Objectives. The aim was to assess the efficacy of two intra-tendinous injections of platelet-rich plasma (PRP) on epicondylitis of recent evolution (≤3 months).
Methods. Our study was a double-blind placebo-controlled randomized trial. Two US-guided injections of either PRP (autologous conditioned plasma) or saline solution were performed with an interval of 4 weeks. The exclusion criterion was previous CS infiltration. Patients were monitored by an independent evaluator blinded to treatment at baseline and 1, 3, 6 and 12 months of follow-up. The primary evaluation criterion was the relative improvement from baseline to 6 months in pain score on visual analog scale (0–10). Secondary criteria were the Roles–Maudsley score and the assessment of pain on isometric contraction of extensor carpi radialis brevis and extensor digitorum communis.
Results. Twenty-five patients were randomly assigned to each group. Three patients in each arm dropped out before 6 months. In both groups, the pain score [mean (S.D.)] decreased significantly between two consecutive visits from 6.8 (0.8) (PRP) and 7 (1) (saline) at baseline to 2.5 (1.6) and 1.6 (1.5) (PRP) and to 2.1 (1.6) and 1.8 (2.1) (saline) at 6 and 12 months, respectively. At 6 months, no statistically significant difference was found between groups for relative improvement in pain score [autologous conditioned plasma: −63.2 (22.4%); saline: −69.7 (25.1%); P = 0.24]. No significant difference was found for the secondary criteria.
Conclusion. Two US-guided PRP injections for epicondylitis of recent evolution were not more efficacious than saline injections, until 6- and 12-months follow-up.
Trial Registration: ClinicalTrials.gov; https://clinicaltrials.gov/; NCT02378285.