Real-World Outcomes of Autologous Osteoblast Implantation in Patients With Osteonecrosis of the Femoral Head: A Retrospective, Multicenter, Single-Arm Cohort Study in India.

Background Recent advancements in orthobiologics suggest that osteoblast cell therapy combined with core decompression is an emerging approach for the treatment of osteonecrosis of the femoral head (ONFH). This study aimed to assess clinical outcomes in patients with ONFH who underwent osteoblast cell therapy with core decompression. Methods This retrospective, multicenter, single-arm cohort study included patients who underwent osteoblast cell therapy for the treatment of stages I, II, and IIIA ONFH between April 2017 and April 2022, with a follow-up of two to seven years. The primary outcomes included improvements in pain and functional capacity, measured using the Visual Analogue Scale (VAS) score and Harris Hip Score (HHS). The secondary outcome was treatment failure, defined as patients undergoing surgical treatment, including but not limited to total hip arthroplasty (THA), as assessed by the surgeon. Results The study included 319 patients (mean age: 34.4 ± 9.2 years; male: n = 272, 85.3%). Of these, 183 (57.4%) had bilateral ONFH. Of 502 treated hips, most had stage II (n = 226; 45.0%) or stage IIIA (n = 215; 42.8%) ONFH. The mean follow-up was 3.5 years (42.0 ± 5.2 months). The mean change in VAS score (3.78; 95% CI: 3.57-3.99) and HHS (47.01; 95% CI: 45.13-48.89) at follow-up was significant and exceeded the presupposed minimal clinically important difference (MCID). At follow-up, 31 patients (44 hips) required THA; no patient required any other surgical treatment. The patient-wise and hip-wise failure rates were 9.7% and 8.8%, respectively, with a median THA-free survival of 78 months. Conclusions Core decompression with adjuvant osteoblast cell therapy was associated with reduced pain and improved functional capacity in patients with stage I-IIIA ONFH while maintaining femoral head integrity.