PDF(Pubmed)
Abstract：
UNASSIGNED: Scaphoid waist fractures are often stabilised with compression screws, Kirschner wires (K-wires), or a combination of both. While clinical and bio-mechanical studies evaluating their utility are available, the ideal configuration of implant that would provide adequate stability to permit early use of the hand is debatable. We examined configurations of a single screw, one screw along with a K-wire, and two K-wires used for a transverse scaphoid waist fracture fixation aiming to assess the stability provided by each in the immediate postoperative period.
UNASSIGNED: Computer-aided design (CAD) models of the scaphoid, K-wire, and headless compression screw were created. A transverse fracture was created at the scaphoid waist, and the CAD models of the screw and K-wire were used to fix the fracture in different configurations in a distal to proximal direction. Finite Element Analysis (FEA) was used to examine the strength of configurations when they were subjected to compression and distraction forces. The total maximum deformation (TDef) and factor of safety (FoS) for each configuration were calculated and used as indirect indicators of postoperative stability.
UNASSIGNED: When a single screw was used, the configurations with the screw directed posteriorly from either centre or anterior had the best combined TDef and FoS values. For one screw and one K-wire, the configuration with screw and K-wire parallel to each other with the screw located along the long axis in the AP projection and anterior to the K-wire in the lateral projection had the best combined TDef and FoS values. When using two K-wires, configurations with the two wires diverging proximally on the lateral projection had the best combined TDef and FoS values.
UNASSIGNED: When fixing a transverse scaphoid waist fracture with a single screw, the screw directed posteriorly from either the centre or anterior aspect of the distal pole has the best stability, a parallel configuration has the best stability when fixing it using a screw and a K-wire, and divergent configuration has the best stability when fixing it with two K-wires only.
UNASSIGNED: Computer-aided design (CAD) models of the scaphoid, K-wire, and headless compression screw were created. A transverse fracture was created at the scaphoid waist, and the CAD models of the screw and K-wire were used to fix the fracture in different configurations in a distal to proximal direction. Finite Element Analysis (FEA) was used to examine the strength of configurations when they were subjected to compression and distraction forces. The total maximum deformation (TDef) and factor of safety (FoS) for each configuration were calculated and used as indirect indicators of postoperative stability.
UNASSIGNED: When a single screw was used, the configurations with the screw directed posteriorly from either centre or anterior had the best combined TDef and FoS values. For one screw and one K-wire, the configuration with screw and K-wire parallel to each other with the screw located along the long axis in the AP projection and anterior to the K-wire in the lateral projection had the best combined TDef and FoS values. When using two K-wires, configurations with the two wires diverging proximally on the lateral projection had the best combined TDef and FoS values.
UNASSIGNED: When fixing a transverse scaphoid waist fracture with a single screw, the screw directed posteriorly from either the centre or anterior aspect of the distal pole has the best stability, a parallel configuration has the best stability when fixing it using a screw and a K-wire, and divergent configuration has the best stability when fixing it with two K-wires only.
摘要：
■舟骨腰部骨折通常通过加压螺钉稳定，克氏线（K线），或两者的组合。虽然评估其效用的临床和生物力学研究是可用的，提供足够的稳定性以允许早期使用手的植入物的理想配置是有争议的。我们检查了单螺杆的配置，一个螺钉和一根K线，和两根K线用于横向舟骨腰部骨折固定术，旨在评估各自在术后即刻提供的稳定性。
■舟骨的计算机辅助设计（CAD）模型，K线,并创建了无头压缩螺钉。舟骨腰部产生了横向骨折，螺钉和K线的CAD模型用于在远端到近端方向上固定不同构型的骨折。有限元分析（FEA）用于检查结构在承受压缩力和牵张力时的强度。计算每种配置的总最大变形（TDef）和安全系数（FoS），并将其用作术后稳定性的间接指标。
■当使用单螺杆时，螺钉从中心或前部向后的配置具有最佳的TDef和FoS组合值。对于一个螺钉和一个K线，螺钉和K线彼此平行且螺钉沿AP投影中的长轴和横向投影中的K线前方的配置具有最佳的TDef和FoS组合值。使用两根K线时，两条导线在侧向投影上向近侧发散的构型具有最佳的TDef和FoS组合值。
■用单个螺钉固定横向舟骨腰部骨折时，从远端杆的中心或前部向后指向的螺钉具有最佳的稳定性，使用螺钉和K线固定时，平行配置具有最佳的稳定性，和发散的配置具有最好的稳定性时，只有两个K线固定。
■舟骨的计算机辅助设计（CAD）模型，K线,并创建了无头压缩螺钉。舟骨腰部产生了横向骨折，螺钉和K线的CAD模型用于在远端到近端方向上固定不同构型的骨折。有限元分析（FEA）用于检查结构在承受压缩力和牵张力时的强度。计算每种配置的总最大变形（TDef）和安全系数（FoS），并将其用作术后稳定性的间接指标。
■当使用单螺杆时，螺钉从中心或前部向后的配置具有最佳的TDef和FoS组合值。对于一个螺钉和一个K线，螺钉和K线彼此平行且螺钉沿AP投影中的长轴和横向投影中的K线前方的配置具有最佳的TDef和FoS组合值。使用两根K线时，两条导线在侧向投影上向近侧发散的构型具有最佳的TDef和FoS组合值。
■用单个螺钉固定横向舟骨腰部骨折时，从远端杆的中心或前部向后指向的螺钉具有最佳的稳定性，使用螺钉和K线固定时，平行配置具有最佳的稳定性，和发散的配置具有最好的稳定性时，只有两个K线固定。
