In a prospective, randomized, open-label trial, a single intra-articular injection of mesenchymal stem cells (MSCs) safely improved pain and function of patients diagnosed with knee osteoarthritis. Investigators aimed to evaluate the mid-term safety and effectiveness of adipose tissue-derived (AD) MSCs for knee osteoarthritis management.

A total of 11 subjects with osteoarthritic knee were recruited and underwent serial assessments during five-year follow-up of single injection of autologous high-dose (1.0 × 108) ADMSCs. Utilizing World Health Organization Common Toxicity Criteria, the safety profiles were evaluated.

Clinical assessments incorporated  visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for pain and function respectively.

Radiologic assessments incorporated whole-organ magnetic resonance imaging scores (WORMS) and chondral defect area via serial magnetic resonance imaging. Kellgren-Lawrence (K-L) and Hip-knee-ankle axis (HKAA) grades were determined on simple radiographs. No treatment-linked side effects were witnessed during the five-year follow-up. At six months following injection and until the last follow-up, both total WOMAC and VAS scores (Figure 1) substantially improved.