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Updated: May 22, 2026
06:09
Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Dynamic function of coracoclavicular ligament at different shoulder abduction angles: a study using a 3-dimensional
Young-Jin Seo1, Yon-Sik Yoo, Kyu-Cheol Noh
1Department of Orthopaedic Surgery, Hallym University Medical Center, Hwaseong, Republic of Korea.
Summary
The distal clavicle moves significantly during shoulder abduction, with the conoid ligament lengthening and the trapezoid ligament remaining stable then lax. This suggests reciprocal ligament function and challenges synchronous scapular motion.
Area of Science:
- Biomechanics
- Orthopedic Surgery
- Medical Imaging
Background:
- The acromioclavicular (AC) joint's motion during shoulder abduction is complex.
- Understanding coracoclavicular ligament behavior is crucial for AC joint stability.
Purpose of the Study:
- To determine acromioclavicular (AC) motion and coracoclavicular ligament changes during shoulder abduction.
- Utilize a 3D finite element model based on CT scans of normal shoulders.
Main Methods:
- CT scans of 10 shoulders at various abduction angles (0°, 60°, 120°, 180°).
- 3D finite element modeling to simulate AC motion.
- Assessment of conoid and trapezoid ligament length and tension.
Main Results:
- Distal clavicle showed significant internal rotation and posterior/anterior translation with abduction.
- Conoid ligament length increased with abduction; trapezoid ligament length remained consistent then became lax.
- Observed AC motion did not align with synchronous scapular movement.
Conclusions:
- Coracoclavicular ligaments (conoid and trapezoid) function reciprocally during abduction.
- The conoid ligament may limit excessive scapular retraction.
- Separate reconstruction of conoid and trapezoid ligaments is suggested; rigid AC fixation is not recommended.
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