Dynamic ultrasonography to evaluate coracoacromial ligament displacement during motion in shoulders with supraspinatus tendon tears

We evaluated coracoacromial ligament (CAL) displacement during motion in shoulders with supraspinatus tendon tears by dynamic ultrasonography (US). Twenty subjects with unilateral, full‐thickness supraspinatus tendon tears (SST group) and 20 subjects with intact supraspinatus tendons (control group) underwent dynamic US. The CAL displacement in their bilateral shoulders was measured in the transverse US view during passive and active shoulder abduction and internal rotation (SAIR). In the SST group, the CAL displacement was significantly greater in the affected shoulders than in the intact ones (1.9 mm ± 0.8 mm vs. 1.5 mm ± 0.5 mm, p = 0.01) during passive SAIR, but was not significantly different between the shoulders (1.7 mm ± 0.7 mm vs. 1.7 mm ± 0.4 mm, p = 0.81) during active SAIR. In the control group, no difference in the CAL displacement between the shoulders was noted during passive and active SAIR. Thus, dynamic US revealed greater CAL displacement in shoulders with supraspinatus tendon tears than in intact ones during passive SAIR. Dynamic US may help to detect abnormal kinematics in shoulders with such injury. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1430–1434, 2012