An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: two parallel transarticular headless tapered variable pitch screws versus two parallel transarticular AO cortical bone screws inserted in lag fashion

OBJECTIVES: To compare the mean number of cycles to failure under axial compression of equine proximal interphalangeal (PIP) joint arthrodesis constructs created by 2 parallel transarticular Acutrak Plus screws (AP-TS) or 2 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (AO-TLS). STUDY DESIGN: Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. SAMPLE POPULATION: Cadaveric adult equine forelimbs (n=5 pairs). METHODS: For each forelimb pair, 1 PIP joint was stabilized with AP-TS and 1 with AP-TLS. The 5 construct pairs were tested for cyclic fatigue under axial compression. Mean number of cycles to failure for each fixation method were compared by a paired t-test within each group with statistical significance set at P\u3c.05. RESULTS: The mean number of cycles to failure under axial compression for AO-TLS fixation and AP-TS fixation were 57,723±8488 and 35,322±4698, respectively. CONCLUSION: The AO-TLS was superior to the AP-TS in resisting cyclic fatigue under axial compression