Ex vivo biomechanical comparison of reinforced locking plate design and locking compression plates applied in comminuted tibial fractures

• Ano de defesa: 2022
• Autor(a) principal: Silveira, Gabriel Coutinho
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Medicina Veterinária
• Palavras-chave em Português: Ossos - Fraturas; Cães - Fraturas; Tíbia; Fraturas - Fixação interna; Fixadores internos; Clínica Cirúrgica Animal
• Link de acesso: https://locus.ufv.br//handle/123456789/30859; https://doi.org/10.47328/ufvbbt.2022.373

Objectives: The aim of study was to compare four designs of locking plates at biomechanical characteristics for the stabilization of experimentally induced comminuted tibial fractures in dog. Material and Methods: Pelvic limbs were harvested from sixteen dog cadavers. Paired tibiae were stripped of all soft tissues, and sub-divided by bone mineral density in four blocks and randomized complete block design (RCBD) in four treatments (T1, T2, T3 and T4). Four configurations of locking plates with fixed angle and 2.7 mm system were tested, locking compression plate (LCP) without filling center holes (T1) (n=4), a LCP filling the center holes within eight screws heads plugs (T2) (n=4), a locking plate (LP) (T3) (n=4) and a reinforced LP (T4) (n=4), were applied to the medial surface of each tibia. Subsequent analysis of variance (F test, ANOVA) and statistical analysis with Tukey's pairwise test (α = 0.05) were performed. A 1-cm segment of the tibia was excised centrally beneath the plate. The specimens were potted, then tested in failure and destructive four-point mediolateral bending(n=16), and failure and destructive axial compression(n=16). Bending and axial stiffness, yield load and failure load were calculated for each specimen. Results: The LP constructs (T3 and T4) were stiffer than the LCP constructs (T1 and T2) in both tests. Yield load and failure load were not significantly greater for LP constructs compared with LCP constructs in axial test. At bending analysis, yield load and failure load was greater in reinforced LP (T4), with statistical difference between all other treatments. LCP constructs with and without the filling center holes (T1 and T2) did not differs statically at mediolateral bending and axial compression in both tests. Clinical Significance Reinforced LP in central width ensure better bending stiffness, yield load and failure load. The screws head plugs had some influence at stiffness in both tests, but not statically differs. The widening of the locked plates, reinforcing the central area, consecutively reducing the forces at comminuted fracture gap. Further cyclic studies of the designs and clinical investigation is recommended. We conclude that the reinforced locking plates with central larger area is the first choice for treatment of comminuted fractures in dogs, ensuring better bending stiffness, yield load and failure load. Using screw head plugs on LCP did not differ statistically when compared to the same plate but without the filling. Keywords: Comminuted fracture. Static destructive test. Locking plate. Axial compression. Four-point bending.