Treatment of pre-collapse non-traumatic osteonecrosis of the femoral head through Orthopdische Chirurgie Munchen approach combined with autologous bone mixed with β-tricalcium phosphate porous bioceramic bone graft: a retrospective study of mid-term results

Background This study aimed to evaluate the clinical efficacy of femoral head and neck fenestration combined with autologous bone mixed with beta-tricalcium phosphate porous bioceramic bone (light bulb procedure) through Orthopdische Chirurgie Munchen approach (OCM approach) for pre-collapse non-traumatic osteonecrosis of the femoral head(ONFH). Methods The clinical data of 47 patients (47 hips) with ONFH were retrospectively reviewed. The Harris hip score (HHS) was used to evaluate the clinical outcomes. Imaging was assessed by X-ray. Clinical failure was defined as postoperative total hip arthroplasty (THA) or the HHS was poor (< 70). The Kaplan-Meier survival curve was used to conduct a univariate analysis of risk factors. The analysis factors included gender, age, International Association Research Circulation Osseous (ARCO) stage, etiology, body mass index (BMI), 25-hydroxyvitamin D (25(OH)D), and type I collagen carboxy-terminal peptide (CTX). The COX multivariate risk model was used to analyze the risk factors. Results All the 47 hips were followed up for 24-58 months, with an average of 45 months. The Harris score (76.29 +/- 10.38) at the last follow-up was significantly higher than the preoperative HHS (64.45 +/- 2.93) (P < 0.05). The postoperative HHS was excellent with a success rate of 36.17%. Postoperative imaging evaluation showed that 9 hips improved, 28 hips stabilized, and 10 hips progressed. Moreover, 17 out of 47 hips were defined as a postoperative clinical failure and the success rate was 63.83%. 25(OH)D and preoperative ARCO stage were risk factors for postoperative clinical failure (P < 0.05). The COX multivariate risk model analysis showed that IIIA stage was an independent risk factor for postoperative clinical failure (P < 0.05). Conclusions The head and neck fenestration and bone grafting via the OCM approach in the treatment of non-traumatic ONFH in the pre-collapse stage can achieve good clinical outcomes. 25(OH)D deficient patients and ARCO IIIA patients had a higher failure rate of bone graft using this approach.