Which better preserves the hip in femoral head avascular necrosis: hyperbaric oxygen or bone marrow aspirate concentrate?

Avascular necrosis of the femoral head (AVN) is a progressive disorder that may lead to femoral head deformity and total hip arthroplasty (THA). Bone marrow aspirate concentrate (BMAC) and hyperbaric oxygen therapy (HBOT) are used as adjuncts to core decompression (CD), but comparative evidence is limited. In this retrospective cohort study, 87 patients with Ficat–Arlet IIA–IIB AVN underwent CD + BMAC (n = 42, Group A) or CD + HBOT (n = 45, Group B) between 2012 and 2023. Inclusion required MRI-confirmed AVN, Tönnis grade 0–1, and a minimum follow-up of 24 months. Clinical outcomes were assessed using the Harris Hip Score (HHS), and radiological progression using the Tönnis classification. Most baseline characteristics were similar between groups, except for affected side (right-sided involvement: 45.2% versus 66.7%, P = 0.044) and bilaterality (50.0% versus 24.4%, P = 0.014). Among patients who did not undergo THA (n = 66; Group A, n = 31; Group B, n = 35), mean HHS did not differ between groups (83.68 ± 10.34 versus 82.69 ± 11.22, P = 0.711). Tönnis grade distribution (P = 0.361) and THA conversion rates (26.2% versus 22.2%, P = 0.803) also did not differ significantly between groups. Stage IIB patients showed worse outcomes, with shorter THA-free survival (log-rank P = 0.036). Two-way analysis of variance (ANOVA) revealed no treatment × stage interaction (P = 0.193). On multivariable analysis, the combined necrotic angle was the only independent predictor of both radiological progression and THA conversion, whereas Ficat stage was not independently associated with either outcome. The combined necrotic angle showed acceptable discrimination for THA conversion (AUC = 0.773). In this cohort, no significant difference in clinical or radiological outcomes was detected between CD + BMAC and CD + HBOT in early-stage femoral head AVN; however, the study was not powered to establish equivalence. Necrotic lesion extent was the strongest prognostic factor identified in this cohort. Level of Evidence: Therapeutic Level III, retrospective comparative study.