Structural augmentation with biomaterial-loaded allograft threaded cage for the treatment of femoral head osteonecrosis.

Seventy-six patients with femoral head necrosis were allocated to a program of either core decompression (control group) or core decompression and implantation of a biomaterial-loaded allograft threaded cage (treatment group). All patients were followed up prospectively clinically and radiographically. In the control group, no significant improvement in Harris hip score was found, and 13 of the 22 hips had deteriorated to stage III. In the treatment group, the mean Harris hip score was improved from 62.8 to 81.6; the clinical success rate at 36 months postoperatively was 91%. Collapse was seen in 1 hip, and another 3 hips exhibited progressive collapse. The procedure is attractive as a minimally invasive and salvage procedure, which shows encouraging success rates and early clinical results in patients with Steinberg stage I-II osteonecrosis.