Hospitalists need not fear negative consequences when prescribing guideline-recommended antibiotic therapy for children hospitalized with community-acquired pneumonia (CAP), according to a recent study conducted at Cincinnati Children’s Hospital Medical Center (CCHMC).

"Guideline-recommended therapy for pediatric pneumonia did not result in different outcomes than nonrecommended [largely cephalosporin] therapy," lead author and CCHMC-based hospitalist Joanna Thomson MD, MPH, says in an email to The Hospitalist.

Published in the Journal of Hospital Medicine, the study followed the outcomes of 168 pediatric inpatients ages 3 months to 18 years who were prescribed empiric guideline-recommended therapy, which advises using an aminopenicillin first rather than a broad-spectrum antibiotic. The study focused on patients’ outcomes, specifically length of stay (LOS), total cost of hospitalization, and inpatient pharmacy costs, and found no difference in LOS or costs for patients treated according to guidelines compared with those whose treatment varied from the recommendations.

"Given growing concerns regarding antimicrobial resistance, it is pretty easy to extrapolate the benefits of using narrow-spectrum therapy, but we wanted to make sure that it wasn't resulting in negative unintended consequences," Dr. Thomson says. "Indeed, use of guideline-recommended therapy did not change our outcomes."

However, most patients hospitalized with CAP do not currently receive guideline-recommended therapy, according to Dr. Thomson. CCHMC had been one of those institutions overprescribing cephalosporin, with nearly 70% of children admitted with pneumonia receiving the antibiotic. That practice has since changed, she notes.

"The majority of hospitalized patients in the U.S. still receive broad-spectrum cephalosporins," Dr. Thomson says. "I suspect that this may partially be due to fears of unintended negative consequences. We should all be good stewards and prescribe guideline-recommended therapy whenever possible."

Visit our website for more information on antibiotic prescription practices.

Hospitalists need not fear negative consequences when prescribing guideline-recommended antibiotic therapy for children hospitalized with community-acquired pneumonia (CAP), according to a recent study conducted at Cincinnati Children’s Hospital Medical Center (CCHMC).

"Guideline-recommended therapy for pediatric pneumonia did not result in different outcomes than nonrecommended [largely cephalosporin] therapy," lead author and CCHMC-based hospitalist Joanna Thomson MD, MPH, says in an email to The Hospitalist.

Published in the Journal of Hospital Medicine, the study followed the outcomes of 168 pediatric inpatients ages 3 months to 18 years who were prescribed empiric guideline-recommended therapy, which advises using an aminopenicillin first rather than a broad-spectrum antibiotic. The study focused on patients’ outcomes, specifically length of stay (LOS), total cost of hospitalization, and inpatient pharmacy costs, and found no difference in LOS or costs for patients treated according to guidelines compared with those whose treatment varied from the recommendations.

"Given growing concerns regarding antimicrobial resistance, it is pretty easy to extrapolate the benefits of using narrow-spectrum therapy, but we wanted to make sure that it wasn't resulting in negative unintended consequences," Dr. Thomson says. "Indeed, use of guideline-recommended therapy did not change our outcomes."

However, most patients hospitalized with CAP do not currently receive guideline-recommended therapy, according to Dr. Thomson. CCHMC had been one of those institutions overprescribing cephalosporin, with nearly 70% of children admitted with pneumonia receiving the antibiotic. That practice has since changed, she notes.

"The majority of hospitalized patients in the U.S. still receive broad-spectrum cephalosporins," Dr. Thomson says. "I suspect that this may partially be due to fears of unintended negative consequences. We should all be good stewards and prescribe guideline-recommended therapy whenever possible."

Visit our website for more information on antibiotic prescription practices.

Hospitalists need not fear negative consequences when prescribing guideline-recommended antibiotic therapy for children hospitalized with community-acquired pneumonia (CAP), according to a recent study conducted at Cincinnati Children’s Hospital Medical Center (CCHMC).

"Guideline-recommended therapy for pediatric pneumonia did not result in different outcomes than nonrecommended [largely cephalosporin] therapy," lead author and CCHMC-based hospitalist Joanna Thomson MD, MPH, says in an email to The Hospitalist.

Published in the Journal of Hospital Medicine, the study followed the outcomes of 168 pediatric inpatients ages 3 months to 18 years who were prescribed empiric guideline-recommended therapy, which advises using an aminopenicillin first rather than a broad-spectrum antibiotic. The study focused on patients’ outcomes, specifically length of stay (LOS), total cost of hospitalization, and inpatient pharmacy costs, and found no difference in LOS or costs for patients treated according to guidelines compared with those whose treatment varied from the recommendations.

"Given growing concerns regarding antimicrobial resistance, it is pretty easy to extrapolate the benefits of using narrow-spectrum therapy, but we wanted to make sure that it wasn't resulting in negative unintended consequences," Dr. Thomson says. "Indeed, use of guideline-recommended therapy did not change our outcomes."

However, most patients hospitalized with CAP do not currently receive guideline-recommended therapy, according to Dr. Thomson. CCHMC had been one of those institutions overprescribing cephalosporin, with nearly 70% of children admitted with pneumonia receiving the antibiotic. That practice has since changed, she notes.

"The majority of hospitalized patients in the U.S. still receive broad-spectrum cephalosporins," Dr. Thomson says. "I suspect that this may partially be due to fears of unintended negative consequences. We should all be good stewards and prescribe guideline-recommended therapy whenever possible."

Visit our website for more information on antibiotic prescription practices.

Attendees at ASH 2014

Photo courtesy of ASH

SAN FRANCISCO—Two recent studies have shown combination therapy with brentuximab vedotin to be highly active in newly diagnosed patients with Hodgkin lymphoma (HL) and in relapsed or refractory patients after frontline therapy.

The first study evaluated brentuximab with ABVD or AVD and the second with bendamustine.

Objective response rates were 95% with ABVD, 96% with AVD, and 96% with bendamustine.

Both studies were presented at the 2014 ASH Annual Meeting, and both were sponsored by Seattle Genetics, Inc., the company developing brentuximab vedotin.

Brentuximab with ABVD or AVD

Standard frontline therapy with ABVD (adriamycin, bleomycin, vinblastine, and dacarbazine) or AVD (the same regimen without bleomycin) fails to cure up to 30% of patients with HL.

So investigators decided to try a new approach to increase efficacy and reduce toxicity—combining brentuximab with standard therapy.

Joseph M. Connors, MD, of the BC Cancer Agency and University of British Columbia in Vancouver, Canada, presented long-term outcomes of the brentuximab-ABVD combination as abstract 292.*

Phase 1 dose-escalation study

The key initial study of the combination determined the maximum tolerated dose of brentuximab to be 1.2 mg/kg delivered on a 2-week schedule to match the other agents in the ABVD regimen. Brentuximab was delivered for up to 6 cycles.

Of the 50 patients treated, 75% were males with an ECOG status of 0 or 1. Their median age was 32.5 years (range, 18 to 59). Approximately 80% were stage III or IV.

“We learned several key lessons from that initial study,” Dr Connors said. “The first was that when one adds brentuximab vedotin to the full-dose combination ABVD, unacceptable levels of pulmonary toxicity occurred, with 44% of the patients eventually experiencing pulmonary toxicity, typically manifest between the third and sixth cycle of treatment.”

The toxicity resolved in 9 of the 11 patients, but was fatal in 2. The median time to resolution was 2.6 weeks.

Eight patients discontinued bleomycin but were able to complete treatment with AVD and brentuximab.

“When we dropped bleomycin from the combination and shifted to AVD without bleomycin, no patients experienced pulmonary toxicity,” Dr Connors added.

Ultimately, the combination produced a response rate of 95% with ABVD and 96% with AVD.

Long-term follow-up

Investigators then assessed the durability of the response and the time distribution of any relapses.

All but 1 patient was available for follow-up. Patients were followed for a median of 45 months in the ABVD arm and 36 months in the AVD arm.

In the ABVD arm, 22 of 24 patients are living, and all 26 patients in the AVD group are alive. Altogether, there have been 5 relapses—3 in the ABVD arm (occurring at 9, 22, and 23 months) and 2 in the AVD arm (occurring at 7 and 22 months).

The 3-year failure-free survival is 79% with ABVD and 92% with AVD.  And the 3-year overall survival is 92% in the ABVD arm and 100% in the AVD arm.

No deaths from HL have occurred, and all 5 relapsed patients have undergone autologous stem cell transplant. One of those has subsequently relapsed.

“So far,” Dr Connors said, “survival has been excellent.” And responses are durable.

“This has encouraged activation of the large, international trial,” Dr Connors said, comparing AVD plus brentuximab to standard ABVD in frontline treatment of HL.

Brentuximab with bendamustine

Brentuximab is also active as a single agent in relapsed/refractory HL, producing a 34% complete response (CR) rate. And the alkylating agent bendamustine produces a 33% CR rate in these patients. Furthermore, both agents have manageable safety profiles and different mechanisms of action.

Investigators therefore hypothesized that brentuximab in combination with bendamustine could induce more CRs in HL patients with relapsed or refractory disease after frontline therapy.

Ann LaCasce, MD, of Dana-Farber Cancer Institute in Boston, presented the data at ASH as abstract 293.*

Ten patients were enrolled in the phase 1 portion of the study to determine the optimal dose level of bendamustine and to assess safety and tolerability.

No dose-limiting toxicities were observed. So the investigators used bendamustine at 90 mg/m² and brentuximab at 1.8 mg/kg. Patients received a median of 2 cycles (range, 1 to 6) of combination therapy.

Patients had the option to proceed to an autologous stem cell transplant at any time after cycle 2 and could receive brentuximab monotherapy thereafter for up to 16 total doses.

The phase 2 expansion portion enrolled 44 patients and assessed the best response, duration of response, and progression-free survival.

Results

Patients were a median age of 37 years (range, 27 to 51), and 57% were male. Ninety-eight percent were ECOG status 0 or 1, and 54% had stage III or IV disease at diagnosis.

The majority of patients had received ABVD as frontline therapy, Dr LaCasce pointed out.

The most common treatment-emergent adverse event was infusion-related reactions, accounting for 96% of the events. Dyspnea (15%), chills (13%), and flushing (13%) were the most common symptoms, and hypotension requiring vasopressor support also occurred.

Most reactions occurred within 24 hours of the cycle 2 infusion and were considered related to both agents. However, delayed hypersensitivity reactions also occurred, Dr LaCasce said, the most common being rash in 14 patients up to 22 days after infusion.

“Based on the number of infusion-related reactions after 24 patients, the protocol was amended to require mandatory corticosteroids and anthistamine premedication,” Dr LaCasce explained. “[T]his resulted in a significant decrease in the severity of the infusion-related reactions.”

The best clinical response for the 48 evaluable patients was 83% CR and 13% partial remission, for an objective response rate of 96%.

The median progression-free survival has not yet been reached, and the combination has had no negative impact on stem cell mobilization or engraftment to date.

The response rate compares very favorably to historical data, Dr LaCasce said, and the combination represents a promising salvage regimen for HL patients.

*Data in the presentation differ from the abstract.

Attendees at ASH 2014

Photo courtesy of ASH

SAN FRANCISCO—Two recent studies have shown combination therapy with brentuximab vedotin to be highly active in newly diagnosed patients with Hodgkin lymphoma (HL) and in relapsed or refractory patients after frontline therapy.

The first study evaluated brentuximab with ABVD or AVD and the second with bendamustine.

Objective response rates were 95% with ABVD, 96% with AVD, and 96% with bendamustine.

Both studies were presented at the 2014 ASH Annual Meeting, and both were sponsored by Seattle Genetics, Inc., the company developing brentuximab vedotin.

Brentuximab with ABVD or AVD

Standard frontline therapy with ABVD (adriamycin, bleomycin, vinblastine, and dacarbazine) or AVD (the same regimen without bleomycin) fails to cure up to 30% of patients with HL.

So investigators decided to try a new approach to increase efficacy and reduce toxicity—combining brentuximab with standard therapy.

Joseph M. Connors, MD, of the BC Cancer Agency and University of British Columbia in Vancouver, Canada, presented long-term outcomes of the brentuximab-ABVD combination as abstract 292.*

Phase 1 dose-escalation study

The key initial study of the combination determined the maximum tolerated dose of brentuximab to be 1.2 mg/kg delivered on a 2-week schedule to match the other agents in the ABVD regimen. Brentuximab was delivered for up to 6 cycles.

Of the 50 patients treated, 75% were males with an ECOG status of 0 or 1. Their median age was 32.5 years (range, 18 to 59). Approximately 80% were stage III or IV.

“We learned several key lessons from that initial study,” Dr Connors said. “The first was that when one adds brentuximab vedotin to the full-dose combination ABVD, unacceptable levels of pulmonary toxicity occurred, with 44% of the patients eventually experiencing pulmonary toxicity, typically manifest between the third and sixth cycle of treatment.”

The toxicity resolved in 9 of the 11 patients, but was fatal in 2. The median time to resolution was 2.6 weeks.

Eight patients discontinued bleomycin but were able to complete treatment with AVD and brentuximab.

“When we dropped bleomycin from the combination and shifted to AVD without bleomycin, no patients experienced pulmonary toxicity,” Dr Connors added.

Ultimately, the combination produced a response rate of 95% with ABVD and 96% with AVD.

Long-term follow-up

Investigators then assessed the durability of the response and the time distribution of any relapses.

All but 1 patient was available for follow-up. Patients were followed for a median of 45 months in the ABVD arm and 36 months in the AVD arm.

In the ABVD arm, 22 of 24 patients are living, and all 26 patients in the AVD group are alive. Altogether, there have been 5 relapses—3 in the ABVD arm (occurring at 9, 22, and 23 months) and 2 in the AVD arm (occurring at 7 and 22 months).

The 3-year failure-free survival is 79% with ABVD and 92% with AVD.  And the 3-year overall survival is 92% in the ABVD arm and 100% in the AVD arm.

No deaths from HL have occurred, and all 5 relapsed patients have undergone autologous stem cell transplant. One of those has subsequently relapsed.

“So far,” Dr Connors said, “survival has been excellent.” And responses are durable.

“This has encouraged activation of the large, international trial,” Dr Connors said, comparing AVD plus brentuximab to standard ABVD in frontline treatment of HL.

Brentuximab with bendamustine

Brentuximab is also active as a single agent in relapsed/refractory HL, producing a 34% complete response (CR) rate. And the alkylating agent bendamustine produces a 33% CR rate in these patients. Furthermore, both agents have manageable safety profiles and different mechanisms of action.

Investigators therefore hypothesized that brentuximab in combination with bendamustine could induce more CRs in HL patients with relapsed or refractory disease after frontline therapy.

Ann LaCasce, MD, of Dana-Farber Cancer Institute in Boston, presented the data at ASH as abstract 293.*

Ten patients were enrolled in the phase 1 portion of the study to determine the optimal dose level of bendamustine and to assess safety and tolerability.

No dose-limiting toxicities were observed. So the investigators used bendamustine at 90 mg/m² and brentuximab at 1.8 mg/kg. Patients received a median of 2 cycles (range, 1 to 6) of combination therapy.

Patients had the option to proceed to an autologous stem cell transplant at any time after cycle 2 and could receive brentuximab monotherapy thereafter for up to 16 total doses.

The phase 2 expansion portion enrolled 44 patients and assessed the best response, duration of response, and progression-free survival.

Results

Patients were a median age of 37 years (range, 27 to 51), and 57% were male. Ninety-eight percent were ECOG status 0 or 1, and 54% had stage III or IV disease at diagnosis.

The majority of patients had received ABVD as frontline therapy, Dr LaCasce pointed out.

The most common treatment-emergent adverse event was infusion-related reactions, accounting for 96% of the events. Dyspnea (15%), chills (13%), and flushing (13%) were the most common symptoms, and hypotension requiring vasopressor support also occurred.

Most reactions occurred within 24 hours of the cycle 2 infusion and were considered related to both agents. However, delayed hypersensitivity reactions also occurred, Dr LaCasce said, the most common being rash in 14 patients up to 22 days after infusion.

“Based on the number of infusion-related reactions after 24 patients, the protocol was amended to require mandatory corticosteroids and anthistamine premedication,” Dr LaCasce explained. “[T]his resulted in a significant decrease in the severity of the infusion-related reactions.”

The best clinical response for the 48 evaluable patients was 83% CR and 13% partial remission, for an objective response rate of 96%.

The median progression-free survival has not yet been reached, and the combination has had no negative impact on stem cell mobilization or engraftment to date.

The response rate compares very favorably to historical data, Dr LaCasce said, and the combination represents a promising salvage regimen for HL patients.

*Data in the presentation differ from the abstract.

Attendees at ASH 2014

Photo courtesy of ASH

SAN FRANCISCO—Two recent studies have shown combination therapy with brentuximab vedotin to be highly active in newly diagnosed patients with Hodgkin lymphoma (HL) and in relapsed or refractory patients after frontline therapy.

The first study evaluated brentuximab with ABVD or AVD and the second with bendamustine.

Objective response rates were 95% with ABVD, 96% with AVD, and 96% with bendamustine.

Both studies were presented at the 2014 ASH Annual Meeting, and both were sponsored by Seattle Genetics, Inc., the company developing brentuximab vedotin.

Brentuximab with ABVD or AVD

Standard frontline therapy with ABVD (adriamycin, bleomycin, vinblastine, and dacarbazine) or AVD (the same regimen without bleomycin) fails to cure up to 30% of patients with HL.

So investigators decided to try a new approach to increase efficacy and reduce toxicity—combining brentuximab with standard therapy.

Joseph M. Connors, MD, of the BC Cancer Agency and University of British Columbia in Vancouver, Canada, presented long-term outcomes of the brentuximab-ABVD combination as abstract 292.*

Phase 1 dose-escalation study

The key initial study of the combination determined the maximum tolerated dose of brentuximab to be 1.2 mg/kg delivered on a 2-week schedule to match the other agents in the ABVD regimen. Brentuximab was delivered for up to 6 cycles.

Of the 50 patients treated, 75% were males with an ECOG status of 0 or 1. Their median age was 32.5 years (range, 18 to 59). Approximately 80% were stage III or IV.

“We learned several key lessons from that initial study,” Dr Connors said. “The first was that when one adds brentuximab vedotin to the full-dose combination ABVD, unacceptable levels of pulmonary toxicity occurred, with 44% of the patients eventually experiencing pulmonary toxicity, typically manifest between the third and sixth cycle of treatment.”

The toxicity resolved in 9 of the 11 patients, but was fatal in 2. The median time to resolution was 2.6 weeks.

Eight patients discontinued bleomycin but were able to complete treatment with AVD and brentuximab.

“When we dropped bleomycin from the combination and shifted to AVD without bleomycin, no patients experienced pulmonary toxicity,” Dr Connors added.

Ultimately, the combination produced a response rate of 95% with ABVD and 96% with AVD.

Long-term follow-up

Investigators then assessed the durability of the response and the time distribution of any relapses.

All but 1 patient was available for follow-up. Patients were followed for a median of 45 months in the ABVD arm and 36 months in the AVD arm.

In the ABVD arm, 22 of 24 patients are living, and all 26 patients in the AVD group are alive. Altogether, there have been 5 relapses—3 in the ABVD arm (occurring at 9, 22, and 23 months) and 2 in the AVD arm (occurring at 7 and 22 months).

The 3-year failure-free survival is 79% with ABVD and 92% with AVD.  And the 3-year overall survival is 92% in the ABVD arm and 100% in the AVD arm.

No deaths from HL have occurred, and all 5 relapsed patients have undergone autologous stem cell transplant. One of those has subsequently relapsed.

“So far,” Dr Connors said, “survival has been excellent.” And responses are durable.

“This has encouraged activation of the large, international trial,” Dr Connors said, comparing AVD plus brentuximab to standard ABVD in frontline treatment of HL.

Brentuximab with bendamustine

Brentuximab is also active as a single agent in relapsed/refractory HL, producing a 34% complete response (CR) rate. And the alkylating agent bendamustine produces a 33% CR rate in these patients. Furthermore, both agents have manageable safety profiles and different mechanisms of action.

Investigators therefore hypothesized that brentuximab in combination with bendamustine could induce more CRs in HL patients with relapsed or refractory disease after frontline therapy.

Ann LaCasce, MD, of Dana-Farber Cancer Institute in Boston, presented the data at ASH as abstract 293.*

Ten patients were enrolled in the phase 1 portion of the study to determine the optimal dose level of bendamustine and to assess safety and tolerability.

No dose-limiting toxicities were observed. So the investigators used bendamustine at 90 mg/m² and brentuximab at 1.8 mg/kg. Patients received a median of 2 cycles (range, 1 to 6) of combination therapy.

Patients had the option to proceed to an autologous stem cell transplant at any time after cycle 2 and could receive brentuximab monotherapy thereafter for up to 16 total doses.

The phase 2 expansion portion enrolled 44 patients and assessed the best response, duration of response, and progression-free survival.

Results

Patients were a median age of 37 years (range, 27 to 51), and 57% were male. Ninety-eight percent were ECOG status 0 or 1, and 54% had stage III or IV disease at diagnosis.

The majority of patients had received ABVD as frontline therapy, Dr LaCasce pointed out.

The most common treatment-emergent adverse event was infusion-related reactions, accounting for 96% of the events. Dyspnea (15%), chills (13%), and flushing (13%) were the most common symptoms, and hypotension requiring vasopressor support also occurred.

Most reactions occurred within 24 hours of the cycle 2 infusion and were considered related to both agents. However, delayed hypersensitivity reactions also occurred, Dr LaCasce said, the most common being rash in 14 patients up to 22 days after infusion.

“Based on the number of infusion-related reactions after 24 patients, the protocol was amended to require mandatory corticosteroids and anthistamine premedication,” Dr LaCasce explained. “[T]his resulted in a significant decrease in the severity of the infusion-related reactions.”

The best clinical response for the 48 evaluable patients was 83% CR and 13% partial remission, for an objective response rate of 96%.

The median progression-free survival has not yet been reached, and the combination has had no negative impact on stem cell mobilization or engraftment to date.

The response rate compares very favorably to historical data, Dr LaCasce said, and the combination represents a promising salvage regimen for HL patients.

*Data in the presentation differ from the abstract.

The US Food and Drug Administration (FDA) has approved the INTERCEPT Blood System for platelets, the first system of its kind to be approved in the US.

It is used to inactivate viruses, bacteria, spirochetes, parasites, and leukocytes in apheresis platelet components.

This can reduce the risk of transfusion-transmitted infection and, potentially, transfusion-associated graft-vs-host disease, although the system cannot inactivate all pathogens.

Certain non-enveloped viruses (such as HAV, HEV, B19, and poliovirus) and Bacillus cereus spores have demonstrated resistance to the INTERCEPT process.

Earlier this week, the FDA approved the INTERCEPT Blood System for plasma (also the first system of its kind to gain FDA approval).

The platelet and plasma systems use the same illumination device, the same active compound (amotosalen), and very similar production steps.

The INTERCEPT systems target a basic biological difference between the therapeutic components of blood. Platelets, plasma, and red blood cells do not require functional DNA or RNA for therapeutic efficacy. But pathogens and white blood cells do, in order to transmit infection.

The INTERCEPT systems use a proprietary molecule that, when activated by UVA light, binds to and blocks the replication of DNA and RNA, preventing nucleic acid replication and rendering the pathogen inactive.

The INTERCEPT Blood System for platelets has been approved in Europe since 2002 and is currently used in 20 countries.

The system was recently made available in the US and its territories under an investigational device exemption study to reduce the risk of transfusion-transmitted dengue and Chikungunya viruses, both of which are epidemic in the Caribbean region, including Puerto Rico, as well as sporadically in the southern US. No approved blood bank screening tests are available for either virus.

Researchers have evaluated INTERCEPT-processed platelets in 10 controlled clinical trials. Details on these trials can be found in the package insert.

The US Food and Drug Administration (FDA) has approved the INTERCEPT Blood System for platelets, the first system of its kind to be approved in the US.

It is used to inactivate viruses, bacteria, spirochetes, parasites, and leukocytes in apheresis platelet components.

This can reduce the risk of transfusion-transmitted infection and, potentially, transfusion-associated graft-vs-host disease, although the system cannot inactivate all pathogens.

Certain non-enveloped viruses (such as HAV, HEV, B19, and poliovirus) and Bacillus cereus spores have demonstrated resistance to the INTERCEPT process.

Earlier this week, the FDA approved the INTERCEPT Blood System for plasma (also the first system of its kind to gain FDA approval).

The platelet and plasma systems use the same illumination device, the same active compound (amotosalen), and very similar production steps.

The INTERCEPT systems target a basic biological difference between the therapeutic components of blood. Platelets, plasma, and red blood cells do not require functional DNA or RNA for therapeutic efficacy. But pathogens and white blood cells do, in order to transmit infection.

The INTERCEPT systems use a proprietary molecule that, when activated by UVA light, binds to and blocks the replication of DNA and RNA, preventing nucleic acid replication and rendering the pathogen inactive.

The INTERCEPT Blood System for platelets has been approved in Europe since 2002 and is currently used in 20 countries.

The system was recently made available in the US and its territories under an investigational device exemption study to reduce the risk of transfusion-transmitted dengue and Chikungunya viruses, both of which are epidemic in the Caribbean region, including Puerto Rico, as well as sporadically in the southern US. No approved blood bank screening tests are available for either virus.

Researchers have evaluated INTERCEPT-processed platelets in 10 controlled clinical trials. Details on these trials can be found in the package insert.

The US Food and Drug Administration (FDA) has approved the INTERCEPT Blood System for platelets, the first system of its kind to be approved in the US.

It is used to inactivate viruses, bacteria, spirochetes, parasites, and leukocytes in apheresis platelet components.

This can reduce the risk of transfusion-transmitted infection and, potentially, transfusion-associated graft-vs-host disease, although the system cannot inactivate all pathogens.

Certain non-enveloped viruses (such as HAV, HEV, B19, and poliovirus) and Bacillus cereus spores have demonstrated resistance to the INTERCEPT process.

Earlier this week, the FDA approved the INTERCEPT Blood System for plasma (also the first system of its kind to gain FDA approval).

The platelet and plasma systems use the same illumination device, the same active compound (amotosalen), and very similar production steps.

The INTERCEPT systems target a basic biological difference between the therapeutic components of blood. Platelets, plasma, and red blood cells do not require functional DNA or RNA for therapeutic efficacy. But pathogens and white blood cells do, in order to transmit infection.

The INTERCEPT systems use a proprietary molecule that, when activated by UVA light, binds to and blocks the replication of DNA and RNA, preventing nucleic acid replication and rendering the pathogen inactive.

The INTERCEPT Blood System for platelets has been approved in Europe since 2002 and is currently used in 20 countries.

The system was recently made available in the US and its territories under an investigational device exemption study to reduce the risk of transfusion-transmitted dengue and Chikungunya viruses, both of which are epidemic in the Caribbean region, including Puerto Rico, as well as sporadically in the southern US. No approved blood bank screening tests are available for either virus.

Researchers have evaluated INTERCEPT-processed platelets in 10 controlled clinical trials. Details on these trials can be found in the package insert.

Blood for transfusion

Credit: Elise Amendola

Two studies shed new light on the prevalence of transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) in the US.

The research showed that postoperative TRALI is significantly underreported and more common than previously thought, with an overall rate of 1.4%.

And the rate of TACO is on the decline, but the risk to surgical patients remains high, at 4%, similar to previous TACO estimates in non-surgical patients.

“An accurate understanding of the risks associated with blood transfusions is essential when determining the safety and appropriateness of transfusion therapies for patients,” said Daryl Kor, MD, senior author of both studies and an associate professor at Mayo Clinic in Rochester, Minnesota.

“Our research provides a greater awareness of the incidence of TRALI and TACO in surgical patients, a population that has been perhaps underrepresented in studies in this area. We believe this to be an important first step in our efforts to prevent these life-threatening transfusion complications.”

Dr Kor and his colleagues described this research in Anesthesiology alongside a related editorial.

In the two retrospective studies, the researchers examined the incidence of TRALI in 3379 patients and TACO in 4070 patients who received blood transfusions during non-cardiac surgery under general anesthesia in 2004 and 2011.

Using a novel algorithm, followed by a rigorous manual review, the team performed a detailed epidemiologic analysis for both complications.

The first study showed that TRALI occurred in 1.4% of surgical patients, with higher rates in specific surgical populations such as those having surgery inside the chest cavity, on major blood vessels, or having an organ transplant. Patients who received larger volumes of blood were also at increased risk.

Previous studies investigating TRALI rates have primarily focused on the critically ill and reported variable incidence rates. Many studies have reported incidences between 0.02% and 0.05%.

The second study showed that TACO occurs in 4.3% of surgical patients, with higher rates associated with increased volume of blood transfused, advanced age, and total intraoperative fluid balance. Again, patients having surgery inside the chest cavity, on major blood vessels, or organ transplants were at the greatest risk.

The study also revealed that the rate of TACO decreased significantly from 2004 to 2011—from 5.5% to 3%. This decline was not fully explained by any of the patient or transfusion characteristics evaluated in the study.

The researchers said future studies are needed to further explore which mechanisms and risk factors are responsible for TACO and TRALI.

“With improved understanding of the mechanisms underlying TRALI and TACO, we may be able to refine the novel electronic algorithms used to screen patients in these studies,” Dr Kor said. “Ultimately, we hope to develop a real-time prediction model for these complications so that we can identify those at greatest risk and perhaps implement strategies to reduce this risk.”

Blood for transfusion

Credit: Elise Amendola

Two studies shed new light on the prevalence of transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) in the US.

The research showed that postoperative TRALI is significantly underreported and more common than previously thought, with an overall rate of 1.4%.

And the rate of TACO is on the decline, but the risk to surgical patients remains high, at 4%, similar to previous TACO estimates in non-surgical patients.

“An accurate understanding of the risks associated with blood transfusions is essential when determining the safety and appropriateness of transfusion therapies for patients,” said Daryl Kor, MD, senior author of both studies and an associate professor at Mayo Clinic in Rochester, Minnesota.

“Our research provides a greater awareness of the incidence of TRALI and TACO in surgical patients, a population that has been perhaps underrepresented in studies in this area. We believe this to be an important first step in our efforts to prevent these life-threatening transfusion complications.”

Dr Kor and his colleagues described this research in Anesthesiology alongside a related editorial.

In the two retrospective studies, the researchers examined the incidence of TRALI in 3379 patients and TACO in 4070 patients who received blood transfusions during non-cardiac surgery under general anesthesia in 2004 and 2011.

Using a novel algorithm, followed by a rigorous manual review, the team performed a detailed epidemiologic analysis for both complications.

The first study showed that TRALI occurred in 1.4% of surgical patients, with higher rates in specific surgical populations such as those having surgery inside the chest cavity, on major blood vessels, or having an organ transplant. Patients who received larger volumes of blood were also at increased risk.

Previous studies investigating TRALI rates have primarily focused on the critically ill and reported variable incidence rates. Many studies have reported incidences between 0.02% and 0.05%.

The second study showed that TACO occurs in 4.3% of surgical patients, with higher rates associated with increased volume of blood transfused, advanced age, and total intraoperative fluid balance. Again, patients having surgery inside the chest cavity, on major blood vessels, or organ transplants were at the greatest risk.

The study also revealed that the rate of TACO decreased significantly from 2004 to 2011—from 5.5% to 3%. This decline was not fully explained by any of the patient or transfusion characteristics evaluated in the study.

The researchers said future studies are needed to further explore which mechanisms and risk factors are responsible for TACO and TRALI.

“With improved understanding of the mechanisms underlying TRALI and TACO, we may be able to refine the novel electronic algorithms used to screen patients in these studies,” Dr Kor said. “Ultimately, we hope to develop a real-time prediction model for these complications so that we can identify those at greatest risk and perhaps implement strategies to reduce this risk.”

Blood for transfusion

Credit: Elise Amendola

Two studies shed new light on the prevalence of transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) in the US.

The research showed that postoperative TRALI is significantly underreported and more common than previously thought, with an overall rate of 1.4%.

And the rate of TACO is on the decline, but the risk to surgical patients remains high, at 4%, similar to previous TACO estimates in non-surgical patients.

“An accurate understanding of the risks associated with blood transfusions is essential when determining the safety and appropriateness of transfusion therapies for patients,” said Daryl Kor, MD, senior author of both studies and an associate professor at Mayo Clinic in Rochester, Minnesota.

“Our research provides a greater awareness of the incidence of TRALI and TACO in surgical patients, a population that has been perhaps underrepresented in studies in this area. We believe this to be an important first step in our efforts to prevent these life-threatening transfusion complications.”

Dr Kor and his colleagues described this research in Anesthesiology alongside a related editorial.

In the two retrospective studies, the researchers examined the incidence of TRALI in 3379 patients and TACO in 4070 patients who received blood transfusions during non-cardiac surgery under general anesthesia in 2004 and 2011.

Using a novel algorithm, followed by a rigorous manual review, the team performed a detailed epidemiologic analysis for both complications.

The first study showed that TRALI occurred in 1.4% of surgical patients, with higher rates in specific surgical populations such as those having surgery inside the chest cavity, on major blood vessels, or having an organ transplant. Patients who received larger volumes of blood were also at increased risk.

Previous studies investigating TRALI rates have primarily focused on the critically ill and reported variable incidence rates. Many studies have reported incidences between 0.02% and 0.05%.

The second study showed that TACO occurs in 4.3% of surgical patients, with higher rates associated with increased volume of blood transfused, advanced age, and total intraoperative fluid balance. Again, patients having surgery inside the chest cavity, on major blood vessels, or organ transplants were at the greatest risk.

The study also revealed that the rate of TACO decreased significantly from 2004 to 2011—from 5.5% to 3%. This decline was not fully explained by any of the patient or transfusion characteristics evaluated in the study.

The researchers said future studies are needed to further explore which mechanisms and risk factors are responsible for TACO and TRALI.

“With improved understanding of the mechanisms underlying TRALI and TACO, we may be able to refine the novel electronic algorithms used to screen patients in these studies,” Dr Kor said. “Ultimately, we hope to develop a real-time prediction model for these complications so that we can identify those at greatest risk and perhaps implement strategies to reduce this risk.”

Prescription medications

Credit: CDC

The UK’s National Institute for Health and Care Excellence (NICE) has published a final guidance recommending the anticoagulant dabigatran (Pradaxa, Boehringer Ingelheim) as an option for treating and preventing recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE) in adults.

The guidance says dabigatran can provide a benefit for these patients, with cost- and clinical-effectiveness similar to rivaroxaban and added convenience compared to warfarin.

“For many people, using warfarin can be difficult because of the need for frequent tests to see if the blood is clotting properly, and having to adjust the dose of the

drug if it is not,” said Carole Longson, NICE Health Technology Evaluation Centre Director.

“The appraisal committee felt that dabigatran represents a potential benefit for many people who have had a DVT or PE, particularly those who have risk factors for recurrence of a blood clot and who therefore need longer-term treatment. We are pleased, therefore, to be able to recommend dabigatran as a cost-effective option for treating DVT and PE and preventing further episodes in adults.”

NICE expects dabigatran to be available on the National Health Service within 3 months.

Cost considerations

Dabigatran costs £65.90 for a 60-capsule pack of the 150 mg or 110 mg doses (excluding tax) and £2.20 per day of treatment, although costs may vary in different settings.

The most plausible incremental cost-effectiveness ratio (ICER) for dabigatran compared with warfarin for acute treatment was uncertain.

However, both Boehringer Ingelheim’s and the evidence review group’s exploratory ICER remained in the range that could be considered a cost-effective use of National Health Service resources. That is, both were under £20,000 per quality-adjusted life-year gained (QALY).

Neither Boehringer Ingelheim nor the evidence review group found any significant difference in efficacy between dabigatran and rivaroxaban for acute treatment of venous thromboembolism (VTE) in their indirect comparisons, and the costs were also very similar between these two treatments.

For combined treatment and secondary prevention of VTE, the appraisal committee said the company’s base case ICER for dabigatran compared with warfarin was likely too low (£9973 per QALY gained).

But the evidence review group’s exploratory base case for dabigatran compared with warfarin may have overestimated the ICER (£35,786 per QALY gained). So the ICER probably lies somewhere between these estimates.

Clinical evidence

To assess the clinical effectiveness of dabigatran, the appraisal committee evaluated data from the RECOVER, RE-MEDY, and RESONATE trials.

In the first RE-COVER trial, dabigatran proved noninferior to warfarin for preventing VTE recurrence, and rates of major bleeding were similar between the treatment arms.

However, patients were more likely to discontinue dabigatran due to adverse events. Results from this trial were presented at ASH 2009 and published in NEJM.

The RE-COVER II trial also suggested that dabigatran was noninferior to warfarin for preventing VTE recurrence and related deaths, and dabigatran was associated with a lower rate of major bleeding.

Rates of death, adverse events, and acute coronary syndromes were similar between the treatment arms. Results from this trial were published in Circulation in 2013.

The RE-MEDY and RE-SONATE trials were designed to evaluate dabigatran as extended VTE prophylaxis. Results of both trials were reported in a single NEJM article published in 2013.

The RE-MEDY trial suggested that dabigatran was noninferior to warfarin as extended prophylaxis for recurrent VTE, and warfarin presented a significantly higher risk of bleeding.

Results of the RE-SONATE trial indicated that dabigatran was superior to placebo for preventing recurrent VTE, although the drug significantly increased the risk of major or clinically relevant bleeding.

Prescription medications

Credit: CDC

The UK’s National Institute for Health and Care Excellence (NICE) has published a final guidance recommending the anticoagulant dabigatran (Pradaxa, Boehringer Ingelheim) as an option for treating and preventing recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE) in adults.

The guidance says dabigatran can provide a benefit for these patients, with cost- and clinical-effectiveness similar to rivaroxaban and added convenience compared to warfarin.

“For many people, using warfarin can be difficult because of the need for frequent tests to see if the blood is clotting properly, and having to adjust the dose of the

drug if it is not,” said Carole Longson, NICE Health Technology Evaluation Centre Director.

“The appraisal committee felt that dabigatran represents a potential benefit for many people who have had a DVT or PE, particularly those who have risk factors for recurrence of a blood clot and who therefore need longer-term treatment. We are pleased, therefore, to be able to recommend dabigatran as a cost-effective option for treating DVT and PE and preventing further episodes in adults.”

NICE expects dabigatran to be available on the National Health Service within 3 months.

Cost considerations

Dabigatran costs £65.90 for a 60-capsule pack of the 150 mg or 110 mg doses (excluding tax) and £2.20 per day of treatment, although costs may vary in different settings.

The most plausible incremental cost-effectiveness ratio (ICER) for dabigatran compared with warfarin for acute treatment was uncertain.

However, both Boehringer Ingelheim’s and the evidence review group’s exploratory ICER remained in the range that could be considered a cost-effective use of National Health Service resources. That is, both were under £20,000 per quality-adjusted life-year gained (QALY).

Neither Boehringer Ingelheim nor the evidence review group found any significant difference in efficacy between dabigatran and rivaroxaban for acute treatment of venous thromboembolism (VTE) in their indirect comparisons, and the costs were also very similar between these two treatments.

For combined treatment and secondary prevention of VTE, the appraisal committee said the company’s base case ICER for dabigatran compared with warfarin was likely too low (£9973 per QALY gained).

But the evidence review group’s exploratory base case for dabigatran compared with warfarin may have overestimated the ICER (£35,786 per QALY gained). So the ICER probably lies somewhere between these estimates.

Clinical evidence

To assess the clinical effectiveness of dabigatran, the appraisal committee evaluated data from the RECOVER, RE-MEDY, and RESONATE trials.

In the first RE-COVER trial, dabigatran proved noninferior to warfarin for preventing VTE recurrence, and rates of major bleeding were similar between the treatment arms.

However, patients were more likely to discontinue dabigatran due to adverse events. Results from this trial were presented at ASH 2009 and published in NEJM.

The RE-COVER II trial also suggested that dabigatran was noninferior to warfarin for preventing VTE recurrence and related deaths, and dabigatran was associated with a lower rate of major bleeding.

Rates of death, adverse events, and acute coronary syndromes were similar between the treatment arms. Results from this trial were published in Circulation in 2013.

The RE-MEDY and RE-SONATE trials were designed to evaluate dabigatran as extended VTE prophylaxis. Results of both trials were reported in a single NEJM article published in 2013.

The RE-MEDY trial suggested that dabigatran was noninferior to warfarin as extended prophylaxis for recurrent VTE, and warfarin presented a significantly higher risk of bleeding.

Results of the RE-SONATE trial indicated that dabigatran was superior to placebo for preventing recurrent VTE, although the drug significantly increased the risk of major or clinically relevant bleeding.

Prescription medications

Credit: CDC

The UK’s National Institute for Health and Care Excellence (NICE) has published a final guidance recommending the anticoagulant dabigatran (Pradaxa, Boehringer Ingelheim) as an option for treating and preventing recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE) in adults.

The guidance says dabigatran can provide a benefit for these patients, with cost- and clinical-effectiveness similar to rivaroxaban and added convenience compared to warfarin.

“For many people, using warfarin can be difficult because of the need for frequent tests to see if the blood is clotting properly, and having to adjust the dose of the

drug if it is not,” said Carole Longson, NICE Health Technology Evaluation Centre Director.

“The appraisal committee felt that dabigatran represents a potential benefit for many people who have had a DVT or PE, particularly those who have risk factors for recurrence of a blood clot and who therefore need longer-term treatment. We are pleased, therefore, to be able to recommend dabigatran as a cost-effective option for treating DVT and PE and preventing further episodes in adults.”

NICE expects dabigatran to be available on the National Health Service within 3 months.

Cost considerations

Dabigatran costs £65.90 for a 60-capsule pack of the 150 mg or 110 mg doses (excluding tax) and £2.20 per day of treatment, although costs may vary in different settings.

The most plausible incremental cost-effectiveness ratio (ICER) for dabigatran compared with warfarin for acute treatment was uncertain.

However, both Boehringer Ingelheim’s and the evidence review group’s exploratory ICER remained in the range that could be considered a cost-effective use of National Health Service resources. That is, both were under £20,000 per quality-adjusted life-year gained (QALY).

Neither Boehringer Ingelheim nor the evidence review group found any significant difference in efficacy between dabigatran and rivaroxaban for acute treatment of venous thromboembolism (VTE) in their indirect comparisons, and the costs were also very similar between these two treatments.

For combined treatment and secondary prevention of VTE, the appraisal committee said the company’s base case ICER for dabigatran compared with warfarin was likely too low (£9973 per QALY gained).

But the evidence review group’s exploratory base case for dabigatran compared with warfarin may have overestimated the ICER (£35,786 per QALY gained). So the ICER probably lies somewhere between these estimates.

Clinical evidence

To assess the clinical effectiveness of dabigatran, the appraisal committee evaluated data from the RECOVER, RE-MEDY, and RESONATE trials.

In the first RE-COVER trial, dabigatran proved noninferior to warfarin for preventing VTE recurrence, and rates of major bleeding were similar between the treatment arms.

However, patients were more likely to discontinue dabigatran due to adverse events. Results from this trial were presented at ASH 2009 and published in NEJM.

The RE-COVER II trial also suggested that dabigatran was noninferior to warfarin for preventing VTE recurrence and related deaths, and dabigatran was associated with a lower rate of major bleeding.

Rates of death, adverse events, and acute coronary syndromes were similar between the treatment arms. Results from this trial were published in Circulation in 2013.

The RE-MEDY and RE-SONATE trials were designed to evaluate dabigatran as extended VTE prophylaxis. Results of both trials were reported in a single NEJM article published in 2013.

The RE-MEDY trial suggested that dabigatran was noninferior to warfarin as extended prophylaxis for recurrent VTE, and warfarin presented a significantly higher risk of bleeding.

Results of the RE-SONATE trial indicated that dabigatran was superior to placebo for preventing recurrent VTE, although the drug significantly increased the risk of major or clinically relevant bleeding.

Three-dimensional (3-D) printing is a rapidly evolving technology with both medical and nonmedical applications.^1,2 Rapid prototyping involves creating a physical model of human tissue from a 3-D computer-generated rendering.³ The method relies on export of Digital Imaging and Communications in Medicine (DICOM)–based computed tomography (CT) or magnetic resonance imaging (MRI) data into standard triangular language (STL) format. Reducing CT or MRI slice thickness increases resolution of the final model.² Five types of rapid prototyping exist: STL, selective laser sintering, fused deposition modeling, multijet modeling, and 3-D printing.

Most implant manufacturers can produce a 3-D model based on surgeon-provided DICOM images. The ability to produce anatomical models in an office-based setting is a more recent development. Three-dimensional modeling may allow for more accurate and extensive preoperative planning than radiographic examination alone does, and may even allow surgeons to perform procedures as part of preoperative preparation. This can allow for early recognition of unanticipated intraoperative problems or of the need for special techniques and implants that would not have been otherwise available, all of which may ultimately reduce operative time.

The breadth of applications for office-based 3-D prototyping is not well described in the orthopedic surgery literature. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning in which use of a 3-D printer allowed for “mock” surgery before the actual procedures. In 3 of the cases, the models were made by the implant manufacturers. Working with these models prompted us to buy a 3-D printer (Fortus 250; Stratasys, Eden Prairie, Minnesota) for in-office use. In the other 4 cases, we used this printer to create our own models. As indicated in the manufacturer’s literature, the printer uses fused deposition modeling, which builds a model layer by layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled pathways.

We present preoperative images, preoperative 3-D modeling, and intraoperative and postoperative images along with brief case descriptions (Table). The patients provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 28-year-old woman with a history of spondyloepiphyseal dysplasia presented to our clinic with bilateral hip pain. About 8 years earlier, she had undergone bilateral proximal and distal femoral osteotomies. Her function had initially improved, but over the 2 to 3 years before presentation she began having more pain and stiffness with activity. At time of initial evaluation, she was able to walk only 1 to 2 blocks and had difficulty getting in and out of a car and up out of a seated position.

On physical examination, the patient was 3 feet 10 inches tall and weighed 77 pounds. She ambulated with decreased stance phase on both lower extremities and had developed a significant amount of increased forward pelvic inclination and increased lumbar lordosis. Both hips and thighs had multiple healed scars from prior surgeries and pin tracts. Range of motion (ROM) on both sides was restricted to 85° of flexion, 10° of internal rotation, 15° of external rotation, and 15° of abduction.

Plain radiographs showed advanced degenerative joint disease (DJD) of both hips with dysplastic acetabuli and evidence of healed osteotomies (Figure 1). Femoral deformities, noted bilaterally, consisted of marked valgus proximally and varus distally. Preoperative CT was used to create a 3-D model of the pelvis and femur. The model was created by the same implant manufacturer that produced the final components (Depuy, Warsaw, Indiana). Corrective femoral osteotomy was performed on the model to allow for design and use of a custom implant, while the modeled pelvis confirmed the ability to reproduce the normal hip center with a 44-mm conventional hemispherical socket.

After surgery, the patient was able to ambulate without a limp and return to work. Her hip ROM was pain-free passively and actively with flexion to 100°, internal rotation to 35°, external rotation to 20°, and abduction to 30°.

Case 2

A 48-year-old woman with a history of Crowe IV hip dysplasia presented to our clinic with a chronically dislocated right total hip arthroplasty (THA) (Figure 2). Her initial THA was revised 1 year later because of acetabular component failure. Two years later, she was diagnosed with a deep periprosthetic infection, which was ultimately treated with 2-stage reimplantation. She subsequently dislocated and underwent re-revision of the S-ROM body and stem (DePuy Synthes, Warsaw, Indiana). At a visit after that revision, she was noted to be chronically dislocated, and was sent to our clinic for further management.

Preoperative radiographs showed a right uncemented THA with the femoral head dislocated toward the false acetabulum, retained hardware, and an old ununited trochanteric fragment. Both the femoral and acetabular components appeared well-fixed, though the acetabular component was positioned inferior, toward the obturator foramen.

Preoperative CT with metal artifact subtraction was used to create a 3-D model of the residual bony pelvis. The model was made by an implant manufacturer (Zimmer, Warsaw, Indiana). The shape of the superior defect was amenable to reconstruction using a modified revision trabecular metal socket. The pelvic model was reamed to accept a conventional hemispherical socket. The defect was reamed to accept a modified revision trabecular metal socket. The real implant was fashioned before surgery and was sterilized to avoid the need for intraoperative modification. Use of the preoperative model significantly reduced the time that would have been needed to modify the implant during actual surgery.

The patient’s right THA was revised. At time of surgery, the modified revision trabecular metal acetabular component was noted to seat appropriately in the superior defect. The true acetabulum was reestablished, and a hemispherical socket was placed with multiple screws. The 2 components were then unitized using cement in the same manner as would be done with an off-the-shelf augment.

Case 3

A 57-year-old man presented with a 10-year history of right knee pain. About 30 years before presentation at our clinic, he was treated for an open right tibia fracture sustained in a motorcycle accident. He had been treated nonsurgically, with injections, but they failed to provide sustained relief.

Preoperative radiographs showed severe advanced DJD in conjunction with an extra-articular posttraumatic varus tibial shaft deformity (Figure 3). An implant manufacturer (Zimmer) used a CT scan to create a model of the deformity. The resultant center of rotation angle was calculated using preoperative images and conventional techniques for deformity correction, and a lateral closing-wedge osteotomy was performed on the CT-based model. The initial attempt at deformity correction was slightly excessive, and the amount of resected bone slightly thicker than the calculated wedge, resulting in a valgus deformity. This error was noted, and the decision was made to recut a new model with a slight amount of residual varus that could be corrected during the final knee arthroplasty procedure.

Corrective osteotomy was performed with a lateral plate. Six months later, the patient had no residual pain, and CT confirmed union at the osteotomy site and a slight amount of residual varus. The patient then underwent routine total knee arthroplasty (TKA) using an abbreviated keel to avoid the need for removal of the previously placed hardware. The varus deformity was completely corrected.

Case 4

A 73-year-old man had a history of shoulder pain dating back to his childhood. Despite treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and injections, his debilitating pain persisted. Physical examination revealed limited ROM and an intact rotator cuff.

Plain radiographs showed severe DJD of the glenohumeral joint (Figure 4). Severe erosions of the glenoid were noted, prompting further workup with CT, which showed significant bone loss, particularly along the posterior margin of the glenoid. We used our 3-D printer to create a model of the scapula from CT images. The model was then reamed in the usual fashion to accept a 3-pegged glenoid component. On placement of a trial implant, a large deficiency was seen posteriorly. We thought the size and location of the defect made it amenable to grafting using the patient’s humeral head.

The patient elected to undergo right total shoulder arthroplasty. During the procedure, the glenoid defect was found to be identical to what was encountered with the model before surgery. A portion of the patient’s humeral head was then fashioned to fit the defect, and was secured with three 2.7-mm screws, after provisional fixation using 2.0-mm Kirschner wires. The screws were countersunk, and the graft was contoured by hand to match the previous reaming. A 3-pegged 52-mm glenoid component was then cemented into position with excellent stability.

Case 5

A 64-year-old man presented to our clinic with left hip pain 40 years after THA. The original procedure was performed for resolved proximal femoral osteomyelitis. Plain radiographs showed a loose cemented McKee-Farrar hip arthroplasty (Figure 5). Because of the elevated position of the acetabular component relative to the native hip center, CT was used to determine the amount of femoral bone loss.

We used our 3-D printer to create a model and tried to recreate the native hip center with conventional off-the-shelf implants. A 50-mm hemispherical socket trial was placed in the appropriate location, along with a trabecular metal augment trial to provide extended coverage over the superolateral portion of the socket. Noted between the socket and the augment was a large gap; a substantial amount of cement would have been needed to unitize the construct. We thought a custom acetabular component would avoid the need for cement. In addition, given the patient’s small stature, the conventional acetabular component would allow a head only 32 mm in diameter. With a custom implant, the head could be enlarged to 36 mm, providing improved ROM and stability.

The patient underwent revision left hip arthroplasty using a custom acetabular component. A 3-D model available at time of surgery was used to aid implant placement.

Case 6

A 23-year-old man with multiple hereditary exostoses presented to our clinic with a painful mass in the left calf. Plain radiographs showed extensive osteochondromatosis involving the left proximal tibiofibular joint (Figure 6). The exostosis extended posteromedially, displacing the arterial trifurcation. MRI showed a small cartilage cap without evidence of malignant transformation.

CT angiogram allowed the vasculature to be modeled along with the deformity. A 3-D model was fabricated. The model included the entire proximal tibiofibular joint, as well as the anterior tibial, peroneal, and posterior tibial arteries. Cautious intralesional resection was recommended because of the proximity to all 3 vessels.

The patient underwent tumor resection through a longitudinal posterior approach. The interval between the medial and lateral heads of the gastrocnemius muscles was developed to expose the underlying soleus muscle. The soleus was split longitudinally from its hiatus to the inferior portion of the exostosis. This allowed for identification of the trifurcation and the tibial nerve, which were protected. Osteotomes were used to resect the mass at its base, the edges were carefully trimmed, and bone wax was placed over the defect. Anterior and lateral to this mass was another large mass (under the soleus muscle), which was also transected using an osteotome. The gastrocnemius and soleus muscles were then reflected off the fibula in order to remove 2 other exostoses, beneath the neck and head of the fibula.

Case 7

A 71-year-old man with a history of idiopathic lymphedema and peripheral neuropathy presented to our clinic with a left cavovarus foot deformity and a history of recurrent neuropathic foot ulcers (Figure 7). Physical examination revealed a callus over the lateral aspect of the base of the fifth metatarsal. Preoperative radiograph showed evidence of prior triple arthrodesis with a cavovarus foot deformity. CT scan was used to create a 3-D model of the foot. The model was then used to identify an appropriate location for lateral midtarsal and calcaneal closing-wedge osteotomies.

The patient underwent midfoot and hindfoot surgical correction. At surgery, the lateral closing-wedge osteotomies were performed according to the preoperative model. Radiographs 1 year after surgery showed correction of the forefoot varus.

Discussion

Three-dimensional printing for medical applications of anatomical modeling is not a new concept.^1,3,4 Its use has been reported for a variety of applications in orthopedic surgery, including the printing of porous and metallic surfaces⁵ and bone-tissue engineering.^6-9 Rapid prototyping for medical application was first reported in 1990 when a CT-based model was used to create a cranial bone.¹⁰ Reports of using the technique are becoming more widespread, particularly in the dental and maxillofacial literature, which includes reports on a variety of applications, including patient-specific drill guides, splints, and implants.^11-14 The ability to perform mock surgery in advance of an actual procedure provides an invaluable opportunity to anticipate potential intraoperative problems, reduce operative time, and improve the accuracy of reconstruction.

Office-based rapid prototyping that uses an in-house 3-D printer is a novel application of this technology. It allows for creation of a patient-specific model for preoperative planning purposes. We are unaware of any other reports demonstrating the breadth and utility of office-based rapid prototyping in orthopedic surgery. For general reference, a printer similar to ours requires an initial investment of $52,000 to $56,000. This cost generally covers the printer, printer base cabinet, installation, training, and printer software (different from the 3-D modeling software), plus a 1-year warranty. A service agreement costs about $4000 annually. Printer and model supply expenses depend on the material used for the model (eg, ABS [acrylonitrile butadiene styrene]) and on the size and complexity of the 3-D models created. Average time to generate an appropriately formatted 3-D printing file is about 1 hour, though times can vary largely, according to amount of metal artifact subtraction necessary and the experience of the software user. For the rare, extremely complex deformities that require a significant amount of metal artifact subtraction, file preparation times can exceed 3 or 4 hours. We think these preparation times will decrease as communication between radiology file export format and modeling software ultimately allows for metal artifact subtraction images to function within the modeling software environment. Once an appropriately formatted file has been created, typical printing times vary according to the size of the to-be-modeled bone. For a hemipelvis, printing time is 30 to 40 hours; printing that is started on a Friday afternoon will be complete by Monday morning.

There are few reports of rapid prototyping in orthopedic surgery. In 2003, Minns and colleagues¹⁵ used a 3-D model in the planning of a tibial resection for TKA. They found the model to be accurate at time of surgery, resulting in appropriate tibial coverage by a conventional meniscal-bearing implant. Munjal and colleagues¹⁶ reported on 10 complex failed hip arthroplasty cases in which patients had revision surgery after preoperative planning using 3-D modeling techniques. The authors found that, in 8 of the 10 cases, conventional classification systems of bone loss were inaccurate in comparison with the prototype. Four cases required reconstruction with a custom triflange when conventional implants were not deemed reasonable based on the pelvic model. Tam and colleagues¹⁷ reported using a 3-D prototype as an aid in surgical planning for resection of a scapular osteochondroma in a 6-year-old patient. They found the rapid prototype to be useful at time of resection—similar to what we found with 1 patient (case 6). Adding contrast media to our patient’s scan allowed for 3-D visualization of the lesion and the encased vasculature. Fu and colleagues¹⁸ reported using a patient-specific drill template to insert anterior transpedicular screws. They constructed 24 prototypes of a formalin-preserved cervical vertebra to create a patient-specific biocompatible drill template for use in correcting multilevel cervical instability. They found the technique to be highly reproducible and accurate. Zein and colleagues¹⁹ used a rapid prototype of 3 consecutive human livers to preoperatively identify the vascular and biliary tract anatomy. They reported a high degree of accuracy—mean dimensional errors of less than 4 mm for the entire model and 1.3 mm for the vascular diameter.

The models created by implant manufacturers in this series were used to perform “mock” surgery before the actual procedures. Working with these models prompted us to buy our own 3-D printer. The learning curve can be steep, but commercially available 3-D printers allow for prompt in-office production of high-quality realistic prototypes at relatively low per-case cost (Figure 8). Three-dimensional modeling allows surgeons to assess the accuracy of their original surgical plans and, if necessary, correct them before surgery. Although computer-aided design models are useful, the ability to “perform surgery preoperatively” adds another element to surgeons’ understanding of the potential issues that may arise. Also, an in-office printer can help improve surgeons’ understanding and control over the process by which images are translated from radiographic file to 3-D model. Disadvantages of an in-office system include start-up and maintenance costs, office space requirements, and a significant learning curve for software and hardware applications. In addition, creation of 3-D models requires close interaction with radiologists who can provide appropriately formatted DICOM images, as metal artifact subtraction can be challenging. We think that, as image formatting and software capabilities are continually refined, this technology will become an invaluable part of multiple subspecialties across orthopedic surgery, with potentially infinite clinical, educational, and research applications.

Three-dimensional (3-D) printing is a rapidly evolving technology with both medical and nonmedical applications.^1,2 Rapid prototyping involves creating a physical model of human tissue from a 3-D computer-generated rendering.³ The method relies on export of Digital Imaging and Communications in Medicine (DICOM)–based computed tomography (CT) or magnetic resonance imaging (MRI) data into standard triangular language (STL) format. Reducing CT or MRI slice thickness increases resolution of the final model.² Five types of rapid prototyping exist: STL, selective laser sintering, fused deposition modeling, multijet modeling, and 3-D printing.

Most implant manufacturers can produce a 3-D model based on surgeon-provided DICOM images. The ability to produce anatomical models in an office-based setting is a more recent development. Three-dimensional modeling may allow for more accurate and extensive preoperative planning than radiographic examination alone does, and may even allow surgeons to perform procedures as part of preoperative preparation. This can allow for early recognition of unanticipated intraoperative problems or of the need for special techniques and implants that would not have been otherwise available, all of which may ultimately reduce operative time.

The breadth of applications for office-based 3-D prototyping is not well described in the orthopedic surgery literature. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning in which use of a 3-D printer allowed for “mock” surgery before the actual procedures. In 3 of the cases, the models were made by the implant manufacturers. Working with these models prompted us to buy a 3-D printer (Fortus 250; Stratasys, Eden Prairie, Minnesota) for in-office use. In the other 4 cases, we used this printer to create our own models. As indicated in the manufacturer’s literature, the printer uses fused deposition modeling, which builds a model layer by layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled pathways.

We present preoperative images, preoperative 3-D modeling, and intraoperative and postoperative images along with brief case descriptions (Table). The patients provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 28-year-old woman with a history of spondyloepiphyseal dysplasia presented to our clinic with bilateral hip pain. About 8 years earlier, she had undergone bilateral proximal and distal femoral osteotomies. Her function had initially improved, but over the 2 to 3 years before presentation she began having more pain and stiffness with activity. At time of initial evaluation, she was able to walk only 1 to 2 blocks and had difficulty getting in and out of a car and up out of a seated position.

On physical examination, the patient was 3 feet 10 inches tall and weighed 77 pounds. She ambulated with decreased stance phase on both lower extremities and had developed a significant amount of increased forward pelvic inclination and increased lumbar lordosis. Both hips and thighs had multiple healed scars from prior surgeries and pin tracts. Range of motion (ROM) on both sides was restricted to 85° of flexion, 10° of internal rotation, 15° of external rotation, and 15° of abduction.

Plain radiographs showed advanced degenerative joint disease (DJD) of both hips with dysplastic acetabuli and evidence of healed osteotomies (Figure 1). Femoral deformities, noted bilaterally, consisted of marked valgus proximally and varus distally. Preoperative CT was used to create a 3-D model of the pelvis and femur. The model was created by the same implant manufacturer that produced the final components (Depuy, Warsaw, Indiana). Corrective femoral osteotomy was performed on the model to allow for design and use of a custom implant, while the modeled pelvis confirmed the ability to reproduce the normal hip center with a 44-mm conventional hemispherical socket.

After surgery, the patient was able to ambulate without a limp and return to work. Her hip ROM was pain-free passively and actively with flexion to 100°, internal rotation to 35°, external rotation to 20°, and abduction to 30°.

Case 2

A 48-year-old woman with a history of Crowe IV hip dysplasia presented to our clinic with a chronically dislocated right total hip arthroplasty (THA) (Figure 2). Her initial THA was revised 1 year later because of acetabular component failure. Two years later, she was diagnosed with a deep periprosthetic infection, which was ultimately treated with 2-stage reimplantation. She subsequently dislocated and underwent re-revision of the S-ROM body and stem (DePuy Synthes, Warsaw, Indiana). At a visit after that revision, she was noted to be chronically dislocated, and was sent to our clinic for further management.

Preoperative radiographs showed a right uncemented THA with the femoral head dislocated toward the false acetabulum, retained hardware, and an old ununited trochanteric fragment. Both the femoral and acetabular components appeared well-fixed, though the acetabular component was positioned inferior, toward the obturator foramen.

Preoperative CT with metal artifact subtraction was used to create a 3-D model of the residual bony pelvis. The model was made by an implant manufacturer (Zimmer, Warsaw, Indiana). The shape of the superior defect was amenable to reconstruction using a modified revision trabecular metal socket. The pelvic model was reamed to accept a conventional hemispherical socket. The defect was reamed to accept a modified revision trabecular metal socket. The real implant was fashioned before surgery and was sterilized to avoid the need for intraoperative modification. Use of the preoperative model significantly reduced the time that would have been needed to modify the implant during actual surgery.

The patient’s right THA was revised. At time of surgery, the modified revision trabecular metal acetabular component was noted to seat appropriately in the superior defect. The true acetabulum was reestablished, and a hemispherical socket was placed with multiple screws. The 2 components were then unitized using cement in the same manner as would be done with an off-the-shelf augment.

Case 3

A 57-year-old man presented with a 10-year history of right knee pain. About 30 years before presentation at our clinic, he was treated for an open right tibia fracture sustained in a motorcycle accident. He had been treated nonsurgically, with injections, but they failed to provide sustained relief.

Preoperative radiographs showed severe advanced DJD in conjunction with an extra-articular posttraumatic varus tibial shaft deformity (Figure 3). An implant manufacturer (Zimmer) used a CT scan to create a model of the deformity. The resultant center of rotation angle was calculated using preoperative images and conventional techniques for deformity correction, and a lateral closing-wedge osteotomy was performed on the CT-based model. The initial attempt at deformity correction was slightly excessive, and the amount of resected bone slightly thicker than the calculated wedge, resulting in a valgus deformity. This error was noted, and the decision was made to recut a new model with a slight amount of residual varus that could be corrected during the final knee arthroplasty procedure.

Corrective osteotomy was performed with a lateral plate. Six months later, the patient had no residual pain, and CT confirmed union at the osteotomy site and a slight amount of residual varus. The patient then underwent routine total knee arthroplasty (TKA) using an abbreviated keel to avoid the need for removal of the previously placed hardware. The varus deformity was completely corrected.

Case 4

A 73-year-old man had a history of shoulder pain dating back to his childhood. Despite treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and injections, his debilitating pain persisted. Physical examination revealed limited ROM and an intact rotator cuff.

Plain radiographs showed severe DJD of the glenohumeral joint (Figure 4). Severe erosions of the glenoid were noted, prompting further workup with CT, which showed significant bone loss, particularly along the posterior margin of the glenoid. We used our 3-D printer to create a model of the scapula from CT images. The model was then reamed in the usual fashion to accept a 3-pegged glenoid component. On placement of a trial implant, a large deficiency was seen posteriorly. We thought the size and location of the defect made it amenable to grafting using the patient’s humeral head.

The patient elected to undergo right total shoulder arthroplasty. During the procedure, the glenoid defect was found to be identical to what was encountered with the model before surgery. A portion of the patient’s humeral head was then fashioned to fit the defect, and was secured with three 2.7-mm screws, after provisional fixation using 2.0-mm Kirschner wires. The screws were countersunk, and the graft was contoured by hand to match the previous reaming. A 3-pegged 52-mm glenoid component was then cemented into position with excellent stability.

Case 5

A 64-year-old man presented to our clinic with left hip pain 40 years after THA. The original procedure was performed for resolved proximal femoral osteomyelitis. Plain radiographs showed a loose cemented McKee-Farrar hip arthroplasty (Figure 5). Because of the elevated position of the acetabular component relative to the native hip center, CT was used to determine the amount of femoral bone loss.

We used our 3-D printer to create a model and tried to recreate the native hip center with conventional off-the-shelf implants. A 50-mm hemispherical socket trial was placed in the appropriate location, along with a trabecular metal augment trial to provide extended coverage over the superolateral portion of the socket. Noted between the socket and the augment was a large gap; a substantial amount of cement would have been needed to unitize the construct. We thought a custom acetabular component would avoid the need for cement. In addition, given the patient’s small stature, the conventional acetabular component would allow a head only 32 mm in diameter. With a custom implant, the head could be enlarged to 36 mm, providing improved ROM and stability.

The patient underwent revision left hip arthroplasty using a custom acetabular component. A 3-D model available at time of surgery was used to aid implant placement.

Case 6

A 23-year-old man with multiple hereditary exostoses presented to our clinic with a painful mass in the left calf. Plain radiographs showed extensive osteochondromatosis involving the left proximal tibiofibular joint (Figure 6). The exostosis extended posteromedially, displacing the arterial trifurcation. MRI showed a small cartilage cap without evidence of malignant transformation.

CT angiogram allowed the vasculature to be modeled along with the deformity. A 3-D model was fabricated. The model included the entire proximal tibiofibular joint, as well as the anterior tibial, peroneal, and posterior tibial arteries. Cautious intralesional resection was recommended because of the proximity to all 3 vessels.

The patient underwent tumor resection through a longitudinal posterior approach. The interval between the medial and lateral heads of the gastrocnemius muscles was developed to expose the underlying soleus muscle. The soleus was split longitudinally from its hiatus to the inferior portion of the exostosis. This allowed for identification of the trifurcation and the tibial nerve, which were protected. Osteotomes were used to resect the mass at its base, the edges were carefully trimmed, and bone wax was placed over the defect. Anterior and lateral to this mass was another large mass (under the soleus muscle), which was also transected using an osteotome. The gastrocnemius and soleus muscles were then reflected off the fibula in order to remove 2 other exostoses, beneath the neck and head of the fibula.

Case 7

A 71-year-old man with a history of idiopathic lymphedema and peripheral neuropathy presented to our clinic with a left cavovarus foot deformity and a history of recurrent neuropathic foot ulcers (Figure 7). Physical examination revealed a callus over the lateral aspect of the base of the fifth metatarsal. Preoperative radiograph showed evidence of prior triple arthrodesis with a cavovarus foot deformity. CT scan was used to create a 3-D model of the foot. The model was then used to identify an appropriate location for lateral midtarsal and calcaneal closing-wedge osteotomies.

The patient underwent midfoot and hindfoot surgical correction. At surgery, the lateral closing-wedge osteotomies were performed according to the preoperative model. Radiographs 1 year after surgery showed correction of the forefoot varus.

Discussion

Three-dimensional printing for medical applications of anatomical modeling is not a new concept.^1,3,4 Its use has been reported for a variety of applications in orthopedic surgery, including the printing of porous and metallic surfaces⁵ and bone-tissue engineering.^6-9 Rapid prototyping for medical application was first reported in 1990 when a CT-based model was used to create a cranial bone.¹⁰ Reports of using the technique are becoming more widespread, particularly in the dental and maxillofacial literature, which includes reports on a variety of applications, including patient-specific drill guides, splints, and implants.^11-14 The ability to perform mock surgery in advance of an actual procedure provides an invaluable opportunity to anticipate potential intraoperative problems, reduce operative time, and improve the accuracy of reconstruction.

Office-based rapid prototyping that uses an in-house 3-D printer is a novel application of this technology. It allows for creation of a patient-specific model for preoperative planning purposes. We are unaware of any other reports demonstrating the breadth and utility of office-based rapid prototyping in orthopedic surgery. For general reference, a printer similar to ours requires an initial investment of $52,000 to $56,000. This cost generally covers the printer, printer base cabinet, installation, training, and printer software (different from the 3-D modeling software), plus a 1-year warranty. A service agreement costs about $4000 annually. Printer and model supply expenses depend on the material used for the model (eg, ABS [acrylonitrile butadiene styrene]) and on the size and complexity of the 3-D models created. Average time to generate an appropriately formatted 3-D printing file is about 1 hour, though times can vary largely, according to amount of metal artifact subtraction necessary and the experience of the software user. For the rare, extremely complex deformities that require a significant amount of metal artifact subtraction, file preparation times can exceed 3 or 4 hours. We think these preparation times will decrease as communication between radiology file export format and modeling software ultimately allows for metal artifact subtraction images to function within the modeling software environment. Once an appropriately formatted file has been created, typical printing times vary according to the size of the to-be-modeled bone. For a hemipelvis, printing time is 30 to 40 hours; printing that is started on a Friday afternoon will be complete by Monday morning.

There are few reports of rapid prototyping in orthopedic surgery. In 2003, Minns and colleagues¹⁵ used a 3-D model in the planning of a tibial resection for TKA. They found the model to be accurate at time of surgery, resulting in appropriate tibial coverage by a conventional meniscal-bearing implant. Munjal and colleagues¹⁶ reported on 10 complex failed hip arthroplasty cases in which patients had revision surgery after preoperative planning using 3-D modeling techniques. The authors found that, in 8 of the 10 cases, conventional classification systems of bone loss were inaccurate in comparison with the prototype. Four cases required reconstruction with a custom triflange when conventional implants were not deemed reasonable based on the pelvic model. Tam and colleagues¹⁷ reported using a 3-D prototype as an aid in surgical planning for resection of a scapular osteochondroma in a 6-year-old patient. They found the rapid prototype to be useful at time of resection—similar to what we found with 1 patient (case 6). Adding contrast media to our patient’s scan allowed for 3-D visualization of the lesion and the encased vasculature. Fu and colleagues¹⁸ reported using a patient-specific drill template to insert anterior transpedicular screws. They constructed 24 prototypes of a formalin-preserved cervical vertebra to create a patient-specific biocompatible drill template for use in correcting multilevel cervical instability. They found the technique to be highly reproducible and accurate. Zein and colleagues¹⁹ used a rapid prototype of 3 consecutive human livers to preoperatively identify the vascular and biliary tract anatomy. They reported a high degree of accuracy—mean dimensional errors of less than 4 mm for the entire model and 1.3 mm for the vascular diameter.

The models created by implant manufacturers in this series were used to perform “mock” surgery before the actual procedures. Working with these models prompted us to buy our own 3-D printer. The learning curve can be steep, but commercially available 3-D printers allow for prompt in-office production of high-quality realistic prototypes at relatively low per-case cost (Figure 8). Three-dimensional modeling allows surgeons to assess the accuracy of their original surgical plans and, if necessary, correct them before surgery. Although computer-aided design models are useful, the ability to “perform surgery preoperatively” adds another element to surgeons’ understanding of the potential issues that may arise. Also, an in-office printer can help improve surgeons’ understanding and control over the process by which images are translated from radiographic file to 3-D model. Disadvantages of an in-office system include start-up and maintenance costs, office space requirements, and a significant learning curve for software and hardware applications. In addition, creation of 3-D models requires close interaction with radiologists who can provide appropriately formatted DICOM images, as metal artifact subtraction can be challenging. We think that, as image formatting and software capabilities are continually refined, this technology will become an invaluable part of multiple subspecialties across orthopedic surgery, with potentially infinite clinical, educational, and research applications.

Three-dimensional (3-D) printing is a rapidly evolving technology with both medical and nonmedical applications.^1,2 Rapid prototyping involves creating a physical model of human tissue from a 3-D computer-generated rendering.³ The method relies on export of Digital Imaging and Communications in Medicine (DICOM)–based computed tomography (CT) or magnetic resonance imaging (MRI) data into standard triangular language (STL) format. Reducing CT or MRI slice thickness increases resolution of the final model.² Five types of rapid prototyping exist: STL, selective laser sintering, fused deposition modeling, multijet modeling, and 3-D printing.

Most implant manufacturers can produce a 3-D model based on surgeon-provided DICOM images. The ability to produce anatomical models in an office-based setting is a more recent development. Three-dimensional modeling may allow for more accurate and extensive preoperative planning than radiographic examination alone does, and may even allow surgeons to perform procedures as part of preoperative preparation. This can allow for early recognition of unanticipated intraoperative problems or of the need for special techniques and implants that would not have been otherwise available, all of which may ultimately reduce operative time.

The breadth of applications for office-based 3-D prototyping is not well described in the orthopedic surgery literature. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning in which use of a 3-D printer allowed for “mock” surgery before the actual procedures. In 3 of the cases, the models were made by the implant manufacturers. Working with these models prompted us to buy a 3-D printer (Fortus 250; Stratasys, Eden Prairie, Minnesota) for in-office use. In the other 4 cases, we used this printer to create our own models. As indicated in the manufacturer’s literature, the printer uses fused deposition modeling, which builds a model layer by layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled pathways.

We present preoperative images, preoperative 3-D modeling, and intraoperative and postoperative images along with brief case descriptions (Table). The patients provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 28-year-old woman with a history of spondyloepiphyseal dysplasia presented to our clinic with bilateral hip pain. About 8 years earlier, she had undergone bilateral proximal and distal femoral osteotomies. Her function had initially improved, but over the 2 to 3 years before presentation she began having more pain and stiffness with activity. At time of initial evaluation, she was able to walk only 1 to 2 blocks and had difficulty getting in and out of a car and up out of a seated position.

On physical examination, the patient was 3 feet 10 inches tall and weighed 77 pounds. She ambulated with decreased stance phase on both lower extremities and had developed a significant amount of increased forward pelvic inclination and increased lumbar lordosis. Both hips and thighs had multiple healed scars from prior surgeries and pin tracts. Range of motion (ROM) on both sides was restricted to 85° of flexion, 10° of internal rotation, 15° of external rotation, and 15° of abduction.

Plain radiographs showed advanced degenerative joint disease (DJD) of both hips with dysplastic acetabuli and evidence of healed osteotomies (Figure 1). Femoral deformities, noted bilaterally, consisted of marked valgus proximally and varus distally. Preoperative CT was used to create a 3-D model of the pelvis and femur. The model was created by the same implant manufacturer that produced the final components (Depuy, Warsaw, Indiana). Corrective femoral osteotomy was performed on the model to allow for design and use of a custom implant, while the modeled pelvis confirmed the ability to reproduce the normal hip center with a 44-mm conventional hemispherical socket.

After surgery, the patient was able to ambulate without a limp and return to work. Her hip ROM was pain-free passively and actively with flexion to 100°, internal rotation to 35°, external rotation to 20°, and abduction to 30°.

Case 2

A 48-year-old woman with a history of Crowe IV hip dysplasia presented to our clinic with a chronically dislocated right total hip arthroplasty (THA) (Figure 2). Her initial THA was revised 1 year later because of acetabular component failure. Two years later, she was diagnosed with a deep periprosthetic infection, which was ultimately treated with 2-stage reimplantation. She subsequently dislocated and underwent re-revision of the S-ROM body and stem (DePuy Synthes, Warsaw, Indiana). At a visit after that revision, she was noted to be chronically dislocated, and was sent to our clinic for further management.

Preoperative radiographs showed a right uncemented THA with the femoral head dislocated toward the false acetabulum, retained hardware, and an old ununited trochanteric fragment. Both the femoral and acetabular components appeared well-fixed, though the acetabular component was positioned inferior, toward the obturator foramen.

Preoperative CT with metal artifact subtraction was used to create a 3-D model of the residual bony pelvis. The model was made by an implant manufacturer (Zimmer, Warsaw, Indiana). The shape of the superior defect was amenable to reconstruction using a modified revision trabecular metal socket. The pelvic model was reamed to accept a conventional hemispherical socket. The defect was reamed to accept a modified revision trabecular metal socket. The real implant was fashioned before surgery and was sterilized to avoid the need for intraoperative modification. Use of the preoperative model significantly reduced the time that would have been needed to modify the implant during actual surgery.

The patient’s right THA was revised. At time of surgery, the modified revision trabecular metal acetabular component was noted to seat appropriately in the superior defect. The true acetabulum was reestablished, and a hemispherical socket was placed with multiple screws. The 2 components were then unitized using cement in the same manner as would be done with an off-the-shelf augment.

Case 3

A 57-year-old man presented with a 10-year history of right knee pain. About 30 years before presentation at our clinic, he was treated for an open right tibia fracture sustained in a motorcycle accident. He had been treated nonsurgically, with injections, but they failed to provide sustained relief.

Preoperative radiographs showed severe advanced DJD in conjunction with an extra-articular posttraumatic varus tibial shaft deformity (Figure 3). An implant manufacturer (Zimmer) used a CT scan to create a model of the deformity. The resultant center of rotation angle was calculated using preoperative images and conventional techniques for deformity correction, and a lateral closing-wedge osteotomy was performed on the CT-based model. The initial attempt at deformity correction was slightly excessive, and the amount of resected bone slightly thicker than the calculated wedge, resulting in a valgus deformity. This error was noted, and the decision was made to recut a new model with a slight amount of residual varus that could be corrected during the final knee arthroplasty procedure.

Corrective osteotomy was performed with a lateral plate. Six months later, the patient had no residual pain, and CT confirmed union at the osteotomy site and a slight amount of residual varus. The patient then underwent routine total knee arthroplasty (TKA) using an abbreviated keel to avoid the need for removal of the previously placed hardware. The varus deformity was completely corrected.

Case 4

A 73-year-old man had a history of shoulder pain dating back to his childhood. Despite treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and injections, his debilitating pain persisted. Physical examination revealed limited ROM and an intact rotator cuff.

Plain radiographs showed severe DJD of the glenohumeral joint (Figure 4). Severe erosions of the glenoid were noted, prompting further workup with CT, which showed significant bone loss, particularly along the posterior margin of the glenoid. We used our 3-D printer to create a model of the scapula from CT images. The model was then reamed in the usual fashion to accept a 3-pegged glenoid component. On placement of a trial implant, a large deficiency was seen posteriorly. We thought the size and location of the defect made it amenable to grafting using the patient’s humeral head.

The patient elected to undergo right total shoulder arthroplasty. During the procedure, the glenoid defect was found to be identical to what was encountered with the model before surgery. A portion of the patient’s humeral head was then fashioned to fit the defect, and was secured with three 2.7-mm screws, after provisional fixation using 2.0-mm Kirschner wires. The screws were countersunk, and the graft was contoured by hand to match the previous reaming. A 3-pegged 52-mm glenoid component was then cemented into position with excellent stability.

Case 5

A 64-year-old man presented to our clinic with left hip pain 40 years after THA. The original procedure was performed for resolved proximal femoral osteomyelitis. Plain radiographs showed a loose cemented McKee-Farrar hip arthroplasty (Figure 5). Because of the elevated position of the acetabular component relative to the native hip center, CT was used to determine the amount of femoral bone loss.

We used our 3-D printer to create a model and tried to recreate the native hip center with conventional off-the-shelf implants. A 50-mm hemispherical socket trial was placed in the appropriate location, along with a trabecular metal augment trial to provide extended coverage over the superolateral portion of the socket. Noted between the socket and the augment was a large gap; a substantial amount of cement would have been needed to unitize the construct. We thought a custom acetabular component would avoid the need for cement. In addition, given the patient’s small stature, the conventional acetabular component would allow a head only 32 mm in diameter. With a custom implant, the head could be enlarged to 36 mm, providing improved ROM and stability.

The patient underwent revision left hip arthroplasty using a custom acetabular component. A 3-D model available at time of surgery was used to aid implant placement.

Case 6

A 23-year-old man with multiple hereditary exostoses presented to our clinic with a painful mass in the left calf. Plain radiographs showed extensive osteochondromatosis involving the left proximal tibiofibular joint (Figure 6). The exostosis extended posteromedially, displacing the arterial trifurcation. MRI showed a small cartilage cap without evidence of malignant transformation.

CT angiogram allowed the vasculature to be modeled along with the deformity. A 3-D model was fabricated. The model included the entire proximal tibiofibular joint, as well as the anterior tibial, peroneal, and posterior tibial arteries. Cautious intralesional resection was recommended because of the proximity to all 3 vessels.

The patient underwent tumor resection through a longitudinal posterior approach. The interval between the medial and lateral heads of the gastrocnemius muscles was developed to expose the underlying soleus muscle. The soleus was split longitudinally from its hiatus to the inferior portion of the exostosis. This allowed for identification of the trifurcation and the tibial nerve, which were protected. Osteotomes were used to resect the mass at its base, the edges were carefully trimmed, and bone wax was placed over the defect. Anterior and lateral to this mass was another large mass (under the soleus muscle), which was also transected using an osteotome. The gastrocnemius and soleus muscles were then reflected off the fibula in order to remove 2 other exostoses, beneath the neck and head of the fibula.

Case 7

A 71-year-old man with a history of idiopathic lymphedema and peripheral neuropathy presented to our clinic with a left cavovarus foot deformity and a history of recurrent neuropathic foot ulcers (Figure 7). Physical examination revealed a callus over the lateral aspect of the base of the fifth metatarsal. Preoperative radiograph showed evidence of prior triple arthrodesis with a cavovarus foot deformity. CT scan was used to create a 3-D model of the foot. The model was then used to identify an appropriate location for lateral midtarsal and calcaneal closing-wedge osteotomies.

The patient underwent midfoot and hindfoot surgical correction. At surgery, the lateral closing-wedge osteotomies were performed according to the preoperative model. Radiographs 1 year after surgery showed correction of the forefoot varus.

Discussion

Three-dimensional printing for medical applications of anatomical modeling is not a new concept.^1,3,4 Its use has been reported for a variety of applications in orthopedic surgery, including the printing of porous and metallic surfaces⁵ and bone-tissue engineering.^6-9 Rapid prototyping for medical application was first reported in 1990 when a CT-based model was used to create a cranial bone.¹⁰ Reports of using the technique are becoming more widespread, particularly in the dental and maxillofacial literature, which includes reports on a variety of applications, including patient-specific drill guides, splints, and implants.^11-14 The ability to perform mock surgery in advance of an actual procedure provides an invaluable opportunity to anticipate potential intraoperative problems, reduce operative time, and improve the accuracy of reconstruction.

Office-based rapid prototyping that uses an in-house 3-D printer is a novel application of this technology. It allows for creation of a patient-specific model for preoperative planning purposes. We are unaware of any other reports demonstrating the breadth and utility of office-based rapid prototyping in orthopedic surgery. For general reference, a printer similar to ours requires an initial investment of $52,000 to $56,000. This cost generally covers the printer, printer base cabinet, installation, training, and printer software (different from the 3-D modeling software), plus a 1-year warranty. A service agreement costs about $4000 annually. Printer and model supply expenses depend on the material used for the model (eg, ABS [acrylonitrile butadiene styrene]) and on the size and complexity of the 3-D models created. Average time to generate an appropriately formatted 3-D printing file is about 1 hour, though times can vary largely, according to amount of metal artifact subtraction necessary and the experience of the software user. For the rare, extremely complex deformities that require a significant amount of metal artifact subtraction, file preparation times can exceed 3 or 4 hours. We think these preparation times will decrease as communication between radiology file export format and modeling software ultimately allows for metal artifact subtraction images to function within the modeling software environment. Once an appropriately formatted file has been created, typical printing times vary according to the size of the to-be-modeled bone. For a hemipelvis, printing time is 30 to 40 hours; printing that is started on a Friday afternoon will be complete by Monday morning.

There are few reports of rapid prototyping in orthopedic surgery. In 2003, Minns and colleagues¹⁵ used a 3-D model in the planning of a tibial resection for TKA. They found the model to be accurate at time of surgery, resulting in appropriate tibial coverage by a conventional meniscal-bearing implant. Munjal and colleagues¹⁶ reported on 10 complex failed hip arthroplasty cases in which patients had revision surgery after preoperative planning using 3-D modeling techniques. The authors found that, in 8 of the 10 cases, conventional classification systems of bone loss were inaccurate in comparison with the prototype. Four cases required reconstruction with a custom triflange when conventional implants were not deemed reasonable based on the pelvic model. Tam and colleagues¹⁷ reported using a 3-D prototype as an aid in surgical planning for resection of a scapular osteochondroma in a 6-year-old patient. They found the rapid prototype to be useful at time of resection—similar to what we found with 1 patient (case 6). Adding contrast media to our patient’s scan allowed for 3-D visualization of the lesion and the encased vasculature. Fu and colleagues¹⁸ reported using a patient-specific drill template to insert anterior transpedicular screws. They constructed 24 prototypes of a formalin-preserved cervical vertebra to create a patient-specific biocompatible drill template for use in correcting multilevel cervical instability. They found the technique to be highly reproducible and accurate. Zein and colleagues¹⁹ used a rapid prototype of 3 consecutive human livers to preoperatively identify the vascular and biliary tract anatomy. They reported a high degree of accuracy—mean dimensional errors of less than 4 mm for the entire model and 1.3 mm for the vascular diameter.

The models created by implant manufacturers in this series were used to perform “mock” surgery before the actual procedures. Working with these models prompted us to buy our own 3-D printer. The learning curve can be steep, but commercially available 3-D printers allow for prompt in-office production of high-quality realistic prototypes at relatively low per-case cost (Figure 8). Three-dimensional modeling allows surgeons to assess the accuracy of their original surgical plans and, if necessary, correct them before surgery. Although computer-aided design models are useful, the ability to “perform surgery preoperatively” adds another element to surgeons’ understanding of the potential issues that may arise. Also, an in-office printer can help improve surgeons’ understanding and control over the process by which images are translated from radiographic file to 3-D model. Disadvantages of an in-office system include start-up and maintenance costs, office space requirements, and a significant learning curve for software and hardware applications. In addition, creation of 3-D models requires close interaction with radiologists who can provide appropriately formatted DICOM images, as metal artifact subtraction can be challenging. We think that, as image formatting and software capabilities are continually refined, this technology will become an invaluable part of multiple subspecialties across orthopedic surgery, with potentially infinite clinical, educational, and research applications.

Children often present to orthopedic surgeons with angular deformities about the knee. Temporary hemiepiphysiodesis, which is a frequently performed procedure to address such deformities, is safe and reversible. Specifically, tension band plating has become one of the most commonly performed techniques, especially given its low complication rates and minimally invasive nature.^1-4 Complications reported with this method include mechanical hardware failure,⁵ implant migration,⁴ and recurvatum.³

We present an unreported complication of a synovial fistula formation after the removal of a tension band plate in a child who had achieved appropriate correction of her genu valgum. The patient and her family provided written informed consent for print and electronic publication of this case report.

Case Report

An 11-year-old girl presented to the pediatric orthopedics clinic with concern for genu valgum of the right lower extremity. She underwent a right proximal tibia medial hemiepiphysiodesis via tension band plating technique. Her clinic visit 4 weeks after surgery showed well-healed incisions and no signs of infection. She achieved appropriate correction and underwent hardware removal approximately 6 months after her initial surgery. 

One month after hardware removal, the patient began to notice increased swelling and erythema around her incision site with associated pain. No fluid or drainage was seen at that time. She underwent irrigation and débridement shortly thereafter, and the wound was left open for wet-to-dry dressing changes (Figure 1). Intraoperative cultures were negative, but the patient received empiric antibiotic therapy. She continued to have difficulty with wound healing for the next month and was referred to plastic surgery. She underwent repeat irrigation and débridement, followed by coverage with a split-thickness skin graft by the plastic surgery service. Intraoperative cultures were again negative. During both irrigation and débridement procedures, care was taken to remain superficial and not violate the knee capsule.

At her 2-week postoperative check, the bolster covering the split thickness skin graft was removed, which revealed a 2×2-mm area of clear erosion near the central portion of her wound with synovial fluid drainage (Figure 2). Because of concern for a synovial fistula, magnetic resonance imaging (MRI) of the right knee was obtained, which confirmed the synovial fistula (Figures 3A, 3B). The coronal cut on MRI clearly showed the fistula with synovial fluid tracking into the epiphyseal screw tract through the breached capsule and to the level of the skin. She was immobilized in a long leg cast with the knee in extension for 6 weeks. Upon return, her fistula had closed, and she has not had any more wound issues. 

Discussion

To our knowledge, this is the first report of a synovial fistula after temporary hemiepiphysiodesis performed via tension band plating. Capsular knee anatomy may explain the etiology of the synovial fistula after hardware removal. The medial knee capsule composition and attachment sites have been extensively studied.⁶ In contrast to other joints, such as the shoulder, elbow, ankle, and hip, the metaphysis of the knee lies outside the capsule because the capsule inserts proximal at the level of the physis.⁷ During tension band plating, the epiphyseal screw breaches the capsule but serves as a plug while in place, which prevents the formation of a synovial fistula. When the screw is removed, the capsular rent spontaneously closes in almost all cases. However, the opportunity exists for a synovial fistula to form while the capsule heals, as evidenced by the current case. Such an issue does not apply to the metaphyseal screw because it is inserted outside the capsule.  

Although it is possible that the synovial fistula was inadvertently created during one of the irrigation and débridement procedures, this is very unlikely. The surgeons who performed these washout procedures are knowledgeable and familiar with knee anatomy. Both irrigation and débridement procedures were superficial, and care was taken not to violate the knee capsule.

A synovial fistula after knee surgery is rare. Larsen⁸ described the fistula as a phenomenon that develops when excessive synovial fluid forces its way through a synovial incision with knee flexion and muscle contraction. Such a complication is most routinely described after knee arthroscopy. Proffer and colleagues⁹ reported an incidence of 6.1 per 1000 after knee arthroscopies. The average number of days until fistula diagnosis was 6 days (range, 3-10 days). All fistulae were treated with immobilization and closed after an average of 9 days (range, 7-14 days). There were no associated infections, although prophylactic antibiotics were given. A national survey found that knee fistulae accounted for only 3.2% of all complications of knee arthroscopy.¹⁰ 

The treatment for a synovial fistula is largely nonoperative. Most will resolve with a brief period of immobilization, which allows the fistula to close.^9-10 Literature addressing fistulae that fail to heal with nonoperative treatment is limited. Excision and direct closure of the fistula, especially when chronic, often proves futile and leads to a high recurrence rate.¹¹ An alternative but more extensive treatment involves excision and coverage with a myofascial flap.¹²

Complications reported after tension band plating are uncommon. Two studies reported no complications regarding the use of the tension band plate.^1-2 Burghardt and colleagues,⁵ in reporting the results of a multicenter survey, found that 15% of surgeons who had used tension band plating had seen a total of 65 cases of mechanical failure. In all cases, the screws, not the plate, failed. Another study reported implant migration in 1 patient but attributed the complication to a technical error from placing the distal screw too close to the physis.⁴ A third study documented that 2 patients developed clinically significant recurvatum, most likely because of anterior placement of the plate.³ It is important to identify a synovial fistula postoperatively because it provides a direct route for pathogens from the external environment to enter the intra-articular space and the opportunity for a septic joint to develop. Infection should always be ruled out and, if present, appropriately treated. 

Conclusion

Physicians performing tension band plating in the knee should be aware of the possible complication of a synovial fistula, which has traditionally been reported only in relation to knee arthroscopy. Given the proposed etiology of the synovial fistula, we recommend a brief period of immobilization of 3 to 5 days after tension band plate removal, allowing the capsular rent to heal and minimizing the risk of a synovial fistula.

Children often present to orthopedic surgeons with angular deformities about the knee. Temporary hemiepiphysiodesis, which is a frequently performed procedure to address such deformities, is safe and reversible. Specifically, tension band plating has become one of the most commonly performed techniques, especially given its low complication rates and minimally invasive nature.^1-4 Complications reported with this method include mechanical hardware failure,⁵ implant migration,⁴ and recurvatum.³

We present an unreported complication of a synovial fistula formation after the removal of a tension band plate in a child who had achieved appropriate correction of her genu valgum. The patient and her family provided written informed consent for print and electronic publication of this case report.

Case Report

An 11-year-old girl presented to the pediatric orthopedics clinic with concern for genu valgum of the right lower extremity. She underwent a right proximal tibia medial hemiepiphysiodesis via tension band plating technique. Her clinic visit 4 weeks after surgery showed well-healed incisions and no signs of infection. She achieved appropriate correction and underwent hardware removal approximately 6 months after her initial surgery. 

One month after hardware removal, the patient began to notice increased swelling and erythema around her incision site with associated pain. No fluid or drainage was seen at that time. She underwent irrigation and débridement shortly thereafter, and the wound was left open for wet-to-dry dressing changes (Figure 1). Intraoperative cultures were negative, but the patient received empiric antibiotic therapy. She continued to have difficulty with wound healing for the next month and was referred to plastic surgery. She underwent repeat irrigation and débridement, followed by coverage with a split-thickness skin graft by the plastic surgery service. Intraoperative cultures were again negative. During both irrigation and débridement procedures, care was taken to remain superficial and not violate the knee capsule.

At her 2-week postoperative check, the bolster covering the split thickness skin graft was removed, which revealed a 2×2-mm area of clear erosion near the central portion of her wound with synovial fluid drainage (Figure 2). Because of concern for a synovial fistula, magnetic resonance imaging (MRI) of the right knee was obtained, which confirmed the synovial fistula (Figures 3A, 3B). The coronal cut on MRI clearly showed the fistula with synovial fluid tracking into the epiphyseal screw tract through the breached capsule and to the level of the skin. She was immobilized in a long leg cast with the knee in extension for 6 weeks. Upon return, her fistula had closed, and she has not had any more wound issues. 

Discussion

To our knowledge, this is the first report of a synovial fistula after temporary hemiepiphysiodesis performed via tension band plating. Capsular knee anatomy may explain the etiology of the synovial fistula after hardware removal. The medial knee capsule composition and attachment sites have been extensively studied.⁶ In contrast to other joints, such as the shoulder, elbow, ankle, and hip, the metaphysis of the knee lies outside the capsule because the capsule inserts proximal at the level of the physis.⁷ During tension band plating, the epiphyseal screw breaches the capsule but serves as a plug while in place, which prevents the formation of a synovial fistula. When the screw is removed, the capsular rent spontaneously closes in almost all cases. However, the opportunity exists for a synovial fistula to form while the capsule heals, as evidenced by the current case. Such an issue does not apply to the metaphyseal screw because it is inserted outside the capsule.  

Although it is possible that the synovial fistula was inadvertently created during one of the irrigation and débridement procedures, this is very unlikely. The surgeons who performed these washout procedures are knowledgeable and familiar with knee anatomy. Both irrigation and débridement procedures were superficial, and care was taken not to violate the knee capsule.

A synovial fistula after knee surgery is rare. Larsen⁸ described the fistula as a phenomenon that develops when excessive synovial fluid forces its way through a synovial incision with knee flexion and muscle contraction. Such a complication is most routinely described after knee arthroscopy. Proffer and colleagues⁹ reported an incidence of 6.1 per 1000 after knee arthroscopies. The average number of days until fistula diagnosis was 6 days (range, 3-10 days). All fistulae were treated with immobilization and closed after an average of 9 days (range, 7-14 days). There were no associated infections, although prophylactic antibiotics were given. A national survey found that knee fistulae accounted for only 3.2% of all complications of knee arthroscopy.¹⁰ 

The treatment for a synovial fistula is largely nonoperative. Most will resolve with a brief period of immobilization, which allows the fistula to close.^9-10 Literature addressing fistulae that fail to heal with nonoperative treatment is limited. Excision and direct closure of the fistula, especially when chronic, often proves futile and leads to a high recurrence rate.¹¹ An alternative but more extensive treatment involves excision and coverage with a myofascial flap.¹²

Complications reported after tension band plating are uncommon. Two studies reported no complications regarding the use of the tension band plate.^1-2 Burghardt and colleagues,⁵ in reporting the results of a multicenter survey, found that 15% of surgeons who had used tension band plating had seen a total of 65 cases of mechanical failure. In all cases, the screws, not the plate, failed. Another study reported implant migration in 1 patient but attributed the complication to a technical error from placing the distal screw too close to the physis.⁴ A third study documented that 2 patients developed clinically significant recurvatum, most likely because of anterior placement of the plate.³ It is important to identify a synovial fistula postoperatively because it provides a direct route for pathogens from the external environment to enter the intra-articular space and the opportunity for a septic joint to develop. Infection should always be ruled out and, if present, appropriately treated. 

Conclusion

Physicians performing tension band plating in the knee should be aware of the possible complication of a synovial fistula, which has traditionally been reported only in relation to knee arthroscopy. Given the proposed etiology of the synovial fistula, we recommend a brief period of immobilization of 3 to 5 days after tension band plate removal, allowing the capsular rent to heal and minimizing the risk of a synovial fistula.

Children often present to orthopedic surgeons with angular deformities about the knee. Temporary hemiepiphysiodesis, which is a frequently performed procedure to address such deformities, is safe and reversible. Specifically, tension band plating has become one of the most commonly performed techniques, especially given its low complication rates and minimally invasive nature.^1-4 Complications reported with this method include mechanical hardware failure,⁵ implant migration,⁴ and recurvatum.³

We present an unreported complication of a synovial fistula formation after the removal of a tension band plate in a child who had achieved appropriate correction of her genu valgum. The patient and her family provided written informed consent for print and electronic publication of this case report.

Case Report

An 11-year-old girl presented to the pediatric orthopedics clinic with concern for genu valgum of the right lower extremity. She underwent a right proximal tibia medial hemiepiphysiodesis via tension band plating technique. Her clinic visit 4 weeks after surgery showed well-healed incisions and no signs of infection. She achieved appropriate correction and underwent hardware removal approximately 6 months after her initial surgery. 

One month after hardware removal, the patient began to notice increased swelling and erythema around her incision site with associated pain. No fluid or drainage was seen at that time. She underwent irrigation and débridement shortly thereafter, and the wound was left open for wet-to-dry dressing changes (Figure 1). Intraoperative cultures were negative, but the patient received empiric antibiotic therapy. She continued to have difficulty with wound healing for the next month and was referred to plastic surgery. She underwent repeat irrigation and débridement, followed by coverage with a split-thickness skin graft by the plastic surgery service. Intraoperative cultures were again negative. During both irrigation and débridement procedures, care was taken to remain superficial and not violate the knee capsule.

At her 2-week postoperative check, the bolster covering the split thickness skin graft was removed, which revealed a 2×2-mm area of clear erosion near the central portion of her wound with synovial fluid drainage (Figure 2). Because of concern for a synovial fistula, magnetic resonance imaging (MRI) of the right knee was obtained, which confirmed the synovial fistula (Figures 3A, 3B). The coronal cut on MRI clearly showed the fistula with synovial fluid tracking into the epiphyseal screw tract through the breached capsule and to the level of the skin. She was immobilized in a long leg cast with the knee in extension for 6 weeks. Upon return, her fistula had closed, and she has not had any more wound issues. 

Discussion

To our knowledge, this is the first report of a synovial fistula after temporary hemiepiphysiodesis performed via tension band plating. Capsular knee anatomy may explain the etiology of the synovial fistula after hardware removal. The medial knee capsule composition and attachment sites have been extensively studied.⁶ In contrast to other joints, such as the shoulder, elbow, ankle, and hip, the metaphysis of the knee lies outside the capsule because the capsule inserts proximal at the level of the physis.⁷ During tension band plating, the epiphyseal screw breaches the capsule but serves as a plug while in place, which prevents the formation of a synovial fistula. When the screw is removed, the capsular rent spontaneously closes in almost all cases. However, the opportunity exists for a synovial fistula to form while the capsule heals, as evidenced by the current case. Such an issue does not apply to the metaphyseal screw because it is inserted outside the capsule.  

Although it is possible that the synovial fistula was inadvertently created during one of the irrigation and débridement procedures, this is very unlikely. The surgeons who performed these washout procedures are knowledgeable and familiar with knee anatomy. Both irrigation and débridement procedures were superficial, and care was taken not to violate the knee capsule.

A synovial fistula after knee surgery is rare. Larsen⁸ described the fistula as a phenomenon that develops when excessive synovial fluid forces its way through a synovial incision with knee flexion and muscle contraction. Such a complication is most routinely described after knee arthroscopy. Proffer and colleagues⁹ reported an incidence of 6.1 per 1000 after knee arthroscopies. The average number of days until fistula diagnosis was 6 days (range, 3-10 days). All fistulae were treated with immobilization and closed after an average of 9 days (range, 7-14 days). There were no associated infections, although prophylactic antibiotics were given. A national survey found that knee fistulae accounted for only 3.2% of all complications of knee arthroscopy.¹⁰ 

The treatment for a synovial fistula is largely nonoperative. Most will resolve with a brief period of immobilization, which allows the fistula to close.^9-10 Literature addressing fistulae that fail to heal with nonoperative treatment is limited. Excision and direct closure of the fistula, especially when chronic, often proves futile and leads to a high recurrence rate.¹¹ An alternative but more extensive treatment involves excision and coverage with a myofascial flap.¹²

Complications reported after tension band plating are uncommon. Two studies reported no complications regarding the use of the tension band plate.^1-2 Burghardt and colleagues,⁵ in reporting the results of a multicenter survey, found that 15% of surgeons who had used tension band plating had seen a total of 65 cases of mechanical failure. In all cases, the screws, not the plate, failed. Another study reported implant migration in 1 patient but attributed the complication to a technical error from placing the distal screw too close to the physis.⁴ A third study documented that 2 patients developed clinically significant recurvatum, most likely because of anterior placement of the plate.³ It is important to identify a synovial fistula postoperatively because it provides a direct route for pathogens from the external environment to enter the intra-articular space and the opportunity for a septic joint to develop. Infection should always be ruled out and, if present, appropriately treated. 

Conclusion

Physicians performing tension band plating in the knee should be aware of the possible complication of a synovial fistula, which has traditionally been reported only in relation to knee arthroscopy. Given the proposed etiology of the synovial fistula, we recommend a brief period of immobilization of 3 to 5 days after tension band plate removal, allowing the capsular rent to heal and minimizing the risk of a synovial fistula.

The goal of surgical treatment of adolescent idiopathic scoliosis (AIS) is to prevent disability associated with curve progression.¹ Early studies tended to focus on radiographic measures, such as curve correction and sagittal balance, rather than on improvements in quality of life (QOL).^2-5 Although studies have reported on QOL in patients treated surgically for scoliosis,^6-11 these studies were largely limited by small sample size and inclusion of patients with congenital and neuromuscular scoliosis,⁹ lack of a generic measure of QOL,^6,7 or lack of surgical treatment of patients in the cohort.¹⁰

We conducted a study to determine disease-specific and general health-related QOL (HR-QOL) in young adults who underwent surgical correction of their spinal deformity during adolescence and to evaluate associated complications and reoperations.

Materials and Methods

After obtaining institutional review board approval, we queried the surgical database of a large metropolitan tertiary referral center for consecutive patients who had undergone spine deformity correction between the ages of 10 and 17 years (January 1993–December 2003). Hospital and medical records were retrospectively reviewed to confirm the diagnosis of AIS. Patients with congenital, neuromuscular, juvenile, or infantile scoliosis were excluded. Patients with intraspinal pathology (eg, tethered cord, syringomyelia), developmental delay, chromosomal abnormality, or congenital heart disease were also excluded. Patients were contacted by mail or telephone, and the Scoliosis Research Society–22R (SRS-22R)^12-15 and the Short Form–12 (SF-12)¹⁶ were administered. Standard demographic and surgical data were also collected.

The SRS-22R is a scoliosis-specific HR-QOL questionnaire with 22 items, 5 domains (pain, activity, appearance, mental, satisfaction), and a total score.^12-15 Each domain score ranges from 1 to 5 (higher scores indicating better outcomes). The SRS-22R is the outcome instrument most widely used to measure HR-QOL changes in patients with scoliosis, and it is available in several languages.^17-26

The SF-12, a 12-item self-administered short-form health status survey developed in the Medical Outcomes Study, measures patient-based health status. Two composite scores can be calculated: physical composite summary (PCS) and mental composite summary (MCS).¹⁶ Using norm-based scoring, all domain scales have a mean (SD) of 50 (10) based on the general 1998 US population. Thus, scores under 50 fall below the general population mean.

In addition, patients were surveyed to determine the incidence of spine-related symptoms and complaints, including activity limitations, rib prominence, waistline asymmetry, back pain, limited range of motion (ROM), shortness of breath, wound/scar problems, lung disease/asthma, heart disease, high blood pressure, and arthritis. Data regarding postoperative treatment regimens of physical therapy, narcotic pain medication, spinal/epidural injections, and nonsteroidal anti-inflammatory drug (NSAID) use were collected. Patients were also queried regarding their current working status and smoking status.

Standard demographic and surgical data were collected from hospital and office charts and radiographs. Data collected included history of bracing, age at index surgery, number of levels fused, surgical approach (anterior, posterior, combined), postoperative complications (eg, ileus, wound infection, anemia, pneumonia), and immediate preoperative and final postoperative radiographic measures. Data on need for subsequent revision surgery and indications for revision surgery were also collected.

Preoperative and latest follow-up radiographs were measured to determine curve magnitude, sagittal and coronal balance, and percentage curve correction. Coronal balance was defined as the distance between a plumb line drawn vertically from the spinous process of C7 and the central sacral line on full-length posteroanterior radiographs. Sagittal balance was defined as the distance of a plumb line drawn vertically from the center of the body of C7 and the posterosuperior endplate of S1.²⁷

Regression analysis was performed to identify factors predictive of SRS-22R total scores. Factors included in the analysis were sex, age at surgery, Lenke type, surgery type (anterior, posterior, anteroposterior), number of levels fused, lowest instrumented vertebra, perioperative complications, percentage curve correction, postoperative coronal and sagittal balance, smoking status, and need for revision surgery. Although age and sex were considered variables outside the surgeon’s control, they were included in the model, as previous studies have shown that SRS scores varied by age and sex both in adolescents²⁸ and adults.²⁹ Significance was set at P < .01. All data analysis was performed with IBM SPSS Version 19.0 (Somers, New York).

Results

Of the 384 postoperative patients identified for study inclusion, 134 (35%) completed surveys. Sixteen patients with nonidiopathic scoliosis were excluded, leaving 118 available for analysis. Of the remaining patients, 248 (64%) could not be contacted because of a change in address or phone number. Two patients (1%) were unwilling to complete survey requests. There was no statistically significant difference in demographics between patients with and without follow-up data available. Demographics are summarized in Table 1. There were 109 females (92%). Mean (SD) age at surgery was 14.1 (1.9) years. Only 37 (31%) were braced before surgery. Table 2 summarizes the radiographic data. Mean (SD) major Cobb angle was 49.7° (7.8°). Eighty-five patients (72%) underwent posterior fusion with instrumentation using hooks only; another 16 (14%) had anterior-only surgery, and another 17 (14%) had combined anterior-posterior surgery. A mean of 7.8 levels were fused. Index surgery data and lowest instrumented vertebra distribution are summarized in Table 3. Mean (SD) percentage curve correction was 48.9% (8.4%).

Seven patients had a total of 8 perioperative complications: anemia requiring transfusion (2), ileus necessitating nasogastric tube insertion (2), superficial wound infection treated with oral antibiotics and local wound care (2), wound drainage and erythema (1), and pneumonia (1). Mean (SD) length of clinical and radiographic follow-up was 57.9 (36.3) months.

Table 4 summarizes the long-term complications. Of the 38 patients with long-term complications, 14 required reoperation. The indications were disc herniation (2 patients), painful instrumentation (7), crankshaft phenomenon (1), nonunion (1), and adjacent-level degeneration (3). Both disc herniations were at L5–S1, several segments below the distal extent of the fusion. Of the 7 patients who had painful instrumentation removed, 6 had the entire construct removed, and 1 had the proximal half of a rod taken out. The 3 patients with adjacent-level degeneration had stenosis at the distal end of the construct—at L5–S1 (2 patients) or L2–L3 (1 patient).

Mean (SD) time between surgery and completion of the surveys/questionnaires was 12.7 (3.2) years (range, 10-18 years). Mean age of respondents was 26.8 years. Twenty-five respondents (21%) were smokers. Mean (SD) outcome scores were 50.9 (9.4) for SF-12 PCS and 49.4 (10.2) for SF-12 MCS. Eighteen patients (15%) had SF-12 PCS scores 1 SD below normal, and 15 (13%) had SF-12 MCS scores 1 SD below normal. Mean (SD) SRS-22R Total score was 4.0 (0.7). Means, standard deviations, and distribution of SRS domain scores are summarized in Table 5. Of the variables, only current smoking (P < .001) was predictive of SRS-22R Total scores, accounting for 20% of their variability (Table 6).

One hundred patients (85%) had jobs, mostly desk jobs. The postoperative limitations most commonly reported are summarized in Table 7. These included at least intermittent back pain in 90 patients (76%), limited ROM in 52 (44%), and activity limitations in 54 (46%). Less common limitations were waistline imbalance in 41 (35%), rib prominence in 28 (24%), wound/scar problems in 18 (15%), and shortness of breath in 18 (15%). Other related medical problems were lung disease/asthma in 11 (9%), osteoarthritis/degenerative arthritis in 11 (9%), heart disease in 3 (3%), and high blood pressure in 2 (2%).

A minority of patients also participated in postoperative treatment regimens. The most common treatment was regular use of NSAIDs (25 patients, 21%). Other treatments were physical therapy (14, 12%), narcotic pain medication use (5, 4%), and epidural steroid injections (5, 4%). Table 8 summarizes the postoperative treatments used by patients with scoliosis.

Discussion

A major concern about prophylactic interventions for diseases is that the treatment will harm the patient. This is especially true for major spine surgery performed on adolescents with minimal symptoms. Although the incidence of perioperative complications in children undergoing corrective spinal surgery for AIS has been reported,^30-32 the effect of the surgery on the disease-specific HR-QOL outcomes of these individuals as young adults has not been previously studied. Over the past few decades, a paradigm shift in understanding health and disability has occurred, with increased emphasis being placed on HR-QOL outcomes measures and understanding disability as relating to a measureable impact of the functioning of an individual after a change in health or environment. This change was substantiated when the World Health Organization endorsed the International Classification of Functioning, Disability and Health.³³ In light of this shift, we present the disease-specific and general HR-QOL outcomes of young adults who had undergone surgical correction for spinal deformity during adolescence, as well as their associated complications and reoperations, in an attempt to identify targets for improvement.

Our patient-reported outcomes demonstrated a high incidence of occasional back pain, activity-related complaints, and limited ROM. Comparison of our cohort’s SRS-22R outcomes with previously published normative values for the unaffected adolescent population^28,34 suggests worse scores for the disease-specific SRS-22R domains of pain and appearance. In 2012, Daubs and colleagues³⁴ reported that normative scores on various SRS-22 domains were statistically lower with age (scores decreased from age 10 to age 19 years). Both Verma and colleagues²⁸ and Daubs and colleagues³⁴ reported lower scores for females than for males. Therefore, it is unclear whether the differences observed in our cohort may be accounted for by the larger proportion of females compared with the normative data.

General health scores on the SF-12 were similar to the population norm (mean [SD]) of 50 (10) referenced by Ware and colleagues.¹⁶ These findings suggest that, though pain and appearance may be statistically lower in our cohort—as measured with the SRS-22R—the cohort’s spine-related symptoms do not seem to lower its general health. Eighty-five percent of the patients were working at the time of the survey, further supporting a relatively normal level of overall function. In a retrospective review by Takayama and colleagues,⁹ similar results were found with regard to working after AIS fusion surgery. Of 32 patients treated surgically for scoliosis, at a mean of 21.1 years after the index fusion 27 (84.4%) were or had been engaged in various occupations without marked difficulty.

Our results in a cohort of patients with segmental instrumentation using hooks are similar to results in other studies of long-term HR-QOL measures in patients with AIS and Harrington rod instrumentation. Danielsson and Nachemson³⁵ evaluated patients with surgically treated AIS with at least 20-year follow-up and reported that, in their surgical cohort with a mean age of 39.7 years, mean SF-36 PCS score was 50.9, and mean SF-36 MCS score was 50.2. In a recent study of patients with AIS and Harrington rod instrumentation, those of a mean age of 32.3 years had a mean score of 50.9 for both SF-36 PCS and SF-36 MCS.³⁶

Regression analysis identified only smoking as a predictor of SRS-22R Total scores. This finding, that smokers have a lower health state, is expected even in the general population.³⁷ Interestingly, bracing before surgery, Lenke type, surgery type, number of levels fused, lowest instrumented vertebra, incidence of perioperative complications, percentage curve correction, postoperative sagittal and coronal balance, and need for revision surgery did not influence HR-QOL measures in this cohort.

Our cohort’s incidence of occasional back pain was 76% (90/118 patients). Other reports have had similar findings. In 2012, Bas and colleagues³⁸ studied self-reported pain in 126 consecutive patients with scoliosis and instrumented fusion. In their cohort, “most participants reported ‘no pain’ (38.5%) or ‘mild pain’ (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal.” Also in 2012, Rushton and Grevitt³⁹ reported on a review and statistical analysis of the literature on HR-QOL in adolescents with untreated AIS and in unaffected adolescents. Their goal was to identify whether there were any differences in HR-QOL and, if so, whether they were clinically relevant. The authors concluded that pain and self-image tended to be statistically lower among cohorts with AIS but that only self-image was consistently different clinically between untreated patients with AIS and their unaffected peers.

Cosmetic complaints, though less common than functional concerns, affected a substantial percentage of our cohort. Waistline imbalance complaints were more common than rib prominence or scar-related complaints. The validity of patient-reported waistline imbalance is not known but may contribute to the SRS-22R outcomes in this cohort, particularly with regard to appearance scores. Respiratory symptoms, particularly those related to shortness of breath, were reported by 15% of patients. Respiratory symptoms may be in part secondary to underlying lung disease; smoking was reported by 21% of patients and asthma by 9%.

Few additional postoperative treatments were reported by patients. The most common treatment was regular use of NSAIDs (21%), followed by postoperative physical therapy (12%). Opiate medication use and spinal injections were rare—consistent with results reported by Danielsson and Nachemson³⁵ in 2003.

Implant-related complaints, including painful instrumentation (13%) and implant prominence (9%), were some of the most common complaints in our study group. Although not all symptomatic instrumentation required surgical revision, 7 (50%) of the 14 additional spine surgeries were related to painful and/or prominent posterior instrumentation. Additional spine surgery was reported in 11.9% of our patients. Other indications for reoperation were disc herniation, crankshaft phenomenon, nonunion, and adjacent-level degeneration. Our rate of revision surgery is supported by the literature. In 2009, Luhmann and colleagues⁴⁰ reported that 41 (3.9%) of 1057 primary spine fusions for idiopathic scoliosis required reoperation; the indications included infection (16/1057, 1.5%), pseudarthrosis (12, 1.1%), and painful/prominent implant (7, 0.7%). Richards and colleagues⁴¹ similarly reported on 1046 patients who underwent fusion for AIS. Of these patients, 135 underwent 172 repeat surgical interventions (12.9% reoperation rate), with 29 (21.5%) of the 135 undergoing 2 or more separate procedures. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. The authors concluded that repeat surgeries were relatively common after the initial surgical procedures. Having a clearer understanding of instrumentation-related complaints and reoperations may lead to improvement in this surgeon-controlled variable.

There are limitations to this study. The data regarding clinical courses were collected by retrospective chart review, which has known limitations. To offset this, we collected prospective outcome data with use of the SF-12, the SRS-22R, and a spine-related complaints questionnaire. No control group was available for comparison of outcomes in our cohort. We used the SF-12 and previously published normative values for the SRS-22R for comparison with population norms. Such comparisons have inherent limitations, as the groups vary by sex and mean age; our cohort was primarily female and more than a decade older than the controls.

Only 35% of the patients who met the inclusion criteria had complete data that could be included in our analysis. Although there was no statistically significant difference in demographics between patients with and without follow-up data available, this low response rate could have introduced selection bias. Ideally, patients should have been seen in clinic, standing radiographs should have been taken, and pulmonary function tests should have been performed. However, these patients were asymptomatic, and ethical and insurance issues prevented those actions. Thus, any radiographic changes occurring over the intervening years, from the last clinic visit to completion of the surveys, were not documented. This situation may or may not have limited our findings, as other authors have found low correlation between radiographic outcomes and clinical outcome measures.^13,14,19,36 During the period when these surgeries were performed, segmental spine instrumentation with hooks was the standard of care for deformity correction in AIS; therefore, all posterior instrumentations were done with hook-only segmental fixation. Current pedicle screw–based techniques that allow for additional correction of the deformity may provide different outcomes in the future.

We think that, despite the inherent limitations of this study, our data will be useful in the treatment of AIS. Our results suggest that postoperative spinal complaints are common and that, compared with an unaffected adolescent population, patients with AIS score significantly lower on pain and appearance domains of outcomes testing at a mean of 12.7 years after index fusion. Nevertheless, the outcomes do not seem to be of sufficient severity to affect general health and QOL as measured by outcomes testing.

Spinal deformity correction is performed to prevent impaired pulmonary function and spine-related disability later in life.^42,43 Thus, longer-term studies, involving patients in their fifth and sixth decades of life, are needed to determine whether patients with AIS will have QOL outcomes, pulmonary function, and spine-related problems similar to those in the general population. In this cohort of young adults, smoking status was the only predictor of HR-QOL measures, and spinal deformity correction did not lead to decreased HR-QOL.

The goal of surgical treatment of adolescent idiopathic scoliosis (AIS) is to prevent disability associated with curve progression.¹ Early studies tended to focus on radiographic measures, such as curve correction and sagittal balance, rather than on improvements in quality of life (QOL).^2-5 Although studies have reported on QOL in patients treated surgically for scoliosis,^6-11 these studies were largely limited by small sample size and inclusion of patients with congenital and neuromuscular scoliosis,⁹ lack of a generic measure of QOL,^6,7 or lack of surgical treatment of patients in the cohort.¹⁰

We conducted a study to determine disease-specific and general health-related QOL (HR-QOL) in young adults who underwent surgical correction of their spinal deformity during adolescence and to evaluate associated complications and reoperations.

Materials and Methods

After obtaining institutional review board approval, we queried the surgical database of a large metropolitan tertiary referral center for consecutive patients who had undergone spine deformity correction between the ages of 10 and 17 years (January 1993–December 2003). Hospital and medical records were retrospectively reviewed to confirm the diagnosis of AIS. Patients with congenital, neuromuscular, juvenile, or infantile scoliosis were excluded. Patients with intraspinal pathology (eg, tethered cord, syringomyelia), developmental delay, chromosomal abnormality, or congenital heart disease were also excluded. Patients were contacted by mail or telephone, and the Scoliosis Research Society–22R (SRS-22R)^12-15 and the Short Form–12 (SF-12)¹⁶ were administered. Standard demographic and surgical data were also collected.

The SRS-22R is a scoliosis-specific HR-QOL questionnaire with 22 items, 5 domains (pain, activity, appearance, mental, satisfaction), and a total score.^12-15 Each domain score ranges from 1 to 5 (higher scores indicating better outcomes). The SRS-22R is the outcome instrument most widely used to measure HR-QOL changes in patients with scoliosis, and it is available in several languages.^17-26

The SF-12, a 12-item self-administered short-form health status survey developed in the Medical Outcomes Study, measures patient-based health status. Two composite scores can be calculated: physical composite summary (PCS) and mental composite summary (MCS).¹⁶ Using norm-based scoring, all domain scales have a mean (SD) of 50 (10) based on the general 1998 US population. Thus, scores under 50 fall below the general population mean.

In addition, patients were surveyed to determine the incidence of spine-related symptoms and complaints, including activity limitations, rib prominence, waistline asymmetry, back pain, limited range of motion (ROM), shortness of breath, wound/scar problems, lung disease/asthma, heart disease, high blood pressure, and arthritis. Data regarding postoperative treatment regimens of physical therapy, narcotic pain medication, spinal/epidural injections, and nonsteroidal anti-inflammatory drug (NSAID) use were collected. Patients were also queried regarding their current working status and smoking status.

Standard demographic and surgical data were collected from hospital and office charts and radiographs. Data collected included history of bracing, age at index surgery, number of levels fused, surgical approach (anterior, posterior, combined), postoperative complications (eg, ileus, wound infection, anemia, pneumonia), and immediate preoperative and final postoperative radiographic measures. Data on need for subsequent revision surgery and indications for revision surgery were also collected.

Preoperative and latest follow-up radiographs were measured to determine curve magnitude, sagittal and coronal balance, and percentage curve correction. Coronal balance was defined as the distance between a plumb line drawn vertically from the spinous process of C7 and the central sacral line on full-length posteroanterior radiographs. Sagittal balance was defined as the distance of a plumb line drawn vertically from the center of the body of C7 and the posterosuperior endplate of S1.²⁷

Regression analysis was performed to identify factors predictive of SRS-22R total scores. Factors included in the analysis were sex, age at surgery, Lenke type, surgery type (anterior, posterior, anteroposterior), number of levels fused, lowest instrumented vertebra, perioperative complications, percentage curve correction, postoperative coronal and sagittal balance, smoking status, and need for revision surgery. Although age and sex were considered variables outside the surgeon’s control, they were included in the model, as previous studies have shown that SRS scores varied by age and sex both in adolescents²⁸ and adults.²⁹ Significance was set at P < .01. All data analysis was performed with IBM SPSS Version 19.0 (Somers, New York).

Results

Of the 384 postoperative patients identified for study inclusion, 134 (35%) completed surveys. Sixteen patients with nonidiopathic scoliosis were excluded, leaving 118 available for analysis. Of the remaining patients, 248 (64%) could not be contacted because of a change in address or phone number. Two patients (1%) were unwilling to complete survey requests. There was no statistically significant difference in demographics between patients with and without follow-up data available. Demographics are summarized in Table 1. There were 109 females (92%). Mean (SD) age at surgery was 14.1 (1.9) years. Only 37 (31%) were braced before surgery. Table 2 summarizes the radiographic data. Mean (SD) major Cobb angle was 49.7° (7.8°). Eighty-five patients (72%) underwent posterior fusion with instrumentation using hooks only; another 16 (14%) had anterior-only surgery, and another 17 (14%) had combined anterior-posterior surgery. A mean of 7.8 levels were fused. Index surgery data and lowest instrumented vertebra distribution are summarized in Table 3. Mean (SD) percentage curve correction was 48.9% (8.4%).

Seven patients had a total of 8 perioperative complications: anemia requiring transfusion (2), ileus necessitating nasogastric tube insertion (2), superficial wound infection treated with oral antibiotics and local wound care (2), wound drainage and erythema (1), and pneumonia (1). Mean (SD) length of clinical and radiographic follow-up was 57.9 (36.3) months.

Table 4 summarizes the long-term complications. Of the 38 patients with long-term complications, 14 required reoperation. The indications were disc herniation (2 patients), painful instrumentation (7), crankshaft phenomenon (1), nonunion (1), and adjacent-level degeneration (3). Both disc herniations were at L5–S1, several segments below the distal extent of the fusion. Of the 7 patients who had painful instrumentation removed, 6 had the entire construct removed, and 1 had the proximal half of a rod taken out. The 3 patients with adjacent-level degeneration had stenosis at the distal end of the construct—at L5–S1 (2 patients) or L2–L3 (1 patient).

Mean (SD) time between surgery and completion of the surveys/questionnaires was 12.7 (3.2) years (range, 10-18 years). Mean age of respondents was 26.8 years. Twenty-five respondents (21%) were smokers. Mean (SD) outcome scores were 50.9 (9.4) for SF-12 PCS and 49.4 (10.2) for SF-12 MCS. Eighteen patients (15%) had SF-12 PCS scores 1 SD below normal, and 15 (13%) had SF-12 MCS scores 1 SD below normal. Mean (SD) SRS-22R Total score was 4.0 (0.7). Means, standard deviations, and distribution of SRS domain scores are summarized in Table 5. Of the variables, only current smoking (P < .001) was predictive of SRS-22R Total scores, accounting for 20% of their variability (Table 6).

One hundred patients (85%) had jobs, mostly desk jobs. The postoperative limitations most commonly reported are summarized in Table 7. These included at least intermittent back pain in 90 patients (76%), limited ROM in 52 (44%), and activity limitations in 54 (46%). Less common limitations were waistline imbalance in 41 (35%), rib prominence in 28 (24%), wound/scar problems in 18 (15%), and shortness of breath in 18 (15%). Other related medical problems were lung disease/asthma in 11 (9%), osteoarthritis/degenerative arthritis in 11 (9%), heart disease in 3 (3%), and high blood pressure in 2 (2%).

A minority of patients also participated in postoperative treatment regimens. The most common treatment was regular use of NSAIDs (25 patients, 21%). Other treatments were physical therapy (14, 12%), narcotic pain medication use (5, 4%), and epidural steroid injections (5, 4%). Table 8 summarizes the postoperative treatments used by patients with scoliosis.

Discussion

A major concern about prophylactic interventions for diseases is that the treatment will harm the patient. This is especially true for major spine surgery performed on adolescents with minimal symptoms. Although the incidence of perioperative complications in children undergoing corrective spinal surgery for AIS has been reported,^30-32 the effect of the surgery on the disease-specific HR-QOL outcomes of these individuals as young adults has not been previously studied. Over the past few decades, a paradigm shift in understanding health and disability has occurred, with increased emphasis being placed on HR-QOL outcomes measures and understanding disability as relating to a measureable impact of the functioning of an individual after a change in health or environment. This change was substantiated when the World Health Organization endorsed the International Classification of Functioning, Disability and Health.³³ In light of this shift, we present the disease-specific and general HR-QOL outcomes of young adults who had undergone surgical correction for spinal deformity during adolescence, as well as their associated complications and reoperations, in an attempt to identify targets for improvement.

Our patient-reported outcomes demonstrated a high incidence of occasional back pain, activity-related complaints, and limited ROM. Comparison of our cohort’s SRS-22R outcomes with previously published normative values for the unaffected adolescent population^28,34 suggests worse scores for the disease-specific SRS-22R domains of pain and appearance. In 2012, Daubs and colleagues³⁴ reported that normative scores on various SRS-22 domains were statistically lower with age (scores decreased from age 10 to age 19 years). Both Verma and colleagues²⁸ and Daubs and colleagues³⁴ reported lower scores for females than for males. Therefore, it is unclear whether the differences observed in our cohort may be accounted for by the larger proportion of females compared with the normative data.

General health scores on the SF-12 were similar to the population norm (mean [SD]) of 50 (10) referenced by Ware and colleagues.¹⁶ These findings suggest that, though pain and appearance may be statistically lower in our cohort—as measured with the SRS-22R—the cohort’s spine-related symptoms do not seem to lower its general health. Eighty-five percent of the patients were working at the time of the survey, further supporting a relatively normal level of overall function. In a retrospective review by Takayama and colleagues,⁹ similar results were found with regard to working after AIS fusion surgery. Of 32 patients treated surgically for scoliosis, at a mean of 21.1 years after the index fusion 27 (84.4%) were or had been engaged in various occupations without marked difficulty.

Our results in a cohort of patients with segmental instrumentation using hooks are similar to results in other studies of long-term HR-QOL measures in patients with AIS and Harrington rod instrumentation. Danielsson and Nachemson³⁵ evaluated patients with surgically treated AIS with at least 20-year follow-up and reported that, in their surgical cohort with a mean age of 39.7 years, mean SF-36 PCS score was 50.9, and mean SF-36 MCS score was 50.2. In a recent study of patients with AIS and Harrington rod instrumentation, those of a mean age of 32.3 years had a mean score of 50.9 for both SF-36 PCS and SF-36 MCS.³⁶

Regression analysis identified only smoking as a predictor of SRS-22R Total scores. This finding, that smokers have a lower health state, is expected even in the general population.³⁷ Interestingly, bracing before surgery, Lenke type, surgery type, number of levels fused, lowest instrumented vertebra, incidence of perioperative complications, percentage curve correction, postoperative sagittal and coronal balance, and need for revision surgery did not influence HR-QOL measures in this cohort.

Our cohort’s incidence of occasional back pain was 76% (90/118 patients). Other reports have had similar findings. In 2012, Bas and colleagues³⁸ studied self-reported pain in 126 consecutive patients with scoliosis and instrumented fusion. In their cohort, “most participants reported ‘no pain’ (38.5%) or ‘mild pain’ (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal.” Also in 2012, Rushton and Grevitt³⁹ reported on a review and statistical analysis of the literature on HR-QOL in adolescents with untreated AIS and in unaffected adolescents. Their goal was to identify whether there were any differences in HR-QOL and, if so, whether they were clinically relevant. The authors concluded that pain and self-image tended to be statistically lower among cohorts with AIS but that only self-image was consistently different clinically between untreated patients with AIS and their unaffected peers.

Cosmetic complaints, though less common than functional concerns, affected a substantial percentage of our cohort. Waistline imbalance complaints were more common than rib prominence or scar-related complaints. The validity of patient-reported waistline imbalance is not known but may contribute to the SRS-22R outcomes in this cohort, particularly with regard to appearance scores. Respiratory symptoms, particularly those related to shortness of breath, were reported by 15% of patients. Respiratory symptoms may be in part secondary to underlying lung disease; smoking was reported by 21% of patients and asthma by 9%.

Few additional postoperative treatments were reported by patients. The most common treatment was regular use of NSAIDs (21%), followed by postoperative physical therapy (12%). Opiate medication use and spinal injections were rare—consistent with results reported by Danielsson and Nachemson³⁵ in 2003.

Implant-related complaints, including painful instrumentation (13%) and implant prominence (9%), were some of the most common complaints in our study group. Although not all symptomatic instrumentation required surgical revision, 7 (50%) of the 14 additional spine surgeries were related to painful and/or prominent posterior instrumentation. Additional spine surgery was reported in 11.9% of our patients. Other indications for reoperation were disc herniation, crankshaft phenomenon, nonunion, and adjacent-level degeneration. Our rate of revision surgery is supported by the literature. In 2009, Luhmann and colleagues⁴⁰ reported that 41 (3.9%) of 1057 primary spine fusions for idiopathic scoliosis required reoperation; the indications included infection (16/1057, 1.5%), pseudarthrosis (12, 1.1%), and painful/prominent implant (7, 0.7%). Richards and colleagues⁴¹ similarly reported on 1046 patients who underwent fusion for AIS. Of these patients, 135 underwent 172 repeat surgical interventions (12.9% reoperation rate), with 29 (21.5%) of the 135 undergoing 2 or more separate procedures. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. The authors concluded that repeat surgeries were relatively common after the initial surgical procedures. Having a clearer understanding of instrumentation-related complaints and reoperations may lead to improvement in this surgeon-controlled variable.

There are limitations to this study. The data regarding clinical courses were collected by retrospective chart review, which has known limitations. To offset this, we collected prospective outcome data with use of the SF-12, the SRS-22R, and a spine-related complaints questionnaire. No control group was available for comparison of outcomes in our cohort. We used the SF-12 and previously published normative values for the SRS-22R for comparison with population norms. Such comparisons have inherent limitations, as the groups vary by sex and mean age; our cohort was primarily female and more than a decade older than the controls.

Only 35% of the patients who met the inclusion criteria had complete data that could be included in our analysis. Although there was no statistically significant difference in demographics between patients with and without follow-up data available, this low response rate could have introduced selection bias. Ideally, patients should have been seen in clinic, standing radiographs should have been taken, and pulmonary function tests should have been performed. However, these patients were asymptomatic, and ethical and insurance issues prevented those actions. Thus, any radiographic changes occurring over the intervening years, from the last clinic visit to completion of the surveys, were not documented. This situation may or may not have limited our findings, as other authors have found low correlation between radiographic outcomes and clinical outcome measures.^13,14,19,36 During the period when these surgeries were performed, segmental spine instrumentation with hooks was the standard of care for deformity correction in AIS; therefore, all posterior instrumentations were done with hook-only segmental fixation. Current pedicle screw–based techniques that allow for additional correction of the deformity may provide different outcomes in the future.

We think that, despite the inherent limitations of this study, our data will be useful in the treatment of AIS. Our results suggest that postoperative spinal complaints are common and that, compared with an unaffected adolescent population, patients with AIS score significantly lower on pain and appearance domains of outcomes testing at a mean of 12.7 years after index fusion. Nevertheless, the outcomes do not seem to be of sufficient severity to affect general health and QOL as measured by outcomes testing.

Spinal deformity correction is performed to prevent impaired pulmonary function and spine-related disability later in life.^42,43 Thus, longer-term studies, involving patients in their fifth and sixth decades of life, are needed to determine whether patients with AIS will have QOL outcomes, pulmonary function, and spine-related problems similar to those in the general population. In this cohort of young adults, smoking status was the only predictor of HR-QOL measures, and spinal deformity correction did not lead to decreased HR-QOL.

The goal of surgical treatment of adolescent idiopathic scoliosis (AIS) is to prevent disability associated with curve progression.¹ Early studies tended to focus on radiographic measures, such as curve correction and sagittal balance, rather than on improvements in quality of life (QOL).^2-5 Although studies have reported on QOL in patients treated surgically for scoliosis,^6-11 these studies were largely limited by small sample size and inclusion of patients with congenital and neuromuscular scoliosis,⁹ lack of a generic measure of QOL,^6,7 or lack of surgical treatment of patients in the cohort.¹⁰

We conducted a study to determine disease-specific and general health-related QOL (HR-QOL) in young adults who underwent surgical correction of their spinal deformity during adolescence and to evaluate associated complications and reoperations.

Materials and Methods

After obtaining institutional review board approval, we queried the surgical database of a large metropolitan tertiary referral center for consecutive patients who had undergone spine deformity correction between the ages of 10 and 17 years (January 1993–December 2003). Hospital and medical records were retrospectively reviewed to confirm the diagnosis of AIS. Patients with congenital, neuromuscular, juvenile, or infantile scoliosis were excluded. Patients with intraspinal pathology (eg, tethered cord, syringomyelia), developmental delay, chromosomal abnormality, or congenital heart disease were also excluded. Patients were contacted by mail or telephone, and the Scoliosis Research Society–22R (SRS-22R)^12-15 and the Short Form–12 (SF-12)¹⁶ were administered. Standard demographic and surgical data were also collected.

The SRS-22R is a scoliosis-specific HR-QOL questionnaire with 22 items, 5 domains (pain, activity, appearance, mental, satisfaction), and a total score.^12-15 Each domain score ranges from 1 to 5 (higher scores indicating better outcomes). The SRS-22R is the outcome instrument most widely used to measure HR-QOL changes in patients with scoliosis, and it is available in several languages.^17-26

The SF-12, a 12-item self-administered short-form health status survey developed in the Medical Outcomes Study, measures patient-based health status. Two composite scores can be calculated: physical composite summary (PCS) and mental composite summary (MCS).¹⁶ Using norm-based scoring, all domain scales have a mean (SD) of 50 (10) based on the general 1998 US population. Thus, scores under 50 fall below the general population mean.

In addition, patients were surveyed to determine the incidence of spine-related symptoms and complaints, including activity limitations, rib prominence, waistline asymmetry, back pain, limited range of motion (ROM), shortness of breath, wound/scar problems, lung disease/asthma, heart disease, high blood pressure, and arthritis. Data regarding postoperative treatment regimens of physical therapy, narcotic pain medication, spinal/epidural injections, and nonsteroidal anti-inflammatory drug (NSAID) use were collected. Patients were also queried regarding their current working status and smoking status.

Standard demographic and surgical data were collected from hospital and office charts and radiographs. Data collected included history of bracing, age at index surgery, number of levels fused, surgical approach (anterior, posterior, combined), postoperative complications (eg, ileus, wound infection, anemia, pneumonia), and immediate preoperative and final postoperative radiographic measures. Data on need for subsequent revision surgery and indications for revision surgery were also collected.

Preoperative and latest follow-up radiographs were measured to determine curve magnitude, sagittal and coronal balance, and percentage curve correction. Coronal balance was defined as the distance between a plumb line drawn vertically from the spinous process of C7 and the central sacral line on full-length posteroanterior radiographs. Sagittal balance was defined as the distance of a plumb line drawn vertically from the center of the body of C7 and the posterosuperior endplate of S1.²⁷

Regression analysis was performed to identify factors predictive of SRS-22R total scores. Factors included in the analysis were sex, age at surgery, Lenke type, surgery type (anterior, posterior, anteroposterior), number of levels fused, lowest instrumented vertebra, perioperative complications, percentage curve correction, postoperative coronal and sagittal balance, smoking status, and need for revision surgery. Although age and sex were considered variables outside the surgeon’s control, they were included in the model, as previous studies have shown that SRS scores varied by age and sex both in adolescents²⁸ and adults.²⁹ Significance was set at P < .01. All data analysis was performed with IBM SPSS Version 19.0 (Somers, New York).

Results

Of the 384 postoperative patients identified for study inclusion, 134 (35%) completed surveys. Sixteen patients with nonidiopathic scoliosis were excluded, leaving 118 available for analysis. Of the remaining patients, 248 (64%) could not be contacted because of a change in address or phone number. Two patients (1%) were unwilling to complete survey requests. There was no statistically significant difference in demographics between patients with and without follow-up data available. Demographics are summarized in Table 1. There were 109 females (92%). Mean (SD) age at surgery was 14.1 (1.9) years. Only 37 (31%) were braced before surgery. Table 2 summarizes the radiographic data. Mean (SD) major Cobb angle was 49.7° (7.8°). Eighty-five patients (72%) underwent posterior fusion with instrumentation using hooks only; another 16 (14%) had anterior-only surgery, and another 17 (14%) had combined anterior-posterior surgery. A mean of 7.8 levels were fused. Index surgery data and lowest instrumented vertebra distribution are summarized in Table 3. Mean (SD) percentage curve correction was 48.9% (8.4%).

Seven patients had a total of 8 perioperative complications: anemia requiring transfusion (2), ileus necessitating nasogastric tube insertion (2), superficial wound infection treated with oral antibiotics and local wound care (2), wound drainage and erythema (1), and pneumonia (1). Mean (SD) length of clinical and radiographic follow-up was 57.9 (36.3) months.

Table 4 summarizes the long-term complications. Of the 38 patients with long-term complications, 14 required reoperation. The indications were disc herniation (2 patients), painful instrumentation (7), crankshaft phenomenon (1), nonunion (1), and adjacent-level degeneration (3). Both disc herniations were at L5–S1, several segments below the distal extent of the fusion. Of the 7 patients who had painful instrumentation removed, 6 had the entire construct removed, and 1 had the proximal half of a rod taken out. The 3 patients with adjacent-level degeneration had stenosis at the distal end of the construct—at L5–S1 (2 patients) or L2–L3 (1 patient).

Mean (SD) time between surgery and completion of the surveys/questionnaires was 12.7 (3.2) years (range, 10-18 years). Mean age of respondents was 26.8 years. Twenty-five respondents (21%) were smokers. Mean (SD) outcome scores were 50.9 (9.4) for SF-12 PCS and 49.4 (10.2) for SF-12 MCS. Eighteen patients (15%) had SF-12 PCS scores 1 SD below normal, and 15 (13%) had SF-12 MCS scores 1 SD below normal. Mean (SD) SRS-22R Total score was 4.0 (0.7). Means, standard deviations, and distribution of SRS domain scores are summarized in Table 5. Of the variables, only current smoking (P < .001) was predictive of SRS-22R Total scores, accounting for 20% of their variability (Table 6).

One hundred patients (85%) had jobs, mostly desk jobs. The postoperative limitations most commonly reported are summarized in Table 7. These included at least intermittent back pain in 90 patients (76%), limited ROM in 52 (44%), and activity limitations in 54 (46%). Less common limitations were waistline imbalance in 41 (35%), rib prominence in 28 (24%), wound/scar problems in 18 (15%), and shortness of breath in 18 (15%). Other related medical problems were lung disease/asthma in 11 (9%), osteoarthritis/degenerative arthritis in 11 (9%), heart disease in 3 (3%), and high blood pressure in 2 (2%).

A minority of patients also participated in postoperative treatment regimens. The most common treatment was regular use of NSAIDs (25 patients, 21%). Other treatments were physical therapy (14, 12%), narcotic pain medication use (5, 4%), and epidural steroid injections (5, 4%). Table 8 summarizes the postoperative treatments used by patients with scoliosis.

Discussion

A major concern about prophylactic interventions for diseases is that the treatment will harm the patient. This is especially true for major spine surgery performed on adolescents with minimal symptoms. Although the incidence of perioperative complications in children undergoing corrective spinal surgery for AIS has been reported,^30-32 the effect of the surgery on the disease-specific HR-QOL outcomes of these individuals as young adults has not been previously studied. Over the past few decades, a paradigm shift in understanding health and disability has occurred, with increased emphasis being placed on HR-QOL outcomes measures and understanding disability as relating to a measureable impact of the functioning of an individual after a change in health or environment. This change was substantiated when the World Health Organization endorsed the International Classification of Functioning, Disability and Health.³³ In light of this shift, we present the disease-specific and general HR-QOL outcomes of young adults who had undergone surgical correction for spinal deformity during adolescence, as well as their associated complications and reoperations, in an attempt to identify targets for improvement.

Our patient-reported outcomes demonstrated a high incidence of occasional back pain, activity-related complaints, and limited ROM. Comparison of our cohort’s SRS-22R outcomes with previously published normative values for the unaffected adolescent population^28,34 suggests worse scores for the disease-specific SRS-22R domains of pain and appearance. In 2012, Daubs and colleagues³⁴ reported that normative scores on various SRS-22 domains were statistically lower with age (scores decreased from age 10 to age 19 years). Both Verma and colleagues²⁸ and Daubs and colleagues³⁴ reported lower scores for females than for males. Therefore, it is unclear whether the differences observed in our cohort may be accounted for by the larger proportion of females compared with the normative data.

General health scores on the SF-12 were similar to the population norm (mean [SD]) of 50 (10) referenced by Ware and colleagues.¹⁶ These findings suggest that, though pain and appearance may be statistically lower in our cohort—as measured with the SRS-22R—the cohort’s spine-related symptoms do not seem to lower its general health. Eighty-five percent of the patients were working at the time of the survey, further supporting a relatively normal level of overall function. In a retrospective review by Takayama and colleagues,⁹ similar results were found with regard to working after AIS fusion surgery. Of 32 patients treated surgically for scoliosis, at a mean of 21.1 years after the index fusion 27 (84.4%) were or had been engaged in various occupations without marked difficulty.

Our results in a cohort of patients with segmental instrumentation using hooks are similar to results in other studies of long-term HR-QOL measures in patients with AIS and Harrington rod instrumentation. Danielsson and Nachemson³⁵ evaluated patients with surgically treated AIS with at least 20-year follow-up and reported that, in their surgical cohort with a mean age of 39.7 years, mean SF-36 PCS score was 50.9, and mean SF-36 MCS score was 50.2. In a recent study of patients with AIS and Harrington rod instrumentation, those of a mean age of 32.3 years had a mean score of 50.9 for both SF-36 PCS and SF-36 MCS.³⁶

Regression analysis identified only smoking as a predictor of SRS-22R Total scores. This finding, that smokers have a lower health state, is expected even in the general population.³⁷ Interestingly, bracing before surgery, Lenke type, surgery type, number of levels fused, lowest instrumented vertebra, incidence of perioperative complications, percentage curve correction, postoperative sagittal and coronal balance, and need for revision surgery did not influence HR-QOL measures in this cohort.

Our cohort’s incidence of occasional back pain was 76% (90/118 patients). Other reports have had similar findings. In 2012, Bas and colleagues³⁸ studied self-reported pain in 126 consecutive patients with scoliosis and instrumented fusion. In their cohort, “most participants reported ‘no pain’ (38.5%) or ‘mild pain’ (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal.” Also in 2012, Rushton and Grevitt³⁹ reported on a review and statistical analysis of the literature on HR-QOL in adolescents with untreated AIS and in unaffected adolescents. Their goal was to identify whether there were any differences in HR-QOL and, if so, whether they were clinically relevant. The authors concluded that pain and self-image tended to be statistically lower among cohorts with AIS but that only self-image was consistently different clinically between untreated patients with AIS and their unaffected peers.

Cosmetic complaints, though less common than functional concerns, affected a substantial percentage of our cohort. Waistline imbalance complaints were more common than rib prominence or scar-related complaints. The validity of patient-reported waistline imbalance is not known but may contribute to the SRS-22R outcomes in this cohort, particularly with regard to appearance scores. Respiratory symptoms, particularly those related to shortness of breath, were reported by 15% of patients. Respiratory symptoms may be in part secondary to underlying lung disease; smoking was reported by 21% of patients and asthma by 9%.

Few additional postoperative treatments were reported by patients. The most common treatment was regular use of NSAIDs (21%), followed by postoperative physical therapy (12%). Opiate medication use and spinal injections were rare—consistent with results reported by Danielsson and Nachemson³⁵ in 2003.

Implant-related complaints, including painful instrumentation (13%) and implant prominence (9%), were some of the most common complaints in our study group. Although not all symptomatic instrumentation required surgical revision, 7 (50%) of the 14 additional spine surgeries were related to painful and/or prominent posterior instrumentation. Additional spine surgery was reported in 11.9% of our patients. Other indications for reoperation were disc herniation, crankshaft phenomenon, nonunion, and adjacent-level degeneration. Our rate of revision surgery is supported by the literature. In 2009, Luhmann and colleagues⁴⁰ reported that 41 (3.9%) of 1057 primary spine fusions for idiopathic scoliosis required reoperation; the indications included infection (16/1057, 1.5%), pseudarthrosis (12, 1.1%), and painful/prominent implant (7, 0.7%). Richards and colleagues⁴¹ similarly reported on 1046 patients who underwent fusion for AIS. Of these patients, 135 underwent 172 repeat surgical interventions (12.9% reoperation rate), with 29 (21.5%) of the 135 undergoing 2 or more separate procedures. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. The authors concluded that repeat surgeries were relatively common after the initial surgical procedures. Having a clearer understanding of instrumentation-related complaints and reoperations may lead to improvement in this surgeon-controlled variable.

There are limitations to this study. The data regarding clinical courses were collected by retrospective chart review, which has known limitations. To offset this, we collected prospective outcome data with use of the SF-12, the SRS-22R, and a spine-related complaints questionnaire. No control group was available for comparison of outcomes in our cohort. We used the SF-12 and previously published normative values for the SRS-22R for comparison with population norms. Such comparisons have inherent limitations, as the groups vary by sex and mean age; our cohort was primarily female and more than a decade older than the controls.

Only 35% of the patients who met the inclusion criteria had complete data that could be included in our analysis. Although there was no statistically significant difference in demographics between patients with and without follow-up data available, this low response rate could have introduced selection bias. Ideally, patients should have been seen in clinic, standing radiographs should have been taken, and pulmonary function tests should have been performed. However, these patients were asymptomatic, and ethical and insurance issues prevented those actions. Thus, any radiographic changes occurring over the intervening years, from the last clinic visit to completion of the surveys, were not documented. This situation may or may not have limited our findings, as other authors have found low correlation between radiographic outcomes and clinical outcome measures.^13,14,19,36 During the period when these surgeries were performed, segmental spine instrumentation with hooks was the standard of care for deformity correction in AIS; therefore, all posterior instrumentations were done with hook-only segmental fixation. Current pedicle screw–based techniques that allow for additional correction of the deformity may provide different outcomes in the future.

We think that, despite the inherent limitations of this study, our data will be useful in the treatment of AIS. Our results suggest that postoperative spinal complaints are common and that, compared with an unaffected adolescent population, patients with AIS score significantly lower on pain and appearance domains of outcomes testing at a mean of 12.7 years after index fusion. Nevertheless, the outcomes do not seem to be of sufficient severity to affect general health and QOL as measured by outcomes testing.

Spinal deformity correction is performed to prevent impaired pulmonary function and spine-related disability later in life.^42,43 Thus, longer-term studies, involving patients in their fifth and sixth decades of life, are needed to determine whether patients with AIS will have QOL outcomes, pulmonary function, and spine-related problems similar to those in the general population. In this cohort of young adults, smoking status was the only predictor of HR-QOL measures, and spinal deformity correction did not lead to decreased HR-QOL.