PLATELET RICH PLASMA FOR CHRONIC TENDINOPATHY
Authors: K Harmon, J Drezner, A Rao
Journal: British Journal of Sports Medicine (2013)

Introduction The aetiology, pathogenesis, and pain generators in chronic tendinopathy remain to be elucidated. Biologic therapies, such autologous blood (AB) and platelet rich plasma (PRP) injections, aimed at stimulating healing of degenerative tendons, have shown promise but clinical research is limited. Methods The purpose of this study was to prospectively investigate the clinical effect of treatment with AB or PRP injection in patients with chronic tendinopathy. Patients over 18 years old were eligible for the study if they had more than 3 months of symptoms and had failed typical conservative treatment such as physical therapy, corticosteroid injections, massage, acupuncture, and/or chiropractic. All tendons were evaluated with musculoskeletal ultrasound and patients received treatment with either AB, leukocyte-rich PRP (LR-PRP), or leukocyte-poor PRP (LP-PRP), injected under ultrasound guidance into the tendinopathic areas. Patients were followed using visual analogue pain scales (VAS), site specific validated outcome scores, and a Likert post-treatment scale at 6 weeks, 12 weeks, 6 months and a year. A decrease in VAS of 20 was considered a clinically significant improvement. Likert post-treatment ratings of much or completely resolved were also considered clinically significant. Results 99 tendons were treated with average age 48.5 years (range 19–82). 44% were female and 56% were male. Patients had symptoms for an average of 34.4 months prior to treatment. Conditions treated included lateral epicondylosis (17), proximal hamstring tendinosis (22), Achilles tendinosis (11), patellar tendinosis (10), plantar fasciosis (9) and other tendinopathies (30). Of patients with at least 12 weeks follow-up, 10 had AB, 77 LR-PRP, and 12 LP-PRP injections. For AB injection the average duration of symptoms was 12.3 months and average follow-up was 22.2 weeks. 70% of ABI patients had some improvement, although only 40% improved at least 20 points on VAS. Average decrease in VAS was 15.2. Of those patients that improved, the average decrease in VAS was 23.1. 60% of those with AB injections considered themselves mostly or completely improved. For LR-PRP the average duration of symptoms was 35.8 months and average follow-up was 33.4 weeks. 78% of patients improved at all with 62% having at least a 20 point decrease in VAS. The average decrease in VAS was 21.8, but for those that improved, it was a 30.9 decrease. 54% of LR-PRP patients rated themselves as mostly or completely improved. For LP-PRP the average duration of symptoms was 37.6 weeks prior to treatment and average follow-up was 39.3 weeks. 92% of patients improved at all with 83% decreasing VAS by at least 20. The average decrease in VAS was 25 and for those who improved it was 29.1. 50% of LP-PRP patients rated themselves as mostly or completely improved. Conclusion Biologic therapies such as AB and PRP injection were moderately effective for treatment of recalcitrant tendinopathy, and PRP appears to be more effective than AB. Further studies comparing these treatments to each other, to other treatment options, and to placebo should be undertaken to better define their clinical utility and indications in the treatment of chronic tendinopathy.