Objectives: To evaluate the biomechanical properties of the combination of circumferential and Krackow sutures using FiberWire, compared to the conventional methods in feline transverse patellar fractures. Methods: Twenty-four feline cadaveric pelvic limbs (mean weight 3.74 kg) were harvested, and the patella of each limb was osteotomized transversely to simulate a fracture. The limbs were then randomly assigned to one of three stabilization methods (n=8 per group). Group 1 (PFW) was stabilized with a modified tension band wire with a 0.9 mm Kirschner wire and No. 2 FiberWire. Group 2 (CFS) was stabilized with a circumferential and figure-of-eight suture with No. 2 FiberWire. Group 3 (CKS) was stabilized with a circumferential and Krackow suture with No. 2 FiberWire. All knee joints were fixed at a 135° neutral standing angle and tested by applying tensile force. Loads at 1, 2, and 3 mm gap formation, the maximum failure load and failure modes were recorded. Results: At 1 mm displacement, Group 3 (96.1±18.6 N) was significantly stronger than Group 1 (p < 0.017). At 2 mm and 3 mm displacements, Group 3 (162.4±12.2 N and 238.6±25.4 N) was significantly stronger than both Group 1 and 2 (p < 0.017). The maximum failure load of Group 3 (352.3±31.0 N) was significantly higher than Group 1 and 2 (p < 0.017). The primary failure mode was pin pull-out (Group 1), suture pull-out (Group 2), and tendon rupture (Group 3). Conclusions and relevance: The combination of circumferential and Krackow suture technique provides greater resistance to fragment displacement and construct failure than conventional methods in this ex vivo feline patella fracture model.
Kim et al. (Thu,) studied this question.