David R. Marker

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.

Effect of changing indications and techniques on total hip resurfacing.

Recently, improved metal-on-metal bearing technology has led to the reemergence of resurfacing as a reasonable option for total hip arthroplasty. During the course of a prospective multicenter FDA-IDE evaluation of metal-on-metal total hip resurfacings, we modified our indications and emphasized surgical technique where the femoral surface area was small due to femoral cysts and small component size. We assessed the influence of these changes on complication rates in the first cohort of 292 patients and the second of 724, and then compared these outcomes in the second cohort with historical reports of resurfacing. We had a minimum followup of 24 months (mean, 33 months; range, 24-60 months). After changes were made in the indications and technique, the overall complication rate decreased from 13.4% to 2.1% with the femoral neck fracture rate reduced from 7.2% to 0.8%. The outcomes of the second cohort compare with modern-day resurfacing devices and appear superior to historical results. The data suggest patients should be carefully selected and technique optimized to reduce complications. Long-term followup is required to see if these promising results will be maintained.Level of Evidence: Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

Osteonecrosis is not a predictor of poor outcomes in primary total hip arthroplasty: a systematic literature review

The primary goals of this critical literature review were to determine whether revision rates of primary total hip arthroplasty in patients with osteonecrosis differ based on the underlying associated risk factors and diagnoses, whether the outcomes of this procedure have improved over the past two decades, and to compare outcomes based on study level of evidence. A systematic literature review yielded 67 reports representing 3,277 hips in 2,593 patients who had a total hip arthroplasty for osteonecrosis of the femoral head. Stratification of outcomes by associated risk factors or diagnoses revealed significantly lower revision rates in patients with idiopathic disease, systemic lupus erythematosus, and after heart transplant, and significantly higher rates in patients with sickle cell disease, Gaucher disease, or after renal failure and/or transplant. There was a significant decrease in revision rates between patients operated upon before 1990 versus those in 1990 or later, with rates of 17% and 3%, respectively. The results for arthroplasties performed in 1990 or later were similar to those for all hips in publicly reported national joint registries. Certain risk factors were associated with higher revision rates in patients with osteonecrosis who were treated by total hip arthroplasty. However, most patients (82%) do not have these associated negative risk factors. Overall, this critical literature review provides evidence that osteonecrosis itself, or when associated with the most common risk factors and/or diagnoses, is not associated with poor outcomes in total hip arthroplasty.

Metal-on-Metal Hip Resurfacing: Advantages and Disadvantages☆

Modern metal-on-metal resurfacing has recently gained popularity as an alternative to standard stemmed total hip arthroplasty. This study analyzed, from a literature review, the purported advantages and disadvantages of resurfacing with a comparison to standard hip arthroplasty. Advantages may include bone conservation on the femoral side with possible lower dislocation rates, more range-of-motion, more normal gait pattern, increased activity levels, increased ease of insertion with proximal femoral deformities or retained hardware, and straightforward revision. Possible disadvantages of resurfacing are increased difficulty to perform the procedure, increased acetabular bone stock loss, femoral neck fractures, and concerns about the effects of metal ions. Many of these issues will need further clarification by well-planned prospective studies and evaluation of longer-term outcomes.

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 …

Functional problems and arthrofibrosis following total knee arthroplasty.

Improved surgical techniques and multidisciplinary rehabilitation protocols that involve coordination among surgeons, physical therapists, anesthesiologists, and social services personnel have led to excellent knee function and range of motion in a large percentage of patients following total knee arthroplasty. Nevertheless, there remains a small number of patients with persistent dysfunction that is difficult to treat1-4. Functional problems following total knee arthroplasty may be incapacitating as a result of persistent pain5, instability6, and a limited range of motion7. It has been shown recently that there is a direct correlation between a decreased range of motion following surgery and a lower perceived quality of life as evaluated with use of the Short Form-36 health survey questionnaire8. Continued dysfunction for any reason ultimately leads to decreased patient satisfaction. There is controversy about treatment methods for patients for whom initial rehabilitation efforts are unsuccessful following total knee arthroplasty. The reported efficacy of both noninvasive and invasive treatment modalities has been variable, with the percentage of patients obtaining improvement ranging from 0% to 90%3,9-12. Patients who have continued dysfunction despite initial rehabilitation efforts may require revision surgery. However, patients who have well-aligned, well-fixed prosthetic components will likely not benefit from a complete revision. Treatment of arthrofibrosis, scarring, soft-tissue contractures, and/or other soft-tissue dysfunction should involve less invasive treatment protocols before surgical options are considered. Nonoperative treatment modalities for restoring the range of motion include intensive rehabilitation protocols, static or dynamic splinting, injections, and application of serial casts13. Manipulation with the patient under anesthesia and invasive procedures, including arthroscopic debridement, open debridement with or without polyethylene exchange, and complete component revision, have been utilized when initial nonoperative rehabilitation efforts have failed. As a result of the …

Knee arthroplasties have similar results in high- and low-activity patients

With increased patient demand to return to active lifestyles, total knee arthroplasties have evolved from primarily providing pain relief to allowing for increased function and mobility. We evaluated the influence of activity on the outcome of total knee arthroplasties. The overall satisfaction, rate of revision, and clinical and radiographic results for high-activity patients were compared with a matched group of low-activity patients at a minimum followup of 4 years (mean, 7 years; range, 4-14 years). There were 22 men and 35 women (72 knees) in each group. High-activity patients fared as well as their low-activity counterparts with no differences in clinical outcomes. At the time of last followup, mean Knee Society objective scores were 95 points (range, 70-100 points) and 96 points (range, 80-100 points) for the high-activity and low-activity groups, respectively. The high-activity group had one clinical failure, and neither group had any revisions. The groups had similar radiographic outcomes with no progressive radiolucencies and no evidence of osteolysis. While we await long-term results, these results suggest that low- to moderate-impact sports activities had no effect on the clinical and/or radiographic outcomes of total knee arthroplasties at midterm followup.Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

High-Impact Sports After Total Knee Arthroplasty

Many patients will attempt high-impact loading activities after total knee arthroplasty. This study analyzed the clinical and radiographic results of these high-demand sports patients. A total of 31 patients (33 knees) were identified who participated in high-impact sports on average 4 times per week (range, 1-7 times per week) for a mean of 3.5 hours per week (range, 1 to 10 hours), including jogging, downhill skiing, singles tennis, racquetball, squash, and basketball. At 4 years mean follow-up (range, 2-9 years), 32 of 33 knees had successful clinical and radiographic outcomes. Overall satisfaction was a mean of 9.1 points on a scale of 0 to 10 points. These results indicate that some patients will participate in high-impact sports and enjoy excellent clinical outcomes at a minimum 4 years after surgery.

Early failure of a unicompartmental knee arthroplasty design with an all-polyethylene tibial component

Refined prosthetic designs and surgical techniques for unicompartmental knee arthroplasty have recently been associated with improved outcomes. The purpose of the present study was to evaluate the clinical and radiographic outcomes of the EIUS unicompartmental design, which has an all-polyethylene tibial component, and to compare these outcomes with published reports of other unicompartmental prostheses. Between February 2002 and March 2005, 113 patients (144 knees) underwent a medial unicompartmental knee arthroplasty, all performed by a single surgeon who used the EIUS prosthesis. At a mean follow-up of 36 months (range, 24-54 months), the mean Knee Society objective and functional scores improved from 55 points (range, 31-77 points) and 49 points (range, 35-60 points) to 92 points (range, 45-100 points) and 89 points (range, 10-100 points), respectively. The implant survival rate was 89%, with 16 knees either revised or scheduled for revision. The reasons for revision included aseptic loosening of the tibial component (eight knees), progressive symptomatic patellofemoral disease (four knees), and tibial component subsidence (four knees). Multiple regression analysis revealed that age, gender, and body mass index were not significantly correlated with success or failure of this design, although nine of the 16 patients who required revision were obese. This prosthesis was associated with higher revision rates than components which utilize metal-backed implants. Further modifications in the design, indications, or technique may be necessary to improve outcomes of this unicompartmental knee arthroplasty system.