Fisher S C, McLaughlin R M, Elder S H
Mississippi State University College of Veterinary Medicine, Department of Clinical Sciences, PO Box 6100, Mississippi State, MS 39762, United States.
Vet Comp Orthop Traumatol. 2012;25(1):36-41. doi: 10.3415/VCOT-11-03-0045. Epub 2011 Oct 26.
The in vitro biomechanical properties of three methods for internal fixation of femoral neck fractures were evaluated. Fifty cadaveric femura from Beagle dogs were used. Ten intact femora served as controls. In 40 femura, an osteotomy of the femoral neck was performed to simulate a transverse fracture. With the remaining 30 femura, three repair methods (two medium Orthofix pins, a 2.7 mm cortical bone screw placed in lag fashion and an anti- rotational Kirschner wire, or three divergent 1.1 mm Kirschner wires) were used to stabilize the osteotomies, and 10 osteotomies were stabilised per repair method. These 30 femura where then subject to monotonic loading to failure. Construct stiffness and load to failure were measured. In the remaining 10 femura, pressure sensitive film was placed at the osteotomy site prior to stabilization with either two Orthofix pins (n = 5) or a screw placed in lag fashion (n = 5) to determine the compressive pressure (MPa), compressive force (KN) and area of compression (cm²). There was no significant difference in the stiffness or load to failure for the three repair methods evaluated. There was no significant difference in the compressive pressure, compressive force or area of compression in osteotomies stabilized with Orthofix pins and 2.7 mm bone screws.
评估了三种股骨颈骨折内固定方法的体外生物力学特性。使用了50根来自比格犬的尸体股骨。10根完整的股骨作为对照。在40根股骨中，进行股骨颈截骨以模拟横行骨折。对于其余30根股骨，采用三种修复方法（两根中等大小的Orthofix针、一枚以拉力方式置入的2.7 mm皮质骨螺钉和一根抗旋转克氏针，或三根呈发散状的1.1 mm克氏针）来稳定截骨，每种修复方法稳定10处截骨。然后对这30根股骨进行单调加载直至破坏。测量结构刚度和破坏载荷。在其余10根股骨中，在分别用两根Orthofix针（n = 5）或一枚拉力方式置入的螺钉（n = 5）稳定截骨之前，在截骨部位放置压敏膜，以确定压缩压力（MPa）、压缩力（KN）和压缩面积（cm²）。所评估的三种修复方法在刚度或破坏载荷方面无显著差异。用Orthofix针和2.7 mm骨螺钉稳定截骨时，在压缩压力、压缩力或压缩面积方面无显著差异。
