Identification of pre-race ultrasonographic abnormalities of the Achilles tendon and association with future injuries in runners.

Objective: To determine if specific morphological changes in ultrasonographic images of Achilles tendons are associated with the development of pain in distance runners.

Methods: This study is a blinded, retrospective analysis of 276 Achilles tendon ultrasound images, which were used to determine if specific morphologic findings could positively or negatively predict future Achilles tendon pain development in distance runners. Pre-race ultrasound scans were performed on 138 asymptomatic half- and full marathon runners (276 tendons in total) who were followed for 12 months after their races. Specific patterns of morphologic abnormality were identified (location, size, and appearance of ultrasound abnormality within the tendon). Sonographic findings were blindly assessed by a medical student, a resident, and a physician who has significant sonographic imaging experience. These specific abnormalities were then compared to those who later did or did not develop tendon pain.

Results: Three findings were found to have significant odds of association with the development of pain: 1) focal deep midsubstance intratendinous hypoechogenicity, 2) focal superficial midsubstance intratendinous hypoechogenicity, and 3) linear hyperechogenicity extending into middle of tendon from calcaneus.

Conclusion: These results suggest that the aforementioned specific morphologic abnormalities in the Achilles tendon may be associated with the future development of pain symptoms in distance runners in this cohort. Looking for these specific abnormalities may increase the specificity of identifying precursors to Achilles tendon pain development.