Plate failure by bending following tibial fracture stabilisation in 10 cats

Abstract

Objective: Describe the clinical findings and management of tibial fractures in cats in which plate osteosynthesis failed due to plate bending.Study Design: Multicentre, retrospective clinical study. Methods:Clinical histories and radiographs of 10 cats that suffered plate bending following plate or plate-rod fixation of tibial fractures were reviewed for signalment, fracture configuration and repair, post-operative and post-failure tibial alignment, ultimate treatment and outcome. Tibial alignment post-operatively and post-failure was compared using a paired T-test.Results: Mean age was 5.3 years and mean body weight was 5.0kg. All ten cats sustained complete fracture of the tibia with an accompanying fracture to the fibula. Tibial fractures were generally oblique (4/10) or spiral (4/10) with mild comminution (8/10) and located in the middle (3/10) or distal (6/10) third of the tibia. Initial fracture stabilisation was with a plate (6/10) or plate-rod combination (4/10) with the plate applied to the medial tibial surface. Non-reduced, lateral tibial wedge fragments were present in 5 fractures. Mean time to implant failure was 24 days. Mean tibial valgus angle increased from 12.9° to 30.9°

Biomechanical Comparison of Two Conical Coupling Plate Constructs for Cat Tibial Fracture Stabilization

“…Greater stiffness should be advantageous because plate bending is the mode of implant failure reported most commonly in plated cat tibial fractures. 6 Improving mediolateral bending construct stiffness is an important attribute to mitigate the potential for plate failure following tibial fracture stabilization in cats. 6 Morris and colleagues described tibial valgus angulation due to mediolateral plate bending was the mode of failure in all 10 cats in which tibial fracture fixation failed.…”

“…[1][2][3][4][5] Morris and colleagues described the clinical features and management of cat diaphyseal tibial fractures in which osteosynthesis failed due to plate bending. 6 Plate bending following surgery (mean time to failure: 24 days) represented 13% (8/60) of cases reviewed and was ascribed to acute mechanical overloading. 6 Plates that failed were either a 2.0 mm dynamic compression plate (DCP), 2.4 mm DCP, 2.0 mm limited contact-dynamic compression plate (LC-DCP) or 2.0/2.7 mm veterinary cuttable plate (VCP).…”

“…6 Plate bending following surgery (mean time to failure: 24 days) represented 13% (8/60) of cases reviewed and was ascribed to acute mechanical overloading. 6 Plates that failed were either a 2.0 mm dynamic compression plate (DCP), 2.4 mm DCP, 2.0 mm limited contact-dynamic compression plate (LC-DCP) or 2.0/2.7 mm veterinary cuttable plate (VCP). 6 Improper implant selection may have contributed to failure of fixation in this case series 6 as several sources recommend the use of 2.7 mm DCP or stacking 2.7/2.0 VCP for stabilizing comminuted diaphyseal tibial fractures in cats.…”

“…6 Plates that failed were either a 2.0 mm dynamic compression plate (DCP), 2.4 mm DCP, 2.0 mm limited contact-dynamic compression plate (LC-DCP) or 2.0/2.7 mm veterinary cuttable plate (VCP). 6 Improper implant selection may have contributed to failure of fixation in this case series 6 as several sources recommend the use of 2.7 mm DCP or stacking 2.7/2.0 VCP for stabilizing comminuted diaphyseal tibial fractures in cats. 2,[7][8][9][10] The conical coupling locking plate system (Intrauma FIXIN; Rivoli, Italy) has been used to successfully stabilize diaphyseal tibial fractures in dogs.…”

Veterinary Cuttable Plate in a Plate-Rod Construct for Repair of Diaphyseal Femoral Fractures in the Cat

“…6 Current general recommendations for plate-rod constructs in dogs are the use of a pin that occupies 30 to 40% of the narrowest intramedullary diameter. 5,6,[9][10][11][12][13] No guidelines currently exist in cats for adequate pin to medullary ratio. Interference of the screws with the rod is an important concern with a plate-rod construct, a larger intramedullary pin implying a more challenging screw placement.…”