Micro-fragmented adipose tissue for the treatment of hip osteoarthritis: A prospective pilot study at 1-year follow-up

Purpose: Micro-fragmented adipose tissue (MFAT) has been proposed as a promising option for hip osteoarthritis (OA). The aim of this prospective study was to evaluate clinical outcomes of MFAT injections in patients with hip OA. Methods: Thirty patients (19 men and 11 women, 55.7 ± 8.2 years) with symptomatic hip OA (Tönnis Grade 1–2) were treated with a single ultrasound-guided MFAT injection. Patients were evaluated at baseline and 1–3–6–12 months of follow-up with the Visual Analogue Scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and Harris Hip Score (HHS). Adverse events were also documented. MFAT samples were evaluated for cell analysis and characterization. Results: No major complications were reported, and only three patients failed. The total WOMAC score significantly improved from baseline (31.2 ± 16.4) only at 1 month (21.0 ± 14.3, p = 0.015) and 3 months (19.3 ± 15.8, p = 0.012), while VAS and HHS scores showed a significant improvement from baseline to all follow-ups. The minimal clinically important difference (MCID) for the total WOMAC score was achieved in 56.7% of patients at 6 and 12 months. Better clinical improvement and MCID achievement were observed in mild compared to moderate hip OA. A total of 300.000 cells derived from MFAT produced small colonies from Day 10 (89.9 ± 61.2), increasing by Day 20 (129.9 ± 47.9). Conclusions: A single ultrasound-guided intra-articular MFAT injection represents a safe and promising option for hip OA treatment. However, the clinical benefit was partial, and better outcomes were observed in mild compared to moderate hip OA. Level of Evidence: Level IV.