Lateral tripod 3-pinning provides an effective unilateral approach for stabilizing canine distal femoral physeal fractures.

OBJECTIVE

To biomechanically evaluate the efficacy of the lateral tripod 3-pin (3LTP) technique as an alternative to crosspinning (XP) for Kirschner wire internal fixation of distal femoral physeal fractures in small-breed canines.

METHODS

For this experimental biomechanical study (from February through October 2025), 30 polycarbonate 3-D-printed bone models simulating a Salter-Harris type I (SH-I) fracture were allocated equally (n = 10/group) to 3 fixation groups: the XP group, lateral double-pinning (2LP) group, and 3LTP group, all stabilized with 1.0-mm Kirschner wires. The maximum failure load (Newtons) was recorded as the primary outcome following an axial loading compression test on a universal testing machine until implant failure. Data were statistically analyzed.

RESULTS

A total of 30 models were included in the final analysis (n = 10/group). The mean maximum failure loads were determined to be 385.60 N (95% CI, 367.5 to 403.7) for XP, 330.70 N (95% CI, 311.4 to 350.0) for 2LP, and 445.10 N (95% CI, 412.4 to 477.8) for 3LTP. The failure mode for all groups was implant bending.

CONCLUSIONS

The 3LTP demonstrated superior biomechanical resistance to axial compression compared to XP and 2LP for canine distal femoral SH-I fractures.

CLINICAL RELEVANCE: The utilization of the 3LTP technique offers a biomechanically superior and minimally invasive fixation alternative to XP for repairing canine distal femoral SH-I fractures.