Platelet-rich plasma in the conservative treatment of painful tendinopathy: a systematic review and meta-analysis of controlled studies.

BACKGROUND: Platelet-rich plasma (PRP) seeks to meet the multifaceted demand of degenerated tendons providing several molecules capable of boosting healing. AREAS TIMELY FOR DEVELOPING RESEARCH: PRP is used for managing tendinopathy, but its efficacy is controversial. SOURCES OF DATA: Electronic databases were searched for clinical studies assessing PRP efficacy. Methodological quality was evaluated using the methods described in the Cochrane Handbook for systematic reviews. AREAS OF AGREEMENT: Thirteen prospective controlled studies, comprising 886 patients and diverse tendons were included; 53.8% of studies used identical PRP protocol. AREAS OF CONTROVERSY: Sources of heterogeneity included different comparators, outcome scores, follow-up periods and diverse injection protocols, but not PRP formulation per se. GROWING POINTS: Pooling pain outcomes over time and across different tendons showed that L-PRP injections ameliorated pain in the intermediate-long term compared with control interventions, weighted mean difference (95% CI): 3 months, -0.61 (-0.97, -0.25); 1 year, -1.56 (-2.27, -0.83). However, these findings cannot be applied to the management of individual patients given low power and precision. RESEARCH: Further studies circumventing heterogeneity are needed to reach firm conclusions. Available evidence can help to overcome hurdles to future clinical research and bring forward PRP therapies.