[Sonographic structural analysis of the Achilles tendon and biomechanical implications].

Ruptures of the Achilles tendon mainly occur on the ground of predisposing destruction of tendon structure. The aim of this retrospective US study was to evaluate the location and extent of tendon abnormalities. 62 patients (49 male, 13 female; 19 to 57 years, mean 38) with achillodynia of short duration and/or clinically suspected tendon abnormalities were evaluated sonographically. Together with a review of the literature, US findings (location, extent, and echo pattern) were compared with clinical findings. With US, abnormalities could be detected with a sensitivity of 0,76 and a specificity of 0.9. Pathologic lesions could be grouped as follows: (1) pain without any clinical signs or US findings (tenalgia); (2) nodular tendinitis which in 52% appeared in the form of a tiny hypoechoic lesion in the ventromedial part of the tendon 2-3 cm proximal to the os calcis; (3) peritendinal oedema; (4) circumscribed tendon swelling, (5) extensive inhomogeneities of tendon structure. With US, abnormalities of the Achilles tendon may be detected at an early stage of the disease and hence the risk of tendon rupture may be predicted to better advantage.