Ultrasound of horizontal instability of the acromioclavicular joint

Abstract

Summary Background Horizontal instability influences the clinical outcome after acromioclavicular joint (ACJ) injuries and in joint degeneration. A standardized, dynamic examination of the horizontal instability has not been described before. This current study presents a sonographic method to analyze the dynamics between the clavicle and acromion in the horizontal plane. Methods The horizontal joint play, the ACJ space and the offset between clavicle and acromion were sonographically assessed by a 45° ventrally angulated longitudinal section. A total of four investigators with different experience in the field of musculoskeletal ultrasound examining 20 ACJs in 10 human cadavers. Measurements in the absence of any pressure and under standardized anterior and posterior pressure onto the clavicle were carried out in different ligament status intact acromioclavicular (AC) and coracoclavicular (CC) ligaments as well as in a Rockwood (RW) II and III model. A two-sided t‑test was used to examine the differences between joint positions and ligament status. Results The horizontal joint play was 1.3 ± 0.9 mm with intact ligaments, 1.4 ± 1.2 mm by transecting the AC ligaments and 1.9 ± 1.3 mm after additionally transecting the CC ligament. The joint space was 3.3 ± 1.1 mm with intact ligaments, 4.1 ± 1.8 mm in an iatrogenic RW 2 injury, and 5.3 ± 3.3 mm in an iatrogenic RW 3 injury. Manipulating the clavicle by applying anterior or posterior pressure did not change the difference within one injury pattern. Interobserver reliability was 83.9%. Conclusion Apart from evaluating the ligaments and the joint capsule, measurement of the dynamic horizontal instability is possible in a human cadaver model. The ultrasound-based measurement of horizontal instability dynamics avoids radiation exposure, is readily available and cost-efficient.

Treatment of Acute Acromioclavicular Joint Dislocations Type III and Type V by Rockwood Classification Using a Dynamic Stabilization System under Arthroscopic Control with and without Suture of the Ligaments of the Acromioclavicular Joint

“…All patients were examined using clinical and instrumental methods of diagnostics: cross-body adduction test, O`Brien active compression test, AC resisted extension test, X-ray exami nation in Zanca view, axial view and Alexander view, and ultrasound examination with a functional probe [9]. Dynamical AC joint instability examinations were performed by ultrasound examination in the frontal, axial, and sagittal projections at final follow-up after surgical treatment.…”

Fracture sonography of the extremities

“…Klaviertastenphänomen kann sonographisch gesteuert geprüft werden [32,39]. Ebenso kann eine horizontale Instabilität geprüft werden [31]. .…”

A Stepwise Guide to Performing Shoulder Ultrasound: The Acromio-Clavicular Joint, Biceps, Subscapularis, Impingement, Supraspinatus Protocol

“…There are limited studies describing the normal length, width, and height of the AC joint on ultrasound, and these measurements may be dependent on multiple factors such as age and habitus [9][10][11]. Therefore, a focused evaluation of the horizontal alignment of the clavicle and acromion process is critical to identifying AC joint pathology.…”

“…Therefore, a focused evaluation of the horizontal alignment of the clavicle and acromion process is critical to identifying AC joint pathology. Comparison with the contralateral, asymptomatic side may illuminate significant differences between the AC joints and is therefore useful in diagnosing AC joint pathology [ 10 ].…”

“…Rheumatologic disorders including lupus and gout may cause synovial enlargement or crystal formation. Traumatic AC joint separations are demonstrated by increased horizontal play of the AC joint and downward displacement of the lateral portion following AC ligament injury [ 10 ]. Radiographic AC separations are categorized using Rockwood classifications but an ultrasound classification is yet to be determined [ 12 , 13 ].…”