MULTIPLE DRILLING COMPARED WITH STANDARD CORE DECOMPRESSION FOR THE TREATMENT OF OSTEONECROSIS OF THE FEMORAL HEAD

Abstract

Introduction: The purpose of this study was to compare the results of the efficacy of two decompressive methods (multiple drilling vs standard core decompression) for the treatment of precollapse osteonecrosis of the femoral head.

Methods: The results in a consecutive series of 54 patients (65 hips) who had undergone multiple drilling (31 patients, 35 hips) or core decompression (23 patients, 30 hips) for the treatment of precollapse osteonecrosis of the femoral head between September 1991 and July 2001 were reviewed. The average duration of follow up was 60.3 months (range, 24–103 months) in the multiple drilling group and 44.8 months (range, 24 to 84 months) in the core decompression group. The presence of collapse and radiographic progression in each group was evaluated prospectively with collapse of the femoral head defined as a failure. Harris hip scores (HHS) were used to evaluate clinical status preoperatively and at the most recent follow up.

Results: Radiographically and clinically, high failure was significantly related to the larger size and laterally located lesion (LHI of less than 12%, Urbaniak IIC, Ohzono IC and Kerboul index of more than 240 degrees) in both groups. The average preoperative and the last HHS was 86.7 to 73.7 in the core decompression group and 87.0 to 74.6 in the multiple drilling group. Compared to the core decompression group, the multiple drilling group had significantly longer times before collapse (mean 42.3 months vs 22.6 months, p=0.011) and a lower rate of collapse within 3 years after operation (55.0% vs 85.7%, p=0.03).

Discussion: Decompressive methods have worse outcomes in case of lesions of larger size and lateral location, even in precollapse stage. Multiple drilling has significantly longer time before collapse and a lower rate of collapse within 3 years after operation than standard core decompression.