Intratendinous injection of platelet-rich plasma under US guidance to treat tendinopathy: a long-term pilot study.

PURPOSE To assess the potential therapeutic effect of intratendinous injection of platelet-rich plasma (PRP) under ultrasound (US) guidance to treat tendon tears and tendinosis in a pilot study with long-term follow-up. MATERIALS AND METHODS The study included 408 consecutive patients referred for treatment by PRP injection of tendinopathy in the upper (medial and lateral epicondylar tendons) and the lower (patellar, Achilles, hamstring and adductor longus, and peroneal tendons) limb who received a single intratendinous injection of PRP under US guidance. Clinical and US data were retrospectively collected for each anatomic compartment for upper and lower limbs before treatment (baseline) and 6 weeks after treatment. Late clinical data without US were collected until 32 months after the procedure (mean, 20.2 months). The McNemar test and regression model were used to compare clinical and US data. RESULTS QuickDASH score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and residual US size of lesions were significantly lower after intratendinous injection of PRP under US guidance at 6 weeks and during long-term follow-up compared with baseline (P < .001 in upper and lower limb) independent of age, gender, and type of tendinopathy (P > .29). No clinical complication was reported during follow-up. CONCLUSIONS Intratendinous injection of PRP under US guidance appears to allow rapid tendon healing and is well tolerated.