial fillers.^7,8

As adults age, the soft tissue along the ligaments begins to show atrophy, prime signs of aging that are often improved with fillers. Atrophy along the orbitomalar ligament along the infraorbital rim creates a depressed tear trough, which is an early sign of aging. A 3-point grading system reported by Hirmand⁸ describes the severity of progressive hallowing. There also is atrophy along the zygomatic cutaneous ligament that creates the malar hollow. The SOOF appears to be more prominent when these areas above and below show atrophy, which creates the look of an unwanted bag known as a festoon. Additionally, there is atrophy along the superior orbital notch where the ophthalmic branch of the trigeminal nerve (V1) and the supraorbital artery traverse. Soft-tissue atrophy along the supraorbital notch resembles the peak at the top of the letter A, giving the slang term A-frame deformity.

Periocular fat can atrophy, hypertrophy, herniate forward as the septum weakens, or become ptotic. Some patients develop hypertrophy and herniation of the superior and inferior orbital fat-pads, while others develop unwanted atrophy leaving a hollow superior orbit and loss of support to the levator muscle that contributes to eyelid ptosis. The frontalis fat deflates, leaving veins, arteries, and the hypertrophied corrugators unwantedly visible. Loss of subcutaneous fat in the glabella contributes to the formation of frown lines between the brows (also called number 11’s). The ROOF deflates in some patients adding to brow ptosis. Loss of the facial frame occurs when temple fat atrophies.

Skeletal rotation also occurs. Throughout a patient’s life, the skeleton remodels itself via activity of osteoclasts and osteoblasts. Pessa et al^9,10 has described the expansion of the anterior orbital aperture superomedially and inferolaterally as well as maxillary retrusion that results in angular changes of the midface in relation to the orbital rim. Lambros’ algorithm describes the rotational changes of the cranium where the superior orbit protrudes as the maxilla retreats posteriorly.^9-11 The equator of the globe does not change its distance from the ROOF of the orbit, presumably because of its suspension in the orbit by the optic nerve after it passes through the optic canal and trochlea via the superior oblique muscle, but the distance of the inferior equator of the globe to the floor of the orbit increases as the floor of the orbit descends.¹²

Dermal Fillers for Periocular Rejuvenation

Hyaluronic acid (HA) was first pioneered for use in humans in the late 1970s by ophthalmologists for anterior segment surgery.^13-15 Biocompatibility for orthopedic and dermal applications was explored in the early 1990s.¹⁶

At this time, no dermal filler is approved by the US Food and Drug Administration for use in the periorbital area. Some fillers are approved for subdermal areas extending to the preperiosteal plane and can be used in the midface such as HA fillers (eg, Restylane Lyft [Galderma Laboratories, LP]), Juvéderm Voluma XC [Allergan, Inc]), poly-L-lactic acid (PLLA), and calcium hydroxylapatite (CaHA). No dermal fillers are approved for use in the forehead, glabella, or temples. Their use is becoming increasingly popular but is considered off label. In addition, cannulas are not approved for use in these areas. Cannulas may be beneficial in that they are thought to create less bruising and have less chance of entering a vessel than needles, but some injectors prefer needles because they are stiffer and therefore more precise.

The ideal filler for the tear trough, superior sulcus, ROOF, over the orbitomalar ligament, forehead, and glabella is one that is somewhat moldable but does not migrate, is not hydrophilic, is smooth to inject, and is reversible should there be any complications. No single filler fits this ideal description, but HAs typically are the first choice.

In vitro studies to determine the stiffness (G') and the ability to flow (viscosity) have been performed.^17,18 Calcium hydroxylapatite has the most stiffness, while Belotero Balance (Merz Aesthetics) and Juvéderm Ultra XC (Allergan, Inc) are more soft¹⁷ (Table). These guidelines are important but may not correlate directly with how the fillers behave in vivo as demonstrated in animal models.¹⁸

Periocular Injection Considerations

An experienced injector is one who has developed not only an artistic eye for the face and excellent sense of anatomy but also has a sensitive ability to predict the filler-tissue interaction based on tactile feedback dependent on 3 main qualities: (1) stiffness and viscosity of the filler, (2) gauge of the needle or cannula, and (3) depth of the needle in the tissue. Periocular injections of dermal fillers can be delivered with needles or cannulas, diluted or undiluted. Smaller-gauge needles require more force than larger-gauge needles and cannulas that flow more freely. A needle in the dense dermis will require more force than one placed in the loose subcutaneous space.

The tear trough is generally preferable to fill with a mid-level G' HA filler that is less apt to migrate. A neutral gaze during the injection is preferred because closing or moving the eyes can distort the position of the inferior orbital fat-pads (Figure 1). A needle or cannula can be used, diluted or undiluted. The tear trough can be filled with the injection directed horizontally or vertically via a fanning technique. If needles are used, the skin should be stretched to view the 3 to 5 vertical veins and then the needle should be advanced beneath them to avoid bruising. Avoidance of hydrophilic fillers in the tear trough is important to avoid edema. The superior sulcus can be filled both anteriorly and posteriorly to the septum, which is a highly advanced injection for experienced injectors because of the proximity to the supratrochlear and supraorbital arteries as well as the superior ophthalmic vein (Figure 2). Sharp creases such as deep lateral periocular rhytides known as crow’s-feet are nicely filled with intradermal HAs with a low G'.

Image courtesy of Julie A. Woodward, MD.

Adding volume to the midface is important because it is the continuum of the lower eyelid. Fillers can be injected into multiple levels in this area: deep (to act as pillars to lift the malar eminence and replace bone that has rotated and soft tissue that has become atrophic or descended) and subcutaneous (to efface soft tissue along the zygomatic cutaneous ligament). Higher G' HA fillers and CaHA often are used in the midface along with PLLA. Facial framing of the temples, lateral cheeks, and preauricular area is often accomplished with PLLA but also can be done with mid to high G' HA fillers or CaHA. A cannula may be used to undermine and break apart the zygomatic cutaneous ligament’s cutaneous attachments prior to delivery of the filler in the subcutaneous plane.²⁶ If not done, filler may track away from the hollow area where the ligament is attached and instead move to adjacent areas that will accentuate the hollow and make it look worse.

The temples and lateral face often are filled with PLLA for framing. Mid or high G' HA fillers and CaHA also are used in the temples both beneath the temporalis muscle and also above the deep temporalis fascia or sometimes in the subcutaneous plane.²⁷

Prevention and Management of Periocular Complications

Blindness is the most devastating periocular complication of facial fillers, which is caused by retrograde arterial embolization followed by anterograde flow into the ophthalmic then central retinal arteries. Injectables that have caused blindness include (in descending order of frequency) fat, HA, collagen, paraffin, polymethyl methacrylate, silicone, PLLA, CaHA, polyacrylamide hydrogel, and micronized acellular dermal matrix. Of the 98 cases of blindness from periocular complications from dermal fillers reported in the world literature, the order of affected sites include the glabella (38 cases), nose (25), nasolabial folds (13), superior forehead (12), infraorbital rim (6), temples (1), malar area (1), lip (1), and chin (1). Prevention includes avoidance of danger zone arteries including the supratrochlear, supraorbital, dorsal nasal, angular, infraorbital, zygomaticofacial and zygomaticotemporal arteries.²⁸

Avoiding the average critical volume of 0.84 in any single aliquot dispensed is key to avoid filling of these periocular arteries to the critical bifurcation point that can result in anterograde flow into the eye (Freudenthal Nicolau syndrome). The smallest supratrochlear artery’s volume in this study was 0.04 cc, so aliquots that do not exceed 0.03 cc are ideal.^29,30

The injector should always be thinking about the anatomy of the danger zones (eg, infratrochlear and supratrochlear arteries, supraorbital artery, frontal branch of the superficial temporal artery, lacrimal artery, dorsal nasal artery, infraorbital artery, angular artery, zygomaticofacial artery, zygomaticotemporal artery)(Figure 3).

Image courtesy of Julie A. Woodward, MD.

Conclusion

In summary, periocular injections of facial fillers are useful tools for rejuvenation of the upper face when used with great caution and respect for anatomy.

Rejuvenation of the periocular area is in high demand among patients who want to look and feel their best. Physicians should understand the complicated anatomy surrounding the eyes before attempting to inject this area with facial fillers, both to understand the aging process and to minimize treatment complications.

Basic Oculoplastic and Orbital Anatomy

The injector should understand the anatomy of the periocular muscles, the orbital osteology, and the secretory and lacrimal system, in addition to the fat, ligaments, and vascular anatomy in this area.¹

The eyes are surrounded by fat compartments that provide glide planes for the motion of the eyelids and globe. There are 2 upper eyelid fat-pads—nasal and central [preaponeurotic])—in the upper lid, leaving room for the lacrimal gland laterally. There are 3 fat compartments—nasal, central, and lateral—in the lower eyelid. The nasal and central compartments are separated by the inferior oblique muscle, which elevates and extorts the eye. The orbital septum holds the fat-pads in place in the orbit. The brow fat-pad is the retro-orbicularis oculi fat-pad (ROOF). There are fat compartments that lie in the subcutaneous space along the entire forehead and in the temple. The suborbicularis oculi fat-pad (SOOF) lies over the malar eminence. Superficial and deep submuscular fat compartments of the face have been described.² Deep fat compartments also have been examined on computed tomography.³

Orbital circulation comes from the internal carotid artery and anastomoses with the supply from the external carotid artery to supply the orbit. The first branch off of the carotid artery is the ophthalmic artery, and the first branch off of the ophthalmic artery is the central retinal artery that enters the optic nerve sheath 1 cm behind the globe to supply the retina. The supraorbital and supratrochlear arteries branch off of the ophthalmic artery and supply the forehead. The supraorbital artery runs through the supraorbital notch (foramen in 8%)¹ and can usually be palpated with one’s finger. There are 15 to 20 short posterior ciliary arteries leading to the choroid, 2 long posterior ciliary arteries to the iris circle, and 7 anterior ciliary arteries to the extraocular muscles. The superior and inferior venous systems drain into the cavernous sinus.⁴

The ligaments are important to signs of facial aging because tissue atrophy occurs along them. The main orbital ligaments are the lateral orbital thickening (known as the LOT) that adheres the eyelids to the lateral orbital rim and the orbitomalar ligament (orbicularis retaining ligament), which is a condensation fibrous tissue that attaches the skin to the inferior orbital rim and orbital septum along the arcus marginalis and defines the superior edge of the SOOF.⁵ The zygomatic ligament not only suspends the zygomaticus major and zygomaticus minor muscles to the malar eminence but there are osseocutaneous attachments that connect the skin over the zygoma’s malar eminence and demarcate the inferior edge of the SOOF.⁶

Periocular Aging

The skin, fat, muscles, and bones change and rotate with aging, and not all orbits age in the same manner. Older patients with dermatochalasis (excess skin fat and muscle) often undergo rejuvenation with blepharoplasty, a brow-lift, and a midface-lift, but many atrophic changes can be improved with facial fillers.^7,8

As adults age, the soft tissue along the ligaments begins to show atrophy, prime signs of aging that are often improved with fillers. Atrophy along the orbitomalar ligament along the infraorbital rim creates a depressed tear trough, which is an early sign of aging. A 3-point grading system reported by Hirmand⁸ describes the severity of progressive hallowing. There also is atrophy along the zygomatic cutaneous ligament that creates the malar hollow. The SOOF appears to be more prominent when these areas above and below show atrophy, which creates the look of an unwanted bag known as a festoon. Additionally, there is atrophy along the superior orbital notch where the ophthalmic branch of the trigeminal nerve (V1) and the supraorbital artery traverse. Soft-tissue atrophy along the supraorbital notch resembles the peak at the top of the letter A, giving the slang term A-frame deformity.

Periocular fat can atrophy, hypertrophy, herniate forward as the septum weakens, or become ptotic. Some patients develop hypertrophy and herniation of the superior and inferior orbital fat-pads, while others develop unwanted atrophy leaving a hollow superior orbit and loss of support to the levator muscle that contributes to eyelid ptosis. The frontalis fat deflates, leaving veins, arteries, and the hypertrophied corrugators unwantedly visible. Loss of subcutaneous fat in the glabella contributes to the formation of frown lines between the brows (also called number 11’s). The ROOF deflates in some patients adding to brow ptosis. Loss of the facial frame occurs when temple fat atrophies.

Skeletal rotation also occurs. Throughout a patient’s life, the skeleton remodels itself via activity of osteoclasts and osteoblasts. Pessa et al^9,10 has described the expansion of the anterior orbital aperture superomedially and inferolaterally as well as maxillary retrusion that results in angular changes of the midface in relation to the orbital rim. Lambros’ algorithm describes the rotational changes of the cranium where the superior orbit protrudes as the maxilla retreats posteriorly.^9-11 The equator of the globe does not change its distance from the ROOF of the orbit, presumably because of its suspension in the orbit by the optic nerve after it passes through the optic canal and trochlea via the superior oblique muscle, but the distance of the inferior equator of the globe to the floor of the orbit increases as the floor of the orbit descends.¹²

Dermal Fillers for Periocular Rejuvenation

Hyaluronic acid (HA) was first pioneered for use in humans in the late 1970s by ophthalmologists for anterior segment surgery.^13-15 Biocompatibility for orthopedic and dermal applications was explored in the early 1990s.¹⁶

At this time, no dermal filler is approved by the US Food and Drug Administration for use in the periorbital area. Some fillers are approved for subdermal areas extending to the preperiosteal plane and can be used in the midface such as HA fillers (eg, Restylane Lyft [Galderma Laboratories, LP]), Juvéderm Voluma XC [Allergan, Inc]), poly-L-lactic acid (PLLA), and calcium hydroxylapatite (CaHA). No dermal fillers are approved for use in the forehead, glabella, or temples. Their use is becoming increasingly popular but is considered off label. In addition, cannulas are not approved for use in these areas. Cannulas may be beneficial in that they are thought to create less bruising and have less chance of entering a vessel than needles, but some injectors prefer needles because they are stiffer and therefore more precise.

The ideal filler for the tear trough, superior sulcus, ROOF, over the orbitomalar ligament, forehead, and glabella is one that is somewhat moldable but does not migrate, is not hydrophilic, is smooth to inject, and is reversible should there be any complications. No single filler fits this ideal description, but HAs typically are the first choice.

In vitro studies to determine the stiffness (G') and the ability to flow (viscosity) have been performed.^17,18 Calcium hydroxylapatite has the most stiffness, while Belotero Balance (Merz Aesthetics) and Juvéderm Ultra XC (Allergan, Inc) are more soft¹⁷ (Table). These guidelines are important but may not correlate directly with how the fillers behave in vivo as demonstrated in animal models.¹⁸

Periocular Injection Considerations

An experienced injector is one who has developed not only an artistic eye for the face and excellent sense of anatomy but also has a sensitive ability to predict the filler-tissue interaction based on tactile feedback dependent on 3 main qualities: (1) stiffness and viscosity of the filler, (2) gauge of the needle or cannula, and (3) depth of the needle in the tissue. Periocular injections of dermal fillers can be delivered with needles or cannulas, diluted or undiluted. Smaller-gauge needles require more force than larger-gauge needles and cannulas that flow more freely. A needle in the dense dermis will require more force than one placed in the loose subcutaneous space.

The tear trough is generally preferable to fill with a mid-level G' HA filler that is less apt to migrate. A neutral gaze during the injection is preferred because closing or moving the eyes can distort the position of the inferior orbital fat-pads (Figure 1). A needle or cannula can be used, diluted or undiluted. The tear trough can be filled with the injection directed horizontally or vertically via a fanning technique. If needles are used, the skin should be stretched to view the 3 to 5 vertical veins and then the needle should be advanced beneath them to avoid bruising. Avoidance of hydrophilic fillers in the tear trough is important to avoid edema. The superior sulcus can be filled both anteriorly and posteriorly to the septum, which is a highly advanced injection for experienced injectors because of the proximity to the supratrochlear and supraorbital arteries as well as the superior ophthalmic vein (Figure 2). Sharp creases such as deep lateral periocular rhytides known as crow’s-feet are nicely filled with intradermal HAs with a low G'.

Image courtesy of Julie A. Woodward, MD.

Adding volume to the midface is important because it is the continuum of the lower eyelid. Fillers can be injected into multiple levels in this area: deep (to act as pillars to lift the malar eminence and replace bone that has rotated and soft tissue that has become atrophic or descended) and subcutaneous (to efface soft tissue along the zygomatic cutaneous ligament). Higher G' HA fillers and CaHA often are used in the midface along with PLLA. Facial framing of the temples, lateral cheeks, and preauricular area is often accomplished with PLLA but also can be done with mid to high G' HA fillers or CaHA. A cannula may be used to undermine and break apart the zygomatic cutaneous ligament’s cutaneous attachments prior to delivery of the filler in the subcutaneous plane.²⁶ If not done, filler may track away from the hollow area where the ligament is attached and instead move to adjacent areas that will accentuate the hollow and make it look worse.

The temples and lateral face often are filled with PLLA for framing. Mid or high G' HA fillers and CaHA also are used in the temples both beneath the temporalis muscle and also above the deep temporalis fascia or sometimes in the subcutaneous plane.²⁷

Prevention and Management of Periocular Complications

Blindness is the most devastating periocular complication of facial fillers, which is caused by retrograde arterial embolization followed by anterograde flow into the ophthalmic then central retinal arteries. Injectables that have caused blindness include (in descending order of frequency) fat, HA, collagen, paraffin, polymethyl methacrylate, silicone, PLLA, CaHA, polyacrylamide hydrogel, and micronized acellular dermal matrix. Of the 98 cases of blindness from periocular complications from dermal fillers reported in the world literature, the order of affected sites include the glabella (38 cases), nose (25), nasolabial folds (13), superior forehead (12), infraorbital rim (6), temples (1), malar area (1), lip (1), and chin (1). Prevention includes avoidance of danger zone arteries including the supratrochlear, supraorbital, dorsal nasal, angular, infraorbital, zygomaticofacial and zygomaticotemporal arteries.²⁸

Avoiding the average critical volume of 0.84 in any single aliquot dispensed is key to avoid filling of these periocular arteries to the critical bifurcation point that can result in anterograde flow into the eye (Freudenthal Nicolau syndrome). The smallest supratrochlear artery’s volume in this study was 0.04 cc, so aliquots that do not exceed 0.03 cc are ideal.^29,30

The injector should always be thinking about the anatomy of the danger zones (eg, infratrochlear and supratrochlear arteries, supraorbital artery, frontal branch of the superficial temporal artery, lacrimal artery, dorsal nasal artery, infraorbital artery, angular artery, zygomaticofacial artery, zygomaticotemporal artery)(Figure 3).

Image courtesy of Julie A. Woodward, MD.

Conclusion

In summary, periocular injections of facial fillers are useful tools for rejuvenation of the upper face when used with great caution and respect for anatomy.

Myth: UVB phototherapy causes skin cancer

Phototherapy is a common treatment modality for psoriasis patients that can be used in the physician’s office or psoriasis clinic or at home. Options include UVB phototherapy (broadband and narrowband), which slows the growth of affected skin cells; psoralen plus UVA (PUVA), which slows excessive skin cell growth; and excimer laser therapy, which targets select areas of the skin affected by mild to moderate psoriasis and is particularly useful for scalp psoriasis. Each of these therapies may be combined with other topical and/or systemic psoriasis treatments. The effects of UV light on the skin and the connection to skin cancer is widely known. Therefore, patient education on the risk for skin cancer with phototherapy is essential.

Evidence suggests that UVB phototherapy remains a safe treatment modality. In a 2005 analysis of prospective and retrospective studies on skin cancer risk from UVB phototherapy, 11 studies (10 concerning psoriasis patients) were reviewed and the researchers concluded that all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers and found an increased rate of genital tumors associated with UVB phototherapy.

Another analysis to define the long-term carcinogenic risk for narrowband UVB treatment found that there was no association between narrowband UVB exposure alone (without PUVA) and any skin cancer. For patients treated with narrowband UVB and PUVA, there was a small increase in basal cell carcinomas.

Dermatologists should monitor psoriasis patients for self-administered treatment with tanning beds. Based on a questionnaire sent to approximately 14,000 subscribers of National Psoriasis Foundation emails, 62% of 617 tanners started tanning to treat psoriasis; they were more likely to have received medical phototherapy and had more severe psoriasis. Approximately 30% of these patients indicated that they used tanning as a self-treatment for psoriasis because of the inconvenience and cost of UV light treatment in a physician’s office as well as treatment failure of other therapies prescribed by the physician. “Our results imply that tanning bed usage among psoriasis sufferers is widespread and linked with tanning addiction,” reported Felton et al. “Practitioners should be particularly vigilant to the possibility of tanning bed usage in at-risk patients.” These patients may be at increased risk for skin cancer. Problematic tanning behaviors may be seen in younger female patients diagnosed with psoriasis at an early age as well as patients with severe psoriasis who were previously prescribed phototherapy treatment.

Expert Commentary on next page

Expert Commentary

UVB phototherapy is an effective therapy that does not increase the risk of nonmelanoma skin cancers (NMSCs), according to the 2 analyses mentioned above. When I discuss the risks and benefits of UVB phototherapy with psoriasis patients, I do say that there is a theoretical increased risk for NMSC but that the 2005 study mentioned above does not indicate an increased risk. However, UVB phototherapy and cyclosporine should not be combined, as this combination does increase the risk for NMSC.

Psoralen plus UVA definitely will increase the risk for NMSC, particularly squamous cell carcinoma. However, in this age of the biologics, PUVA use has fallen out of favor, partly due to the increased risk for NMSC, and many patients will not encounter dermatology practices that still use PUVA.
—Jashin J. Wu, MD (Los Angeles, California)

Myth: UVB phototherapy causes skin cancer

Phototherapy is a common treatment modality for psoriasis patients that can be used in the physician’s office or psoriasis clinic or at home. Options include UVB phototherapy (broadband and narrowband), which slows the growth of affected skin cells; psoralen plus UVA (PUVA), which slows excessive skin cell growth; and excimer laser therapy, which targets select areas of the skin affected by mild to moderate psoriasis and is particularly useful for scalp psoriasis. Each of these therapies may be combined with other topical and/or systemic psoriasis treatments. The effects of UV light on the skin and the connection to skin cancer is widely known. Therefore, patient education on the risk for skin cancer with phototherapy is essential.

Evidence suggests that UVB phototherapy remains a safe treatment modality. In a 2005 analysis of prospective and retrospective studies on skin cancer risk from UVB phototherapy, 11 studies (10 concerning psoriasis patients) were reviewed and the researchers concluded that all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers and found an increased rate of genital tumors associated with UVB phototherapy.

Another analysis to define the long-term carcinogenic risk for narrowband UVB treatment found that there was no association between narrowband UVB exposure alone (without PUVA) and any skin cancer. For patients treated with narrowband UVB and PUVA, there was a small increase in basal cell carcinomas.

Dermatologists should monitor psoriasis patients for self-administered treatment with tanning beds. Based on a questionnaire sent to approximately 14,000 subscribers of National Psoriasis Foundation emails, 62% of 617 tanners started tanning to treat psoriasis; they were more likely to have received medical phototherapy and had more severe psoriasis. Approximately 30% of these patients indicated that they used tanning as a self-treatment for psoriasis because of the inconvenience and cost of UV light treatment in a physician’s office as well as treatment failure of other therapies prescribed by the physician. “Our results imply that tanning bed usage among psoriasis sufferers is widespread and linked with tanning addiction,” reported Felton et al. “Practitioners should be particularly vigilant to the possibility of tanning bed usage in at-risk patients.” These patients may be at increased risk for skin cancer. Problematic tanning behaviors may be seen in younger female patients diagnosed with psoriasis at an early age as well as patients with severe psoriasis who were previously prescribed phototherapy treatment.

Expert Commentary on next page

Expert Commentary

UVB phototherapy is an effective therapy that does not increase the risk of nonmelanoma skin cancers (NMSCs), according to the 2 analyses mentioned above. When I discuss the risks and benefits of UVB phototherapy with psoriasis patients, I do say that there is a theoretical increased risk for NMSC but that the 2005 study mentioned above does not indicate an increased risk. However, UVB phototherapy and cyclosporine should not be combined, as this combination does increase the risk for NMSC.

Psoralen plus UVA definitely will increase the risk for NMSC, particularly squamous cell carcinoma. However, in this age of the biologics, PUVA use has fallen out of favor, partly due to the increased risk for NMSC, and many patients will not encounter dermatology practices that still use PUVA.
—Jashin J. Wu, MD (Los Angeles, California)

Myth: UVB phototherapy causes skin cancer

Phototherapy is a common treatment modality for psoriasis patients that can be used in the physician’s office or psoriasis clinic or at home. Options include UVB phototherapy (broadband and narrowband), which slows the growth of affected skin cells; psoralen plus UVA (PUVA), which slows excessive skin cell growth; and excimer laser therapy, which targets select areas of the skin affected by mild to moderate psoriasis and is particularly useful for scalp psoriasis. Each of these therapies may be combined with other topical and/or systemic psoriasis treatments. The effects of UV light on the skin and the connection to skin cancer is widely known. Therefore, patient education on the risk for skin cancer with phototherapy is essential.

Evidence suggests that UVB phototherapy remains a safe treatment modality. In a 2005 analysis of prospective and retrospective studies on skin cancer risk from UVB phototherapy, 11 studies (10 concerning psoriasis patients) were reviewed and the researchers concluded that all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers and found an increased rate of genital tumors associated with UVB phototherapy.

Another analysis to define the long-term carcinogenic risk for narrowband UVB treatment found that there was no association between narrowband UVB exposure alone (without PUVA) and any skin cancer. For patients treated with narrowband UVB and PUVA, there was a small increase in basal cell carcinomas.

Dermatologists should monitor psoriasis patients for self-administered treatment with tanning beds. Based on a questionnaire sent to approximately 14,000 subscribers of National Psoriasis Foundation emails, 62% of 617 tanners started tanning to treat psoriasis; they were more likely to have received medical phototherapy and had more severe psoriasis. Approximately 30% of these patients indicated that they used tanning as a self-treatment for psoriasis because of the inconvenience and cost of UV light treatment in a physician’s office as well as treatment failure of other therapies prescribed by the physician. “Our results imply that tanning bed usage among psoriasis sufferers is widespread and linked with tanning addiction,” reported Felton et al. “Practitioners should be particularly vigilant to the possibility of tanning bed usage in at-risk patients.” These patients may be at increased risk for skin cancer. Problematic tanning behaviors may be seen in younger female patients diagnosed with psoriasis at an early age as well as patients with severe psoriasis who were previously prescribed phototherapy treatment.

Expert Commentary on next page

Expert Commentary

UVB phototherapy is an effective therapy that does not increase the risk of nonmelanoma skin cancers (NMSCs), according to the 2 analyses mentioned above. When I discuss the risks and benefits of UVB phototherapy with psoriasis patients, I do say that there is a theoretical increased risk for NMSC but that the 2005 study mentioned above does not indicate an increased risk. However, UVB phototherapy and cyclosporine should not be combined, as this combination does increase the risk for NMSC.

Psoralen plus UVA definitely will increase the risk for NMSC, particularly squamous cell carcinoma. However, in this age of the biologics, PUVA use has fallen out of favor, partly due to the increased risk for NMSC, and many patients will not encounter dermatology practices that still use PUVA.
—Jashin J. Wu, MD (Los Angeles, California)

The Nuremberg Code in 1947,¹ the Declaration of Helsinki in 1964,² and the Belmont Report in 1979³ were cornerstones in the establishment of ethical principles in the medical field. These documents specifically highlight the concept of informed consent, which maintains that to practice ethical medicine, physicians must fully inform patients of all therapeutic benefits and especially risks as well as treatment alternatives before they consent to therapeutic intervention. Educating patients about risks of treatment is obligatory. Risk communication involves a mutual exchange of information between physicians and patients; the physician presents risk information in an understandable manner that adequately conveys pertinent data that is critical for the patient to make an informed therapeutic decision.⁴

An inherent problem with risk education is that patients may be terrified about risks associated with treatment. Some patients will refuse needed treatment because of fear.⁵ When patients have concerns about the safety profile of a treatment regimen and potential adverse effects, they may be less compliant with treatment.⁶ The intelligent noncompliance phenomenon occurs when a patient knowingly makes the choice to not adhere to treatment, and concern regarding treatment risks relative to benefits is a common reason underlying this phenomenon.^7,8

Behavioral economists have studied how individuals weigh risks. Kahneman and Tversky’s⁹ prospect theory asserts that individuals tend to overweigh unlikely risks and underweigh more certain risks, which they call the certainty effect; it is the basis of the human tendency to avoid risks in situations of likely gain and to pursue risks in situations of likely loss. The tendency to overweigh rare risks is even more pronounced for affect-rich events such as serious side effects.¹⁰ The way data are presented can affect how patients interpret the information. Context and framing of data affect patients’ perceptions.¹¹ We describe several ways to present safety data using graphical presentation of psoriasis treatment safety data as an example and explain how each one can affect patients’ perception of treatment risks.

Approaches to Presenting Safety Data

There are numerous ways to present safety data to patients, including verbal, numeric, and visual strategies.¹² Many methods of presentation are a combination of these strategies. Graphs are visual strategies to further categorize and present numeric data, and physicians may choose to incorporate these aids when presenting safety information to patients. Graphical presentations give the patient a mental picture of the data. Numerous types of graphs can be constructed. Kalb et al¹³ determined the effect of psoriasis treatment on the risk of serious infection from the Psoriasis Longitudinal Assessment and Registry (PSOLAR). We used the results from this study to demonstrate multiple ways of presenting safety data (Figures 1–3).

A graphical presentation with a truncated y-axis is a common approach (Figure 1). Graphs with truncated axes are sometimes used to conserve space or to accentuate certain differences in the graph that would otherwise be less obvious without the zoomed in y-axis.¹⁴ These graphs present quantitatively accurate information that can be visually misleading at the same time. Truncated axes accentuate differences, creating mental impressions that are not reflective of the magnitude of the numeric differences. Alternatively, a graph with a full y-axis includes both the maximum and minimum data values on the y-axis (Figure 2). The y-axis also extends maximally to the total number of patients or patient-years studied. This type of graph presents all of the numeric data without distortion.

Focus on the Patients Who Do Not Have Adverse Effects of Treatments

Fear of adverse effects is one of the most commonly reported causes of poor treatment adherence.¹⁵ New therapies for psoriasis are highly effective and safe, but as with all treatments, they also are associated with some risks. Patients may latch onto those risks too tightly or perhaps, in other circumstances, not tightly enough. The method used by a physician to present safety data to a patient may determine the patient’s perception about treatments.

When trying to give patients an accurate impression of treatment risks, it may be helpful to avoid approaches that focus on presenting the (few) cases of severe adverse drug effects since patients (and physicians) are likely to overweigh the unlikely risk of having an adverse effect if presented with this information. It may be more reassuring to focus on presenting information about the chance of not having an adverse drug effect, assuming the physician’s goal is to be reassuring.

Poor communication with patients when presenting safety data can foster exaggerated fears of an unlikely consequence to the point that patients can be left undertreated and sustaining disease symptoms.¹⁶ Physicians may strive to do no harm to their patients, but without careful presentation of safety data in the process of helping the patient make an informed decision, it is possible to do mental harm to patients in the form of fear or even, in the case of nonadherence or treatment refusal, physical harm in the form of continued disease symptoms.

One limitation of this review is that we only used graphical presentation of data as an example. Similar concerns apply to numerical data presentation. Telling a patient the risk of a severe adverse reaction is doubled by a certain treatment may be terrifying, though if the baseline risk is rare, doubling the baseline risk may represent only a minimal increase in the absolute risk. Telling a patient the risk is only 1 in 1000 may still be alarming because many patients tend to focus on the 1, but telling a patient that 999 of 1000 patients do not have a problem can be much more reassuring.

The physician’s goal—to help patients make informed decisions about their treatment—calls for him/her to assimilate safety data into useful information that the patient can use to make an informed decision.¹⁷ Overly comforting or alarming, confusing, and inaccurate information can misguide the patient, violating the ethical principle of nonmaleficence. Although there is an obligation to educate patients about risks, there may not be a purely objective way to do it. When physicians present objective data to patients, whether in numerical or graphical form, there will be an unavoidable subjective interpretation of the data. The form of presentation will have a critical effect on patients’ subjective perceptions. Physicians can present objective data in such a way as to be reassuring or frightening.

Conclusion

Despite physicians’ best-intentioned efforts, it may be impossible to avoid presenting safety data in a way that will be subjectively interpreted by patients. Physicians have a choice in how they present data to patients; their best judgment should be used in how they present data to inform patients, guide them, and offer them the best treatment outcomes.

Acknowledgment

We thank Scott Jaros, BA (Winston-Salem, North Carolina), for his assistance in the revision of the manuscript.

The Nuremberg Code in 1947,¹ the Declaration of Helsinki in 1964,² and the Belmont Report in 1979³ were cornerstones in the establishment of ethical principles in the medical field. These documents specifically highlight the concept of informed consent, which maintains that to practice ethical medicine, physicians must fully inform patients of all therapeutic benefits and especially risks as well as treatment alternatives before they consent to therapeutic intervention. Educating patients about risks of treatment is obligatory. Risk communication involves a mutual exchange of information between physicians and patients; the physician presents risk information in an understandable manner that adequately conveys pertinent data that is critical for the patient to make an informed therapeutic decision.⁴

An inherent problem with risk education is that patients may be terrified about risks associated with treatment. Some patients will refuse needed treatment because of fear.⁵ When patients have concerns about the safety profile of a treatment regimen and potential adverse effects, they may be less compliant with treatment.⁶ The intelligent noncompliance phenomenon occurs when a patient knowingly makes the choice to not adhere to treatment, and concern regarding treatment risks relative to benefits is a common reason underlying this phenomenon.^7,8

Behavioral economists have studied how individuals weigh risks. Kahneman and Tversky’s⁹ prospect theory asserts that individuals tend to overweigh unlikely risks and underweigh more certain risks, which they call the certainty effect; it is the basis of the human tendency to avoid risks in situations of likely gain and to pursue risks in situations of likely loss. The tendency to overweigh rare risks is even more pronounced for affect-rich events such as serious side effects.¹⁰ The way data are presented can affect how patients interpret the information. Context and framing of data affect patients’ perceptions.¹¹ We describe several ways to present safety data using graphical presentation of psoriasis treatment safety data as an example and explain how each one can affect patients’ perception of treatment risks.

Approaches to Presenting Safety Data

There are numerous ways to present safety data to patients, including verbal, numeric, and visual strategies.¹² Many methods of presentation are a combination of these strategies. Graphs are visual strategies to further categorize and present numeric data, and physicians may choose to incorporate these aids when presenting safety information to patients. Graphical presentations give the patient a mental picture of the data. Numerous types of graphs can be constructed. Kalb et al¹³ determined the effect of psoriasis treatment on the risk of serious infection from the Psoriasis Longitudinal Assessment and Registry (PSOLAR). We used the results from this study to demonstrate multiple ways of presenting safety data (Figures 1–3).

A graphical presentation with a truncated y-axis is a common approach (Figure 1). Graphs with truncated axes are sometimes used to conserve space or to accentuate certain differences in the graph that would otherwise be less obvious without the zoomed in y-axis.¹⁴ These graphs present quantitatively accurate information that can be visually misleading at the same time. Truncated axes accentuate differences, creating mental impressions that are not reflective of the magnitude of the numeric differences. Alternatively, a graph with a full y-axis includes both the maximum and minimum data values on the y-axis (Figure 2). The y-axis also extends maximally to the total number of patients or patient-years studied. This type of graph presents all of the numeric data without distortion.

Focus on the Patients Who Do Not Have Adverse Effects of Treatments

Fear of adverse effects is one of the most commonly reported causes of poor treatment adherence.¹⁵ New therapies for psoriasis are highly effective and safe, but as with all treatments, they also are associated with some risks. Patients may latch onto those risks too tightly or perhaps, in other circumstances, not tightly enough. The method used by a physician to present safety data to a patient may determine the patient’s perception about treatments.

When trying to give patients an accurate impression of treatment risks, it may be helpful to avoid approaches that focus on presenting the (few) cases of severe adverse drug effects since patients (and physicians) are likely to overweigh the unlikely risk of having an adverse effect if presented with this information. It may be more reassuring to focus on presenting information about the chance of not having an adverse drug effect, assuming the physician’s goal is to be reassuring.

Poor communication with patients when presenting safety data can foster exaggerated fears of an unlikely consequence to the point that patients can be left undertreated and sustaining disease symptoms.¹⁶ Physicians may strive to do no harm to their patients, but without careful presentation of safety data in the process of helping the patient make an informed decision, it is possible to do mental harm to patients in the form of fear or even, in the case of nonadherence or treatment refusal, physical harm in the form of continued disease symptoms.

One limitation of this review is that we only used graphical presentation of data as an example. Similar concerns apply to numerical data presentation. Telling a patient the risk of a severe adverse reaction is doubled by a certain treatment may be terrifying, though if the baseline risk is rare, doubling the baseline risk may represent only a minimal increase in the absolute risk. Telling a patient the risk is only 1 in 1000 may still be alarming because many patients tend to focus on the 1, but telling a patient that 999 of 1000 patients do not have a problem can be much more reassuring.

The physician’s goal—to help patients make informed decisions about their treatment—calls for him/her to assimilate safety data into useful information that the patient can use to make an informed decision.¹⁷ Overly comforting or alarming, confusing, and inaccurate information can misguide the patient, violating the ethical principle of nonmaleficence. Although there is an obligation to educate patients about risks, there may not be a purely objective way to do it. When physicians present objective data to patients, whether in numerical or graphical form, there will be an unavoidable subjective interpretation of the data. The form of presentation will have a critical effect on patients’ subjective perceptions. Physicians can present objective data in such a way as to be reassuring or frightening.

Conclusion

Despite physicians’ best-intentioned efforts, it may be impossible to avoid presenting safety data in a way that will be subjectively interpreted by patients. Physicians have a choice in how they present data to patients; their best judgment should be used in how they present data to inform patients, guide them, and offer them the best treatment outcomes.

Acknowledgment

We thank Scott Jaros, BA (Winston-Salem, North Carolina), for his assistance in the revision of the manuscript.

The Nuremberg Code in 1947,¹ the Declaration of Helsinki in 1964,² and the Belmont Report in 1979³ were cornerstones in the establishment of ethical principles in the medical field. These documents specifically highlight the concept of informed consent, which maintains that to practice ethical medicine, physicians must fully inform patients of all therapeutic benefits and especially risks as well as treatment alternatives before they consent to therapeutic intervention. Educating patients about risks of treatment is obligatory. Risk communication involves a mutual exchange of information between physicians and patients; the physician presents risk information in an understandable manner that adequately conveys pertinent data that is critical for the patient to make an informed therapeutic decision.⁴

An inherent problem with risk education is that patients may be terrified about risks associated with treatment. Some patients will refuse needed treatment because of fear.⁵ When patients have concerns about the safety profile of a treatment regimen and potential adverse effects, they may be less compliant with treatment.⁶ The intelligent noncompliance phenomenon occurs when a patient knowingly makes the choice to not adhere to treatment, and concern regarding treatment risks relative to benefits is a common reason underlying this phenomenon.^7,8

Behavioral economists have studied how individuals weigh risks. Kahneman and Tversky’s⁹ prospect theory asserts that individuals tend to overweigh unlikely risks and underweigh more certain risks, which they call the certainty effect; it is the basis of the human tendency to avoid risks in situations of likely gain and to pursue risks in situations of likely loss. The tendency to overweigh rare risks is even more pronounced for affect-rich events such as serious side effects.¹⁰ The way data are presented can affect how patients interpret the information. Context and framing of data affect patients’ perceptions.¹¹ We describe several ways to present safety data using graphical presentation of psoriasis treatment safety data as an example and explain how each one can affect patients’ perception of treatment risks.

Approaches to Presenting Safety Data

There are numerous ways to present safety data to patients, including verbal, numeric, and visual strategies.¹² Many methods of presentation are a combination of these strategies. Graphs are visual strategies to further categorize and present numeric data, and physicians may choose to incorporate these aids when presenting safety information to patients. Graphical presentations give the patient a mental picture of the data. Numerous types of graphs can be constructed. Kalb et al¹³ determined the effect of psoriasis treatment on the risk of serious infection from the Psoriasis Longitudinal Assessment and Registry (PSOLAR). We used the results from this study to demonstrate multiple ways of presenting safety data (Figures 1–3).

A graphical presentation with a truncated y-axis is a common approach (Figure 1). Graphs with truncated axes are sometimes used to conserve space or to accentuate certain differences in the graph that would otherwise be less obvious without the zoomed in y-axis.¹⁴ These graphs present quantitatively accurate information that can be visually misleading at the same time. Truncated axes accentuate differences, creating mental impressions that are not reflective of the magnitude of the numeric differences. Alternatively, a graph with a full y-axis includes both the maximum and minimum data values on the y-axis (Figure 2). The y-axis also extends maximally to the total number of patients or patient-years studied. This type of graph presents all of the numeric data without distortion.

Focus on the Patients Who Do Not Have Adverse Effects of Treatments

Fear of adverse effects is one of the most commonly reported causes of poor treatment adherence.¹⁵ New therapies for psoriasis are highly effective and safe, but as with all treatments, they also are associated with some risks. Patients may latch onto those risks too tightly or perhaps, in other circumstances, not tightly enough. The method used by a physician to present safety data to a patient may determine the patient’s perception about treatments.

When trying to give patients an accurate impression of treatment risks, it may be helpful to avoid approaches that focus on presenting the (few) cases of severe adverse drug effects since patients (and physicians) are likely to overweigh the unlikely risk of having an adverse effect if presented with this information. It may be more reassuring to focus on presenting information about the chance of not having an adverse drug effect, assuming the physician’s goal is to be reassuring.

Poor communication with patients when presenting safety data can foster exaggerated fears of an unlikely consequence to the point that patients can be left undertreated and sustaining disease symptoms.¹⁶ Physicians may strive to do no harm to their patients, but without careful presentation of safety data in the process of helping the patient make an informed decision, it is possible to do mental harm to patients in the form of fear or even, in the case of nonadherence or treatment refusal, physical harm in the form of continued disease symptoms.

One limitation of this review is that we only used graphical presentation of data as an example. Similar concerns apply to numerical data presentation. Telling a patient the risk of a severe adverse reaction is doubled by a certain treatment may be terrifying, though if the baseline risk is rare, doubling the baseline risk may represent only a minimal increase in the absolute risk. Telling a patient the risk is only 1 in 1000 may still be alarming because many patients tend to focus on the 1, but telling a patient that 999 of 1000 patients do not have a problem can be much more reassuring.

The physician’s goal—to help patients make informed decisions about their treatment—calls for him/her to assimilate safety data into useful information that the patient can use to make an informed decision.¹⁷ Overly comforting or alarming, confusing, and inaccurate information can misguide the patient, violating the ethical principle of nonmaleficence. Although there is an obligation to educate patients about risks, there may not be a purely objective way to do it. When physicians present objective data to patients, whether in numerical or graphical form, there will be an unavoidable subjective interpretation of the data. The form of presentation will have a critical effect on patients’ subjective perceptions. Physicians can present objective data in such a way as to be reassuring or frightening.

Conclusion

Despite physicians’ best-intentioned efforts, it may be impossible to avoid presenting safety data in a way that will be subjectively interpreted by patients. Physicians have a choice in how they present data to patients; their best judgment should be used in how they present data to inform patients, guide them, and offer them the best treatment outcomes.

Acknowledgment

We thank Scott Jaros, BA (Winston-Salem, North Carolina), for his assistance in the revision of the manuscript.

In both elective and revision surgery, removal of retained hardware can be unpredictable. Broken hardware, whether identified before or during surgery, presents a significant challenge. Cases often require enlisting a large variety of equipment and techniques that often result in larger dissection and potential for wider soft-tissue or bony destruction. Broken intramedullary devices, located entirely within the cortices of bone, pose unique challenges.^1,2 Various techniques have been used to remove broken cannulated nails.^1-9 There is, however, a paucity of techniques for removing broken solid nails from within the tibia.^1,2 Moreover, many of these techniques require significant metaphyseal and cortical bone destruction that may compromise the integrity of the long bone.^1,3,9 In this article, we describe a modified technique for removal of a broken solid nail, with minimal cortical bone destruction, in the setting of a tibial nonunion.

Technique

A 23-year-old man presented with a symptomatic valgus nonunion of the tibia, which had been treated with a solid intramedullary 9-mm nail (Orthofix). The patient was taken to the operative theater for nonunion takedown and exchanged reamed intramedullary nailing. The proximal fragment of the anterograde intramedullary nail was removed in standard fashion using the Winquist Universal Extraction Set (Shukla Medical). When threading the extractor into the proximal aspect of the nail, we found it helpful to leave one of the cross-locks in place to prevent nail rotation.¹⁰ Inspection of the removed nail revealed a fracture of the device at the more proximal of 2 distal cross-locks (Figures 1A, 1B, 2).

To remove the distal fragment of the nail, we used a 5.0-mm smooth Steinmann pin. After cross-lock removal, the pin was placed unicortically through the distal medial cortex at the tip of the retained implant. The distal nail fragment was pushed proximally using the pin as a lever with the interposed cortical bone serving as a fulcrum (Figures 3A, 3B).

Discussion

Removal of broken solid intramedullary tibial nails presents orthopedic surgeons with a unique challenge. We have described a technique that modifies and incorporates previously described techniques while exploiting available surgical windows to facilitate hardware removal. This technique obviates the need for further bony and soft-tissue dissection, potentially mitigating surgical morbidity.

Other techniques for removing broken solid intramedullary devices have been reported. Krettek and colleagues⁷ described a technique in which the short distal fragment of a broken solid femoral intramedullary nail was removed with use of retrograde levering through a cortical window just proximal to the articular surface. The same window was then used for anterograde nail removal with a small Hohmann retractor serving as a guide. This technique is limited by the need for a large bony window, which potentially creates a stress riser within the distal segment. In addition, a short, distal nail fragment is required in order to facilitate manipulation through the metaphyseal bone. This technique is more readily used within the distal femur, given the large metaphyseal volume, in contrast with the distal tibial metaphysis. Giannoudis and colleagues¹ described a method (for both tibia and femur) in which the intramedullary canal was proximally reamed to permit retrograde removal of an anterograde nail. The authors described reaming the canal to 4 mm larger than the nail to create access for a cleaning trephine and then a ratcheting extractor. This technique can be easily applied to the tibia or femur but requires special equipment that may not be readily available. Other retrograde techniques for the femur⁸ are not as suitable for the tibia, as they would cause significant chondral damage to the tibiotalar joint.

Am J Orthop. 2016;45(6):E352-E354. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

In both elective and revision surgery, removal of retained hardware can be unpredictable. Broken hardware, whether identified before or during surgery, presents a significant challenge. Cases often require enlisting a large variety of equipment and techniques that often result in larger dissection and potential for wider soft-tissue or bony destruction. Broken intramedullary devices, located entirely within the cortices of bone, pose unique challenges.^1,2 Various techniques have been used to remove broken cannulated nails.^1-9 There is, however, a paucity of techniques for removing broken solid nails from within the tibia.^1,2 Moreover, many of these techniques require significant metaphyseal and cortical bone destruction that may compromise the integrity of the long bone.^1,3,9 In this article, we describe a modified technique for removal of a broken solid nail, with minimal cortical bone destruction, in the setting of a tibial nonunion.

Technique

A 23-year-old man presented with a symptomatic valgus nonunion of the tibia, which had been treated with a solid intramedullary 9-mm nail (Orthofix). The patient was taken to the operative theater for nonunion takedown and exchanged reamed intramedullary nailing. The proximal fragment of the anterograde intramedullary nail was removed in standard fashion using the Winquist Universal Extraction Set (Shukla Medical). When threading the extractor into the proximal aspect of the nail, we found it helpful to leave one of the cross-locks in place to prevent nail rotation.¹⁰ Inspection of the removed nail revealed a fracture of the device at the more proximal of 2 distal cross-locks (Figures 1A, 1B, 2).

To remove the distal fragment of the nail, we used a 5.0-mm smooth Steinmann pin. After cross-lock removal, the pin was placed unicortically through the distal medial cortex at the tip of the retained implant. The distal nail fragment was pushed proximally using the pin as a lever with the interposed cortical bone serving as a fulcrum (Figures 3A, 3B).

Discussion

Removal of broken solid intramedullary tibial nails presents orthopedic surgeons with a unique challenge. We have described a technique that modifies and incorporates previously described techniques while exploiting available surgical windows to facilitate hardware removal. This technique obviates the need for further bony and soft-tissue dissection, potentially mitigating surgical morbidity.

Other techniques for removing broken solid intramedullary devices have been reported. Krettek and colleagues⁷ described a technique in which the short distal fragment of a broken solid femoral intramedullary nail was removed with use of retrograde levering through a cortical window just proximal to the articular surface. The same window was then used for anterograde nail removal with a small Hohmann retractor serving as a guide. This technique is limited by the need for a large bony window, which potentially creates a stress riser within the distal segment. In addition, a short, distal nail fragment is required in order to facilitate manipulation through the metaphyseal bone. This technique is more readily used within the distal femur, given the large metaphyseal volume, in contrast with the distal tibial metaphysis. Giannoudis and colleagues¹ described a method (for both tibia and femur) in which the intramedullary canal was proximally reamed to permit retrograde removal of an anterograde nail. The authors described reaming the canal to 4 mm larger than the nail to create access for a cleaning trephine and then a ratcheting extractor. This technique can be easily applied to the tibia or femur but requires special equipment that may not be readily available. Other retrograde techniques for the femur⁸ are not as suitable for the tibia, as they would cause significant chondral damage to the tibiotalar joint.

Am J Orthop. 2016;45(6):E352-E354. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

In both elective and revision surgery, removal of retained hardware can be unpredictable. Broken hardware, whether identified before or during surgery, presents a significant challenge. Cases often require enlisting a large variety of equipment and techniques that often result in larger dissection and potential for wider soft-tissue or bony destruction. Broken intramedullary devices, located entirely within the cortices of bone, pose unique challenges.^1,2 Various techniques have been used to remove broken cannulated nails.^1-9 There is, however, a paucity of techniques for removing broken solid nails from within the tibia.^1,2 Moreover, many of these techniques require significant metaphyseal and cortical bone destruction that may compromise the integrity of the long bone.^1,3,9 In this article, we describe a modified technique for removal of a broken solid nail, with minimal cortical bone destruction, in the setting of a tibial nonunion.

Technique

A 23-year-old man presented with a symptomatic valgus nonunion of the tibia, which had been treated with a solid intramedullary 9-mm nail (Orthofix). The patient was taken to the operative theater for nonunion takedown and exchanged reamed intramedullary nailing. The proximal fragment of the anterograde intramedullary nail was removed in standard fashion using the Winquist Universal Extraction Set (Shukla Medical). When threading the extractor into the proximal aspect of the nail, we found it helpful to leave one of the cross-locks in place to prevent nail rotation.¹⁰ Inspection of the removed nail revealed a fracture of the device at the more proximal of 2 distal cross-locks (Figures 1A, 1B, 2).

To remove the distal fragment of the nail, we used a 5.0-mm smooth Steinmann pin. After cross-lock removal, the pin was placed unicortically through the distal medial cortex at the tip of the retained implant. The distal nail fragment was pushed proximally using the pin as a lever with the interposed cortical bone serving as a fulcrum (Figures 3A, 3B).

Discussion

Removal of broken solid intramedullary tibial nails presents orthopedic surgeons with a unique challenge. We have described a technique that modifies and incorporates previously described techniques while exploiting available surgical windows to facilitate hardware removal. This technique obviates the need for further bony and soft-tissue dissection, potentially mitigating surgical morbidity.

Other techniques for removing broken solid intramedullary devices have been reported. Krettek and colleagues⁷ described a technique in which the short distal fragment of a broken solid femoral intramedullary nail was removed with use of retrograde levering through a cortical window just proximal to the articular surface. The same window was then used for anterograde nail removal with a small Hohmann retractor serving as a guide. This technique is limited by the need for a large bony window, which potentially creates a stress riser within the distal segment. In addition, a short, distal nail fragment is required in order to facilitate manipulation through the metaphyseal bone. This technique is more readily used within the distal femur, given the large metaphyseal volume, in contrast with the distal tibial metaphysis. Giannoudis and colleagues¹ described a method (for both tibia and femur) in which the intramedullary canal was proximally reamed to permit retrograde removal of an anterograde nail. The authors described reaming the canal to 4 mm larger than the nail to create access for a cleaning trephine and then a ratcheting extractor. This technique can be easily applied to the tibia or femur but requires special equipment that may not be readily available. Other retrograde techniques for the femur⁸ are not as suitable for the tibia, as they would cause significant chondral damage to the tibiotalar joint.

Am J Orthop. 2016;45(6):E352-E354. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.