Intratendinous tears of the Achilles tendon - a new pathology? Analysis of a large 4-year cohort.

BACKGROUND Achillodynia is common and includes Achilles tendinopathy, partial Achilles tears and Achilles tendon ruptures. However, we believe an additional pathology should be considered for Achillodynia differentials - the intratendinous tear (ITT). METHODS Examinations of 740 achillodynic patients in one specialist centre were reviewed. ITTs were defined as a clearly visualised echopoor area situated centrally and extending to, but not through the tendon periphery, with pain on palpation and no clinical findings consistent with Achilles rupture. Descriptive statistics were used to analyse differences between pathological sub-groups, and images described qualitatively. RESULTS 5% (29 males, 8 females) of 740 patients had an ITT. Patients typically presented with a history of sudden onset localised pain and the ability to train but not reach maximal loading. Average age was 36.3 years (range 20-64), significantly lower than mid-tendon tendinopathy (8.48 years; p<0.01). 92% had concurrent Achilles tendinopathy. Elite sportspeople were more highly represented in the ITT than mid-tendon tendi nopathy groups (86.2% ITT group vs 13.8% mid-tendon AT group; p<0.01). CONCLUSIONS ITTs should be actively searched for in patients with Achilles pathology, especially in elite male athletes with a history of high-impact pain. Prospective research is warranted concerning diagnosis and management. LEVEL OF EVIDENCE IV.