RESPONSE TO PLATELET-RICH PLASMA ACROSS DIFFERENT SUBTYPES OF PARTIAL-THICKNESS ROTATOR CUFF TEARS: IDENTIFICATION OF THE SUBTYPE WITH THE BEST RESPONSE THROUGH A COMPARATIVE REVIEW

Abstract

Partial-thickness rotator cuff tears are a frequent cause of shoulder pain and functional impairment, and platelet-rich plasma (PRP) has emerged as a biological treatment option for patients undergoing nonoperative management. This study aimed to comparatively analyze the therapeutic response to PRP in partial-thickness rotator cuff tears, considering anatomical lesion characteristics, clinical and functional outcomes, structural findings, and duration of treatment effects. A comparative literature review was conducted using clinical studies, randomized trials, systematic reviews, and meta-analyses selected from the predefined bibliographic framework. Outcomes included pain, shoulder function, imaging findings, follow-up duration, and PRP protocol characteristics. The main quantitative synthesis comprised 11 studies and 641 participants, including 318 treated with PRP and 323 controls. Compared with other conservative treatments, PRP was associated with functional improvement at 8–12 weeks (SMD 0.40; 95% CI 0.17–0.62) and beyond 24 weeks (SMD 0.31; 95% CI 0.05–0.56), as well as greater pain reduction at 8–12 weeks (SMD −0.36; 95% CI −0.62 to −0.11) and beyond 24 weeks (SMD −0.62; 95% CI −0.95 to −0.30). The evidence showed greater consistency for pain reduction than for long-term functional and structural outcomes. Anatomically specific evidence was identified for interstitial/intratendinous supraspinatus tears; however, the available studies did not provide uniform comparative stratification among articular-sided, bursal-sided, and intratendinous tears. Considerable variability was also observed in PRP preparation, number of applications, injection site, and follow-up periods. PRP therefore showed clinically relevant benefits for partial-thickness rotator cuff tears, particularly regarding pain and function, while anatomical characterization emerged as an important dimension for interpreting treatment response. Future prospective studies using standardized PRP protocols and predefined anatomical stratification are required to clarify the role of tear morphology in therapeutic response.