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Core decompression in treating ischemic necrosis of the femoral head.

BACKGROUND
The application of core decompression in the treatment of ischemic necrosis of femoral head (INFH) is to preserve the joint at early stage of the disease. Although excellent results have been obtained in many series, its effectiveness is questionable because of high rates of failure. This study is to evaluate the effectiveness of this technique in our patients with INFH receiving core decompression as the sole treatment.


METHODS
Although 91 patients were treated with core decompression in Veterans General Hospital-Taipei from 1980 to 1993, only 71 were considered as the valid cases after having been followed for 24 to 165 months (mean 56.7 months). Of 84 hips treated, 49 hips were steroid induced, 20 idiopathic, 14 alcohol related, and one related to trauma. Twenty-five hips were at Steinberg stage I, 32 at stage II, nine at stage III, 17 at stage IV, and one at stage VI.


RESULTS
The results were poor in 22 (26.19%) hips since the patients required hip prosthesis. Fair results were rated in 37 (44.05%) hips since progressive collapse occurred in the femoral head and the patients suffered from moderate hip pain. Good results were found in nine (10.71%) hips since the lesion showed no progression and the patients had only occasional pain. Excellent results were obtained in 16 (19.05%) hips since the patients had no pain and the lesion had no progressive change. The satisfactory rate in the nonsteroid-related hips (33% or 12/35) was significantly higher than in the steroid-related hips (27% or 13/49). The overall satisfactory result was only 30%.


CONCLUSIONS
Although core decompression may not be effective in preventing progression of INFH, it may relieve temporary pain and delays the need for hip arthroplasty in some patients.