Mesenchymal stem cells for chronic knee pain secondary to osteoarthritis: A systematic review and meta-analysis of randomized trials

Abstract

ObjectiveTo assess the effectiveness of mesenchymal stem cells (MSCs) for chronic knee pain secondary to osteoarthritis (OA). MethodsWe searched MEDLINE, EMBASE, CINAHL, and Cochrane Central to September 2023 for trials that: (1) enrolled patients with chronic pain associated with knee OA, and (2) randomized them to MSC therapy vs. placebo or usual care. We performed random-effects meta-analysis for all patient-important outcomes and used GRADE to assess the certainty of evidence. ResultsWe included 16 trials (807 participants). At 3-6 months, when restricted to low risk of bias studies, MSC therapy probably results in little to no difference in pain relief (weighted mean difference [WMD] -0.74cm on a 10cm visual analogue scale [VAS], 95%CI -1.16 to -0.33; minimally important difference [MID] 1.5cm) or physical functioning (WMD 2.23 points on 100-point SF-36 physical functioning subscale, 95%CI -0.97 to 5.43; MID 10-points; both moderate certainty). At 12-months, injection of MSCs probably results in little to no difference in pain (WMD -0.73 cm on a 10cm VAS, 95%CI -1.69 to 0.24; moderate certainty, restricted to low risk of bias studies) and may improve physical functioning (WMD 19.36 points on 100-point SF-36 PF subscale, 95%CI -0.19 to 38.9; low certainty). MSC therapy may increase risk of any adverse events (RR 2.67, 95%CI 1.19 to 5.99; low certainty) and pain and swelling of the knee joint (RR 1.58, 95%CI 1.04 to 2.38; low certainty). ConclusionsWhen restricted to moderate certainty evidence, compared to placebo, intra-articular injection of MSCs for chronic knee pain associated with OA probably provides little to no improvement in pain or physical function.