Metabolic development of necrotic bone in the femoral head following resurfacing arthroplasty. A clinical [18F]fluoride-PET study in 11 asymptomatic hips.

BACKGROUND AND PURPOSE: One concern regarding resurfacing arthroplasty is the viability of the diminished femoral head and the postoperative risk of collapse, or a femoral neck fracture. (18)F-fluoride positron emission tomography (F-PET) enables us to assess bone viability despite there being a covering metal component. By F-PET studies, we recently showed the absence of metabolism in the remaining part of femoral heads, 1-4 years after surgery in 11 of 46 consecutive cases. We now present the further development of bone metabolism in these 11 cases. PATIENTS AND METHODS: 10 patients (11 chips) with previously shown loss of femoral head metabolism were evaluated by radiography and repeated F-PET scans, 3-6.5 years after surgery. The size of the area with low (18)F-fluoride PET uptake in the femoral head was compared to that in earlier PET images. RESULTS: No patients had any clinical symptoms; nor was any necrotic bone area visible in plain radiographs. On F-PET scans, 2 patients showed a diminished area with low uptake, 4 were unchanged, and 5 had enlarged areas. INTERPRETATION: Bone metabolism surrounding a volume of bone with no metabolic activity changes dynamically even 5 years after surgery. The presence of bone with minor uptake of F-tracer, indicating low or no bone metabolism, with further progression in 5 of 11 cases leads us to conclude that resurfacing THA should be used restrictively.

Osteonecrosis following resurfacing arthroplasty.

BACKGROUND AND PURPOSE: One of the main concerns regarding resurfacing arthroplasty is the viability of the remaining part of the femoral head, and the postoperative risk of a femoral neck fracture or collapse. In contrast to radiographic methods, positron emission tomography using the radiotracer [18F]-fluoride (Fluoride-PET) enables us to visualize the viability of bone in the remaining part of the head, despite the presence of the covering metal component. PATIENTS AND METHODS: This is preliminary prospective study of 14 patients who underwent an ASR resurfacing arthroplasty. Apart from clinical and radiographic analyses, all patients were analyzed by PET scan 1 week, 4 months, and 1 year after surgery. RESULTS: 1 patient had a minor region of osteonecrosis on PET scan at 1 week and at 4 months. After 1 year, the necrosis had increased to include most of the head. 2 other patients, normal at 4 months, had developed equally large osteonecrosis at 1 year. A fourth patient had a minor osteonecrosis at 1 year. None of the patients had clinical symptoms, and the necrotic areas were not visible on plain radiographs. CONCLUSIONS: We found Fluoride PET to be a sensitive and useful method for evaluation of bone metabolism at resurfacing arthroplasty. 3 of the 14 patients had developed osteonecrosis, involving most of the head at 1 year. The late onset of the phenomenon does not support the hypothesis of surgically damaged vascularity. The presence of this complication together with the lack of visibility on plain radiographs gives reason for concern.

Femoral head viability following resurfacing arthroplasty. A clinical positron emission tomography study.

Hip resurfacing (HR) carries attendant risks of avascular necrosis (AVN) and femoral neck fracture. We used fluoride positron emission tomography (PET) scans to analyze bone metabolism 2-5 years after surgery in 35 cases. Three of the patients had been clinical failures. Using PET scans in the remaining 32 cases, 7 were found to have an area of non-viable bone in the femoral head. This was seen following both posterior and antero lateral approaches. Fluoride PET is a sensitive and useful method for evaluating bone metabolism following HR.

One hundred eighteen Bristow-Latarjet repairs for recurrent anterior dislocation of the shoulder prospectively followed for fifteen years: study I--clinical results.

In this prospective study on the Bristow-Latarjet repair, which started in 1980 and ended in 2001, we report the outcome in 118 shoulders where the patients have been followed up for 15 years (mean, 15.2 years; range, 14.3-20.8 years). The study was based on a physical examination, scoring with the system of Rowe et al, and the patients' subjective assessment of the operative result. After 2 years, 1 of 118 shoulders had redislocated and 98% of patients were satisfied with the operative repair. At 15 years' follow-up, 1 patient had undergone revision surgery as a result of recurrence of instability. One patient had had one redislocation during the follow-up period, and one patient reported three recurrences 3 years postoperatively. This patient has had no redislocations during the last 12 years. Furthermore, one more patient had had two recurrences 9 and 12 years after surgery but was very satisfied at follow-up. Subluxations occurred once in 4 patients and several times in 7 patients. These patients were, however, satisfied with the procedures at follow-up. One patient reported posterior subluxations at follow-up. Apprehension was significantly more common in patients with bilateral instability (P =.04) and was found in 19 of 109 shoulders. Of the patients, 90 (76%) were very satisfied with the operative result, 26 were satisfied (22%), and 1 did not know. The patient with revision surgery was considered to be dissatisfied. The incidence of bilateral shoulder instability increased from 22 of 118 (19%) at the time of surgery to 41 of 117 (35%) at 15 years after surgery. We conclude that the overall clinical results, with a satisfaction rate of 98% 15 years after the Bristow-Latarjet repair, were as good as the results reported after any operative method for recurrent anterior shoulder dislocation. However, until the radiologic part of this study is completed, we recommend the procedure only for shoulders with revision because of failed previous surgery and to surgeons familiar with the method.