Prognostic Value of Conventional Ultrasound and MRI Features for Clinical Outcomes in Athletes With Patellar Tendinopathy After Exercise Therapy

Background: Structural abnormalities assessed with conventional ultrasound (US) or magnetic resonance imaging (MRI) are associated with the risk of developing patellar tendinopathy (PT). However, their prognostic value for athletes with PT performing exercise therapy remains unclear. Hypothesis: Baseline imaging features could be associated with changes in pain and disability over 24 weeks in athletes with PT after exercise treatment. Study Design: Cohort study. Level of Evidence: Level II. Methods: Athletes with PT were randomly allocated to 2 different programs of exercise therapy for 24 weeks. Imaging features at baseline included patellar tendon thickness, intratendinous calcifications, patellar erosions, and Doppler flow on US, as well as tendon fiber disruption, infrapatellar fat pad (IFP) edema, bone marrow edema, and deep infrapatellar bursitis on MRI scan. Clinical outcomes were measured at baseline, and at 12- and 24-week follow-up, using the visual analog scale after single-leg squat (VAS-SLDS) for pain on loading, and Victorian Institute of Sports Assessment-Patella (VISA-P) questionnaire for disability. Linear mixed-effects models, incorporating interaction terms tested using likelihood ratio tests, evaluated the prognostic value of baseline imaging features. Results: Of 76 included athletes (58 male, 18 female; average age, 24 ± 4 years), abnormal US features were identified in 26% to 78% of cases. Among 72 MRI scans analyzed, abnormal features were demonstrated in 43% to 81% of cases. No significant associations were identified between individual imaging features and 24-week changes in VAS-SLDS or VISA-P scores (all P interaction > 0.10), or between the total number of imaging abnormalities and clinical outcomes (all P interaction > 0.50). Conclusion: There was no evidence of an association between baseline abnormalities assessed using conventional US or MRI and 24-week changes in pain or disability among athletes with PT undergoing exercise therapy. Clinical Relevance: Healthcare professionals should avoid relying on conventional imaging findings to predict prognosis.