Symptomatic hip osteonecrosis is a disabling condition with a poorly understood aetiology and pathogenesis. Numerous treatment options for hip osteonecrosis are described, which include non-operative management and joint preserving procedures, as well as total hip replacement (THR). Non-operative or joint preserving treatment may improve outcomes when an early diagnosis is made before the lesion has become too large or there is radiographic evidence of femoral head collapse. The presence of a crescent sign, femoral head flattening, and acetabular involvement indicate a more advanced-stage disease in which joint preserving options are less effective than THR. Since many patients present after disease progression, primary THR is often the only reliable treatment option available. Prior to the 1990s, outcomes of THR for osteonecrosis were poor. However, according to recent reports and systemic reviews, it is encouraging that with the introduction of newer ceramic and/or highly cross-linked polyethylene bearings as well as highly-porous fixation interfaces, THR appears to be a reliable option in the management of end-stage arthritis following hip osteonecrosis in this historically difficult to treat patient population.

Cite this article: Bone Joint J 2013;95-B, Supple A:46–50.

The February 2013 Foot & Ankle Roundup. 360 . looks at: replacement in osteonecrosis of the talus; ankle instability in athletes; long-term follow-up of lateral ankle ligament reconstruction; an operation for Stage II TPD; whether you should operate on Achilles tendon ruptures; Weil osteotomies and Freiberg’s disease; MRI scanning not sensitive for intra-articular lesions; and single-stage debridement and reconstruction in Charcot feet

The purpose of this study is to evaluate short to mid-term clinical and radiological results of metal on metal resurfacing arthroplasty in osteonecrosis of the femoral head (ONFH). 185 hips of 169 patients who underwent metal on metal resurfacing arthroplasty using Birmingham Hip Resurfacing system (Midland Medical Technololgies, Birmingham, UK) between December 1998 and May 2005 were available for this study and all cases were followed up over 3 years. All preoperative diagnoses were ONFH. The extents of necrotic area were analyzed by preoperative MRI scanning. Their mean age at the time of operation was 37.7(range, 16–67) years old and mean period of follow-up was 88(range, 36–113) months. For the clinical assessments, Harris hip scores, UCLA activity scores, pain and ROM were evaluated. Radiological changes such as radiolucencies around the stem, impingement sign, neck narrowing, osteolysis around head and neck junction, loosening of implants, heterotopic ossifications were evaluated in the serial antero-posterior, translateral radiographs of the hip joint. Preoperative necrotic area was average 42.7(range, 11.5–60) %. Clinically, the average Harris hip score was improved from 85.2 points to 97.1 points at final follow-up. Average UCLA activity scores at the last follow-up was 8.8 and almost of the patients showed high activity and returned to their original job. ROM were very satisfactory. Radiologically, the mean inclination of acetabular component was 48.0°. There were no radiolucent lines around the acetabular components, but 3 cases showed radiolucent lines around the stem of femoral components. Osteolytic lesions were noticed in 10 cases around head-neck junction. Nine hips had impingement signs around the head-neck junction. There was no case which showed evidence of stress shielding. Moderate neck narrowing were shown in 3 cases. There were 6 cases of heterotopic ossification. One hip had a revision surgery to a total hip arthroplasty using big metal ball because of loosening of acetabular component. There was no patient complained limb length discrepancy and no infection, dislocation, thigh pain. The midterm performance of metal on metal resurfacing arthroplasty in ONFH was very excellent in the aspects of pain relief, ROM of hip joints, rehabilitation and return to preoperative activity and minimization of common complications of conventional total hip arthroplasty. There was no mechanical failure related to the osteonecrosis and we can conclude that performing resurfacing arthorplasty in osteonecrosis less than 50% of extent can be justified. However, performing resurfacing arthroplasties in osteonecrosis of femoral heads needs meticulous surgical techniques and longer learning curve to prevent early failure. Even though our midterm follow-up study revealed excellent results, more long-term follow-up studies are mandatory to determine the survivorship and to verify the problems related to the increased serum metal ion and metal ion toxicity after resurfacing arthroplasty

Although total hip arthroplasty (THA) is quite predictable and durable in older patients, young and active patients have higher rates of revision and these rates are especially increased when the etiology is osteonecrosis. Recent advancement of hip resurfacing technology, HRA has been revived again. Numerous advantages and promising results of HRA have been published. But patient selection and techniques etc still remain issues for HRA in general and especially for patients with osteonecrosis. In the case of HRA in patients with osteoarthritis, the bone quality is stronger and there is no head necrosis and surgical techniques are fundamentally different when compared to osteonecrosis. In osteonecrosis, there is a higher risk and greater concern of the neck fracture due to necrosis and osteoporosis, insecure fixations as well as a progression of necrosis in the subchondral bone. These factors should be considered when assessing hips with osteonecrosis. The ultimate assessment is the condition of the prepared femoral head. This makes resurfacing arthroplasty for osteonecrosis a challenging procedure. This study was performed to assess the overall clinical and radiological results of the total resurfacing arthroplasty for the patients with osteonecrosis of the femoral head(ONFH) after a minimum 5 year-follow-up. 444 hips of ONFH received resurfacing arthroplasty from Sep 1998 to Mar.2008. 88 hips which were followed up minimally 5 years were included in this study. Among 88 hips(79 patients) of ONFH that have underwent hip resurfacing arthroplasties from Dec 1998 to Apr 2003, 85 hips(76 patients) were available for the complete study. The mean age at the time of operation was 37 (16–67) years old. The average follow-up period was 80 (60–112) months. The patients were clinically evaluated with the Harris hip score, hip or thigh pain, limb length discrepancy and range of motion. As a radiological evaluation, we observed the changes of implant position, patterns of bone remodeling in the neck and complications such as femoral neck fracture, loosening and osteolysis. Metal ion in the serum was also analysed. The Harris hip score increased from 77.8 preoperatively to 98.4 at the final visit. Hip abduction/adduction and rotations significantly improved after the operation. Flexion contracture disappeared and further flexion also returned to almost normal. No patient complained of limb length discrepancy and pain on the hip or thigh at the last visit. Although they are not related to the clinical result, some cases showed various types of radiographic changes in the neck of the proximal femur. Neck narrowing was observed in 3 hips. There was no detectable wear or change of position of the acetabular cup and femoral stem. Our experience with resurfacing arthroplasty in osteonecrosis of the femoral head indicates that the overall results are superior to conventional THA in the aspect of pain relief, the range of hip motion, earlier rehabilitation and earlier return to preoperative activity. This procedure of his resurfacing arthroplasty could be an alternative between joint preserving procedures and THA in the case of early-to-mid staged osteonecrosis of the femoral head especially in younger patients who need arthroplasty. Extent and location of necrosis, and bone quality are the most important factors in resurfacing arthroplasty in osteonecrosis. Precise preoperative planning and meticulous surgical technique is needed to perform resurfacing arthroplasty. But long-term studies are needed to determine the survivorship and to evaluate the metal toxicity after resurfacing arthroplasty