Micro-Core decompression combined with intralesional zoledronic acid as a treatment of osteonecrosis of femoral head: A novel technique

Abstract

Background: Avascular necrosis (AVN)/osteonecrosis of the femoral head is a debilitating condition affecting the hip joint and is one of the most common causes of total hip replacement. The available treatments include pharmacological and surgical options with total hip arthroplasty (THA) being the mainstay of treatment. This present study is a novel technique of combining micro core decompression with intra-lesional bisphosphonate as a treatment for osteonecrosis of the hip. Methods: A prospective study of 19 hips was done. There were 11 males and 4 females ranging 42-63 years. Four hips were stage I, ten hips were stage IIA, three hips were stage IIb and two hips were stage III. 16 hips (40%) had stage IIb and 24 hips (60%) had stage III ONFH. The minimum period of follow up was 24 months. All patients were assessed according to the Harris hip score. The operative procedure includes decompressing the avascular area with drilling then injecting the zoledronic acid locally. Results: The mean preoperative modified Harris hip score in stage I (n=4), stage IIa (n=10), stage IIb (n=3) and stage III (n=2) were 81.9, 72.7, 68.8 and 59.2 respectively. The mean postoperative modified Harris hip score at two years in stage I, stage IIa, stage IIb and stage III were 97.3, 91.1, 88.4 and 82.5 respectively. Conclusions: We found that the use of micro core-decompression with intra-lesional bisphosphonate will provide higher chances towards hip preservation especially in late cases or cases with larger lesions where core decompression may not be successful.