Abstract
OBJECTIVE: This finite element analysis compared the biomechanical performance of two surgical approaches for Neer Type II distal clavicle fractures: isolated locking plate fixation versus locking plate fixation combined with anatomical double-bundle coracoclavicular ligament reconstruction. METHODS: A three-dimensional finite element model of the shoulder was developed from the CT scan of a 30-year-old healthy male. Three conditions were simulated: an intact joint (Group A, control), a fractured joint fixed with a locking plate alone (Group B), and a fractured joint fixed with a locking plate plus ligament reconstruction (Group C). Materials were assigned linear elastic properties. Under a simulated 90° arm abduction load, we analyzed the distribution of Von Mises stress, the displacement of the distal clavicular fracture fragment, and the subacromial contact pressure. RESULTS: Compared to Group B, Group C exhibited a more favorable biomechanical profile. The combined technique reduced the peak Von Mises stress at the distal clavicle by 37% (44.28 MPa vs. 70.12 MPa). Fragment displacement decreased by 42% in the horizontal plane (4.52 mm vs. 7.76 mm) and by 45% vertically (2.87 mm vs. 5.23 mm). The peak subacromial pressure was also lower in Group C (980 kPa vs. 1520 kPa). CONCLUSION: Within the constraints of this finite element model, augmenting plate fixation with anatomical coracoclavicular ligament reconstruction reduced stress concentration and improved fragment stability in Neer type II fractures, suggesting a biomechanical advantage over plating alone. These computational results support the continued clinical investigation of this combined technique.