逆行骨釘與鎖定骨板治療遠端股骨骨折之有限元素比較

Abstract

臨床上膝關節病變患者裝置人工膝關節後，其中0.3-2.5%的患者可能發生遠端股骨骨折，一旦發生骨折會因為手術的複雜程度，會大幅提高治療的困難度。目前對於鄰近人工膝關節骨折手術治療的植入物有很多種選擇，其中常使用的是骨髓內釘與鎖定骨板；而臨床上亦有使用鎖定骨板加置異體骨的新嘗試，然而他們的療效仍缺乏完整的分析資料。因此本研究的目的是利用有限元素法對於鄰近人工膝關節骨折進行分析，探討在不同斷裂角及不同受力狀況下，鎖定骨板與骨髓內釘比較，以及鎖定骨板與鎖定骨板加置異體骨之比較。最後再針對老年病患常有的骨質疏鬆症狀，本研究亦進行了不同骨質疏鬆條件的評估分析。 本研究的結果發現，鎖定骨板的應力大於骨髓內釘，而鎖定骨板加置異體骨的應力最小；鎖定骨板的勁度大於骨髓內釘，且鎖定骨板加置異體骨的勁度最大；鎖定骨板與骨髓內釘的相對微動沒有明顯差異，而鎖定骨板加置異體骨的相對微動最小。故在需要考慮較高穩定的粉碎性骨折與骨質疏鬆情況下，本研究之結果建議使用鎖定骨板加置異體骨。

Periprosthetic supracondylar femur fracture is an uncommon complication that occur in 0.3 to 2.5% of patients with total knee arthroplasty. If fracture happens, the operation will be difficult because of the geometrical constraint of artificial knee. There are many choices for surgical treatment of periprosthetic supracondylar femur fracture, and the most common use are intramedullary nail and locking plate. Resently, a new attempt which combined the use of locking plate with allograft was proposed clinically. However, there are not sufficient data exist concerning the effects of the three surgical treatments for the periprosthetic supracondylar femur fracture. The purpose of this study is thus to use finite element method to explore the differences between locking plate, intramedullary nail, and locking plate combined with allograft in treating the above mentioned fracture with different fracture angles and loading conditions. The study is also focused on the different conditions of osteoporosis for elderly patients who sufer most from the above fractures. The results from the analysis revealed that the stress of locking plate is larger than that of the intramedullary nail, while the stress on the locking plate combined with allograft is the smallest. The stiffness with locking plate is greater than that of the intramedullary nail, and the stiffness with locking plate combined with allograft is the maximum. Although the relative micro motion of locking plate and intramedullary nail is of no significant difference, the locking plate combined with allograft still has the minimum micro motion. Therefore, Locking plate combined with allograft is recommended to be used in periprosthetic supracondylar femur fracture.