Magnetic resonance imaging outcomes in a randomised, controlled trial of prolotherapy for lateral epicondylosis

Objective: To determine whether clinical improvement in lateral epicondylosis (LE) is associated with normalisation of magnetic resonance images (MRI). Patients and Methods: Twenty-four adults with refractory LE took part in a double-blind, randomised, controlled trial. Participants received prolotherapy or saline (control) injections at baseline, 4 and 8 weeks. Participants were assessed with clinical (0–10 visual analogue scale) and functional (grip and isometric strength) measures and scanned using an Artoscan 0.2 Tesla scanner, at baseline, 8 weeks and 16 weeks. The primary MRI outcome was an ordinal 0–3 severity grade based on common extensor tendon T1 and T2 signal intensity. Secondary MRI outcomes were the T2 area of pathology and a global impression of disease severity change. Results: The clinical results have been published. Prolotherapy subjects, compared to controls, showed significant and clinically dramatic improvements in pain and biomechanical outcomes. In the current analysis, all participants showed similar MRI-demonstrated severity at baseline consistent with LE. While prolotherapy subjects clinically improved compared to controls, primary and secondary MRI outcome measures did not change compared to either baseline status or control participants. Conclusions: There was a non-association between MRI-based severity and clinical severity at baseline and at 8-week and 16-week follow-up despite dramatic clinical improvement in response to prolotherapy compared to control injections. Future studies may benefit from a stronger MRI and follow-up time of more than 16 weeks.