Screw Loosening and Pelvic Canal Narrowing After Lateral Plating of Feline Ilial Fractures With Locking and Nonlocking Plates

Abstract

Screw loosening occurred less often but the change in pelvic canal alignment was not significantly different in ilial fractures repaired with LPS or dLPS compared to ilial fractures repaired with DCP. Locking plating of ilial fractures in cats may offer advantages compared to nonlocking plating.

Biomechanical properties of plate constructs for feline ilial fracture gap stabilization

“…Screw loosening, which was observed in all nonlocking constructs, was consistent with the high incidence that has been reported in clinical cases treated with nonlocking plates . It is interesting to note that the sacral screw in the lateral plating group in which nonlocking screws were used never loosened, likely because of its longer working length.…”

“…Cantilever bending and a single loading direction were selected as the best testing methods to evaluate fixation of feline ilial fractures. This testing setup is supported by the dorsal and medial displacement of the caudal fragment that was noted during testing, resembling the typical clinical scenario in case of screw loosening and loss of reduction . Another limitation is that the gap model used in this study does not represent the most common fracture types of the feline ilium, which are simple or minimally comminuted fractures .…”

“…For this purpose, the size of each pelvis was determined by measuring the ilioacetabular length (IAL), defined as the distance from the cranial border of the acetabulum to the most cranial aspect of the border of the ilial wing as measured on mediolateral radiographs. Only specimens exhibiting an IAL of 4.8 ± 0.48 cm were included …”

“…Locking screws may also be advantageous in the fixation of the feline ilium because its thin cortices may increase the risk of screw loosening. In a recent retrospective comparison of fixation methods for ilial fractures in cats, screw loosening was detected in 50% of cases treated with nonlocking plates, whereas no screw loosening occurred after locking fixation . Although some biomechanical studies evaluating fixation constructs for ilial fractures in small animals have been published, the proposed mechanical advantages of locking compared with nonlocking plate techniques remains unclear in feline ilial fractures.…”

“…Although some biomechanical studies evaluating fixation constructs for ilial fractures in small animals have been published, the proposed mechanical advantages of locking compared with nonlocking plate techniques remains unclear in feline ilial fractures. Double plating has been reported as a successful method of repair for comminuted ilial fractures in cats, but the biomechanics of orthogonal nonlocking plating in comminuted iliac fractures have not been evaluated. Therefore, this study sought to determine the biomechanical properties of plating techniques in a fracture model that simulated comminuted ilial fractures in cats.…”