Conversion to Knee Arthroplasty Following Intra-Articular Injection of Microfragmented Adipose Tissue in Patients with Knee Osteoarthritis

Abstract

Background. Few studies have investigated the need for additional treatment after use of intra-articular injection of microfragmented adipose tissue (MFAT) in treatment of knee osteoarthritis. We assessed the rate of conversion to knee arthroplasty and 1-year clinical outcomes after intra-articular injection of MFAT for knee osteoarthritis. Methods. We retrospectively reviewed data from consecutive patients who underwent a single intra-articular MFAT injection for the treatment of symptomatic knee osteoar-thritis with average 1-year follow-up. Results. Of 56 knees (39 patients), three knees (two patients) had follow-up only to 13 and 28 weeks. All other knees were followed to a minimum of 1 year or through conversion to knee arthroplasty. The 1-year rate of conversion to knee arthroplasty was 17.9%, with an increase to 32.1% within the second year of follow-up. There was a significant improvement in mean Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores at each post-procedure time point (p < 0.05) and in mean Short Form 12 physical function scores at 6 weeks and 1 year postoperative-ly (p < 0.05). Conversion to knee arthroplasty was associated with significantly lower KOOS JR score at 1 year (mean difference, 10.1 ± 4.9, p = 0.04). Conclusions. Use of a single intra-articular injection of MFAT was associated with a high rate of conversion to knee arthroplasty despite a significant improvement in knee pain, stiffness, and function at an average of 1-year follow-up. MFAT may be more appropriately considered as a temporizing agent rather than a means to avoid knee arthroplasty.