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

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.