Is there structural change on MRI in gluteal tendinopathy after treatment? Single outcome measure extension of an RCT

Abstract

Abstract Background The etiology of tendinopathy remains controversial and it is unknown whether degenerative structural changes in tendinopathies are reversible. Hypothesis There will be no structural change on magnetic resonance imaging (MRI) taken > 2-years after treatment for gluteal tendinopathy. Study Design Extension of a single site, double-blind, prospective randomized-controlled trial to analyze the additional outcome measure; MRI changes. Methods University of Melbourne ethics approval number: 1852900, trial registration: ACTRN12613000677707. Participants with gluteal tendinopathy who had previously received a leukocyte-rich platelet-rich plasma injection (LR-PRP) or a corticosteroid injection (CSI) had a post treatment MRI between at least 2-years and up to 7 years following trial completion. A blinded, senior musculoskeletal radiologist graded all de-identified MRI scans using the Melbourne Hip Score (MHIP). The primary outcome measure was the change in overall pre- and post-treatment score. Results Participants (n = 20) underwent MRI at mean time of 4.15 (SD 1.11; range 2–7) years after their initial treatment. There was no change in the overall mean MHIP score for the CSI group (Pre 4.3 (SD 2.3) Post 4.3 (SD 1.1), p = 1.00). Although there was an improvement in the LR-PRP group mean MHIP score (Pre 5.3 (SD 3.0) Post 4.77 (SD 2.5), p = 0.56) it was not statistically significant. However, in the LR-PRP intervention group, five out of nine of participants’ MHIP score improved, with four of these improving by 2–4 points. Conclusion The hypothesis that there would be no improvement in MHIP scores following treatment of gluteal tendinopathy was supported. Findings of improvement in the LR-PRP group at 4 years would support further studies powered to look for structural improvement. These findings suggest that structural change following treatment for tendinopathy may be possible supporting the inclusion of MRI as a core outcome for future studies. Clinical relevance The study suggests that degenerative structural changes in tendons may be reversible.