BackgroundOne of the commonest causes of shoulder pain and disability is partial thickness tear of the rotator cuff. Platelet-rich plasma (PRP) therapy is a volume of the plasma fraction of autologous blood that has platelet concentration above the baseline. It is theorized that PRP may help stimulate the development of normal-appearing histologic tissue characteristics at the repair site and improve clinical outcomes. Our purpose is to assess the efficacy of PRP therapy in treatment of rotator cuff tear. This prospective single-center study involved 30 patients (aged 31.7 ± 7.7 years, 63.3% males) complaining of symptomatic rotator cuff tear. Platelet-rich plasma (PRP) injection was done to all patients. Before and after injection of PRP, scoring was done using visual analog score, Shoulder Pain and Disability Index (SPADI), and musculoskeletal ultrasound scoring of the tear. Reassessment was done 4 weeks after the injections.ResultsThe pre-injection VAS pain score was 7.1 ± 0.99 after injection, and it became 3.7 ± 1.09. Also, SPADI score decreased from 78.03 ± 8.25 pre-injection to 42.1 ± 13.97 post-injection. There was a highly statistically significant difference in VAS pain score and SPADI score before and after PRP injection (p < 0.001). There was highly statistically significant positive correlation between the improvement of US grading score change and the improvement of VAS score change, and between it and SPADI improvement change (r = 0.695, p < 0.001 and r = 0.693, p < 0.001, respectively). There was a highly statistically significant difference between US grading score before and after PRP injection (p < 0.001).ConclusionPRP can be considered an effective method for treatment of rotator cuff tear and less invasive compared to surgical treatment. It improves the pain, shoulder function, and tear size.