BACKGROUND To explore the effectiveness of platelet-rich plasma (PRP) injection regarding functional recovery, pain relief, and range of motion (ROM) of shoulder compared with the corticosteroid injection in patients with rotator cuff lesions treated non-operatively. METHODS An electronic literature search was performed by 2 authors in the PubMed, Embase, Cochrane Library, and Web of Science databases to identify relevant randomized
controlled trial (RCTs) that were published up to July 20, 2020. The quality of the included RCTs was evaluated using the approach recommended by the Cochrane Handbook for Systematic Reviews of Interventions. Standardized mean differences (SMDs) or mean differences (MDs) with 95% confidence intervals (CIs) were applied to calculate the pooled effect sizes. RESULTS Six RCTs were included in this systematic review. Meta-analysis revealed that corticosteroid injection yielded statistically significant superior functional recovery (SMD = -0.80; 95% CI, -1.42 to -0.18; P = .01) and pain relief (MD = 1.59; 95% CI, 0.30-2.89; P = .02) compared with PRP injection for rotator cuff lesions during the short-term follow-up period. However, at the medium-term and long-term follow-up, no statistically significant difference was identified between the 2 groups. Regarding the ROM of shoulder, no statistically significant difference was found between the 2 groups during the whole follow-up period. CONCLUSIONS The current clinical evidence revealed short-term efficacy of corticosteroid injection and no significant medium- to long-term difference between corticosteroid and PRP injection in the treatment of rotator cuff lesions. Additional studies with longer follow-ups, larger sample sizes, and more rigorous designs are needed to draw more reliable and accurate conclusions.