Ronald E. Delanois

The Natural History of Untreated Asymptomatic Osteonecrosis of the Femoral Head: A Systematic Literature Review

BACKGROUND An asymptomatic hip with osteonecrosis is typically discovered as the contralateral hip of a patient with one symptomatic joint. Treatment of the asymptomatic hip is controversial. While some authors claim a benign natural history, others have reported a rate of femoral head collapse exceeding 50%. The purpose of this report was to systematically review the published literature regarding asymptomatic osteonecrosis of the femoral head to evaluate the overall prevalence of progression to symptomatic disease and/or femoral head collapse as well as to determine whether various radiographic and demographic factors influence progression of the disorder. METHODS A comprehensive literature search was performed to identify prognostic studies evaluating asymptomatic hip osteonecrosis. Demographic, radiographic, and outcome data were extracted from all relevant studies. The prevalence of progression to symptomatic disease and/or femoral head collapse was determined. Next, outcomes were stratified by lesion size, lesion location, radiographic stage, associated risk factors and/or disease, and the level of evidence of the study. RESULTS Sixteen studies that included a total of 664 hips were available for an analysis of outcomes. Overall, 394 hips (59%) had progression to symptoms or collapse. Differences in outcomes based on lesion size, lesion location, and radiographic stage at the time of diagnosis were seen. Small, medially located lesions had the best prognosis, with a prevalence of collapse of <10%. Patients with sickle cell disease had the highest frequency of progression, and those with a history of systemic lupus erythematosus had the most benign course. CONCLUSIONS Data extracted from previously published studies suggest that asymptomatic osteonecrosis has a high prevalence of progression to symptomatic disease and femoral head collapse. While small, medially located lesions have a low rate of progression, the natural history of asymptomatic medium-sized, and especially large, osteonecrotic lesions is progression in a substantial number of patients. For this reason, it may be beneficial to consider joint-preserving surgical treatment in asymptomatic patients with a medium-sized or large, and/or laterally located, lesion.

Use of metal-on-metal total hip resurfacing for the treatment of osteonecrosis of the femoral head.

BACKGROUND Recently, with the advent of improved metal-on-metal prostheses, total hip resurfacing has emerged as a viable arthroplasty option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is cemented onto dead bone. The purpose of this study was to analyze the clinical and radiographic outcomes of metal-on-metal total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head. In addition, this group was compared with a matched group of patients who were diagnosed as having osteoarthritis. METHODS Forty-two osteonecrotic hips that were treated with a metal-on-metal total hip resurfacing arthroplasty were studied. They were matched by gender, age, prosthesis, surgeon, and surgical approach to forty-two osteoarthritic hips that were treated with the same metal-on-metal prosthesis. In the osteonecrosis group, there were twenty-five men and eleven women, and in the osteoarthritis group, there were twenty-eight men and thirteen women. The mean age at the time of surgery was forty-two years. Patients were followed both clinically and radiographically for a mean of forty-one months. RESULTS The clinical outcomes were similar for both groups, with a good or excellent outcome in thirty-nine hips (93%) with osteonecrosis and a good or excellent outcome in forty-one hips (98%) with osteoarthritis. In each of the two groups, there were two failures that required conversion to a standard total hip arthroplasty. Survivorship curves were similar for the two patient groups. CONCLUSIONS The short-term results for metal-on-metal total hip resurfacing for this challenging patient population with osteonecrosis were excellent and comparable with those seen in patients with osteoarthritis. We await long-term results to see if these early results are maintained. LEVEL OF EVIDENCE Prognostic Level II. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Preoperative Chlorhexidine Preparation and the Incidence of Surgical Site Infections After Hip Arthroplasty

The purpose of this study was to evaluate effectiveness of an advance, at-home chlorhexidine-impregnated skin preparation cloth in decreasing the incidence of deep periprosthetic hip arthroplasty infections. Arthroplasty surgeons at the senior authors institution provided their patients with chlorhexidine-impregnated single-use cloths for use at home the night before and the morning of surgery. Between January 2007 and December 2009, the compliance of this practice, as well as the incidence of periprosthetic infections, was monitored for all patients who underwent hip arthroplasty. Of the 1134 patients who underwent hip arthroplasty, 157 patients completely complied with the preoperative chlorhexidine preparation protocol. There were 14 infections in the group that was not compliant (1.6% infection rate), and there were no infections in the compliant patient population. Based on the results of this study, at-home preoperative patient skin preparation appears to be a simple and cost-effective method to reduce periprosthetic hip infection rates.

Advance pre-operative chlorhexidine reduces the incidence of surgical site infections in knee arthroplasty

Surgical site infections following elective knee arthroplasties occur most commonly as a result of colonisation by the patient’s native skin flora. The purpose of this study was to evaluate the incidence of deep surgical site infections in knee arthroplasty patients who used an advance cutaneous disinfection protocol and who were compared to patients who had peri-operative preparation only. All adult reconstruction surgeons at a single institution were approached to voluntarily provide patients with chlorhexidine gluconate-impregnated cloths and a printed sheet instructing their use the night before and morning of surgery. Records for all knee arthroplasties performed between January 2007 and December 2008 were reviewed to determine the incidence of deep incisional and periprosthetic surgical site infections. Overall, the advance pre-operative protocol was used in 136 of 912 total knee arthroplasties (15%). A lower incidence of surgical site infection was found in patients who used the advance cutaneous preparation protocol as compared to patients who used the in-hospital protocol alone. These findings were maintained when patients were stratified by surgical infection risk category. No surgical site infections occurred in the 136 patients who completed the protocol as compared to 21 infections in 711 procedures (3.0%) performed in patients who did not. Patient-directed skin disinfection using chlorhexidine gluconate-impregnated cloths the evening before, and the morning of, elective knee arthroplasty appeared to effectively reduce the incidence of surgical site infection when compared to patients who underwent in-hospital skin preparation only.

Treatment of early stage osteonecrosis of the femoral head.

Osteonecrosis is a devastating disease that primarily affects weight-bearing joints. The hip is the most commonly affected joint. Although hip osteonecrosis can affect patients of any age group, it typically presents in young patients between the ages of twenty and forty years1. The factors that affect the progression of this disease are still not fully understood, but radiographic lesion size, femoral head collapse (if present), and, occasionally, clinical presentation at the time of diagnosis have been shown to be predictive of the eventual clinical outcome2,3. After collapse, most patients will require a standard total hip arthroplasty4,5. However, because of the young age of many of these patients, a hip replacement cannot be expected to last the patients lifetime and therefore, when feasible, attempts should be made to save the femoral head prior to collapse with use of less invasive treatment modalities. The efficacy of these procedures has been variable, with reported success rates ranging between 60% and 80% at the time of short-term and midterm follow-up6-8. Current treatments range from pharmacotherapies to surgical interventions that include core decompression, vascularized or nonvascularized bone-grafting, and osteotomy. Recently there have been attempts to enhance these surgical techniques with use of various growth and differentiation factors. The primary purpose of this report is threefold: (1) to discuss the importance of early diagnosis and the standards for identifying and staging osteonecrosis; (2) to assess the efficacy of various treatment modalities and techniques by conducting an extensive literature review and comparing reported outcomes with those of patients treated at our institution; and (3) to provide a recommended treatment algorithm based on the assessment of these treatment options. All patients who were treated at our institution for early stage osteonecrosis of the hip …

Uncemented Total Hip Arthroplasty In Young Adults With Osteonecrosis Of The Femoral Head: A Comparative Study

BACKGROUND The outcome of uncemented total hip arthroplasty in patients with osteonecrosis of the femoral head in general, and in young adults in particular, remains largely unknown. This study evaluated the clinical and radiographic results of uncemented total hip arthroplasty in young adults with osteonecrosis of the femoral head and compared these results to those seen in young adults with osteoarthritis. METHODS Forty-one consecutive patients with osteonecrosis of the femoral head (fifty-two hips) and forty patients with osteoarthritis (fifty-two hips) were treated with an uncemented total hip arthroplasty at our institution. The mean age for the osteonecrosis group was thirty-eight years, and, for the osteoarthritis group, forty-two years. Clinical and radiographic outcomes at a minimum of two years were assessed. RESULTS At a mean duration of follow-up of three years, the functional improvement was significant in both groups (p < 0.05). The outcome was good to excellent for 94% (forty-nine hips) in the osteonecrosis group and 96% (fifty hips) in the osteoarthritis group. There were two revisions in the osteonecrosis group and one revision in the osteoarthritis group. Survivorship free of revision at the time of the latest follow-up was 96.1% for the osteonecrosis group and 98% for the osteoarthritis group. CONCLUSIONS The short-term results of cementless total hip arthroplasty in patients with osteonecrosis of the femoral head were encouraging and comparable with the results of a matched group of patients with osteoarthritis. We await further follow-up to see if these promising results hold true. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Sports activity after total hip and knee arthroplasty : specific recommendations concerning tennis.

Lower extremity total joint arthroplasties are among the most successful operations in orthopaedics. Presently, it appears that some patients wish to not only have general functions restored, but also desire the opportunity to return or continue on a high level of activity. This review summarises the literature concerning athletic activity, and tennis in particular, in relation to lower extremity total joint arthroplasties. Orthopaedic surgeons frequently recommend participation in low-impact sports such as swimming, walking, bicycling, bowling and golf. The patient’s return to these recreational activities appears to be without problems. In contrast, there has been a general consensus from surgeons to avoid high-impact sports such as tennis and jogging after total joint arthroplasty, but there have been numerous studies that reported functional results being compatible with these activity levels. Conflicts emerge with some studies that describe lower survival rates for hip and knee arthroplasty in patients participating in high-impact sports. Most of these studies report that participation in sporting activities following total joint arthroplasty refers to increased polyethylene wear and debris, which could eventually result in implant failure. With recent advances in implant technology and surgical technique, the survival rates for modern prosthetic designs and patients with these high demands are promising. Various studies assessing the association between clinical outcome and participation in tennis did not demonstrate a harmful effect on implant survival rates. Although the majority of these studies do not reflect a true representation of the average patient undergoing total joint arthroplasty, more surgeons are confronted with the patients’ desire to continue with sports activity. To optimise results, patients who demand higher levels of activity must be carefully selected, and must have the motivation and drive to optimise their results. In general, all patients should be encouraged to remain physically active to improve general health, maintain good bone quality, and improve implant fixation. There is still a need for prospective, randomised controlled studies concerning high activity and its impact on total joint arthroplasty.

Operative management and outcome of complex wounds following total Knee arthroplasty

This study describes the treatment protocol for and the outcome of the management of complex wounds around total knee replacements. An analysis of 28 patients (29 knees) with complex defects who had surgery between January 1, 1986, and July 30, 1996, was performed. A specific management protocol was applied to each knee on the basis of the size and depth of the wound, the presence of infection, and the quality of soft tissue. Primary treatment included local wound care, debridement, and skin grafting or coverage with a fasciocutaneous flap, pedicled muscle flap, or free muscle transfer. Postoperatively, knees were evaluated using the Knee Society objective score. Successful salvage of the lower extremity was obtained in 28 knees (97 percent) and of the knee prosthesis in 24 of 29 knees (83 percent). Secondary plastic surgery procedures were necessary in five knees (17 percent), and secondary orthopedic procedures were necessary in four knees (14 percent). Successful salvage of total knee arthroplasty in the presence of a complex wound requires early identification of infection, aggressive irrigation and debridement, and early appropriate soft-tissue coverage. The use of our proposed algorithm will facilitate management of these complex wounds.

Cementation of a polyethylene liner into a metal shell. Factors related to mechanical stability.

BACKGROUND Various clinical situations may make polyethylene liner exchange desirable in the setting of a well-fixed metal shell. Options have included a simple polyethylene liner exchange or revision of the entire acetabular shell. A recently introduced technique involves cementation of a new liner into a well-fixed metal shell. The purposes of this study were to quantify the mechanical integrity of this method of liner fixation, to evaluate the factors that may influence immediate liner fixation, and to compare this construct with a standard locking mechanism. METHODS One modular acetabular cup design was evaluated. Variables that may contribute to the mechanical integrity of the construct were evaluated via lever-out and multiaxis dislocation testing methods. The variables included the size of the liner (undersized versus oversized), type of liner (all-polyethylene versus modular design), modification of the modular liner (unmodified versus grooved), and groove configuration (cruciform versus circumferential). Metal shells with and without screw-holes were also tested. The modular locking mechanism was used as the control. RESULTS None of the constructs failed at the cement-metal interface. All undersized liners required significantly higher loads to failure than either the controls (p < 0.001) or the oversized liners (p < 0.001). Oversized unmodified liners failed at significantly lower loads than the controls did (p < 0.01). The creation of circumferential grooves in the oversized liners significantly improved the strength of the constructs (p < 0.01), making them comparable with the controls. No significant differences were found among the four undersized groups (p > 0.3). The standard locking construct (control) and the oversized unmodified construct failed at a force of 2000 N in the multiaxis dislocation test. No other construct failed with use of this test mode. CONCLUSIONS Cementation of a polyethylene liner into a metal shell can be stronger than a conventional locking mechanism if the liner is undersized. Cementation of an oversized liner into a shell should be performed with caution. The long-term durability of this fixation remains unknown.

Surgical treatment and customized rehabilitation for stiff knee arthroplasties.

Treating patients who have arthrofibrotic or stiff knees after total knee arthroplasty can be difficult. Treatment with arthroscopic débridement, arthrolysis of adhesions with polyethylene spacer exchange, or complete revision arthroplasty often has led to less than optimal range of motion and functional outcomes. We used a combination of surgical arthrolysis and an intensive postoperative rehabilitation protocol, including functional bracing, to treat this condition. We then retrospectively reviewed 18 knees in 17 patients who had stiff knees after total knee arthroplasty with no other detectable clinical or radiographic abnormalities, at a mean followup of 30 months. Seventeen knees (94%) had gains in knee range of motion with a mean increased range of motion of 31°. Although 16 of 17 patients had clinical improvement and were satisfied with the procedure, only ⅔ of the patients (12 of 18 patients) had excellent or good Knee Society objective scores. This combined surgical and rehabilitation method can lead to an increased range of motion. All patients improved clinically, but good functional results were less predictable. The authors think treatment of these difficult knees should be aimed at soft tissue operative releases supplemented by an intensive rehabilitation protocol.Level of Evidence: Therapeutic study, level IV (prospective study). See Guidelines for Authors for a complete description of levels of evidence.