BACKGROUND It is unclear how and which factors affect the clinical efficacy of platelet-rich plasma (PRP) applied during arthroscopic rotator cuff repair. PURPOSE To evaluate the clinical efficacy of PRP for arthroscopic repair of full-thickness rotator cuff tear and investigate the factors that affect its clinical efficacy. STUDY DESIGN Systematic review; Level of evidence, 1. METHODS We searched Cochrane Library,
EMBASE, MEDLINE, and OVID to identify randomized controlled trials (RCTs) of patients who received PRP treatment and arthroscopic rotator cuff repair (PRP group) versus controls (no-PRP group). The primary outcomes included retear rate, Constant-Murley score, University of California Los Angeles (UCLA) score, short-term American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS) score for pain, and adverse events. RESULTS A total of 14 RCTs were included in this systematic review. Significant improvement in Constant-Murley, UCLA, and VAS pain scores were found in the PRP group during short-term, midterm, and long-term follow-up. The PRP group had a significantly decreased retear rate (risk ratio [RR], 0.57 [95% CI, 0.42 to 0.78]; P = .0003), especially for long-term follow-up (RR, 0.38 [95% CI, 0.17 to 0.83]; P = .02), large to massive tears (RR, 0.58 [95% CI, 0.42 to 0.80]; P = .0008), use of leukocyte-poor PRP (RR, 0.50 [95% CI, 0.33 to 0.76]; P = .001), and intraoperative application of PRP (RR, 0.57 [95% CI, 0.42 to 0.79]; P = .0007). No significant difference between the 2 groups was found in the incidence of adverse events (RR, 1.34 [95% CI, 0.83 to 2.15]; P = .23) or in ASES scores at short-term follow-up (weighted mean difference, 1.04 [95% CI, -3.10 to 5.19]; P = .62). CONCLUSION The results of this review indicated that arthroscopic rotator cuff repair with PRP significantly reduced the long-term retear rate and shoulder pain and provided improved long-term shoulder function in patients. Intraoperative application of PRP, use of leukocyte-poor plasma, and large to massive tear size contributed to a significantly decreased retear rate for rotator cuff repair combined with PRP.