Modified Kerboul Angle Predicts Outcome of Core Decompression With or Without Additional Cell Therapy

Abstract

BackgroundCore decompression is the most common procedure for early-stage osteonecrosis of the femoral head (ONFH). This study investigated outcomes of core decompression with/without bone marrow aspirate concentrate (BMAC), based on the Kerboul combined necrotic angles using magnetic resonance imaging. MethodsWe reviewed 66 patients (83 hips) with early ONFH, Association Research Circulation Osseous stages I-IIIa, who underwent core decompression alone (26 patients, 33 hips) or in combination with BMAC (40 patients, 50 hips). Survival rate and progressive collapse were analyzed using the Kaplan-Meier method, and conversion to total hip arthroplasty (THA) was evaluated. Subgroup analyses based on the modified Kerboul angle were performed: grade I (<200°), grade II (200°-249°), grade III (250°-299°), and grade IV (≥300°). ResultsMean follow-up was 36 ± 23 months. Femoral head collapse with BMAC (16 hips, 32%) was significantly lower than without BMAC (19 hips, 58%, P = .019). Conversion THA was significantly lower with BMAC (28%) than without (58%, P = .007). Survival rates among groups showed significant differences (P = .017). In grade I, 0/12 hips with BMAC collapsed while 3/9 (33%) without BMAC collapsed (P = .063); in grade II, 2/16 hips (12%) with BMAC collapsed while 7/13 (54%) without BMAC collapsed (P = .023). There was no significant difference in collapse with (64%) or without (82%) BMAC in grade III-IV hips (P = .256). ConclusionCore decompression with/without BMAC had a high failure rate, by increasing disease progression and the necessity for THA, for combined necrotic angles >250°. In our study, addition of BMAC had more reliable outcomes than isolated core decompression for precollapse ONFH if the combined necrotic angles were <250°.