Platelet-Rich Plasma Injection With Arthroscopic Acromioplasty for Chronic Rotator Cuff Tendinopathy

Background: Platelet-rich plasma (PRP) has been proposed to augment tendon healing through improving tissue structure during the initial repair phase. Purpose: To investigate both the clinical and tissue effects of the coapplication of PRP injection with arthroscopic acromioplasty (AA) in patients with chronic rotator cuff tendinopathy. Design: Randomized controlled trial; Level of evidence, 1. Methods: The study comprised 60 randomized patients diagnosed with rotator cuff tendinopathy (55% women) aged between 35 and 75 years. Patients were randomized to AA alone or in combination with an injection of autologous PRP into the subacromial bursa (AA + PRP). Efficacy of treatment was assessed by analysis of patient-reported outcomes up to 2 years after treatment (Oxford Shoulder Score [OSS]) and by analysis of tendon biopsy specimens taken 12 weeks after treatment. Results: There was no significant difference in the OSS between AA alone and AA + PRP at any time point in the study. From 12 weeks onward, there was a significant increase in the OSS for both groups compared with their baseline scores ( P < .001). Bonar scoring determined no significant change in tissue structure with the coapplication of PRP compared with surgery alone. The number of blood vessels and tendon cellularity were significantly decreased in tissue biopsy specimens taken from PRP-treated patients. The expression of p53-positive apoptotic cells increased after AA + PRP but decreased after AA alone. Conclusion: Arthroscopic acromioplasty significantly improves long-term clinical outcomes up to 2 years. The coapplication of PRP did not affect clinical outcomes. PRP significantly alters the tissue characteristics in tendons after surgery with reduced cellularity and vascularity and increased levels of apoptosis. Clinical Relevance: The coapplication of PRP did not improve clinical outcomes and may have potential deleterious effects on healing tendons. Registry Number: ISRCTN 10464365