Finite element analysis of internal fixation with clavicular hook plate vs. adjustable loop plate for Neer Type IIB...

To compare the biomechanical stability of clavicular hook plates vs. adjustable strap plates in treating Neer Type IIB distal clavicle fractures, providing evidence for clinical procedure selection.

Based on CT data from a healthy volunteer, a three-dimensional finite element model of the shoulder joint-including bones, ligaments, and internal implants-was constructed using Mimics, Geomagic, and SOLIDWORKS software. Model A simulated fixation with a clavicular hook plate, while Model B simulated fixation with an adjustable strap plate. Muscle loads (simulating holding a 0.5 kg teacup) and boundary conditions were set based on literature. Static mechanical analysis was performed in ANSYS Workbench. Observed metrics included Total Deformation at the path node on the clavicular upper surface (assessing stability) and Equivalent Stress (assessing refracture risk), with statistical comparisons conducted.

Under simulated loading, both models provided effective fixation. Internal fixation material Stresses remained below their respective yield strengths (titanium alloy: 830 MPa; suture: 1,208.87 ± 164.87 MPa), indicating no fracture risk. Model A (hook plate) exhibited a smaller maximum Deformation on the clavicle (0.54 mm) compared to Model B (0.79 mm), but the mean Deformation at path nodes showed no statistically significant difference (P > 0.05). The mean Equivalent Stress at the clavicular path node for Model A (3.42 MPa) was greater than that for Model B (2.87 MPa), with a statistically significant difference (P < 0.05). The maximum Stress in Model A was concentrated at the hook bend (221.15 MPa), potentially generating localized high pressure on the subacromial surface; the maximum Stress in Model B was located at the midpoint of the strap connection line (278.67 MPa).

Finite element analysis indicates that both the clavicular hook plate and the adjustable strap plate provide adequate biomechanical stability for Neer Type IIB distal clavicle fractures. While both demonstrate comparable fixation strength, they exhibit distinct Stress distribution characteristics. Considering the risk of complications such as subacromial impingement associated with clavicle hook plates, while arthroscopic strap plate techniques can simultaneously address concomitant shoulder injuries without requiring secondary surgery for removal, the latter may offer greater overall advantages.