前十字韌帶脛骨擴張式內釘設計及生物力學測試

Biomechanical test for a new design of tibial dilation nail for anteriorcruciate ligament reconstruction

前言：近年來由於運動風氣盛行，提高人們對於運動傷害的重視。前十字靭帶重建術是運動傷害手術中常見且重要的手術。決定重建手術成功的關鍵在於是否能有效地固定肌腱靭帶，而臨床上，因鬆脫而導致手術失敗是最需要被解決的問題。目前現有的植入物及治療方式都無法有效地解決上述的問題，因此本研究的目的是設計出一擴張式脛骨內釘以解決這個問題。方法：本研究所設計的擴張式脛骨內釘，製作出實體以模擬手術進行的方式將成品植入豬隻的膝關節，手術模擬過程我們將對照組及實驗組1、3模擬正常植入情形，而實驗組2、4則模擬手術植入時位置有些偏差。再將其放到材料試驗機上進行力學測試。並以市售產品做為實驗對照組。結果:本研究所設計的擴張式脛骨內釘，在模擬正常植入位置時的破壞模式是因植入靭帶撕裂時，其最大拉出力量的平均值遠大於對照組。在模擬植入位置有偏差其破壞模式為鎖合處靭帶滑脫，其最大拉出力量的平均值與對照組差不多。結論與建議：新設計的擴張式內釘模擬正常植入位置的鎖合強度大於目前常用的interference螺釘，主要的原因是內釘打入後再利用擴張的內釘逼緊軟組織與骨穴而不會傷害軟組織，因此可以增強鎖合的強度。而比較相同設計的擴張式內釘在正常植入位置與位置有偏差時也證實當植入位置有偏差時，原本應正常擴張的內釘無法發揮其功能，進而降低鎖合的強度。由結果與對照組比較，證實新設計的擴張式內釘的確有較好的鎖合能力，證明臨床使用的可行性。

Purpose: The purpose of this study is to design a dilation nail to improve the fixation strength ofautograft tendon for anterior cruciate ligament reconstruction. Methods: Four new design dilationnails were manufactured and were implanted into pig knee joint by simulating anterior cruciateligament reconstruction surgery. One interference screw was used as a control group， two dilationnails was implanted into proper position and the other two dilation nails was implanted assimulating malposition. The pig knee joint was mounted onto the material testing system and themaximum pull out strength was record to evaluate the fixation strength of the new dilation nail andthe interference screw fixation methods. Results: Two new design dilation nails with properimplanted were failure due to autograft ligament torn and their maximum pull out strength werelarger than the control group. The other two new design dilation nails with malposition implantedwere failure on the fixation position that had the similar maximum pull out strength comparing withcontrol group. Conclusions: From this study， we found the fixation strength of new design dilationnail is greater than the control interference screw group. It is revealed the feasibility of this newdesign in clinical application.