遠端股骨骨折往往涉及關節面，為使術後膝關節的併發症降至最低，骨折塊復位的準確性是相當重要的。術中為了確認骨折塊復位情況，必須進行多次放射線檢查，不僅增加輻射暴露量，手術時間與失血量都會因此增加，尤其年長者或多重內科疾病患者的手術時間更需要控制。本研究開發應用於遠端股骨骨折復位手術的術前骨折塊辨識分離與復位模擬軟體，以虛擬三維環境進行骨折塊復位，提供醫師於術前瞭解骨折塊的空間關係、移位狀況與旋轉程度，以規劃復位方式。期望在最短時間、最低放射劑量暴露下，達到骨折塊的復位，協助下一階段骨釘骨板的固定。軟體匯入由醫療數位影像傳輸協定(Digital Imaging and Communications in Medicine; DICOM)影像重建後的模型，進行骨折塊分離與復位，以種子點與區域成長法(Region Growing)將分離模型成獨立物件。視分離後的骨折塊為目標物件，鏡射患部對側未骨折之股骨或內建樣板模型為參考物件。經初步對位再以最近點疊代(Iterative Closest Point; ICP)演算法進行細部復位。提供局部區域對位功能，減少運算量，降低點匹配時間，完成遠端股骨骨折復位模擬。實驗驗證復位軟體精度，得平均誤差0.4475±0.2938mm，平均角度誤差1.6366°±1.2716°。根據醫學文獻定義1-2mm為手術後可接受之復位誤差，故本研究之復位模擬誤差應在合理範圍。

Distal femur fracture usually involve the articular surface. To minimize complications associated with the knee joint, accurate fragment reduction is necessary. In order to achieve reduction surgery, multiple radiographic inspections during operation are needed. The X-ray inspections not only increase radiation exposure, but also extend the operation time. To control the operation time for the elders who may have multiple underlying diseases are especially critical. Therefore, we developed a simulation software for distal femur reduction surgery. The surgical planning software was used for multiple fragments reduction in three dimensions, provide the surgeon gain better understandings of the positions of fragments. We aim to rehearsal fracture fragments reduction for distal femur before surgery that may reduce radiation exposure during surgery before fragments fixation on plate by screws.

Distal femur fracture was reconstructed from DICOM imaging and segmented into individual objects by the region growing method. We set the segmented fragments to be the target, mirrored contralateral side to be the reference. In case contralateral femur cannot be obtained, a built-in template model of the intact femur will be used as a reference. After gross reduction process, the iterative closest point algorithm is used for advanced reduction. More restricting conditions are added to reduce computations. The average distance and angular deviations are 0.4475±0.2938mm and 1.6366°±1.2716°, respectively. Based on relevant orthopedic literature, 1mm to 2mm displacement after reduction surgery are acceptable. Therefore, outcomes of the reduction simulation are within the acceptable domain.

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