A modified separate vertical fixation by wires and titanium cables for comminuted inferior patella fracture: A technique note and finite element analysis.

PURPOSE: Comminuted inferior patellar pole fractures are challenging injuries and require adequate treatment due to the extension mechanism of the knee.

METHODS

A modified separate vertical fixation by wires and Titanium cables was established according to a finite element biomechanical study. Between September 2018 and May 2021, 18 patients with inferior pole fractures of the patella were retrospectively enrolled in this study.

RESULTS

The results of the finite element analysis showed the concentration of stress in the intermediate vertical wire and the cerclage wire. As a partial replacement for steel wires, Titanium cables provide less concentration of stress on the vertical wire (489.4 MPa vs 441.2 Mpa) and less cutting force on the bone (75.87 Mpa vs 53.27), which reduces the possibility of internal fixation failure and improves the stability of internal fixation. In the clinic study, No patients experienced non-union of the fracture, loss of fracture repositioning, malunion of wounds, or wire breakage. At the last follow-up, the average range of motion was 134.7°±11.2°, and the Lysholm Score was 90.7 ± 3.9.

CONCLUSIONS

The separate vertical fixation by wires and titanium cables is an effective fixation method for treating displaced, comminuted inferior pole fractures, which attributes to early exercise and better function.