No differences in the efficacy among various core decompression modalities and non-operative treatment: a network meta-analysis

Background: Core decompression (CD) has been used to treat early-stage (pre-collapse) osteonecrosis of the femoral head (ONFH) in an attempt to prevent collapse. Recently, other adjunctive treatments including bone grafting (BG) and bone marrow mononuclear cells (BMMC) were combined to traditional CD to improve the results. We assessed the efficacy of various CD modalities and non-operative treatment through a network meta-analysis (NMA). Methods: Nine randomized controlled trials with a minimum two year follow-up were retrieved from PubMed, Embase, and Cochrane Library search. Treatment modalities categorized into five; (1) traditional CD alone, (2) CD combining BG, (3) CD combining BMMC, (4) CD combining BG and BMMC, and (5) non-operative treatment. The rate of conversion to total hip arthroplasty (THA) and the radiologic progression were compared among the five treatments. Results: A total of 453 hips were included in our NMA; 151 hips in CD, 70 hips in CD combining BG, 116 hips in CD combining BMMC, 25 hips in CD combining BG and BMMC, and 91 hips in non-operative treatment. There were no differences in the rate of THA conversion across all five treatment modalities. The pooled risk ratio compared with non-operative treatment for THA conversion was 0.92 (95% CI, 0.19–4.43; p = 0.915) in traditional CD; 4.10 (95% CI, 0.37–45.42; p = 0.250) in CD combining BG; 0.30 (95% CI, 0.04–2.49; p = 0.267) in CD combining BMMC; and 1.78 (95% CI, 0.05–63.34; p = 0.750) in CD combining BG and BMMC. No significant differences were found in terms of the radiologic progression across all treatments. Conclusions: In the current NMA, we did not find any differences in the rates of THA conversion and radiologic progression across all CD modalities and non-operative treatment. These results question the assumption that CD changes the natural course of ONFH. Considering that size of necrotic portion is the major determinant of future collapse of the necrotic femoral head and the collapse does not occur in small lesions even without any treatment, a large-scale randomized controlled trial is necessary to confirm the effectiveness of CD. Level of evidence: Level I, meta-analysis.