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Updated: Dec 24, 2025

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Position of the acromioclavicular joint and relation to the critical shoulder angle in shoulders with rotator cuff
Hannes Kubo1, Fariha Piela1, Thilo Patzer2
1Department of Orthopaedics and Traumatology, University Hospital of Duesseldorf, Moorenstraße 5, 40225, Duesseldorf, Germany.
Objective:
To evaluate the position of the acromioclavicular joint (ACJ) and relation to the critical shoulder angle (CSA) in shoulders with rotator cuff tears (RCT).
Methods:
In a matched pair study including 75 shoulders with arthroscopically validated RCT and 75 controls (mean age 59.4 ± 7.9 years) the position of the ACJ in relation to the glenoid and the CSA were measured on true ap radiographs.
Results:
The CSA is larger (p = 0.0018) and the position of the ACJ is more lateral (p = 0.0016) in shoulders with RCT in comparison to matched controls.
Conclusion:
The more lateral position of the ACJ in shoulders with a large CSA might be an additional component in the multifactorial pathogenesis of RCT.
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