Low-load exercise program and platelet-rich plasma for intrasubstance tear in lateral elbow tendinopathy: protocol for a double-blinded randomized clinical trial

Background: Lateral elbow tendinopathy (LET) is one of the most common musculoskeletal conditions. Treatment includes a series of therapeutic alternatives. However, the resolution takes nearly 24 months. Platelet-rich plasma (PRP) is an effective option, especially when the tendon presents an intrasubstance tear (IST). It is unknown what type of rehabilitation plan is more effective after this treatment. Aim: To perform a study protocol of a double-blinded, randomized clinical trial to determine the efficacy of a specific low-load exercise program in patients with LET and IST treatment with PRP under US-guided Methods: A single-center, parallel-controlled, randomized, double-blinded, phase III trial was pro-posed. Patients over 18 years-old diagnosed with LET and IST treated with US-guided PRP will be selected. Two arms of treatment will be allocated with a ratio a 1:1 ratio (low-load exercise protocol vs. conventional exercise program). The principal outcome will be the reduction of the tendon tear size. Secondary outcomes will include Patient-Rated Tennis Elbow Evaluation score, visual analogue scale, and handgrip at baseline, 3, 6, and 12 months of follow-up. Statistical tests will be 2-sided t-test with an alpha level (significance level) of 0.05. Discussion: The intervention aims to significantly reduce tendon tear size and improve pain and functionality in patients with LET and IST treated with US-guided PRP. We proposed one of the first studies in the literature that considered a detailed standardized exercise protocol applied to these patients. The result could be used to speed up treatment save time and money, help evaluate guidelines, and improve patients' and athletes' quality of life.