Hip

We report the case of a patient who was treated with total hip arthroplasty (THA) for osteoarthritis but was found to have a large acetabular defect caused by pulmonary metastasis. She was promptly referred to our orthopedic oncology clinic for revision because she had experienced no improvement in her symptoms. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 61-year-old woman was referred to us for evaluation of a large right supra-acetabular lesion after undergoing a right THA at another hospital 3 weeks earlier. Preoperative radiographs showed severe osteoarthritis of the right hip but there was no diagnosis of an acetabular lesion in her medical history. During the operation, the surgeon noted poor acetabulum bone quality and sent acetabular reamings for histopathologic analysis, which revealed adenocarcinoma. The arthroplasty was completed in a normal fashion, and the patient was discharged. Postoperatively, her pain did not resolve, and her functional status deteriorated from ambulating with a walker to very limited activity and weight-bearing.

When the patient came to our clinic, we learned she underwent a lobectomy in 2011 for lung cancer resulting from her 40-pack-year history of smoking and had a strong family history of breast cancer. She also had a history of coronary artery disease, hypertension, hyperlipidemia, morbid obesity, and depression. We obtained plain films and a computed tomography (CT) scan that showed a 6.5×7.1×6.5-cm lytic lesion arising from the right acetabulum with cortical penetration and an extraosseous soft-tissue component. Two smaller 10-mm to 12-mm lesions were also found superior and medial to the large lesion. These radiographs and CT images are shown in Figures 1-3.

We discussed nonoperative and operative options for treatment with the patient and her family, and she elected to undergo palliative surgical curettage and fixation. Significant bone erosion of the acetabulum and a resultant lack of mechanical support for the acetabular cup were found intraoperatively. An unusual surgical approach was selected in order to minimize morbidity and avoid performing a revision acetabular component if the cup was found to be stable from the standpoint of osseointegration. We approached from the superior side of the ilium, removing the abductors in the superperiosteal fashion extending down from the supra-acetabular ilium, sparing the hip capsule. When the acetabular component was exposed and stressed under fluoroscopy, there was no evidence of loosening. We decided to reconstruct the mechanical defect without revision of the acetabular component and to leave the screw in place. After partial excision of the right supra-acetabular ilium, specimens were sent to pathology. We placed five 4.8-mm and four 4.0-mm threaded Steinmann pins intraosseously through the iliac wing to abut the acetabular cup. In this way, the Steinmann pins provided a stable roof to the cup for weight-bearing and scaffolding for methylmethacrylate cement impregnated with tobramycin. A postoperative radiograph of the patient’s pelvis is shown in Figure 4.

Immediately after her surgery, the patient was bearing weight as tolerated and participating in physical therapy 3 times a day. Two months postoperatively, she was able to walk 1 block with use of a walker, and her pain was controlled with oral pain medication. At her 1-year visit, she was walking without pain for prolonged distances. She had a mild limp but did not need ambulatory aids. She had full range of motion, was able to perform all of her desired activities, and was quite pleased with her result. One-year postoperative radiographs (Figure 5) show stable placement of her acetabular cup with her pins and cement in an unchanged position without recurrence of her destructive lesion. There was no evidence of progression of her cancer, although she had some heterotopic bone in her lateral soft tissues.

Discussion

Many cases have been reported in the literature of metastases to the pelvis and acetabulum; almost 10% of bone metastases are in the pelvis.¹ Although many are seen on radiographs, pelvic metastases, especially if they involve the acetabulum, can present with hip pain, decreased joint range of motion, and reduced ambulatory function, all symptoms that are similar to osteoarthritis. While the presence of metastases indicates late-stage disease, many patients still live for years with hip symptoms before succumbing to cancer.¹ Palliative treatment initially consists of protected weight-bearing, analgesics, antineoplastic medications ,and radiation. When these first-line therapies fail, palliative operative treatment can be considered, with goals to maintain stability and to preserve mobility, independence, and comfort.² Patients should be offered this only if there is a reasonable chance that structural stability can be achieved via reconstruction and if the patient will live long enough to realize the functional improvement.³ Harrington⁴ described patterns of acetabular metastases and surgical treatments in his classic series of 58 patients. For class II and III lesions, he concluded it was necessary to provide additional structural support to the acetabular component of a THA, either in the form of a protrusion shell or with Steinmann pins and bone cement.⁴ Antiprotrusion cages combined with arthroplasty have been used with modest success for cases where implant bone integration is unlikely.^5-6 Several studies since Harrington have shown that constructs with cement reinforced with Steinmann pins can provide reduced pain and improved mobility with a low failure rate for the remainder of the patient’s life.^7-9

In addition, a few cases have been reported of metastases to endoprostheses, which were implanted long before the diagnosis of cancer.¹⁰ To an unsuspecting surgeon, the lytic periprosthetic metastases may look like osteolysis or pseudotumor. Fabbri and colleagues¹¹ presented 4 cases showing how sarcoma around a joint endoprosthesis can easily be mistaken for pseudotumor. A patient considering primary or revision THA for bone loss caused by osteolysis would be given different options than if the bone loss were secondary to metastases. Revision techniques in the setting of acetabular osteolysis include acetabular liner exchanges, cementless hemispherical components and jumbo cups, structural allografts, metal augments, impaction grafting, and acetabular cages and cup-cage constructs. Rarely are “Harrington” reconstructions performed for this reason.¹²

This case is unusual because the diagnosis of metastatic disease was missed and THA was performed under the presumptive diagnosis of osteoarthritis. While a malignant process was recognized intraoperatively, the joint replacement was completed nonetheless, with revision surgery inevitably occurring within a few weeks. Our patient’s history of lung cancer reinforces the importance of preoperative history taking, and the missed diagnosis highlights the need for clinicians to maintain a broad differential, even in seemingly simple arthritis cases. Proper preoperative imaging, biopsies, and cultures are also paramount. Lesions that are painful, involve the whole cortex, appear soon after implementation, and are rapidly progressing should raise concern for malignancy.¹⁰ If there is concern for osteolysis, quantitative CT with 3-dimensional reconstructions can help visualize the lesions and help in planning surgery.¹³ Had a timely diagnosis been made, the proper reconstruction could have been planned before the index procedure, and our patient could have been spared the pain, risk, and morbidity of a second operation.

The second lesson of this case is that, as long as the cup was stable, the etiology of the hip pain was lack of mechanical support. Once corrected, the total hip functioned as planned. A minimally invasive approach that allowed for observation of the cup without exposing the entire hip saved a patient a significant amount of morbidity and led to an acceptable outcome.

We report the case of a patient who was treated with total hip arthroplasty (THA) for osteoarthritis but was found to have a large acetabular defect caused by pulmonary metastasis. She was promptly referred to our orthopedic oncology clinic for revision because she had experienced no improvement in her symptoms. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 61-year-old woman was referred to us for evaluation of a large right supra-acetabular lesion after undergoing a right THA at another hospital 3 weeks earlier. Preoperative radiographs showed severe osteoarthritis of the right hip but there was no diagnosis of an acetabular lesion in her medical history. During the operation, the surgeon noted poor acetabulum bone quality and sent acetabular reamings for histopathologic analysis, which revealed adenocarcinoma. The arthroplasty was completed in a normal fashion, and the patient was discharged. Postoperatively, her pain did not resolve, and her functional status deteriorated from ambulating with a walker to very limited activity and weight-bearing.

When the patient came to our clinic, we learned she underwent a lobectomy in 2011 for lung cancer resulting from her 40-pack-year history of smoking and had a strong family history of breast cancer. She also had a history of coronary artery disease, hypertension, hyperlipidemia, morbid obesity, and depression. We obtained plain films and a computed tomography (CT) scan that showed a 6.5×7.1×6.5-cm lytic lesion arising from the right acetabulum with cortical penetration and an extraosseous soft-tissue component. Two smaller 10-mm to 12-mm lesions were also found superior and medial to the large lesion. These radiographs and CT images are shown in Figures 1-3.

We discussed nonoperative and operative options for treatment with the patient and her family, and she elected to undergo palliative surgical curettage and fixation. Significant bone erosion of the acetabulum and a resultant lack of mechanical support for the acetabular cup were found intraoperatively. An unusual surgical approach was selected in order to minimize morbidity and avoid performing a revision acetabular component if the cup was found to be stable from the standpoint of osseointegration. We approached from the superior side of the ilium, removing the abductors in the superperiosteal fashion extending down from the supra-acetabular ilium, sparing the hip capsule. When the acetabular component was exposed and stressed under fluoroscopy, there was no evidence of loosening. We decided to reconstruct the mechanical defect without revision of the acetabular component and to leave the screw in place. After partial excision of the right supra-acetabular ilium, specimens were sent to pathology. We placed five 4.8-mm and four 4.0-mm threaded Steinmann pins intraosseously through the iliac wing to abut the acetabular cup. In this way, the Steinmann pins provided a stable roof to the cup for weight-bearing and scaffolding for methylmethacrylate cement impregnated with tobramycin. A postoperative radiograph of the patient’s pelvis is shown in Figure 4.

Immediately after her surgery, the patient was bearing weight as tolerated and participating in physical therapy 3 times a day. Two months postoperatively, she was able to walk 1 block with use of a walker, and her pain was controlled with oral pain medication. At her 1-year visit, she was walking without pain for prolonged distances. She had a mild limp but did not need ambulatory aids. She had full range of motion, was able to perform all of her desired activities, and was quite pleased with her result. One-year postoperative radiographs (Figure 5) show stable placement of her acetabular cup with her pins and cement in an unchanged position without recurrence of her destructive lesion. There was no evidence of progression of her cancer, although she had some heterotopic bone in her lateral soft tissues.

Discussion

Many cases have been reported in the literature of metastases to the pelvis and acetabulum; almost 10% of bone metastases are in the pelvis.¹ Although many are seen on radiographs, pelvic metastases, especially if they involve the acetabulum, can present with hip pain, decreased joint range of motion, and reduced ambulatory function, all symptoms that are similar to osteoarthritis. While the presence of metastases indicates late-stage disease, many patients still live for years with hip symptoms before succumbing to cancer.¹ Palliative treatment initially consists of protected weight-bearing, analgesics, antineoplastic medications ,and radiation. When these first-line therapies fail, palliative operative treatment can be considered, with goals to maintain stability and to preserve mobility, independence, and comfort.² Patients should be offered this only if there is a reasonable chance that structural stability can be achieved via reconstruction and if the patient will live long enough to realize the functional improvement.³ Harrington⁴ described patterns of acetabular metastases and surgical treatments in his classic series of 58 patients. For class II and III lesions, he concluded it was necessary to provide additional structural support to the acetabular component of a THA, either in the form of a protrusion shell or with Steinmann pins and bone cement.⁴ Antiprotrusion cages combined with arthroplasty have been used with modest success for cases where implant bone integration is unlikely.^5-6 Several studies since Harrington have shown that constructs with cement reinforced with Steinmann pins can provide reduced pain and improved mobility with a low failure rate for the remainder of the patient’s life.^7-9

In addition, a few cases have been reported of metastases to endoprostheses, which were implanted long before the diagnosis of cancer.¹⁰ To an unsuspecting surgeon, the lytic periprosthetic metastases may look like osteolysis or pseudotumor. Fabbri and colleagues¹¹ presented 4 cases showing how sarcoma around a joint endoprosthesis can easily be mistaken for pseudotumor. A patient considering primary or revision THA for bone loss caused by osteolysis would be given different options than if the bone loss were secondary to metastases. Revision techniques in the setting of acetabular osteolysis include acetabular liner exchanges, cementless hemispherical components and jumbo cups, structural allografts, metal augments, impaction grafting, and acetabular cages and cup-cage constructs. Rarely are “Harrington” reconstructions performed for this reason.¹²

This case is unusual because the diagnosis of metastatic disease was missed and THA was performed under the presumptive diagnosis of osteoarthritis. While a malignant process was recognized intraoperatively, the joint replacement was completed nonetheless, with revision surgery inevitably occurring within a few weeks. Our patient’s history of lung cancer reinforces the importance of preoperative history taking, and the missed diagnosis highlights the need for clinicians to maintain a broad differential, even in seemingly simple arthritis cases. Proper preoperative imaging, biopsies, and cultures are also paramount. Lesions that are painful, involve the whole cortex, appear soon after implementation, and are rapidly progressing should raise concern for malignancy.¹⁰ If there is concern for osteolysis, quantitative CT with 3-dimensional reconstructions can help visualize the lesions and help in planning surgery.¹³ Had a timely diagnosis been made, the proper reconstruction could have been planned before the index procedure, and our patient could have been spared the pain, risk, and morbidity of a second operation.

The second lesson of this case is that, as long as the cup was stable, the etiology of the hip pain was lack of mechanical support. Once corrected, the total hip functioned as planned. A minimally invasive approach that allowed for observation of the cup without exposing the entire hip saved a patient a significant amount of morbidity and led to an acceptable outcome.

We report the case of a patient who was treated with total hip arthroplasty (THA) for osteoarthritis but was found to have a large acetabular defect caused by pulmonary metastasis. She was promptly referred to our orthopedic oncology clinic for revision because she had experienced no improvement in her symptoms. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 61-year-old woman was referred to us for evaluation of a large right supra-acetabular lesion after undergoing a right THA at another hospital 3 weeks earlier. Preoperative radiographs showed severe osteoarthritis of the right hip but there was no diagnosis of an acetabular lesion in her medical history. During the operation, the surgeon noted poor acetabulum bone quality and sent acetabular reamings for histopathologic analysis, which revealed adenocarcinoma. The arthroplasty was completed in a normal fashion, and the patient was discharged. Postoperatively, her pain did not resolve, and her functional status deteriorated from ambulating with a walker to very limited activity and weight-bearing.

When the patient came to our clinic, we learned she underwent a lobectomy in 2011 for lung cancer resulting from her 40-pack-year history of smoking and had a strong family history of breast cancer. She also had a history of coronary artery disease, hypertension, hyperlipidemia, morbid obesity, and depression. We obtained plain films and a computed tomography (CT) scan that showed a 6.5×7.1×6.5-cm lytic lesion arising from the right acetabulum with cortical penetration and an extraosseous soft-tissue component. Two smaller 10-mm to 12-mm lesions were also found superior and medial to the large lesion. These radiographs and CT images are shown in Figures 1-3.

We discussed nonoperative and operative options for treatment with the patient and her family, and she elected to undergo palliative surgical curettage and fixation. Significant bone erosion of the acetabulum and a resultant lack of mechanical support for the acetabular cup were found intraoperatively. An unusual surgical approach was selected in order to minimize morbidity and avoid performing a revision acetabular component if the cup was found to be stable from the standpoint of osseointegration. We approached from the superior side of the ilium, removing the abductors in the superperiosteal fashion extending down from the supra-acetabular ilium, sparing the hip capsule. When the acetabular component was exposed and stressed under fluoroscopy, there was no evidence of loosening. We decided to reconstruct the mechanical defect without revision of the acetabular component and to leave the screw in place. After partial excision of the right supra-acetabular ilium, specimens were sent to pathology. We placed five 4.8-mm and four 4.0-mm threaded Steinmann pins intraosseously through the iliac wing to abut the acetabular cup. In this way, the Steinmann pins provided a stable roof to the cup for weight-bearing and scaffolding for methylmethacrylate cement impregnated with tobramycin. A postoperative radiograph of the patient’s pelvis is shown in Figure 4.

Immediately after her surgery, the patient was bearing weight as tolerated and participating in physical therapy 3 times a day. Two months postoperatively, she was able to walk 1 block with use of a walker, and her pain was controlled with oral pain medication. At her 1-year visit, she was walking without pain for prolonged distances. She had a mild limp but did not need ambulatory aids. She had full range of motion, was able to perform all of her desired activities, and was quite pleased with her result. One-year postoperative radiographs (Figure 5) show stable placement of her acetabular cup with her pins and cement in an unchanged position without recurrence of her destructive lesion. There was no evidence of progression of her cancer, although she had some heterotopic bone in her lateral soft tissues.

Discussion

Many cases have been reported in the literature of metastases to the pelvis and acetabulum; almost 10% of bone metastases are in the pelvis.¹ Although many are seen on radiographs, pelvic metastases, especially if they involve the acetabulum, can present with hip pain, decreased joint range of motion, and reduced ambulatory function, all symptoms that are similar to osteoarthritis. While the presence of metastases indicates late-stage disease, many patients still live for years with hip symptoms before succumbing to cancer.¹ Palliative treatment initially consists of protected weight-bearing, analgesics, antineoplastic medications ,and radiation. When these first-line therapies fail, palliative operative treatment can be considered, with goals to maintain stability and to preserve mobility, independence, and comfort.² Patients should be offered this only if there is a reasonable chance that structural stability can be achieved via reconstruction and if the patient will live long enough to realize the functional improvement.³ Harrington⁴ described patterns of acetabular metastases and surgical treatments in his classic series of 58 patients. For class II and III lesions, he concluded it was necessary to provide additional structural support to the acetabular component of a THA, either in the form of a protrusion shell or with Steinmann pins and bone cement.⁴ Antiprotrusion cages combined with arthroplasty have been used with modest success for cases where implant bone integration is unlikely.^5-6 Several studies since Harrington have shown that constructs with cement reinforced with Steinmann pins can provide reduced pain and improved mobility with a low failure rate for the remainder of the patient’s life.^7-9

In addition, a few cases have been reported of metastases to endoprostheses, which were implanted long before the diagnosis of cancer.¹⁰ To an unsuspecting surgeon, the lytic periprosthetic metastases may look like osteolysis or pseudotumor. Fabbri and colleagues¹¹ presented 4 cases showing how sarcoma around a joint endoprosthesis can easily be mistaken for pseudotumor. A patient considering primary or revision THA for bone loss caused by osteolysis would be given different options than if the bone loss were secondary to metastases. Revision techniques in the setting of acetabular osteolysis include acetabular liner exchanges, cementless hemispherical components and jumbo cups, structural allografts, metal augments, impaction grafting, and acetabular cages and cup-cage constructs. Rarely are “Harrington” reconstructions performed for this reason.¹²

This case is unusual because the diagnosis of metastatic disease was missed and THA was performed under the presumptive diagnosis of osteoarthritis. While a malignant process was recognized intraoperatively, the joint replacement was completed nonetheless, with revision surgery inevitably occurring within a few weeks. Our patient’s history of lung cancer reinforces the importance of preoperative history taking, and the missed diagnosis highlights the need for clinicians to maintain a broad differential, even in seemingly simple arthritis cases. Proper preoperative imaging, biopsies, and cultures are also paramount. Lesions that are painful, involve the whole cortex, appear soon after implementation, and are rapidly progressing should raise concern for malignancy.¹⁰ If there is concern for osteolysis, quantitative CT with 3-dimensional reconstructions can help visualize the lesions and help in planning surgery.¹³ Had a timely diagnosis been made, the proper reconstruction could have been planned before the index procedure, and our patient could have been spared the pain, risk, and morbidity of a second operation.

The second lesson of this case is that, as long as the cup was stable, the etiology of the hip pain was lack of mechanical support. Once corrected, the total hip functioned as planned. A minimally invasive approach that allowed for observation of the cup without exposing the entire hip saved a patient a significant amount of morbidity and led to an acceptable outcome.

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts or animal products. Infection of total knee or hip arthroplasty by Brucella species is a rare complication with only 18 cases reported in the English literature.^1-12 We describe a case of an infected total hip replacement, its treatment, and 2-year follow-up and review the available literature. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 67-year-old Spanish-speaking woman, a native of Mexico, presented with a painful right total hip arthroplasty (THA) 2 years after implantation in Chihuahua, Mexico. The patient reported 1 year of increasing thigh pain with recent onset of start-up pain, and also mild groin pain. The patient reported an uneventful postoperative course without wound drainage and denied any history of fevers, chills, or night sweats after the procedure. Preoperative notes and radiographs were unavailable for review. Radiographic evaluation showed a hybrid construct with a well-fixed–appearing, uncemented acetabular component but a failed cemented femoral stem (Figures 1A, 1B). Although we discussed revision surgery, the patient elected not to proceed with surgery or to undergo evaluation to rule out infection. Nine months later, she returned with worsening pain and requested revision surgery; radiographs showed progressive bone loss around the cement mantle (Figures 2A, 2B).

Hematologic evaluation showed an erythrocyte sedimentation rate (ESR) of 54 mm/h (normal, 0-27 mm/h) and C-reactive protein (CRP) level of 0.24 mg/L (normal, <0.8). An aspiration of the hip with fluoroscopic guidance produced a small sample (0.2 mL) of yellow synovial fluid. There was not enough fluid for cell count, but fluid culture was negative.

The patient was taken to the operating room for revision THA. Because of concern about progressive bone loss and elevated infectious indices, the administration of antibiotics was delayed until we obtained sufficient deep-tissue specimens. Before opening the capsule, we introduced a syringe into the joint and aspirated 10 mL of cloudy yellow synovial fluid that was sent for cell count. Additional findings at surgery included a grossly loose stem with a fragmented cement mantle surrounded by poor bone stock with anterior cortical bone loss and a loose acetabular component with pockets of cavitary bone loss. Frozen section showed up to 5 nucleated cells per high power field, and the cell count showed 1480 nucleated cells/µL (50% polymorphonuclear cells). The equivocal intraoperative findings (cell count and frozen section) and the loose femoral and acetabular components with significant bone loss were sufficiently concerning that we removed the components and placed a cement spacer rather than proceed with revision arthroplasty (Figures 3A, 3B). The surgeon, first assistant, and scrub technician wore body exhaust suits. We performed irrigation of the wound bed with pulse lavage.

Intraoperative cultures (synovial fluid, joint capsule synovium, and femur pseudocapsule) were positive after 8 days and growing B abortus. Infectious disease consultants prescribed rifampin 300 mg twice daily and doxycycline 100 mg twice daily for 5 months. Follow-up ESR and CRP returned to normal range. A preoperative aspiration of the hip was negative as well. The patient returned to the operating room at 6 months for re-implantation using uncemented components; synovial fluid and tissue cultures taken at this time were negative. Two years after re-implantation, the patient is doing well without evidence of infection (Figures 4A, 4B). Additional follow-up will be required to monitor for infection and implant survival. Additional history taken from the patient after the culture results revealed that her development of hip pain was preceded by a febrile illness consistent with brucellosis. 

Because of the nature of the procedure (irrigation and débridement using pulse lavage), we were concerned about aerosolization of Brucella bacteria and possible transmission to all staff present during the procedure. After consulting with the New Mexico Department of Health (NMDOH) and the Centers for Disease Control and Prevention (CDC), all surgical, anesthesia, and support personnel present in the operative suite  and staff who cleaned the room after the procedure were treated prophylactically (rifampin 600 mg daily, doxycycline 100 mg twice daily for 3 weeks) to prevent development of brucellosis.¹³ All 15 operating room personnel who were exposed elected to proceed with antibiotic prophylaxis. In addition to prophylactic antibiotics, serial serologic testing for anti-Brucella antibodies was conducted at baseline and 2, 4, 6, and 24 weeks postexposure to monitor for the development of Brucella infection. There were no conversions to positive antibody status. No personnel complained of symptoms that would indicate development of brucellosis. At the recommendation of NMDOH and CDC, all staff in the operating room during and immediately after the re-implantation procedure wore properly fitting N-95 disposable respiratory masks (3M, St. Paul, Minnesota) to guard against the potential risk of further exposure.

Discussion

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts. Transmission can occur via breaks in the skin in direct contact, through the ingestion of unpasteurized dairy products or raw meat, or through ingestion of aerosolized bacteria. Transmission via aerosolization has been described during medical procedures.

Brucella is endemic in India, Middle Eastern and Mediterranean countries, Central Asia, and South America. Brucella species are gram-negative coccobacilli that are capable of surviving within phagocytic cells, making antibiotic treatment difficult. Brucellosis is a febrile illness that occurs after a 1- to 3-week incubation period and is often accompanied by headache, arthralgias, and hepatosplenomegaly. Osteoarticular infection is the most common complication, occurring in 10% to 85% of cases and usually involves the sacroiliac joint and the large joints of the lower extremity. Spondylitis, bursitis, tenosynovitis, endocarditis, colitis, meningitis, and osteomyelitis have also been described.^7,14-17

As mentioned previously, 18 cases of infected THAs and total knee arthroplasties (TKAs) in 16 patients were identified in the English literature: 9 THAs and 9 TKAs.^1-12 With the exception of 1 case reported in Texas, all others were from the Middle East or the Mediterranean region. In these patients, symptom onset occurred from 2 months to 14 years from the time of the index surgery, and symptom duration ranged from 1 month to 2 years prior to presentation. The exposure was not reported in 2 cases, but the remaining patients either ingested unpasteurized dairy products or worked closely with livestock. Laboratory evaluation revealed elevated ESR or CRP in 8 cases. In 7 cases, no laboratory results were reported, although 1 had a draining sinus. In 1 case, the ESR was normal, but a bone scan was positive. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (one aspirate yielded Acinetobacter baumanii). Only 3 cases reported a time-to-culture positivity (1 “prolonged” and 2 took 7 days).

Eight cases presented with loose components, while 1 case was not reported, and the remaining were presumed to be well-fixed. In cases that were identified as loose, 5 underwent a 2-stage revision and 2 underwent a 1-stage revision (in one of the 1-stage revisions, the infection was identified only after the revision from intra-operative cultures). Of those with well-fixed components, 7 patients with 9 infected joints (including the case where no preoperative description of the components was reported) were treated with oral antibiotics only (range, 6 weeks to 26 months) and 1 with irrigation and débridement and oral antibiotics. Among those treated only with antibiotics, there were 2 failures (2 joints) leading to revision surgery. The other 5 cases were reportedly doing well between 8 months and 5 years after treatment. There were no reports of transmission to hospital or laboratory personnel in any of these cases nor were there reports of precautions to limit exposure for operating room staff or hospital personnel. 

Failure of TKA or THA secondary to periprosthetic infection by Brucella species is rare, and this represents only the second reported case in the United States.⁴ This case highlights several important principles. Maintaining a high level of suspicion for infection in cases of failed joint arthroplasty is important. In addition, as more international travel occurs and patients are seen from areas where Brucella is endemic, the possibility of this infectious etiology should be considered. Based on reported cases, patients will usually have elevated ESR or CRP; all (except 2 cases in which no exposure was reported) had known exposure to unpasteurized dairy products or livestock. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (1 aspirate yielded Acinetobacter baumanii). In this case, ESR and CRP were elevated, and infection was suspected but joint aspiration was negative. The initial aspiration was cultured for 5 days and previous data, as well as that presented here, suggest that prolonged culture may provide diagnostic value.¹⁸ The patient had resided in an endemic area and had exposure to unpasteurized dairy products, but Brucella infection was not considered and, therefore, no precautions were taken.

Of the reported cases, only 1 met major criteria for periprosthetic joint infection (draining sinus) while 10 of the remaining 15 cases were positive for minor criteria of periprosthetic joint infection (elevated ESR or CRP, or positive culture from joint aspiration).¹⁹ Unfortunately, the available case reports did not detail the extent to which preoperative periprosthetic joint infection could be established based on minor criteria for periprosthetic joint infection (elevated joint synovial white blood cell count or neutrophil percentage, intra-articular purulence, or elevated neutrophil count on periprosthetic tissue histologic analysis).¹⁹

Periprosthetic joint infection by Brucella species is so rare that specific recommendations for this infectious etiology based on 18 reported cases would be overreaching. However, Brucella should be considered when evaluating a potentially infected joint replacement where the possibility of exposure exists (eg, travel to or previous residence in endemic areas, close contact with livestock, or ingestion of unpasteurized dairy products in endemic regions), with the potential for transmission to operating room and hospital personnel also considered. If there is concern about Brucella involvement, tissue and fluid specimens should be labeled so that laboratory personnel can take appropriate precautions. Brucella can be cultured using routine techniques on standard, nonselective media, but the culture time-to-growth may be prolonged. Culture plates should be held for 14 days before reporting no growth of Brucella if it is suspected; the New Mexico Department of Health Microbiology Laboratory holds routine cultures for 1 week after a report of no growth. Thus, a suspicion of Brucella should be communicated in order for culture time to be adjusted if the holding of culture plates after an initial report of no growth is not standard practice. If operative intervention is planned and brucellosis is known, personnel should be notified of the possibility of exposure and appropriate measures taken (ie, wearing N-95 respiratory masks during the procedure and considering other methods of irrigation less likely to aerosolize particulates). It is not known if preoperative antibiotic therapy can sufficiently lower the bacterial load to make aerosolization less likely. If brucellosis is suspected but not identified preoperatively, wearing N-95 respiratory masks should be considered during any open procedures. 

Conclusion

In cases of Brucella infection and loose components, 1- or 2-stage revision with appropriate antibiotic therapy is indicated. (There is not enough data to recommend either 1- or 2-stage revision.) Several reports comment on the ability to treat periprosthetic joint infection in the setting of well-fixed components with antibiotic therapy alone. While this appears to have been successful in 7 of 9 infected joints reported in the literature, length of follow-up ranged from 8 months to 5 years, with no report of length of follow-up in some cases. Antibiotic therapy duration ranged from 6 weeks to 26 months, and the antibiotic treatment involved combination therapy with multiple agents reported but, most commonly, doxycycline, rifampin, and streptomycin. With 2 of 9 (22%) joints failing antibiotic therapy alone and those reported to be successful having relatively short-term follow-up, this treatment strategy should be approached with caution.

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts or animal products. Infection of total knee or hip arthroplasty by Brucella species is a rare complication with only 18 cases reported in the English literature.^1-12 We describe a case of an infected total hip replacement, its treatment, and 2-year follow-up and review the available literature. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 67-year-old Spanish-speaking woman, a native of Mexico, presented with a painful right total hip arthroplasty (THA) 2 years after implantation in Chihuahua, Mexico. The patient reported 1 year of increasing thigh pain with recent onset of start-up pain, and also mild groin pain. The patient reported an uneventful postoperative course without wound drainage and denied any history of fevers, chills, or night sweats after the procedure. Preoperative notes and radiographs were unavailable for review. Radiographic evaluation showed a hybrid construct with a well-fixed–appearing, uncemented acetabular component but a failed cemented femoral stem (Figures 1A, 1B). Although we discussed revision surgery, the patient elected not to proceed with surgery or to undergo evaluation to rule out infection. Nine months later, she returned with worsening pain and requested revision surgery; radiographs showed progressive bone loss around the cement mantle (Figures 2A, 2B).

Hematologic evaluation showed an erythrocyte sedimentation rate (ESR) of 54 mm/h (normal, 0-27 mm/h) and C-reactive protein (CRP) level of 0.24 mg/L (normal, <0.8). An aspiration of the hip with fluoroscopic guidance produced a small sample (0.2 mL) of yellow synovial fluid. There was not enough fluid for cell count, but fluid culture was negative.

The patient was taken to the operating room for revision THA. Because of concern about progressive bone loss and elevated infectious indices, the administration of antibiotics was delayed until we obtained sufficient deep-tissue specimens. Before opening the capsule, we introduced a syringe into the joint and aspirated 10 mL of cloudy yellow synovial fluid that was sent for cell count. Additional findings at surgery included a grossly loose stem with a fragmented cement mantle surrounded by poor bone stock with anterior cortical bone loss and a loose acetabular component with pockets of cavitary bone loss. Frozen section showed up to 5 nucleated cells per high power field, and the cell count showed 1480 nucleated cells/µL (50% polymorphonuclear cells). The equivocal intraoperative findings (cell count and frozen section) and the loose femoral and acetabular components with significant bone loss were sufficiently concerning that we removed the components and placed a cement spacer rather than proceed with revision arthroplasty (Figures 3A, 3B). The surgeon, first assistant, and scrub technician wore body exhaust suits. We performed irrigation of the wound bed with pulse lavage.

Intraoperative cultures (synovial fluid, joint capsule synovium, and femur pseudocapsule) were positive after 8 days and growing B abortus. Infectious disease consultants prescribed rifampin 300 mg twice daily and doxycycline 100 mg twice daily for 5 months. Follow-up ESR and CRP returned to normal range. A preoperative aspiration of the hip was negative as well. The patient returned to the operating room at 6 months for re-implantation using uncemented components; synovial fluid and tissue cultures taken at this time were negative. Two years after re-implantation, the patient is doing well without evidence of infection (Figures 4A, 4B). Additional follow-up will be required to monitor for infection and implant survival. Additional history taken from the patient after the culture results revealed that her development of hip pain was preceded by a febrile illness consistent with brucellosis. 

Because of the nature of the procedure (irrigation and débridement using pulse lavage), we were concerned about aerosolization of Brucella bacteria and possible transmission to all staff present during the procedure. After consulting with the New Mexico Department of Health (NMDOH) and the Centers for Disease Control and Prevention (CDC), all surgical, anesthesia, and support personnel present in the operative suite  and staff who cleaned the room after the procedure were treated prophylactically (rifampin 600 mg daily, doxycycline 100 mg twice daily for 3 weeks) to prevent development of brucellosis.¹³ All 15 operating room personnel who were exposed elected to proceed with antibiotic prophylaxis. In addition to prophylactic antibiotics, serial serologic testing for anti-Brucella antibodies was conducted at baseline and 2, 4, 6, and 24 weeks postexposure to monitor for the development of Brucella infection. There were no conversions to positive antibody status. No personnel complained of symptoms that would indicate development of brucellosis. At the recommendation of NMDOH and CDC, all staff in the operating room during and immediately after the re-implantation procedure wore properly fitting N-95 disposable respiratory masks (3M, St. Paul, Minnesota) to guard against the potential risk of further exposure.

Discussion

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts. Transmission can occur via breaks in the skin in direct contact, through the ingestion of unpasteurized dairy products or raw meat, or through ingestion of aerosolized bacteria. Transmission via aerosolization has been described during medical procedures.

Brucella is endemic in India, Middle Eastern and Mediterranean countries, Central Asia, and South America. Brucella species are gram-negative coccobacilli that are capable of surviving within phagocytic cells, making antibiotic treatment difficult. Brucellosis is a febrile illness that occurs after a 1- to 3-week incubation period and is often accompanied by headache, arthralgias, and hepatosplenomegaly. Osteoarticular infection is the most common complication, occurring in 10% to 85% of cases and usually involves the sacroiliac joint and the large joints of the lower extremity. Spondylitis, bursitis, tenosynovitis, endocarditis, colitis, meningitis, and osteomyelitis have also been described.^7,14-17

As mentioned previously, 18 cases of infected THAs and total knee arthroplasties (TKAs) in 16 patients were identified in the English literature: 9 THAs and 9 TKAs.^1-12 With the exception of 1 case reported in Texas, all others were from the Middle East or the Mediterranean region. In these patients, symptom onset occurred from 2 months to 14 years from the time of the index surgery, and symptom duration ranged from 1 month to 2 years prior to presentation. The exposure was not reported in 2 cases, but the remaining patients either ingested unpasteurized dairy products or worked closely with livestock. Laboratory evaluation revealed elevated ESR or CRP in 8 cases. In 7 cases, no laboratory results were reported, although 1 had a draining sinus. In 1 case, the ESR was normal, but a bone scan was positive. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (one aspirate yielded Acinetobacter baumanii). Only 3 cases reported a time-to-culture positivity (1 “prolonged” and 2 took 7 days).

Eight cases presented with loose components, while 1 case was not reported, and the remaining were presumed to be well-fixed. In cases that were identified as loose, 5 underwent a 2-stage revision and 2 underwent a 1-stage revision (in one of the 1-stage revisions, the infection was identified only after the revision from intra-operative cultures). Of those with well-fixed components, 7 patients with 9 infected joints (including the case where no preoperative description of the components was reported) were treated with oral antibiotics only (range, 6 weeks to 26 months) and 1 with irrigation and débridement and oral antibiotics. Among those treated only with antibiotics, there were 2 failures (2 joints) leading to revision surgery. The other 5 cases were reportedly doing well between 8 months and 5 years after treatment. There were no reports of transmission to hospital or laboratory personnel in any of these cases nor were there reports of precautions to limit exposure for operating room staff or hospital personnel. 

Failure of TKA or THA secondary to periprosthetic infection by Brucella species is rare, and this represents only the second reported case in the United States.⁴ This case highlights several important principles. Maintaining a high level of suspicion for infection in cases of failed joint arthroplasty is important. In addition, as more international travel occurs and patients are seen from areas where Brucella is endemic, the possibility of this infectious etiology should be considered. Based on reported cases, patients will usually have elevated ESR or CRP; all (except 2 cases in which no exposure was reported) had known exposure to unpasteurized dairy products or livestock. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (1 aspirate yielded Acinetobacter baumanii). In this case, ESR and CRP were elevated, and infection was suspected but joint aspiration was negative. The initial aspiration was cultured for 5 days and previous data, as well as that presented here, suggest that prolonged culture may provide diagnostic value.¹⁸ The patient had resided in an endemic area and had exposure to unpasteurized dairy products, but Brucella infection was not considered and, therefore, no precautions were taken.

Of the reported cases, only 1 met major criteria for periprosthetic joint infection (draining sinus) while 10 of the remaining 15 cases were positive for minor criteria of periprosthetic joint infection (elevated ESR or CRP, or positive culture from joint aspiration).¹⁹ Unfortunately, the available case reports did not detail the extent to which preoperative periprosthetic joint infection could be established based on minor criteria for periprosthetic joint infection (elevated joint synovial white blood cell count or neutrophil percentage, intra-articular purulence, or elevated neutrophil count on periprosthetic tissue histologic analysis).¹⁹

Periprosthetic joint infection by Brucella species is so rare that specific recommendations for this infectious etiology based on 18 reported cases would be overreaching. However, Brucella should be considered when evaluating a potentially infected joint replacement where the possibility of exposure exists (eg, travel to or previous residence in endemic areas, close contact with livestock, or ingestion of unpasteurized dairy products in endemic regions), with the potential for transmission to operating room and hospital personnel also considered. If there is concern about Brucella involvement, tissue and fluid specimens should be labeled so that laboratory personnel can take appropriate precautions. Brucella can be cultured using routine techniques on standard, nonselective media, but the culture time-to-growth may be prolonged. Culture plates should be held for 14 days before reporting no growth of Brucella if it is suspected; the New Mexico Department of Health Microbiology Laboratory holds routine cultures for 1 week after a report of no growth. Thus, a suspicion of Brucella should be communicated in order for culture time to be adjusted if the holding of culture plates after an initial report of no growth is not standard practice. If operative intervention is planned and brucellosis is known, personnel should be notified of the possibility of exposure and appropriate measures taken (ie, wearing N-95 respiratory masks during the procedure and considering other methods of irrigation less likely to aerosolize particulates). It is not known if preoperative antibiotic therapy can sufficiently lower the bacterial load to make aerosolization less likely. If brucellosis is suspected but not identified preoperatively, wearing N-95 respiratory masks should be considered during any open procedures. 

Conclusion

In cases of Brucella infection and loose components, 1- or 2-stage revision with appropriate antibiotic therapy is indicated. (There is not enough data to recommend either 1- or 2-stage revision.) Several reports comment on the ability to treat periprosthetic joint infection in the setting of well-fixed components with antibiotic therapy alone. While this appears to have been successful in 7 of 9 infected joints reported in the literature, length of follow-up ranged from 8 months to 5 years, with no report of length of follow-up in some cases. Antibiotic therapy duration ranged from 6 weeks to 26 months, and the antibiotic treatment involved combination therapy with multiple agents reported but, most commonly, doxycycline, rifampin, and streptomycin. With 2 of 9 (22%) joints failing antibiotic therapy alone and those reported to be successful having relatively short-term follow-up, this treatment strategy should be approached with caution.

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts or animal products. Infection of total knee or hip arthroplasty by Brucella species is a rare complication with only 18 cases reported in the English literature.^1-12 We describe a case of an infected total hip replacement, its treatment, and 2-year follow-up and review the available literature. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 67-year-old Spanish-speaking woman, a native of Mexico, presented with a painful right total hip arthroplasty (THA) 2 years after implantation in Chihuahua, Mexico. The patient reported 1 year of increasing thigh pain with recent onset of start-up pain, and also mild groin pain. The patient reported an uneventful postoperative course without wound drainage and denied any history of fevers, chills, or night sweats after the procedure. Preoperative notes and radiographs were unavailable for review. Radiographic evaluation showed a hybrid construct with a well-fixed–appearing, uncemented acetabular component but a failed cemented femoral stem (Figures 1A, 1B). Although we discussed revision surgery, the patient elected not to proceed with surgery or to undergo evaluation to rule out infection. Nine months later, she returned with worsening pain and requested revision surgery; radiographs showed progressive bone loss around the cement mantle (Figures 2A, 2B).

Hematologic evaluation showed an erythrocyte sedimentation rate (ESR) of 54 mm/h (normal, 0-27 mm/h) and C-reactive protein (CRP) level of 0.24 mg/L (normal, <0.8). An aspiration of the hip with fluoroscopic guidance produced a small sample (0.2 mL) of yellow synovial fluid. There was not enough fluid for cell count, but fluid culture was negative.

The patient was taken to the operating room for revision THA. Because of concern about progressive bone loss and elevated infectious indices, the administration of antibiotics was delayed until we obtained sufficient deep-tissue specimens. Before opening the capsule, we introduced a syringe into the joint and aspirated 10 mL of cloudy yellow synovial fluid that was sent for cell count. Additional findings at surgery included a grossly loose stem with a fragmented cement mantle surrounded by poor bone stock with anterior cortical bone loss and a loose acetabular component with pockets of cavitary bone loss. Frozen section showed up to 5 nucleated cells per high power field, and the cell count showed 1480 nucleated cells/µL (50% polymorphonuclear cells). The equivocal intraoperative findings (cell count and frozen section) and the loose femoral and acetabular components with significant bone loss were sufficiently concerning that we removed the components and placed a cement spacer rather than proceed with revision arthroplasty (Figures 3A, 3B). The surgeon, first assistant, and scrub technician wore body exhaust suits. We performed irrigation of the wound bed with pulse lavage.

Intraoperative cultures (synovial fluid, joint capsule synovium, and femur pseudocapsule) were positive after 8 days and growing B abortus. Infectious disease consultants prescribed rifampin 300 mg twice daily and doxycycline 100 mg twice daily for 5 months. Follow-up ESR and CRP returned to normal range. A preoperative aspiration of the hip was negative as well. The patient returned to the operating room at 6 months for re-implantation using uncemented components; synovial fluid and tissue cultures taken at this time were negative. Two years after re-implantation, the patient is doing well without evidence of infection (Figures 4A, 4B). Additional follow-up will be required to monitor for infection and implant survival. Additional history taken from the patient after the culture results revealed that her development of hip pain was preceded by a febrile illness consistent with brucellosis. 

Because of the nature of the procedure (irrigation and débridement using pulse lavage), we were concerned about aerosolization of Brucella bacteria and possible transmission to all staff present during the procedure. After consulting with the New Mexico Department of Health (NMDOH) and the Centers for Disease Control and Prevention (CDC), all surgical, anesthesia, and support personnel present in the operative suite  and staff who cleaned the room after the procedure were treated prophylactically (rifampin 600 mg daily, doxycycline 100 mg twice daily for 3 weeks) to prevent development of brucellosis.¹³ All 15 operating room personnel who were exposed elected to proceed with antibiotic prophylaxis. In addition to prophylactic antibiotics, serial serologic testing for anti-Brucella antibodies was conducted at baseline and 2, 4, 6, and 24 weeks postexposure to monitor for the development of Brucella infection. There were no conversions to positive antibody status. No personnel complained of symptoms that would indicate development of brucellosis. At the recommendation of NMDOH and CDC, all staff in the operating room during and immediately after the re-implantation procedure wore properly fitting N-95 disposable respiratory masks (3M, St. Paul, Minnesota) to guard against the potential risk of further exposure.

Discussion

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts. Transmission can occur via breaks in the skin in direct contact, through the ingestion of unpasteurized dairy products or raw meat, or through ingestion of aerosolized bacteria. Transmission via aerosolization has been described during medical procedures.

Brucella is endemic in India, Middle Eastern and Mediterranean countries, Central Asia, and South America. Brucella species are gram-negative coccobacilli that are capable of surviving within phagocytic cells, making antibiotic treatment difficult. Brucellosis is a febrile illness that occurs after a 1- to 3-week incubation period and is often accompanied by headache, arthralgias, and hepatosplenomegaly. Osteoarticular infection is the most common complication, occurring in 10% to 85% of cases and usually involves the sacroiliac joint and the large joints of the lower extremity. Spondylitis, bursitis, tenosynovitis, endocarditis, colitis, meningitis, and osteomyelitis have also been described.^7,14-17

As mentioned previously, 18 cases of infected THAs and total knee arthroplasties (TKAs) in 16 patients were identified in the English literature: 9 THAs and 9 TKAs.^1-12 With the exception of 1 case reported in Texas, all others were from the Middle East or the Mediterranean region. In these patients, symptom onset occurred from 2 months to 14 years from the time of the index surgery, and symptom duration ranged from 1 month to 2 years prior to presentation. The exposure was not reported in 2 cases, but the remaining patients either ingested unpasteurized dairy products or worked closely with livestock. Laboratory evaluation revealed elevated ESR or CRP in 8 cases. In 7 cases, no laboratory results were reported, although 1 had a draining sinus. In 1 case, the ESR was normal, but a bone scan was positive. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (one aspirate yielded Acinetobacter baumanii). Only 3 cases reported a time-to-culture positivity (1 “prolonged” and 2 took 7 days).

Eight cases presented with loose components, while 1 case was not reported, and the remaining were presumed to be well-fixed. In cases that were identified as loose, 5 underwent a 2-stage revision and 2 underwent a 1-stage revision (in one of the 1-stage revisions, the infection was identified only after the revision from intra-operative cultures). Of those with well-fixed components, 7 patients with 9 infected joints (including the case where no preoperative description of the components was reported) were treated with oral antibiotics only (range, 6 weeks to 26 months) and 1 with irrigation and débridement and oral antibiotics. Among those treated only with antibiotics, there were 2 failures (2 joints) leading to revision surgery. The other 5 cases were reportedly doing well between 8 months and 5 years after treatment. There were no reports of transmission to hospital or laboratory personnel in any of these cases nor were there reports of precautions to limit exposure for operating room staff or hospital personnel. 

Failure of TKA or THA secondary to periprosthetic infection by Brucella species is rare, and this represents only the second reported case in the United States.⁴ This case highlights several important principles. Maintaining a high level of suspicion for infection in cases of failed joint arthroplasty is important. In addition, as more international travel occurs and patients are seen from areas where Brucella is endemic, the possibility of this infectious etiology should be considered. Based on reported cases, patients will usually have elevated ESR or CRP; all (except 2 cases in which no exposure was reported) had known exposure to unpasteurized dairy products or livestock. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (1 aspirate yielded Acinetobacter baumanii). In this case, ESR and CRP were elevated, and infection was suspected but joint aspiration was negative. The initial aspiration was cultured for 5 days and previous data, as well as that presented here, suggest that prolonged culture may provide diagnostic value.¹⁸ The patient had resided in an endemic area and had exposure to unpasteurized dairy products, but Brucella infection was not considered and, therefore, no precautions were taken.

Of the reported cases, only 1 met major criteria for periprosthetic joint infection (draining sinus) while 10 of the remaining 15 cases were positive for minor criteria of periprosthetic joint infection (elevated ESR or CRP, or positive culture from joint aspiration).¹⁹ Unfortunately, the available case reports did not detail the extent to which preoperative periprosthetic joint infection could be established based on minor criteria for periprosthetic joint infection (elevated joint synovial white blood cell count or neutrophil percentage, intra-articular purulence, or elevated neutrophil count on periprosthetic tissue histologic analysis).¹⁹

Periprosthetic joint infection by Brucella species is so rare that specific recommendations for this infectious etiology based on 18 reported cases would be overreaching. However, Brucella should be considered when evaluating a potentially infected joint replacement where the possibility of exposure exists (eg, travel to or previous residence in endemic areas, close contact with livestock, or ingestion of unpasteurized dairy products in endemic regions), with the potential for transmission to operating room and hospital personnel also considered. If there is concern about Brucella involvement, tissue and fluid specimens should be labeled so that laboratory personnel can take appropriate precautions. Brucella can be cultured using routine techniques on standard, nonselective media, but the culture time-to-growth may be prolonged. Culture plates should be held for 14 days before reporting no growth of Brucella if it is suspected; the New Mexico Department of Health Microbiology Laboratory holds routine cultures for 1 week after a report of no growth. Thus, a suspicion of Brucella should be communicated in order for culture time to be adjusted if the holding of culture plates after an initial report of no growth is not standard practice. If operative intervention is planned and brucellosis is known, personnel should be notified of the possibility of exposure and appropriate measures taken (ie, wearing N-95 respiratory masks during the procedure and considering other methods of irrigation less likely to aerosolize particulates). It is not known if preoperative antibiotic therapy can sufficiently lower the bacterial load to make aerosolization less likely. If brucellosis is suspected but not identified preoperatively, wearing N-95 respiratory masks should be considered during any open procedures. 

Conclusion

In cases of Brucella infection and loose components, 1- or 2-stage revision with appropriate antibiotic therapy is indicated. (There is not enough data to recommend either 1- or 2-stage revision.) Several reports comment on the ability to treat periprosthetic joint infection in the setting of well-fixed components with antibiotic therapy alone. While this appears to have been successful in 7 of 9 infected joints reported in the literature, length of follow-up ranged from 8 months to 5 years, with no report of length of follow-up in some cases. Antibiotic therapy duration ranged from 6 weeks to 26 months, and the antibiotic treatment involved combination therapy with multiple agents reported but, most commonly, doxycycline, rifampin, and streptomycin. With 2 of 9 (22%) joints failing antibiotic therapy alone and those reported to be successful having relatively short-term follow-up, this treatment strategy should be approached with caution.

Three of the five recommendations in the first-ever list developed by the American Academy of Orthopaedic Surgeons for the American Board of Internal Medicine Foundation’s "Choosing Wisely" campaign focus primarily on treatments for symptomatic osteoarthritis.

The campaign is meant to educate patients and physicians about unnecessary and potentially harmful testing and treatment.

According to the Choosing Wisely website, the AAOS’s list was formed based on a review of the most recent approved clinical practice guidelines previously developed by AAOS physician volunteer work groups and a selection of a variety of topics frequently used in orthopaedic surgical practice with input from specialty society leaders and the Academy’s presidential leadership and board of directors. The list was created with the intent to "serve as an educational tool based on an assessment of the current scientific and clinical information and accepted approaches to treatment."

However, some specialists find fault with the recommendations. For example, Dr. Roy Altman, a professor of medicine in the division of rheumatology and immunology at the University of California, Los Angeles, said the methodology used to create the guidelines overlooks a number of treatments, including multimodal therapy, and could have the unintended consequence of allowing specialists to deny effective care to patients.

"These guidelines are not consistent with my clinical experience," Dr. Altman said. In particular, he noted that many of his patients react positively to injection treatments for osteoarthritis (OA), which the Choosing Wisely recommendations specifically discourage.

AAOS’s recommendations are as follows:

• Avoid using postoperative ultrasonography screening for deep vein thrombosis on patients receiving hip or knee arthroplasty because it is not effective at diagnosing unsuspected cases.

• Don’t use needle lavage for long-term relief in symptomatic OA treatment, as the procedure "does not lead to measurable improvements in pain, function, 50-foot walking time, stiffness, tenderness, or swelling."

• Do not use glucosamine and chondroitin sulfate to treat patients with symptomatic knee OA.

• Lateral wedge or neutral insoles do not improve pain or functional outcomes in patients; on the contrary, patients with OA of the knee may experience fewer symptoms without insoles.

• Routine postoperative splinting of the wrist after the carpal tunnel release procedure does not improve subjective outcomes, and may lead to detrimental effects, including adhesion formation, stiffness, and prevention of nerve and tendon movement.

[email protected]

Three of the five recommendations in the first-ever list developed by the American Academy of Orthopaedic Surgeons for the American Board of Internal Medicine Foundation’s "Choosing Wisely" campaign focus primarily on treatments for symptomatic osteoarthritis.

The campaign is meant to educate patients and physicians about unnecessary and potentially harmful testing and treatment.

According to the Choosing Wisely website, the AAOS’s list was formed based on a review of the most recent approved clinical practice guidelines previously developed by AAOS physician volunteer work groups and a selection of a variety of topics frequently used in orthopaedic surgical practice with input from specialty society leaders and the Academy’s presidential leadership and board of directors. The list was created with the intent to "serve as an educational tool based on an assessment of the current scientific and clinical information and accepted approaches to treatment."

However, some specialists find fault with the recommendations. For example, Dr. Roy Altman, a professor of medicine in the division of rheumatology and immunology at the University of California, Los Angeles, said the methodology used to create the guidelines overlooks a number of treatments, including multimodal therapy, and could have the unintended consequence of allowing specialists to deny effective care to patients.

"These guidelines are not consistent with my clinical experience," Dr. Altman said. In particular, he noted that many of his patients react positively to injection treatments for osteoarthritis (OA), which the Choosing Wisely recommendations specifically discourage.

AAOS’s recommendations are as follows:

• Avoid using postoperative ultrasonography screening for deep vein thrombosis on patients receiving hip or knee arthroplasty because it is not effective at diagnosing unsuspected cases.

• Don’t use needle lavage for long-term relief in symptomatic OA treatment, as the procedure "does not lead to measurable improvements in pain, function, 50-foot walking time, stiffness, tenderness, or swelling."

• Do not use glucosamine and chondroitin sulfate to treat patients with symptomatic knee OA.

• Lateral wedge or neutral insoles do not improve pain or functional outcomes in patients; on the contrary, patients with OA of the knee may experience fewer symptoms without insoles.

• Routine postoperative splinting of the wrist after the carpal tunnel release procedure does not improve subjective outcomes, and may lead to detrimental effects, including adhesion formation, stiffness, and prevention of nerve and tendon movement.

[email protected]

Three of the five recommendations in the first-ever list developed by the American Academy of Orthopaedic Surgeons for the American Board of Internal Medicine Foundation’s "Choosing Wisely" campaign focus primarily on treatments for symptomatic osteoarthritis.

The campaign is meant to educate patients and physicians about unnecessary and potentially harmful testing and treatment.

According to the Choosing Wisely website, the AAOS’s list was formed based on a review of the most recent approved clinical practice guidelines previously developed by AAOS physician volunteer work groups and a selection of a variety of topics frequently used in orthopaedic surgical practice with input from specialty society leaders and the Academy’s presidential leadership and board of directors. The list was created with the intent to "serve as an educational tool based on an assessment of the current scientific and clinical information and accepted approaches to treatment."

However, some specialists find fault with the recommendations. For example, Dr. Roy Altman, a professor of medicine in the division of rheumatology and immunology at the University of California, Los Angeles, said the methodology used to create the guidelines overlooks a number of treatments, including multimodal therapy, and could have the unintended consequence of allowing specialists to deny effective care to patients.

"These guidelines are not consistent with my clinical experience," Dr. Altman said. In particular, he noted that many of his patients react positively to injection treatments for osteoarthritis (OA), which the Choosing Wisely recommendations specifically discourage.

AAOS’s recommendations are as follows:

• Avoid using postoperative ultrasonography screening for deep vein thrombosis on patients receiving hip or knee arthroplasty because it is not effective at diagnosing unsuspected cases.

• Don’t use needle lavage for long-term relief in symptomatic OA treatment, as the procedure "does not lead to measurable improvements in pain, function, 50-foot walking time, stiffness, tenderness, or swelling."

• Do not use glucosamine and chondroitin sulfate to treat patients with symptomatic knee OA.

• Lateral wedge or neutral insoles do not improve pain or functional outcomes in patients; on the contrary, patients with OA of the knee may experience fewer symptoms without insoles.

• Routine postoperative splinting of the wrist after the carpal tunnel release procedure does not improve subjective outcomes, and may lead to detrimental effects, including adhesion formation, stiffness, and prevention of nerve and tendon movement.

[email protected]

Aspirin is an effective, safe, convenient, and inexpensive alternative to low-molecular-weight heparin for extended thromboprophylaxis after total hip arthroplasty, according to a report published online June 3 in Annals of Internal Medicine.

In a multicenter randomized trial involving 786 patients undergoing elective total hip replacement in Canada during a 3-year period, 28 days of oral aspirin prophylaxis was noninferior to and as safe as 28 days of subcutaneous dalteparin injections for preventing venous thromboembolism (VTE), according to Dr. David R. Anderson, who is professor of medicine, pathology, and community health and epidemiology of Dalhousie University, Halifax, N.S., and his associates in the EPCAT (Extended Prophylaxis Comparing Low-Molecular-Weight Heparin to Aspirin in Total Hip Arthroplasty) study.

During this trial, the novel oral anticoagulant rivaroxaban was approved for this indication in Canada, which prompted "a major shift" away from using dalteparin and toward using the new drug in clinical practice. In light of this development, it will be important to "evaluate the benefits and risks of aspirin as extended prophylaxis after [total hip replacement], compared with the new oral anticoagulant agents," noted the EPCAT investigators.

Their findings on the benefits of aspirin also indicate that its role for venous thromboprophylaxis in other settings should now be reconsidered as well, Dr. Anderson and his colleagues added.

In the EPCAT study, patients underwent elective unilateral total hip replacement at 12 university-affiliated tertiary medical centers and received thromboprophylaxis in the form of subcutaneous injections of dalteparin for 10 days. They were randomly assigned to continue receiving dalteparin injections and take placebo oral aspirin tablets (400 patients) or to receive placebo injections and begin taking oral aspirin (81 mg) every day for 28 days (386 patients).

The demographic, medical, and surgical characteristics of the two study groups were comparable. Patients, physicians, study coordinators, and members of the health care teams all were blinded to study assignment.

The introduction of rivaroxaban during the course of the study severely affected ongoing recruitment of subjects, because both patients and orthopedic surgeons became increasingly reluctant to participate in a study requiring daily injections for 38 days when a new oral agent was available. The EPCAT study was terminated early when completion of the intended enrollment appeared "unfeasible" and an interim analysis showed that the primary objective – establishing the noninferiority of aspirin – had been reached.

The primary efficacy outcome was the development of symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE), confirmed by objective testing, during the 90 days after randomization. This outcome occurred in only 0.3% of the aspirin group, compared with 1.3% of the dalteparin group, establishing the noninferiority of aspirin therapy.

There was a single case of proximal DVT in the aspirin group, compared with two cases of proximal DVT and three of PE in the dalteparin group. Another patient in the dalteparin group developed a symptomatic distal DVT in her calf, "but this was not considered an outcome event," the investigators said.

No major bleeding events developed in the aspirin group, but there was one such event in the dalteparin group for an overall rate of 0.3%. Similarly, there were two clinically significant nonmajor bleeding events for aspirin (0.5% rate), compared with four for dalteparin (1.0% rate). And there were eight minor bleeding events for aspirin (2.1% rate), compared with 18 for dalteparin (4.5% rate).

"In a composite analysis of net clinical benefit that combined VTE and clinically relevant major and nonmajor bleeding complications as outcomes," 0.8% of patients receiving aspirin had complications, compared with 2.5% of patients receiving dalteparin.

There were no differences between the two study groups in secondary outcomes such as wound infections, arterial vascular events, MI, stroke, or deaths.

The EPCAT trial was supported by the Canadian Institutes for Health Research. Aspirin was provided by Bayer HealthCare and dalteparin by Pfizer Pharmaceuticals, but neither Bayer nor Pfizer was involved in the design, conduct, or analysis of the study.

Aspirin is an effective, safe, convenient, and inexpensive alternative to low-molecular-weight heparin for extended thromboprophylaxis after total hip arthroplasty, according to a report published online June 3 in Annals of Internal Medicine.

In a multicenter randomized trial involving 786 patients undergoing elective total hip replacement in Canada during a 3-year period, 28 days of oral aspirin prophylaxis was noninferior to and as safe as 28 days of subcutaneous dalteparin injections for preventing venous thromboembolism (VTE), according to Dr. David R. Anderson, who is professor of medicine, pathology, and community health and epidemiology of Dalhousie University, Halifax, N.S., and his associates in the EPCAT (Extended Prophylaxis Comparing Low-Molecular-Weight Heparin to Aspirin in Total Hip Arthroplasty) study.

During this trial, the novel oral anticoagulant rivaroxaban was approved for this indication in Canada, which prompted "a major shift" away from using dalteparin and toward using the new drug in clinical practice. In light of this development, it will be important to "evaluate the benefits and risks of aspirin as extended prophylaxis after [total hip replacement], compared with the new oral anticoagulant agents," noted the EPCAT investigators.

Their findings on the benefits of aspirin also indicate that its role for venous thromboprophylaxis in other settings should now be reconsidered as well, Dr. Anderson and his colleagues added.

In the EPCAT study, patients underwent elective unilateral total hip replacement at 12 university-affiliated tertiary medical centers and received thromboprophylaxis in the form of subcutaneous injections of dalteparin for 10 days. They were randomly assigned to continue receiving dalteparin injections and take placebo oral aspirin tablets (400 patients) or to receive placebo injections and begin taking oral aspirin (81 mg) every day for 28 days (386 patients).

The demographic, medical, and surgical characteristics of the two study groups were comparable. Patients, physicians, study coordinators, and members of the health care teams all were blinded to study assignment.

The introduction of rivaroxaban during the course of the study severely affected ongoing recruitment of subjects, because both patients and orthopedic surgeons became increasingly reluctant to participate in a study requiring daily injections for 38 days when a new oral agent was available. The EPCAT study was terminated early when completion of the intended enrollment appeared "unfeasible" and an interim analysis showed that the primary objective – establishing the noninferiority of aspirin – had been reached.

The primary efficacy outcome was the development of symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE), confirmed by objective testing, during the 90 days after randomization. This outcome occurred in only 0.3% of the aspirin group, compared with 1.3% of the dalteparin group, establishing the noninferiority of aspirin therapy.

There was a single case of proximal DVT in the aspirin group, compared with two cases of proximal DVT and three of PE in the dalteparin group. Another patient in the dalteparin group developed a symptomatic distal DVT in her calf, "but this was not considered an outcome event," the investigators said.

No major bleeding events developed in the aspirin group, but there was one such event in the dalteparin group for an overall rate of 0.3%. Similarly, there were two clinically significant nonmajor bleeding events for aspirin (0.5% rate), compared with four for dalteparin (1.0% rate). And there were eight minor bleeding events for aspirin (2.1% rate), compared with 18 for dalteparin (4.5% rate).

"In a composite analysis of net clinical benefit that combined VTE and clinically relevant major and nonmajor bleeding complications as outcomes," 0.8% of patients receiving aspirin had complications, compared with 2.5% of patients receiving dalteparin.

There were no differences between the two study groups in secondary outcomes such as wound infections, arterial vascular events, MI, stroke, or deaths.

The EPCAT trial was supported by the Canadian Institutes for Health Research. Aspirin was provided by Bayer HealthCare and dalteparin by Pfizer Pharmaceuticals, but neither Bayer nor Pfizer was involved in the design, conduct, or analysis of the study.

Aspirin is an effective, safe, convenient, and inexpensive alternative to low-molecular-weight heparin for extended thromboprophylaxis after total hip arthroplasty, according to a report published online June 3 in Annals of Internal Medicine.

In a multicenter randomized trial involving 786 patients undergoing elective total hip replacement in Canada during a 3-year period, 28 days of oral aspirin prophylaxis was noninferior to and as safe as 28 days of subcutaneous dalteparin injections for preventing venous thromboembolism (VTE), according to Dr. David R. Anderson, who is professor of medicine, pathology, and community health and epidemiology of Dalhousie University, Halifax, N.S., and his associates in the EPCAT (Extended Prophylaxis Comparing Low-Molecular-Weight Heparin to Aspirin in Total Hip Arthroplasty) study.

During this trial, the novel oral anticoagulant rivaroxaban was approved for this indication in Canada, which prompted "a major shift" away from using dalteparin and toward using the new drug in clinical practice. In light of this development, it will be important to "evaluate the benefits and risks of aspirin as extended prophylaxis after [total hip replacement], compared with the new oral anticoagulant agents," noted the EPCAT investigators.

Their findings on the benefits of aspirin also indicate that its role for venous thromboprophylaxis in other settings should now be reconsidered as well, Dr. Anderson and his colleagues added.

In the EPCAT study, patients underwent elective unilateral total hip replacement at 12 university-affiliated tertiary medical centers and received thromboprophylaxis in the form of subcutaneous injections of dalteparin for 10 days. They were randomly assigned to continue receiving dalteparin injections and take placebo oral aspirin tablets (400 patients) or to receive placebo injections and begin taking oral aspirin (81 mg) every day for 28 days (386 patients).

The demographic, medical, and surgical characteristics of the two study groups were comparable. Patients, physicians, study coordinators, and members of the health care teams all were blinded to study assignment.

The introduction of rivaroxaban during the course of the study severely affected ongoing recruitment of subjects, because both patients and orthopedic surgeons became increasingly reluctant to participate in a study requiring daily injections for 38 days when a new oral agent was available. The EPCAT study was terminated early when completion of the intended enrollment appeared "unfeasible" and an interim analysis showed that the primary objective – establishing the noninferiority of aspirin – had been reached.

The primary efficacy outcome was the development of symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE), confirmed by objective testing, during the 90 days after randomization. This outcome occurred in only 0.3% of the aspirin group, compared with 1.3% of the dalteparin group, establishing the noninferiority of aspirin therapy.

There was a single case of proximal DVT in the aspirin group, compared with two cases of proximal DVT and three of PE in the dalteparin group. Another patient in the dalteparin group developed a symptomatic distal DVT in her calf, "but this was not considered an outcome event," the investigators said.

No major bleeding events developed in the aspirin group, but there was one such event in the dalteparin group for an overall rate of 0.3%. Similarly, there were two clinically significant nonmajor bleeding events for aspirin (0.5% rate), compared with four for dalteparin (1.0% rate). And there were eight minor bleeding events for aspirin (2.1% rate), compared with 18 for dalteparin (4.5% rate).

"In a composite analysis of net clinical benefit that combined VTE and clinically relevant major and nonmajor bleeding complications as outcomes," 0.8% of patients receiving aspirin had complications, compared with 2.5% of patients receiving dalteparin.

There were no differences between the two study groups in secondary outcomes such as wound infections, arterial vascular events, MI, stroke, or deaths.

The EPCAT trial was supported by the Canadian Institutes for Health Research. Aspirin was provided by Bayer HealthCare and dalteparin by Pfizer Pharmaceuticals, but neither Bayer nor Pfizer was involved in the design, conduct, or analysis of the study.

BIRMINGHAM, ENGLAND – Contrary to expectations, metal-on-metal hip resurfacing for osteoarthritis was associated with higher patient survival at 10 years than was total hip arthroplasty in a large, population-based study.

Cumulative mortality rates were 2.8% for hip resurfacing versus 7.3% for cemented total hip replacement (THR; hazard ratio, 0.51). Ten-year mortality rates comparing hip resurfacing to uncemented THR were 2.6% and 3.2%, respectively (HR, 0.64).

Furthermore, the number needed to treat with hip resurfacing to prevent 1 excess death was 29 when compared to cemented THR, and it was 88 when compared to uncemented THR.

"Patients who received a metal-on-metal resurfacing [MoMR] procedure seem to have a long-term survival advantage compared to patients receiving cemented or an uncemented THR," said Dr. Adrian Kendal of the National Institute for Health Research (NIHR) Musculoskeletal Biomedical Research Unit at the University of Oxford, England.

"Our findings were robust after adjustment for known confounders," Dr. Kendal said at the British Society for Rheumatology annual conference. Propensity matching was used in the trial, which took age, gender, comorbidity, rurality, and social deprivation into account.

For the study, data from the English Hospital Episode Statistics database were obtained and linked to Office for National Statistics mortality records for all adults (over age 18) undergoing elective primary hip replacement for osteoarthritis in National Health Service hospitals in England and Wales between April 1999 and March 2012.

After propensity score matching, there were 91,633 procedures performed, of which 12,580 were MoMR, 37,740 were cemented THR, and 41,312 were uncemented THR.

In response to a comment that perhaps people opting for MoMR were more likely to be younger, more active, and hence more likely to exercise, Dr. Kendal conceded that other factors might exist that could have affected survival.

Speculating about why there might be such a difference in survival, he said: "I personally don’t think it’s just the use of cement, because that doesn’t explain the group that received an uncemented total hip replacement."

He added that the way the femur is prepared during THR might be important, regardless of whether or not cement is used. The known risk of thrombotic consequences also could affect survival. In addition, health care inequality might be important, as resurfacing procedures are less common than THR, perhaps because of the lack of specialized centers or dedicated teams.

Commenting on the findings after their presentation, consultant rheumatologist Dr. Alex MacGregor, of the University of East Anglia, Norwich, England, noted that similar data were published on this topic last year (BMJ 2012;344:e3319), but the results had proved somewhat controversial as the authors had a conflict of interest in favor of hip resurfacing.

Dr. MacGregor, who is a member of the National Joint Registry Steering Committee, has been involved in a subsequent reanalysis of the paper’s findings and said that the results will be made public later in the year.

"One of my concerns [with this study] is the use of the 10-year mortality endpoint. If these resurfacing procedures are saving lives, then you would expect to see a survival benefit sooner, say at 90 days," Dr. MacGregor said.

Dr. Kendal responded that they tried to account for this, but the answer will need to come from a properly organized, randomized controlled trial.

"We don’t have a conflict of interest here. If anything, we were perhaps looking for the opposite effect; we were expecting to see an increased mortality rate in the resurfacing group," Dr. Kendal said. "That was not the case as it turned out, so I am reasonably confident that our data support the findings of that BMJ article."

Dr. Kendal and Dr. MacGregor reported no conflicts of interest.

[email protected]

BIRMINGHAM, ENGLAND – Contrary to expectations, metal-on-metal hip resurfacing for osteoarthritis was associated with higher patient survival at 10 years than was total hip arthroplasty in a large, population-based study.

Cumulative mortality rates were 2.8% for hip resurfacing versus 7.3% for cemented total hip replacement (THR; hazard ratio, 0.51). Ten-year mortality rates comparing hip resurfacing to uncemented THR were 2.6% and 3.2%, respectively (HR, 0.64).

Furthermore, the number needed to treat with hip resurfacing to prevent 1 excess death was 29 when compared to cemented THR, and it was 88 when compared to uncemented THR.

"Patients who received a metal-on-metal resurfacing [MoMR] procedure seem to have a long-term survival advantage compared to patients receiving cemented or an uncemented THR," said Dr. Adrian Kendal of the National Institute for Health Research (NIHR) Musculoskeletal Biomedical Research Unit at the University of Oxford, England.

"Our findings were robust after adjustment for known confounders," Dr. Kendal said at the British Society for Rheumatology annual conference. Propensity matching was used in the trial, which took age, gender, comorbidity, rurality, and social deprivation into account.

For the study, data from the English Hospital Episode Statistics database were obtained and linked to Office for National Statistics mortality records for all adults (over age 18) undergoing elective primary hip replacement for osteoarthritis in National Health Service hospitals in England and Wales between April 1999 and March 2012.

After propensity score matching, there were 91,633 procedures performed, of which 12,580 were MoMR, 37,740 were cemented THR, and 41,312 were uncemented THR.

In response to a comment that perhaps people opting for MoMR were more likely to be younger, more active, and hence more likely to exercise, Dr. Kendal conceded that other factors might exist that could have affected survival.

Speculating about why there might be such a difference in survival, he said: "I personally don’t think it’s just the use of cement, because that doesn’t explain the group that received an uncemented total hip replacement."

He added that the way the femur is prepared during THR might be important, regardless of whether or not cement is used. The known risk of thrombotic consequences also could affect survival. In addition, health care inequality might be important, as resurfacing procedures are less common than THR, perhaps because of the lack of specialized centers or dedicated teams.

Commenting on the findings after their presentation, consultant rheumatologist Dr. Alex MacGregor, of the University of East Anglia, Norwich, England, noted that similar data were published on this topic last year (BMJ 2012;344:e3319), but the results had proved somewhat controversial as the authors had a conflict of interest in favor of hip resurfacing.

Dr. MacGregor, who is a member of the National Joint Registry Steering Committee, has been involved in a subsequent reanalysis of the paper’s findings and said that the results will be made public later in the year.

"One of my concerns [with this study] is the use of the 10-year mortality endpoint. If these resurfacing procedures are saving lives, then you would expect to see a survival benefit sooner, say at 90 days," Dr. MacGregor said.

Dr. Kendal responded that they tried to account for this, but the answer will need to come from a properly organized, randomized controlled trial.

"We don’t have a conflict of interest here. If anything, we were perhaps looking for the opposite effect; we were expecting to see an increased mortality rate in the resurfacing group," Dr. Kendal said. "That was not the case as it turned out, so I am reasonably confident that our data support the findings of that BMJ article."

Dr. Kendal and Dr. MacGregor reported no conflicts of interest.

[email protected]

BIRMINGHAM, ENGLAND – Contrary to expectations, metal-on-metal hip resurfacing for osteoarthritis was associated with higher patient survival at 10 years than was total hip arthroplasty in a large, population-based study.

Cumulative mortality rates were 2.8% for hip resurfacing versus 7.3% for cemented total hip replacement (THR; hazard ratio, 0.51). Ten-year mortality rates comparing hip resurfacing to uncemented THR were 2.6% and 3.2%, respectively (HR, 0.64).

Furthermore, the number needed to treat with hip resurfacing to prevent 1 excess death was 29 when compared to cemented THR, and it was 88 when compared to uncemented THR.

"Patients who received a metal-on-metal resurfacing [MoMR] procedure seem to have a long-term survival advantage compared to patients receiving cemented or an uncemented THR," said Dr. Adrian Kendal of the National Institute for Health Research (NIHR) Musculoskeletal Biomedical Research Unit at the University of Oxford, England.

"Our findings were robust after adjustment for known confounders," Dr. Kendal said at the British Society for Rheumatology annual conference. Propensity matching was used in the trial, which took age, gender, comorbidity, rurality, and social deprivation into account.

For the study, data from the English Hospital Episode Statistics database were obtained and linked to Office for National Statistics mortality records for all adults (over age 18) undergoing elective primary hip replacement for osteoarthritis in National Health Service hospitals in England and Wales between April 1999 and March 2012.

After propensity score matching, there were 91,633 procedures performed, of which 12,580 were MoMR, 37,740 were cemented THR, and 41,312 were uncemented THR.

In response to a comment that perhaps people opting for MoMR were more likely to be younger, more active, and hence more likely to exercise, Dr. Kendal conceded that other factors might exist that could have affected survival.

Speculating about why there might be such a difference in survival, he said: "I personally don’t think it’s just the use of cement, because that doesn’t explain the group that received an uncemented total hip replacement."

He added that the way the femur is prepared during THR might be important, regardless of whether or not cement is used. The known risk of thrombotic consequences also could affect survival. In addition, health care inequality might be important, as resurfacing procedures are less common than THR, perhaps because of the lack of specialized centers or dedicated teams.

Commenting on the findings after their presentation, consultant rheumatologist Dr. Alex MacGregor, of the University of East Anglia, Norwich, England, noted that similar data were published on this topic last year (BMJ 2012;344:e3319), but the results had proved somewhat controversial as the authors had a conflict of interest in favor of hip resurfacing.

Dr. MacGregor, who is a member of the National Joint Registry Steering Committee, has been involved in a subsequent reanalysis of the paper’s findings and said that the results will be made public later in the year.

"One of my concerns [with this study] is the use of the 10-year mortality endpoint. If these resurfacing procedures are saving lives, then you would expect to see a survival benefit sooner, say at 90 days," Dr. MacGregor said.

Dr. Kendal responded that they tried to account for this, but the answer will need to come from a properly organized, randomized controlled trial.

"We don’t have a conflict of interest here. If anything, we were perhaps looking for the opposite effect; we were expecting to see an increased mortality rate in the resurfacing group," Dr. Kendal said. "That was not the case as it turned out, so I am reasonably confident that our data support the findings of that BMJ article."

Dr. Kendal and Dr. MacGregor reported no conflicts of interest.

[email protected]