Vocational School of Health Services, SANKO University, Gaziantep, Turkey.
Department of Orthopedics and Traumatology, Antalya Training and Research Hospital, Varlık mah., Kazım Karabekir cd., Muratpasa, 07100, Antalya, Turkey.
J Orthop Traumatol. 2023 Jun 26;24(1):30. doi: 10.1186/s10195-023-00714-6.
Conventionally, two 4.5 mm cortical screws inserted toward the posterior tibial cortex are usually advocated for the fixation of Fulkerson osteotomy. This finite element analysis aimed to compare the biomechanical behavior of four different screw configurations to fix the Fulkerson osteotomy.
Fulkerson osteotomy was modeled using computerized tomography (CT) data of a patient with patellofemoral instability and fixed with four different screw configurations using two 4.5 mm cortical screws in the axial plane. The configurations were as follows: (1) two screws perpendicular to the osteotomy plane, (2) two screws perpendicular to the posterior cortex of the tibia, (3) the upper screw perpendicular to the osteotomy plane, but the lower screw is perpendicular to the posterior cortex of the tibia, and (4) the reverse position of the screw configuration in the third scenario. Gap formation, sliding, displacement, frictional stress, and deformation of the components were calculated and reported.
The osteotomy fragment moved superiorly after loading the models with 1654 N patellar tendon traction force. Since the proximal cut is sloped (bevel-cut osteotomy), the osteotomy fragment slid and rested on the upper tibial surface. Afterward, the upper surface of the osteotomy fragment acted as a fulcrum, and the distal part of the fragment began to separate from the tibia while the screws resisted the displacement. The resultant total displacement was 0.319 mm, 0.307 mm, 0.333 mm, and 0.245 mm from the first scenario to the fourth scenario, respectively. The minimum displacement was detected in the fourth scenario (upper screw perpendicular to the osteotomy plane and lower screw perpendicular to the posterior tibial cortex). Maximum frictional stress and maximum pressure between components on both surfaces were highest in the first scenario (both screws perpendicular to the osteotomy plane).
A divergent screw configuration in which the upper screw is inserted perpendicular to the osteotomy plane and the lower screw is inserted perpendicular to the posterior tibial cortex might be a better option for the fixation of Fulkerson osteotomy. Level of evidence Level V, mechanism-based reasoning.
传统上，通常提倡在固定 Fulkerson 截骨术时使用两个朝向胫骨后皮质的 4.5mm 皮质螺钉。本有限元分析旨在比较四种不同螺钉固定方式固定 Fulkerson 截骨术的生物力学行为。
使用计算机断层扫描 (CT) 数据对髌股关节不稳定的患者进行建模，并在矢状面使用两个 4.5mm 皮质螺钉固定 Fulkerson 截骨术。固定方式为：（1）两螺钉垂直于截骨面；（2）两螺钉垂直于胫骨后皮质；（3）上螺钉垂直于截骨面，下螺钉垂直于胫骨后皮质；（4）第三种情况中螺钉位置的反转。计算并报告了间隙形成、滑动、位移、摩擦应力和部件变形。
在施加 1654N 髌腱牵引力后，模型中的截骨块向上移动。由于近端切口倾斜（斜面截骨术），截骨块滑动并停留在胫骨上部表面。然后，截骨块的上表面充当支点，截骨块的远端部分开始与胫骨分离，同时螺钉抵抗位移。从第一种情况到第四种情况，总的位移分别为 0.319mm、0.307mm、0.333mm 和 0.245mm。第四种情况（上螺钉垂直于截骨面，下螺钉垂直于胫骨后皮质）的最小位移。在第一种情况（两螺钉垂直于截骨面）中，两表面之间的组件的最大摩擦应力和最大压力最高。
在上螺钉垂直于截骨面，下螺钉垂直于胫骨后皮质的发散螺钉固定方式可能是固定 Fulkerson 截骨术的更好选择。证据水平 V，基于机制的推理。
