[Finite element analysis of different reconstruction methods of coracoclavicular ligament for acromioclavicular joint dislocation].

Objective: This study aims to examine the biomechanical effects of different reconstruction methods, including single-bundle, double-bundle anatomical reconstruction, and double-bundle truly anatomical reconstruction of the coracoclavicular ligament on the acromioclavicular joint using finite element analysis, to provide a theoretical basis for the clinical application of truly anatomical coracoclavicular ligament reconstruction.

Methods: One volunteer, aged 27 years old, with a height of 178 cm and a weight of 75 kg, was selected for CT scanning of the shoulder joint. Three-dimensional finite element models of single-bundle reconstruction, double-bundle anatomical reconstruction, and double-bundle truly anatomical reconstruction of coracoclavicular ligament were established by using Mimics17.0, Geomagic studio 2012, UG NX 10.0, HyperMesh 14.0 and ABAQUS 6.14 software. The maximum displacement of the middle point of the distal clavicle in the main loading direction and the maximum equivalent stress of the reconstruction device under different loading conditions were recorded and compared.

Results: The maximum forward displacement and the maximum backward displacement of the middle point of the distal clavicle in the double-bundle truly anatomic reconstruction were the lowest, which were 7.76 mm and 7.27 mm respectively. When an upward load was applied, the maximum displacement of the distal clavicle midpoint in the double-beam anatomic reconstruction was the lowest, which was 5.12 mm. Applying three different loads forward, backward, and upward, the maximum equivalent stress of the reconstruction devices in the double-beam reconstruction was lower than that in the single-beam reconstruction. The maximum equivalent stress of the trapezoid ligament reconstruction device in the double-bundle truly anatomical reconstruction was lower than that in the double-bundle anatomical reconstruction, which was 73.29 MPa, but the maximum equivalent stress of the conoid ligament reconstruction device was higher than that of the double-bundle anatomical reconstruction.

Conclusion: The truly anatomical reconstruction of coracoclavicular ligament can improve the horizontal stability of acromioclavicular joint and reduce the stress of the trapezoid ligament reconstruction device. It can be a good method for the treatment of acromioclavicular joint dislocation.