Multiple Drilling compared with Core Decompression for the Treatment of Osteonecrosis of the Femoral Head
SY Kim, DH Kim, IH Park, BC Park, PT Kim, JC Ihn
Department of Orthopedic Surgery, College of Medicine, Kyungpook National University, Daegu, Korea

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

Methods: We reviewed the results in a consecutive series of 54 patients (65 hips) who had undergone multiple drilling (31 patients, 35 hips) and core decompression (23 patients, 30 hips), between September 1991 and July 2001, for the treatment of precollapse osteonecrosis of the femoral head. The average duration of follow up was 60.3 months (range, 24-103 months) in multiple drilling and 44.8 months (range, 24 to 84 months) in core decompression. We evaluated the presence of collapse and radiographic progression in each group prospectively and defined collapse of the femoral head as the failure. We used the Harris hip score (HHS) 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) in both groups. The average preoperative and the last HHS was 86.7 to 73.7 in core decompression and 87.0 to 74.6 in multiple drilling. The group who had undergone multiple drilling had significantly longer time before collapse (mean 42.3 months vs 22.6 months, p=0.011) and lower rate of collapse within 3 years after operation (55.0% vs 85.7%, p=0.03) than core decompression.

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