Department of Orthopaedic Surgery, Stanford Hospitals and Clinics, 300 Pasteur Drive, Room R144, Stanford CA, United States.
Department of Orthopaedic Surgery, Stanford University School of Medicine, 300 Pasteur Drive, Room R144, Stanford CA, United States.
Injury. 2021 Jul;52(7):1670-1672. doi: 10.1016/j.injury.2021.04.056. Epub 2021 May 1.
Bridge plating of distal femur fractures with lateral locking plates is susceptible to varus collapse, fixation failure, and nonunion. While medial and lateral dual plating has been described in clinical series, the biomechanical effects of dual plating of distal femur fractures have yet to be clearly defined. The purpose of this study was to compare dual plating to lateral locked bridge plating alone in a cadaveric distal femur gap osteotomy model.
Gap osteotomies were created in eight matched pairs of cadaveric female distal femurs (average age: 64 yrs (standard deviation ± 4.4 yrs); age range: 57-68 yrs;) to simulate comminuted extraarticular distal femur fractures (AO/OTA 33A). Eight femurs underwent fixation with lateral locked plates alone and were matched with eight femurs treated with dual plating: lateral locked plates with supplemental medial small fragment non-locking fixation. Mechanical testing was performed on an ElectroPuls E10000 materials testing system using a 10 kN/100 Nm biaxial load cell. Specimens were subject to 25,000 cycles of cyclic loading from 100-1000 N at 2 Hz.
Two (2/8) specimens in the lateral only group failed catastrophically prior to completion of testing. All dual plated specimens survived the testing regimen. Dual plated specimens demonstrated significantly less coronal plane displacement (median 0.2 degrees, interquartile range [IQR], 0.0-0.5 degrees) compared to 2.0 degrees (IQR 1.9-3.3, p = 0.02) in the lateral plate only group. Dual plated specimens demonstrated greater bending stiffness compared to the lateral plated group (median 29.0 kN/degree, IQR 1.5-68.2 kN/degree vs median 0.50 kN/degree, IQR 0.23-2.28 kN/degree, p = 0.03).
Contemporary fixation methods with a distal femur fractures are susceptible to mechanical failure and nonunion with lateral plates alone. Dual plate fixation in a cadaveric model of distal femur fractures underwent significantly less displacement under simulated weight bearing conditions and demonstrated greater stiffness than lateral plating alone. Given the significant clinical failure rates of lateral bridge plating in distal femur fractures, supplemental fixation should be considered, and dual plating of distal femurs augments mechanical stability in a clinically relevant magnitude.
使用外侧锁定钢板桥接固定治疗股骨远端骨折容易发生内翻塌陷、固定失败和不愈合。虽然已经在临床系列中描述了内侧和外侧双钢板固定，但股骨远端骨折双钢板固定的生物力学效应尚未明确。本研究的目的是在股骨远端间隙切开模型中比较双钢板固定与外侧锁定桥接钢板固定。
在 8 对配对的女性股骨远端（平均年龄：64 岁（标准差±4.4 岁）；年龄范围：57-68 岁）的尸体上创建间隙切开术，以模拟粉碎性关节外股骨远端骨折（AO/OTA 33A）。8 根股骨采用外侧锁定钢板单独固定，并与 8 根股骨采用双钢板固定进行匹配：外侧锁定钢板加补充内侧小片段非锁定固定。在 ElectroPuls E10000 材料试验机上使用 10kN/100Nm 双轴负载单元进行力学测试。标本在 100-1000N 2Hz 的循环加载下进行 25000 次循环加载。
外侧钢板组中有 2 例（2/8）标本在测试完成前灾难性失效。所有双钢板固定的标本都通过了测试方案。与外侧钢板固定组的 2.0 度（IQR 1.9-3.3）相比，双钢板固定组的冠状面位移明显更小（中位数 0.2 度，IQR 0.0-0.5 度）。与外侧钢板固定组相比，双钢板固定组的弯曲刚度更大（中位数 29.0kN/度，IQR 1.5-68.2kN/度与中位数 0.50kN/度，IQR 0.23-2.28kN/度，p=0.03）。
在使用外侧钢板单独治疗股骨远端骨折时，现代固定方法容易发生机械失败和不愈合。在尸体股骨远端骨折模型中，双钢板固定在模拟负重条件下的位移明显减少，并且与外侧钢板单独固定相比，刚度更大。鉴于外侧桥接钢板固定治疗股骨远端骨折的临床失败率较高，应考虑补充固定，并且股骨远端的双钢板固定以临床相关的幅度增强机械稳定性。
