鎖定式骨釘骨板系統是目前遠端股骨複雜型骨折常用的手術植入系統，醫師常以骨板作為骨折處之復位樣板，將碎骨塊貼合骨板後鎖上骨釘固定，因此選擇適合病患股骨外形的骨板並將骨板安置於較貼合股骨之位置，可減少該病患術後股骨變形。
本研究開發一套分析病患個人股骨之最適鎖定式骨板與最適擺放位置軟體，在手術前協助醫師根據病患股骨幾何外形選擇最合適骨板，找出最適位置，同時模擬骨釘路徑供醫師選擇骨釘長度。分析軟體電腦斷層影像重建的股骨模型結合掃描得的四種型號骨板數位模型進行分析，以三種骨板與股骨遠端幹骺處間距量測方法做為合適度判斷準則，利用可能位置篩選與碰撞檢測方法，快速尋找最適骨板與最適擺放位置。包含股骨模型重建及其前處理，可在約兩小時內完成一例個案之最適骨板與最適位置分析。模擬實驗以軟體分析9位國人之遠端股骨套合在四種常用型號之骨板，發現目前最適骨板為Aplus與Zimmer之NCBDF產品。分析結果顯示部分骨板之遠端幹骺處最大間隙可到14mm，若使用於患者，術後容易發生股骨變形與位移。利用本系統分析挑選適合患者個人最適骨板以及最適位置，可預防術後併發症。

SUMMARY
Locking plate systems are frequently used by surgeons to treat complex distal femur fractures. Geometry fit of plate and bone is important to reduce malalignment and complications after surgery. The goal of this study is to develop a distal femur locking plate selection and fit analysis system to help surgeons choose the best fitting plates and best fixation position prior to surgery.
Three-dimensional plate and bone models were used to evaluate the three methods of fit measuring. Analysis results on nine human distal femurs and four commonly used plates showed that Aplus LDLF and Zimmer NCBDF plate is the best fitting plate while Synthes LISS is the worst fitting plate. Once the gap between the chosen plate and patient’s distal femur within metaphyseal region is greater than 10mm, it might lead to bone deformity if using the plate. We have applied the fit method to the case of distal femur fracture. The process of assessment accomplished within two hours. The chosen of the best fitting locking plate and its best location benefits patient to reduce the risk of post-surgery complications.
Key words: Distal Femur Fracture, Locking Plate System, Fit Analysis, Fixation location

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