Publication

Ultrasound of the coracoacromial ligament in asymptomatic volunteers and patients with shoulder impingement

Journal Paper/Review - Aug 1, 2016

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PubMed
Doi
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Citation
Dietrich T, Jonczy M, Buck F, Sutter R, Puskas G, Pfirrmann C. Ultrasound of the coracoacromial ligament in asymptomatic volunteers and patients with shoulder impingement. Acta Radiol 2016; 57:971-977.
Type
Journal Paper/Review (English)
Journal
Acta Radiol 2016; 57
Publication Date
Aug 1, 2016
Issn Electronic
1600-0455
Pages
971-977
Brief description/objective

BACKGROUND
The coracoacromial ligament is part of the coracoacromial arch, which is considered to be involved in shoulder impingement.

PURPOSE
To compare the coracoacromial ligament on ultrasound in asymptomatic volunteers and in patients with subacromial shoulder impingement.

MATERIAL AND METHODS
Twenty-nine asymptomatic volunteers (mean age, 35.5 years) and 29 patients (mean age, 49.9 years) with shoulder impingement, diagnosed by experienced shoulder surgeons, were prospectively included. Two radiologists obtained and analyzed ultrasound images of the coracoacromial ligament in the longitudinal axis.

RESULTS
The ligament thickness was 1.4 ± 0.2 mm at its midportion, 1.8 ± 0.4 mm at the coracoid, and 2.1 ± 0.6 mm at the acromion in asymptomatic volunteers compared with 1.3 ± 0.2 mm, 1.9 ± 0.5 mm, and 1.9 ± 0.5 mm in impingement patients for observer 1. The ligament length was 30.6 ± 2.4 mm in asymptomatic volunteers compared with 30.4 ± 3.6 mm in impingement patients for observer 1. An anteriorly convex shape of the superficial contour of the coracoacromial ligament was significantly more frequent in impingement patients compared with asymptomatic volunteers for both observers (observer 1: 10% (3/29) versus 45% (13/29), P value <0.01; observer 2: 10% (3/29) versus 38% (11/29), P value <0.03). The comparison of the remaining parameters of the coracoacromial ligament, such as the thickness, length, echogenicity, and fibrillation did not reveal significant differences between volunteers and patients.

CONCLUSION
While thickness or length of the coracoacromial ligament were similar in volunteers and patients with shoulder impingement, an anteriorly convex shape of the superficial contour of the coracoacromial ligament was significantly more frequent in impingement patients compared with asymptomatic volunteers.