Growth factor-based therapies provide additional benefit beyond physical therapy in resistant elbow tendinopathy: a prospective, single-blind, randomised trial of autologous blood injections versus platelet-rich plasma injections.

Background: Growth factor technologies are increasingly used to enhance healing in musculoskeletal injuries, particularly in sports medicine. Two such products; platelet-rich plasma (PRP) and autologous blood, have a growing body of supporting evidence. No previous trial has directly compared the efficacy of these two methods.

Hypothesis: Growth factor administration improves tissue regeneration in patients who have failed to respond to conservative therapy.

Study Design: A prospective, double-blind, randomised trial.

Methods: Elbow tendinopathy patients who had failed conservative physical therapy were divided into two patient groups: PRP injection (N=80) and autologous blood injection (ABI) (N=70). Each patient received two injections at 0 and 1 month. Patient-related tennis elbow evaluation (PRTEE) was recorded by a blinded investigator at 0, 1, 3 and 6 months. The main outcome measure was PRTEE, a validated composite outcome for pain, activities of daily living and physical function, utilising a 0-100 scale.

Results: At 6 months the authors observed a 66% success rate in the PRP group versus 72% in the ABI group, p=NS. There was a higher rate of conversion to surgery in the ABI group (20%) versus the PRP group (10%).

Conclusion: In patients who are resistant to first-line physical therapy such as eccentric loading, ABI or PRP injections are useful second-line therapies to improve clinical outcomes. In this study, up to seven out of 10 additional patients in this difficult to treat cohort benefit from a surgery-sparing intervention.