A recent study published in PLOS ONE evaluated the effectiveness of Platelet Rich Plasma (PRP) in the treatment of degenerative tendinopathies. This study by Wesner et al was a pilot study utilizing both a randomized control trial and synchronous observational cohort study. The randomized group included 9 patients with a rotator cuff tendinopathy and were assigned to either PRP or placebo. The observational cohort consisted of 178 participants with various tendinopathies. Subjects who received PRP were given an injection of 4 mL into the supraspinatus and/or infraspinatus tendons (“Rotator Cuff”). Participants in the control group received 4 mL of saline. All patients were given a standardized home based exercise program (daily) for 3 months.
Study participants were evaluated based on changes in pain scores, disability index scores, and pre/post MRI findings at 3 months and 6 months. While the sample size was small in the randomized trial (N=9), the mean improvement for pain scores in the PRP group was clinically important, but was not for the placebo group. Five out of 7 participants in the PRP group (71%) had noted improvement in MRI findings after the PRP injection.
The second part of the investigation consisted of a retrospective observational cohort study. Participants received 3 to 8 mL of PRP into the affected tendon along with a standardized home exercise program. Patients in this arm of the study were evaluated at 1, 2 and 3 months following PRP injection. Pre-injection VAS (visual analog scale) pain scores were compared to follow-up scores. Of concern with this study, 65 participants (36.5%) were excluded due to incomplete data or loss of follow-up information. Statistical significance and clinical important differences were seen between pre-injection VAS scores and follow-up.
Overall, the authors presented data was positive when considering the use of PRP for tendinopathy. However, caution must be exercised with interpreting both components of this study as the number of participants in the randomized trial (N=9) was very small and there are some major concerns for loss of study participants and varying injection protocol. Statistical testing was also limited.
Wesner M, Defreitas T, Bredy H, et al. A Pilot Study Evaluating the Effectiveness of Platelet-Rich Plasma Therapy for Treating Degenerative Tendinopathies: A Randomized Control Trial with Synchronous Observational Cohort. PLOS ONE. 2016 Feb 5.