Discussion
tendinopathic achilles tendons, tendinopathy, gluteal tendinopathy
DISEASE PROGRESSION, DISEASE, NEOVASCULARIZATION
Our hypothesis was that there would be no improvement in MHIP MRI scores following treatment for gluteal tendinopathy at 2 years or more post-treatment. Overall, the results confirmed this. However, there was a reduction in the mean MHIP scores in the LR-PRP group from 5.3 (SD 3.0) to 4.77 (SD 2.5), p = 0.56) and in five out of nine participants the MHIP score improved. Four of these improved by 2–4 points whilst Our study is unique in that we analyzed MRI between at least two and up to seven years post-treatment (mean follow-up time; 4.15 ± 1.11 years). There are limited studies which look at structural change in tendinopathic tendons post biological injection treatment, and even fewer following patients in the longer-term. In their 2011 RCT, de Vos et al., showed that that there was no difference between the effect of PRP or placebo on structural changes and neovascularization in tendinopathic achilles tendons using ultrasound imaging [To date, tendon clinicians and researchers have a focused on measuring symptomatic rather than structural outcomes to determine improvement in tendinopathy. However, a recent consensus statement identified that almost 70% of tendinopathy researchers felt that structural analysis should be a core domain for tendinopathy assessment [It is possible that effectiveness of treatment in tendinopathy is grade or stage dependent. A recent review of 27 studies gluteal tendinopathy by Ladurner et al., identified good [Timing – both at imaging – and disease stage is likely to be important because time is required for tendons to undergo structural changes following treatment. This would corroborate patient-reported outcome measures from the original RCT by Fitzpatrick et al. which found that participants in the LR-PRP group continued to experience symptomatic improvement beyond 12 months and even further at final follow up at 24 months [Our study was strengthened by use of a reliable grading score for gluteal tendinopathy as a method of comparing disease progression before and after receiving treatment. The MHIP score enables researchers to compare radiological findings pre- and post-treatment, between patient cohorts and across multiple studies [Limitations of our study include that the study extension did not control for patients having subsequent interventions following completion of the trial. The sample size of the study was limited by the availability of baseline MRI scans from the RCT and thus is too small for ensuring significance and the results should be interpreted as hypothesis generating.