The purpose of the present study was to assess, prospectively, the safety, clinical effectiveness, and feasibility of a single intra-articular injection of microfragmented adipose tissue in different stages of knee osteoarthritis (OA). The study included patients (aged 18−70 years), affected by OA (Kellgren−Lawrence I-IV). Unselected patients were evaluated before and prospectively after 6, 12, and 24 months from the injection. Visual analog scale (VAS) and knee injury and osteoarthritis outcome score (KOOS) were used for clinical evaluations. A total of 202 patients were eligible. The mean follow-up time in the cohort of patients was 24.5 ± 9.6 months. Total KOOS significantly improved from pre-operative baseline levels to 6-month follow-up (p < 0.001), and again between 6- and 12-month follow-ups (p < 0.001). The VAS showed a prompt reduction at 6 months (p < 0.001 vs. baseline), but then it increased again at 12 months compared to the 6-month assessment (p < 0.001), even though it remained lower than baseline (p < 0.001). At 24 months, patients with KL-IV demonstrated a lower improvement compared to baseline; patients that had undergone previous corticosteroid injections had a greater risk to further injection treatment. The collected clinical results suggest that MFAT may represent a safe and effective treatment for OA symptoms, offering a low-demanding and minimally invasive treatment.
Keywords: adipose-derived mesenchymal stem cells; autologous microfragment adipose tissue; knee; orthobiologics; osteoarthritis.