BACKGROUNDQuadratus femoris pedicled bone grafting has yielded satisfactory long-term clinical outcome for osteonecrosis of the femoral head (ONFH) in pre-collapse ONFH without extensive lesion. However, for pre-collapse ONFH with extensive necrotic area, it is still challenging to preserve the femoral head. The current study aimed to introduce a new technique of deliquesce strut with titanium mesh containing bone grafting pedicled with the femoral quadratus and to evaluate its short-term outcomes.

METHODSFrom January 2008 to December 2008, 10 ONFH patients (12 hips) underwent operations by a new technique of deliquesce strut with titanium mesh containing bone grafting pedicled with the femoral quadratus (group A). According to the ARCO classification system, there were two hips in stage II B and 10 hips in stage II C. Also in the same period, 12 ONFH patients (16 hips) underwent operations by the conventional procedure of quadratus femoris pedicled bone grafting (group B). There were 6 hips in stage II B and 10 hips in stage II C. All patients were males and suffered from alcohol induced ONFH. For the new technique, the necrotic area was evaluated, and a titanium mesh piece of the same size (range from 2.5 cm × 2.8 cm to 2.8 cm × 3.4 cm) was obtained and shaped to match the contour of the head. The cancellous bone was first placed underneath the subchondral bone and was densely impacted (about 1 to 2 mm thick). Then the titanium mesh piece was inserted. The length of the decompressive trough was measured. A titanium cylinder mesh cage with a diameter of 1.6 cm of the same length was obtained, with a "U" shaped window in the wall being created to make room for the muscle pedicle. The muscle pedicle bone was inserted into the titanium mesh cage to form a bone graft-titanium cage complex and, then the complex was inserted. The hundred percent score method was used for outcome evaluation. Clinical and radiographic outcomes were compared between group A and group B.

RESULTSThe average operative time was 150 minutes (130 to 185 minutes) in group A, with an average of 130 minutes (120 to 180 minutes) in group B. The mean blood loss was 400 ml (300 to 500 ml) in group A and 350 ml (250 to 500 ml) in group B. Group A patients were followed up for an average of 19.2 months (14 to 24 months), with an average of 18.5 months (12 to 24 months) for Group B. Full weight bearing was allowed 5 to 7 months postoperatively. Pain and function were obviously improved. For group A, pain score improved from a mean of 9.8 points preoperatively to an average of 24.6 points postoperatively, and function score improved from a mean of 9.0 points preoperatively to an average of 17.4 points postoperatively. In group B, pain score improved from a mean of 9.5 points preoperatively to an average of 24.2 points postoperatively and function score improved from a mean of 9.2 points preoperatively to an average of 17.2 points postoperatively. The range of motion changed the least, with score improvement from a preoperative mean of 13.9 points to postoperative 16.8 points for group A and from a preoperative mean of 13.7 points to postoperative 16.5 points for group B. Radiographic score improved from preoperative 31 points to postoperative 38 points for group A, in comparison with an improvement from preoperative 31 points to postoperative 37 points for group B. At the latest follow up, 11 hips were rated as excellent and 1 hip was better for group A, with 14 hips being rated as excellent and 2 hips being better in group B. There was no statistically significant difference between groups A and B in clinical and radiographic outcomes.

CONCLUSIONFor ONFH in stage ARCO IIC, satisfactory clinical outcome can be achieved by the new technique in the short-term period while the long-term clinical outcome has yet to be determined.