治療非移位性股骨頸骨折之骨螺絲最佳排列研究

Abstract

非移位性股骨頸骨折是常見的老人外傷，治療方式多以手術原位固定骨折處。因為是關節內骨折，如果植入物對骨折處固定力不足常會造成骨不癒合與股骨頭缺血性壞死，由此喪失活動能力或長期臥床而導致併發症會陸續發生，死亡率非常高。 目前對於非移位性股骨頸骨折手術治療的植入物選擇有很多種，其中最常被使用的是三根骨螺絲的固定方式。雖然關於骨螺絲的排列方式有些原則已經確定（1.骨螺絲必須彼此互相平行，2.螺紋必須超過骨折面，3.骨螺絲間距應儘量加大），然而回顧過去已發表的文章， 尚未發現有討論三根骨螺絲對於骨折處固定的最佳排列方式。 因此，本研究的目的是利用有限元素法對於植入骨螺絲的股骨頸骨折模型進行最佳位置分析，將實際手術中可以達到的骨螺絲排列可能最佳方式分為四組，然後在數種限制下（如骨折面水平夾角、骨密度）找出最佳排列方式，本研究之結果將可提供臨床醫師做為治療時之參考。

Undisplaced femoral neck fracture is a common senile injury. Pinning in situ for the fracture site remains the gold standard of treatment. The fracture site is located in the hip joint, so nonunion and avascular necrosis of femoral head usually develop if sufficient fixation can not be provided by the implant. The implants used in treating undisplaced femoral neck fracture include multiple screws, dynamic hip screw, and dynamic hip screws associated with an enhanced screw. The mostly chosen one is three screws. Although there exist well-documented principles of screws configuration: 1. screws should be inserted parallelly; 2. screw threads should pass across the fracture to provide fracture compression; 3. screws should be spread apart to maximize fixation stability, few literature has discussed the optimal screw arrangement that fixes the fracture site most effectively. The aim of the research is thus to perform biomechanical evaluation on undisplaced femoral neck fracture model fixed with three screws by finite element analysis. Feasible screws configurations have been arranged into four models and the optimal models have been found according to several conditions, such as the angle between the fracture plane and horizontal plane and various Young’s modulus of bone. The results of this study may act as a reference for surgeons’ treatment on undisplaced femoral neck fracture.