Mike S. McGrath

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.

Initial experience with custom-fit total knee replacement: intra-operative events and long-leg coronal alignment

New technology using magnetic resonance imaging (MRI) allows the surgeon to place total knee replacement components into each patient’s pre-arthritic natural alignment. This study evaluated the initial intra-operative experience using this technique. Twenty-one patients had a sagittal MRI of their arthritic knee to determine component placement for a total knee replacement. Cutting guides were machined to control all intra-operative cuts. Intra-operative events were recorded and these knees were compared to a matching cohort of the senior surgeon’s previous 30 conventional total knee replacements. Post-operative scanograms were obtained from each patient and coronal alignment was compared to previous studies using conventional and computer-assisted techniques. There were no intra-operative or acute post-operative complications. There were no differences in blood loss and there was a mean decrease in operative time of 14% compared to a cohort of patients with conventional knee replacements. The average deviation from the mechanical axis was 1.2° of varus, which was comparable to previously reported conventional and computer-assisted techniques. Custom-fit total knee replacement appeared to be a safe procedure for uncomplicated cases of osteoarthritis.RésuméObjectif: les nouvelles technologies utilisant l’IRM doivent permettre aux chirurgiens de mettre en place de façon correcte les composants articulaires d’une prothèse de genou chez les patients et ce, d’une façon identique à l’axe articulaire préexistant à l’arthrose. Le but de cette étude est d’également évaluer en peropératoire l’utilisation de cette technique. Matériels et méthodes: 21 patients ont bénéficié d’une IRM sagittale du genou de façon à déterminer le positionnement des implants lors d’une prothèse totale. Les guides de coupe ont été préparés pour permettre cette évaluation en per oprératoire. Les évènements per opératoires ont été rapportés et ces genoux ont été comparés à une cohorte de 30 genoux traités de façon conventionnelle par le même chirurgien sénior. En postopératoire, une évaluation sur un grand film radiographique, dans le plan frontal, avec mesure des axes a été réalisée pour chaque patient en comparant la technique conventionnelle et celle avec l’aide de l’IRM. Résultats: il n’y a pas eu de complications postopératoires. Il n’y a pas de différence dans les pertes sanguines. Il y a une diminution moyenne du temps opératoire de 14% quand on la compare à la technique conventionnelle. La déviation axiale moyenne est de 1,2° en varus ce qui est comparable pour la technique conventionnelle ou la technique assistée par ordinateur. Conclusion: l’utilisation d’un matériel ancillaire conventionnel dans la prothèse totale du genou est une technique suffisamment sure pour le traitement des arthroses du genou sans complication.

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.

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 …

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.

Total Hip Resurfacing in Patients Who Are Sixty Years of Age or Older

BACKGROUND Metal-on-metal total hip resurfacing arthroplasty has been associated with excellent early results in patients who are younger than sixty years of age, but it remains controversial whether this procedure is appropriate in older patients. The purpose of the present study was to compare the clinical and radiographic outcomes after hip resurfacing in two cohorts of patients: those who were sixty years of age or older, and those who were younger than sixty years of age. METHODS Between November 2002 and August 2005, thirty-five patients (forty hips) who were sixty years of age or older were managed with metal-on-metal total hip resurfacing arthroplasty. The outcomes of these patients were compared with those of 130 patients (153 hips) who were younger than sixty years of age but otherwise had similar preoperative parameters and who had resurfacing arthroplasty performed during the same time interval and by the same surgeon. We evaluated Harris hip scores, Short Form-12 scores, and complications as well as radiographic alignment and radiolucencies. RESULTS At a mean follow-up time of thirty-six months, the mean Harris hip scores improved from 52 points to 94 points in the older patient cohort and from 53 points to 92 points in the younger patient cohort. The final Short Form-12 scores of the two groups were also similar. Two patients who were sixty years or older and five of the younger patients required conversion to a conventional total hip arthroplasty. Femoral neck fracture was the reason for one conversion in each group. There were no impending radiographic failures in either cohort. CONCLUSIONS Although national registries indicate that the risk of femoral neck fracture is higher in older patients, the present study found that these patients had excellent clinical outcomes that were similar to those of patients who were younger. We await longer follow-up results to determine further outcomes in these patients.

Current hand surgery literature as an educational tool for the orthopaedic in-training examination.

The origins of hand surgery as a distinct surgical field in the United States are often credited to the pioneering efforts of Asa Sterling Bunnell around the time of the Second World War1. It has since evolved into an increasingly complex specialty involving hand transplantation, joint arthroplasty, and microsurgery2-6. Recognizing the need for oversight to ensure proper training and education, the orthopaedic, plastic, and surgery primary boards jointly approved a Certificate of Added Qualification in Hand Surgery in 1985, and the first examination for certification in hand surgery was administered in 19897. Because of the continually emerging complexities in this field, it has become increasingly important to evaluate the training of orthopaedic residents in order to ensure that their education and understanding of hand surgery is adequate prior to graduation and possible application for fellowship. The Orthopaedic In-Training Examination (OITE) was established as a measure for orthopaedic resident education and knowledge in the 1960s8. The OITE provides a standardized format to evaluate the hand knowledge of orthopaedic residents. This examination is designed to focus on evidence-based knowledge and skills that a surgeon should know in order to be able to practice effectively. Recent orthopaedic publications are often recommended as one of the main sources of information for surgeons in training, and it has recently been reported that there is a positive correlation between performance on the OITE and frequent review of current orthopaedic journals9. However, we know of no published study that has assessed the correlation between the literature and the hand surgery content tested in the OITE. The primary questions in the present study were: (1) What literature should be recommended to orthopaedic residents who are receiving training and instruction regarding hand surgery and are preparing for …

Results of Total Knee Replacement for Isolated Patellofemoral Arthritis: When Not to Perform a Patellofemoral Arthroplasty

Many procedures have been used to treat advanced isolated patellofemoral arthritis, with varying results. Patellofemoral arthroplasty (PFA) is a bone-conserving procedure that has shown short-term success but has relatively high revision rates. Total knee arthroplasty (TKA) has been recommended for treatment of this disease in patients who are older than 60 years of age. Recent literature indicates that PFA is most successful in patients who have isolated patellofemoral arthritis secondary to trochlear dysplasia or patellar fracture and in patients who are younger than 60 years; TKA is recommended for older patients who have primary or idiopathic isolated patellofemoral arthritis.

Static progressive stretch for the treatment of knee stiffness

Persistent knee stiffness is common after knee arthroplasties, cruciate ligament repairs, and trauma. Static progressive stretch protocols have shown success in treating contractures of the elbow, ankle, and knee in case reports and small case series. This study evaluated static progressive stretch as a treatment method for patients who had refractory knee stiffness, and compared the outcomes to published results of other therapeutic modalities. Forty-one patients who had knee stiffness and who had not improved with conventional physical therapy modalities were treated with a patient-directed orthosis that utilized the principles of static progressive stretch. After a mean of 9 weeks of use (range, 3 to 27 weeks), the total arc of motion increased by a mean of 33 degrees (range, 0 to 85 degrees ). Forty of 41 patients had increased motion at a mean final follow-up time of 1 year (range, 6 months to 2 years), and 93% were satisfied with the results. The outcomes were comparable to other nonoperative treatments reported in the literature, but the results in the present study occurred in a shorter mean treatment time. An orthosis that utilizes the principles of static progressive stretch may be a successful treatment for improving the range of motion and satisfaction of patients who have knee contractures.

Metal-on-Metal Total Hip Resurfacing Arthroplasty in the Presence of Extra-Articular Deformities or Implants

BACKGROUND Hip resurfacing has been proposed as an alternative to total hip replacement in patients who have proximal femoral deformities or retained hardware in the proximal aspect of the femur. In these situations, placement of a conventional stemmed hip prosthesis would be difficult or impossible, possibly necessitating a complex osteotomy or a custom prosthesis. The purpose of this study was to evaluate a series of patients who had extra-articular deformities of the proximal aspect of the femur and/or retained hardware and who were managed with a resurfacing hip prosthesis. METHODS Fifteen patients (seventeen hips) who underwent metal-on-metal resurfacing hip replacements were studied. Ten patients (twelve hips) had bowing or other deformities of the femur secondary to trauma, multiple epiphyseal dysplasia, renal osteodystrophy, or proximal femoral focal deficiency. Five patients (five hips) had retained hardware. Twelve of the patients (thirteen hips) had previously been told by orthopaedic surgeons that, due to the deformity or retained hardware, they could not undergo conventional total hip arthroplasty without also undergoing ancillary surgical procedures. We evaluated perioperative factors (operative time and estimated blood loss), Harris hip scores, complications, and failure rates. RESULTS At a mean follow-up time of three years (range, two to five years), fourteen patients (sixteen hips) were doing well clinically and radiographically. Assessment of the intraoperative records revealed minimal difficulty, with a mean operative time of 104 minutes and a mean blood loss of 621 mL. The mean Harris hip score was 92 points. One patient, a fifty-nine-year-old woman, underwent two subsequent revisions-one for the treatment of a femoral neck fracture, and one for the treatment of acetabular component loosening. CONCLUSIONS Resurfacing hip arthroplasty offers an option for patients when placement of a conventional total hip prosthesis is difficult or impossible because of the presence of proximal femoral deformities or retained hardware in or on the proximal aspect of the femur.