Intraosseous bone marrow concentrate delays total hip arthroplasty in osteoarthritis: A fifteen year matched cohort study with dose–response analysis

PURPOSE: To evaluate whether intraosseous (IO) autologous bone marrow concentrate (BMC), containing mesenchymal stem cells (MSCs) enumerated in vitro as colony forming unit-fibroblasts (CFU‑F), reduces or delays conversion to total hip arthroplasty (THA) compared with matched conservative care, and to assess the influence of disease progression and CFU‑F dose on outcomes. METHODS: A monocentric matched cohort (n = 434 hips; 217 BMC, 217 control) was followed for up to 15 years. Bone marrow was aspirated from the iliac crest, processed into BMC to concentrate nucleated cells, and injected intraosseously into the femoral head under fluoroscopy. Demographics, BMI, osteoarthritis grade, and CFU‑F were recorded. The primary outcome was THA‑free survival by Kaplan-Meier with log‑rank testing. Cox proportional-hazard models provided adjusted effects and predictions. RESULTS: Progression to THA after 15 years occurred in 16.1% (35 of 217) of patients receiving IO BMC versus 40.1% (87 of 217) of control patients receiving conservative care. Kaplan-Meier curves demonstrate superior THA‑free survival with BMC overall, mild osteoarthritis, and with increased CFU‑F dose. No adverse events were observed. Revision surgeries were not performed in those receiving BMC (0 of 35), compared to an 8.0% revision rate among control patients (7 of 87). CONCLUSION: IO BMC was associated with substantially delayed progression to THA with a CFU‑F dose-response and favourable safety profile. These findings suggest that IO BMC may represent a clinically meaningful joint-preserving option for selected patients with hip osteoarthritis, particularly when performed before advanced disease progression and with higher CFU-F doses.