The Value of Platelet-Rich Plasma in Chronic Midportion Achilles Tendinopathy: a Double-blind Randomized Clinical Trial

Introduction- Overuse injury of the Achilles tendon is a common entity in athletes and older athletes are at an increased risk. When the exact origin of tendon pain is unclear, the term tendinopathy is preferred. Most accepted treatment at this moment is an eccentric exercise programme, according to the Dutch guidelines. However, a recent systematic review on the effectiveness of eccentric exercises to treat lower extremity tendinoses concluded that it is unclear whether eccentric exercises are more effective than other forms of treatment.

Recent studies described new treatment strategies in tendinopathies, such as the use of platelet-rich plasma (PRP). Platelets can participate actively in tissue repair processes and stimulate the release of several growth factors. Recently, it was found that platelet-rich plasma clot releasate stimulates cell proliferation, collagen deposition, and enhances the gene expression of matrix degrading enzymes and endogenous growth factors by human tendon cells in vitro. The only published clinical cohort study in tendon research reported 93% reduction of pain for PRP-treated patients with chronic elbow tendinosis. Also on short term follow-up, the PRP injection was more beneficial than injection with an anaesthetic agent.

Aim- To monitor the potential clinical improvement of chronic midportion Achilles tendinopathy after injection with PRP and to evaluate the recovery process in time using a new Ultrasonographic method (Ultrasonographic Tissue Characterisation).

Hypothesis: The average VISA-A score is higher in the patient group treated with eccentric exercise therapy in combination with a PRP injection in comparison with the group treated with a saline injection in combination with eccentric exercises.

Study population- In total, 54 patients with symptomatic Achilles tendinopathy will be included in the study.