Biomechanical evaluation of three fixation methods in a feline transverse patella fracture model.

Abstract

OBJECTIVES: This study aimed to compare the biomechanical properties of three stabilisation techniques in feline patella transverse fractures and select the strongest method with potentially minimal complications. METHODS: Patella fracture was simulated in 27 feline cadaveric pelvic limbs (mean weight of the cadavers 3.78&#x2009;kg), and the limbs were randomly grouped to be stabilised with one of the three stabilisation methods. The modified tension band wiring technique with a single Kirschner wire (0.9&#x2009;mm) and figure-of-eight wiring (20&#x2009;G) was applied to group 1 (n&#x2009;=&#x2009;9). Group 2 (n&#x2009;=&#x2009;9) was stabilised with a combination of circumferential and figure-of-eight wiring techniques with orthopaedic wire (20&#x2009;G). Group 3 (n&#x2009;=&#x2009;9) was stabilised with the same technique as group 2, but with #2 FiberWire. The knee joints were positioned and fixed in the neutral standing angle (135&#xb0;) and tested by applying tensile force. The loads at gap formations of 1, 2 and 3&#x2009;mm were recorded, and the maximum failure load was measured in each group. RESULTS: In all the loads at displacement (1, 2 and 3&#x2009;mm), group 3 was significantly stronger than groups 1 and 2, respectively (<0.017). Group 3 (261.0&#x2009;&#xb1;&#x2009;52.8&#x2009;N) showed significantly stronger fixation in the maximum load compared with group 1 (172.9&#x2009;&#xb1;&#x2009;45.6&#x2009;N) (<0.017). No significant difference was observed between groups 1 and 2 (204.9&#x2009;&#xb1;&#x2009;68.4&#x2009;N) or between groups 2 and 3. CONCLUSIONS AND RELEVANCE: This study shows that the combination of circumferential and figure-of-eight techniques with FiberWire is more resistant to displacement than metal wire in this ex vivo feline patella fracture model.