Core decompression of the femoral head for avascular necrosis: indications and results.

OBJECTIVE

To evaluate the effectiveness and safety of core decompression in the treatment of avascular necrosis (AVN) of the femoral head.

DESIGN

A case study.

SETTING

The department of orthopedic surgery in a major university hospital.

PATIENTS

All patients with AVN of the femoral head, stages I to IVA, were included regardless of the cause of the necrosis. Three hundred hips were available for analysis. The follow-up ranged from 2 to 12 years.

INTERVENTION

Core decompression of the femoral head was performed with an 8-mm Michele trephine inserted from just below the greater trochanter into the centre of the necrotic lesion to within 5 mm of the articular surface. Two more trephine tracts were made with a 5-mm or 6-mm trephine. The normal portion of cancellous bone recovered from the intertrochanteric region was thinned with a rongeur and was placed loosely into the central decompression channel at the end of the procedure to serve as a graft.

MAIN OUTCOME MEASURES

Anteroposterior and lateral radiographs, taken immediately before surgery and at the final follow-up, clinical hip evaluation according to the Harris scoring system, and the need for total hip replacement.

RESULTS

One patient sustained a subcapital fracture 1 month after surgery due to a fall. There was one case of nonfatal pulmonary embolism, one case of pneumonia and one case of thrombophlebitis of the thigh. Forty-six percent of operatively managed hips showed no radiographic progression of disease compared with only 19% of nonoperatively managed hips. Thirty-five percent of the operatively managed hips required total hip replacement compared with 77% of nonoperatively managed hips. The results in hips with early (stages I and II) AVN were only slightly better than those of hips with advanced (stages III and IVA) disease. However, the results in hips with small areas of necrosis in both stages I and II were much better than those with larger lesions; only 7% of the former group required total hip replacement after decompression and cancellous bone grafting.

CONCLUSIONS

Core decompression with cancellous bone grafting is a safe and effective procedure for the treatment of early AVN of the femoral head. Results with this form of treatment are considerably better than those obtained in patients treated nonoperatively. Decompression with or without bone grafting is the author's treatment of choice for patients with early AVN of the femoral head.