Reduced Levels of Aligned Fibrillar Structure Are Not Associated With Achilles and Patellar Tendon Symptoms.

OBJECTIVE: To investigate whether the mean cross-sectional area (mCSA) of aligned fibrillar structure (AFS) was associated with the presence and severity of symptoms. DESIGN: Prospective cohort study. PARTICIPANTS: One hundred seventy-five elite male Australian football players completed monthly Oslo Sports Trauma Research Center overuse injury questionnaires for both the Achilles and patellar tendon over the season to ascertain the presence and severity of symptoms. At the start of the preseason, participants underwent ultrasound tissue characterization (UTC) imaging of the Achilles and patellar tendon. MAIN OUTCOME MEASURES: Images were classified as normal or abnormal based on gray-scale ultrasound. Based on UTC quantification, the mCSA of AFS was compared between those with and without current symptoms. RESULTS: No difference in the mCSA of AFS was observed between those with or without tendon symptoms (P < 0.05). Similar to previous findings, 80% to 92% of abnormal tendons had similar amounts of mCSA of AFS compared with normal tendon. If reduced mCSA of AFS was present, it was not associated with the presence or severity of symptoms. CONCLUSIONS: The prevalence, development, or severity of symptoms was not associated with decreased levels of AFS in the Achilles or patellar tendon. This suggests that a lack of structural integrity is not linked to symptoms and questions the rationale behind regenerative medicine. Most tendons are able to compensate for areas of disorganization and maintain tissue homeostasis.