Talar T1ρ MRI Associates With Patient-reported Function And Physical Activity In Chronic Ankle Instability Patients.

Those with chronic ankle instability (CAI) have early deleterious changes in proteoglycan density (PGD), measured via T1ρ MRI, within the talar cartilage as well as lower levels of self-reported physical function and physical activity relative to uninjured controls. However, the relationship between PGD and patient-reported outcomes in those with CAI remains unknown. Understanding this relationship could facilitate treatments to slow degenerative changes. PURPOSE: To quantify the associations among talar PGD and self-reported physical function and physical activity in those with CAI. METHODS: Thirty-five individuals with CAI (22.6 ± 4.2 years, 23.5 ± 4.03 IdFAI score) participated. Inclusion criteria followedInternational Ankle Consortium guidelines. Participants completed a 30-minute unloading period before completing T1ρMRI in a 3 T scanner while plantarflexed. Mean T1ρ values for the overall Talar dome, a marker of PGD, were calculated. Participants also completed the Tegner and NATA physical activity scales, the Foot and Ankle Ability Measure (FAAM) ADL and Sports subscales, the PROMIS Physical Function scale, and the SF-36 from which the physical function sub-score was extracted. Pearson correlations quantified associations with p < 0.05 determining statistical significance. RESULTS: Greater (worse) Talar T1ρ means (74.64 ± 28.3 ms) was associated with higher (better) FAAM-Sport (r = 0.408, p = 0.015) and PROMIS (r = 0.344, p = 0.046) physical function scores. Greater (worse) Talar T1ρ mean values also associated with higher (better) NATA physical activity scores (r = 0.358, p = 0.034). CONCLUSIONS: Better self-reported physical function and activity is associated with early deleterious changes in PGD in individuals with CAI. We speculate that the repeated injurious events have altered the cartilage biochemistry such that the cartilage is less able to handle the high volumes of cyclical and dynamic loading placed upon it by individuals who remain highly functional and more physically active. Similarly, participants may not recognize deleterious compositional changes within their cartilage as these changes precede morphological changes. Thus, the reported relationship should be taken with caution as it may change once morphological changes within the joint begin to materialize. NATA Research & Education Foundation; #1516OGP001