No effects of PRP on ultrasonographic tendon structure and neovascularisation in chronic midportion Achilles tendinopathy.

OBJECTIVE: To assess whether a platelet-rich plasma (PRP) injection leads to an enhanced tendon structure and neovascularisation, measured with ultrasonographic techniques, in chronic midportion Achilles tendinopathy.

DESIGN: Double-blind, randomised, placebo-controlled clinical trial.

SETTING: Sports medical department of The Hague medical centre.

PATIENTS: 54 patients with chronic midportion Achilles tendinopathy were included.

INTERVENTIONS: Patients were randomised to eccentric exercise therapy with either a PRP injection (PRP group) or a saline injection (placebo group).

MAIN OUTCOME MEASUREMENTS: Tendon structure was evaluated by ultrasonographic tissue characterisation, a novel technique which quantifies tendon structure into four echo-types: echo-types I+II represent organised tendon bundles, whereas echo-types III+IV represent a disorganised tendon structure. Colour Doppler ultrasonography was used to measure the degree of neovascularisation. Follow-up was at 6, 12 and 24 weeks.

RESULTS: A significant improvement in echo-types I+II was found after 24 weeks within both the PRP group (n=27) and the placebo group (n=27), but there was no significant between-group difference (95% CI -1.6 to 7.8, p=0.169). After 6 weeks, the neovascularisation score increased within the PRP group (p=0.001) and the placebo group (p=0.002), but there was no significant between-group difference in change in neovascularisation score at any point in time.

CONCLUSION: Injecting PRP for the treatment of chronic midportion Achilles tendinopathy does not contribute to an increased tendon structure or alter the degree of neovascularisation, compared with placebo.

FUNDING: Biomet Biologics LLC, Warsaw, Indiana.