Autologous bone marrow grafting of avascular osteonecrosis before collapse

Introduction and method

To enhance the rate of bone repair, injection of bone marrow in the necrosis was done during core decompression. The source of bone marrow was the iliac crest. A quantity of 150 ml was obtained by bone marrow aspiration. The whole marrow was concentrated using centrifugation to increase the cell concentration in an aliquot of 25 ml. Bone marrow was injected in the necrosis and in the femoral head by the hole of the core decompression. 42 hips with MRI avascular necrosis without collapse (stage 11) were operated with this technique between 1991 and 1993. The average follow up is 5 years.

Results

Five hips are now failures (collapse) with a stage III at the last revision. The other hips are pain free and stage Il. The postoperative MRI demonstrates a modification of the signal in most cases and a disparition of the necrosis in four cases. The number of transplanted cells was calculated in a laboratory study; the number of nucleated cells was counted in the marrow transplanted and the fibroblast colony forming cells (CFU-F) were cloned to appreciate the activity and the number of progenitor in the marrow transplanted; failures of this technique (five hips with stage 3) occurred in patients with a low number of transplanted cells (average 2000 CFU-F for failures and average 25000 CFU-F for the other hips).

Conclusion

Many different grafts have been used in avascular necrosis to provide structural support or to enhance bone formation. Since bone marrow contains progenitor cells it may be associated to core decompression. It is a simple and easy adjuvant to core decompression.