Microfragmented Adipose Tissue Injection Reduced Pain Compared With a Saline Control Among Patients With Symptomatic Osteoarthritis of the Knee During 1-Year Follow-Up: A Randomized Controlled Trial

Purpose: To evaluate the effectiveness of microfragmented adipose tissue (MFAT) for pain relief and improved joint functionality in osteoarthritis (OA) of the knee in a randomized controlled clinical trial with 1-year follow-up.

Methods: Seventy-five patients were stratified by baseline pain level and randomized to 1 of 3 treatment groups: MFAT, corticosteroid (CS), or saline control (C) injection. Patients 18 years of age or older, diagnosed with symptomatic OA of the knee, with radiographic evidence of OA of the knee and a visual analog pain scale score of 3 of 10 or greater were included. Patients were excluded if they had any previous intra-articular knee injection, current knee ligamentous instability, or an allergy to lidocaine/corticosteroid. The visual analog pain scale, Western Ontario and McMaster Universities Osteoarthritis Index, and the Knee Injury and Osteoarthritis Outcome score (KOOS) were recorded preprocedure and at 2 weeks, 6 weeks, 3 and 6 months, and 1-year follow-up.

Results: MFAT demonstrated consistent and statistically significant improvements across all primary outcome measures for joint pain and functionality compared with C. For MFAT, there was a significant improvement over baseline at each follow-up, with median (95% confidence interval) KOOS Pain score changes of 18.1 (11.1-26.4) at week 2 to 27.8 (19.4-37.5) at 1 year. For CS, the median KOOS pain score reached a maximum of 22.2 (15.3-30.6) at week 2, only to level off to 13.9 (-2.8 to 29.2), a level not statistically different from baseline, at 1 year. The median changes for C hovered around 6 to 11 points, with statistically significant improvements over baseline indicating a placebo effect. Similar trends were seen for the Western Ontario and McMaster Universities Osteoarthritis Index Pain score and VAS Pain score.

Conclusions: In this study, MFAT demonstrated a clinically significant improvement in primary outcome scores compared with the C group, whereas the CS group only showed statistically significant improvement compared with the C group at 2 and 6 weeks. This finding indicates that MFAT may be a viable alternative treatment for patients with OA of the knee who fall into the orthopaedic treatment gap.

Level of evidence: Level II, partially blinded, randomized controlled clinical trial.