Orthopaedic Department, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK. Orthopaedic Department, Blackpool Teaching Hospitals NHS Trust, Blackpool, UK. School of Medicine, University of Central Lancashire, Preston, UK. Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, UK.
Osteoarthritis and cartilage open. 2022;4(4):100318
OBJECTIVE To assess the effect of PRP on knee articular cartilage content (thickness/volume) and examine the correlation between cartilage changes and clinical outcomes in patients with knee OA. METHOD A systematic literature search was performed using the Cochrane methodology in four online databases. Studies were included if they reported on cartilage content with cross-sectional imaging pre- and post-injection. A random-effects
model meta-analysis was performed. Correlation with clinical outcomes was evaluated. RESULTS 14 studies (n = 1099 patients) from 1452 records met the inclusion criteria: seven RCTs (n = 688), one prospective (n = 50), one retrospective (n = 68), and four case-series (n = 224). The PRP preparation process and treatment protocol varied widely (follow-up 6-12 months). In meta-analysis, PRP treatment was not associated with a significant increase in cartilage thickness (4 studies, n = 187, standardized mean difference: Hedges g: 0.079; 95%CI: 0.358 - 0.516; p = 0.723). Meta-analysis of 3 RCTs (n = 112) showed no significant difference in the change of overall knee cartilage content with PRP injections compared with no PRP (Hedges' g: 0.217; 95%CI: 0.177 - 0.611; P = 0.281). CONCLUSION The current literature does not support the PRP as chondrogenic in treatment of knee OA. However, there is substantial heterogeneity in the evaluated studies which limits the robustness of any conclusion. An adequately powered RCT, with a standardized PRP regime and standardized high-resolution MRI is needed to definitely define any effect of PRP on knee cartilage content and its relation to clinical outcomes. Until such high-quality evidence becomes available, we recommend that PRP is not administered with the intention of promoting chondrogenesis.