Two-year clinical outcomes of autologous microfragmented adipose tissue in elderly patients with knee osteoarthritis: a multi-centric, international study

Purpose: The aim of this study is to evaluate the outcomes of autologous microfragmented adipose tissue (MFAT) injection in elderly patients with knee osteoarthritis (OA). We hypothesized that MFAT knee infiltration for the treatment of knee OA would yield good clinical results out to two years follow-up.

Methods: Multi-centric, international, open-label study conducted by orthopedic surgery, and/or regenerative medicine facilities utilizing patient registries. Subjects recruited for eligibility. The primary outcome measure was Knee Injury and Osteoarthritis Outcome Score (KOOS). Outcomes and patient factors were compared to baseline, at six, 12, and 24 months. Statistical models were used to assess KOOS subscores and probability of exceeding the Minimally Clinically Important Difference (MCID) or Patient Acceptable Symptom State (PASS), and to assess the effect of the treatment variables on KOOS - Pain.

Results: Seventy-five patients, 120 primary treatments, mean age 69.6 years, (95%CI 68.3-70.9), BMI 28.4 (95%CI 27.3-29.6), with KL grade 2 to 4 knee OA treated with a single MFAT injection. KL grades 2 (15.1%), 3 (56.3%), and 4 (28.6%), with 20.8% of knees having previously undergone surgery. Patients with KL grade 2 disease had the best results in KOOS - Pain (P = 0.001), at six, 12, and 24 months. Including advanced KL grade 3 and 4 osteoarthritis patients, significant functional and quality of life success was seen in 106/120 treatments (88.3%, 66 patients) at all follow-up time points. Fourteen treatments (11.7%, 9 patients) failed prior to the study endpoint.

Conclusion: This study shows that a single-dose MFAT injection leads to clinical, functional, and quality of life improvement at two years in elderly patients, in KL grades 2 to 4 of knee osteoarthritis. These findings provide evidence that this treatment modality could be a safe and effective option to other commonly available treatments in carefully selected patients.