Stoffel Karl, Lorenz Kai-Uwe, Kuster Markus S
Fremantle Orthopaedic Unit, University of Western Australia, and Orthopaedic Department, Kantonsspital St.Gallen, Switzerland.
J Orthop Trauma. 2007 Jul;21(6):362-8. doi: 10.1097/BOT.0b013e31806dd921.
We compared the biomechanical stability of bone-plate constructs using a compression plate (CP), an internal fixator (IF), and a combination plate (CP/IF).
Standardized simulated shaft fractures with a segmental defect in composite bones (n=60) and intraarticular distal femur fractures with a comminuted supracondylar zone in fresh frozen cadaveric femurs (n=36) were stabilized by CP, IF, and CP/IF. Construct stiffness, plastic deformation, and fixation strength were measured under axial compression and torsion using a biaxial testing machine.
The experimental results indicate for the distal femur fracture model that IF has less loss of reduction by plastic deformation under axial load compared to CP (IF 61% of CP). Under torsion, the CP showed significantly (P<0.05) decreased plastic deformation compared to the IF (CP 51% of IF). The combination (CP/IF) of the 2 fixation principles generally resulted in a higher load to failure under axial compression and torsion (145% failure load of CP and 118% of IF under axial compression, 88% of CP and 109% of IF under torsion). Results were similar between the 2 fracture models.
Under compression, IF provides similar fixation in comminuted fractures and was better than the CP for avoiding loss of reduction, whereas under torsional loading, CP was more important for stiffness, plastic deformation, and load to failure than IF. However, combination (CP/IF) fixation seems advisable in intraarticular and extraarticular fractures of long bones with a metaphyseal comminution. These data may be utilized by surgeons to build a more specific treatment plan in patients with these fracture types.
我们比较了使用加压钢板（CP）、内固定器（IF）和组合钢板（CP/IF）的接骨板结构的生物力学稳定性。
在复合骨中制造具有节段性缺损的标准化模拟骨干骨折（n = 60），并在新鲜冷冻尸体股骨中制造髁上区域粉碎的关节内股骨远端骨折（n = 36），分别使用CP、IF和CP/IF进行固定。使用双轴试验机在轴向压缩和扭转下测量结构刚度、塑性变形和固定强度。
实验结果表明，对于股骨远端骨折模型，与CP相比，IF在轴向载荷下塑性变形导致的复位丢失更少（IF为CP的61%）。在扭转时，与IF相比，CP的塑性变形显著降低（P<0.05）（CP为IF的51%）。两种固定原则的组合（CP/IF）通常在轴向压缩和扭转下导致更高的破坏载荷（轴向压缩下CP破坏载荷的145%和IF的118%，扭转下CP的88%和IF的109%）。两种骨折模型的结果相似。
在压缩状态下，IF在粉碎性骨折中提供类似的固定效果，并且在避免复位丢失方面优于CP，而在扭转载荷下，CP在刚度、塑性变形和破坏载荷方面比IF更重要。然而，对于伴有干骺端粉碎的长骨关节内和关节外骨折，组合（CP/IF）固定似乎是可取的。外科医生可利用这些数据为患有这些骨折类型的患者制定更具体的治疗方案。
