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The Rotator Cable Does Not Stress Shield the Crescent Area During Shoulder Abduction
Christopher C Schmidt1,2,3, Christopher S Spicer2,3, Dimitrios V Papadopoulos1,2
1Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
The Journal of Bone and Joint Surgery. American Volume
|July 20, 2022
Summary
The rotator cable (RCa) does not stress shield the crescent area (CA) during shoulder abduction. Instead, the CA is crucial for transmitting abduction forces to the greater tuberosity.
Area of Science:
- Orthopaedic biomechanics
- Shoulder anatomy and function
Background:
- The rotator cable (RCa) is widely believed to protect the crescent area (CA) like a suspension bridge.
- This study investigated the stress-shielding role of the RCa on the CA during shoulder abduction.
Purpose of the Study:
- To determine if the rotator cable (RCa) stress shields the crescent area (CA) during shoulder abduction.
- To evaluate the role of the CA in force transmission.
Main Methods:
- Strain measurements in the RCa and CA were taken from 20 cadaveric shoulder specimens during abduction.
- Rotator cable insertions were sequentially released to simulate different injury states.
- Shoulder abduction force and tissue thickness were also measured.
Main Results:
- No significant changes in strain magnitude or direction were observed in the RCa or CA after RCa release.
- Shoulder abduction force remained unchanged following RCa release.
- No significant difference in thickness was found between the RCa and CA.
Conclusions:
- The rotator cable (RCa) does not function as a suspension bridge to stress shield the crescent area (CA).
- The crescent area (CA) plays a primary role in transmitting shoulder abduction forces to the greater tuberosity.
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