C-arm影像導引系統應用於股骨幹骨折復位手術

Femoral shaft fracture reduction based on C-arm navigation system

楊志柔(Chih-jo Yang)

指導教授 ： 曾清秀

國立中央大學/工學院/生物醫學工程研究所/碩士(2013年)

摘要

C-arm影像輔助手術導引系統可在使用兩張C-arm影像的情況下，得知病患與手術器械的相對位置，有縮短新進醫師學習時間、降低醫護人員輻射量、減少手術時間及提升手術品質等優點。本研究將既有之C-arm影像導引系統進行軟體測試，確保軟體品質之穩定與強健性，之後增加術前確認系統精準度的功能，以及加入股骨幹骨折復位手術的導引功能。
股骨幹骨折復位手術導引系統是用來協助醫師將斷裂的股骨復位至應有的位置，基於人體左右兩側股骨呈現對稱的特性，將未斷裂側的股骨尺寸與方位做為斷裂側股骨的復位依據。在C-arm影像上選取或以器械尖端點選兩方式得到特徵點座標，包含股骨頭中心、近端股骨幹軸線、遠端股骨幹軸線以及內、外上髁的最凸點位置，並據以分別建立出未斷裂側與斷裂側的近、遠端座標系統。再利用光學式定位器即時追蹤架設於斷裂側之近、遠端斷骨的DRF位置，可計算得到斷裂側的股骨尺寸與方位，藉由比較未斷裂側與斷裂側之股骨尺寸與方位的差異，來得知股骨復位的狀態。
C-arm影像導引系統之軟體測試經過黑箱測試、白箱測試以及回歸測試後，顯示系統軟體已達穩定狀態。股骨幹骨折復位導引實驗是以斷兩截及三截之股骨模型做測試，結果顯示與目標座標系統的原點位置距離誤差平均約為4mm，軸線方向誤差皆小於6度，而復位後的股骨長度誤差小於3mm。其誤差來源主要是以器械尖端點選特徵點時產生的人為操作誤差，將特徵點更改為在C-arm影像上選取，應有助於改善系統的誤差。

關鍵字

C-arm ； 手術導引 ； 電腦輔助手術 ； 骨折復位 ； 軟體測試

並列摘要

A C-arm image assisted surgical navigation system for spine surgery has been developed to enable the surgeon to position surgical tools accurately and safely. It only needs two C-arm images to compute the orientations and positions of the targets, which reduces radiation exposure to the surgical team and patient. Software verification of the system is performed in this study to improve and verify its reliability and robustness. A new feature of the system for diaphyseal femoral fracture reduction is also developed.
Based on the symmetric characteristic of both femurs of single person, the anatomic dimensions of non-fractured femur are used as a navigation reference to reconstruct fractured femur. The anatomic dimensions are determined by the proximal and distal femoral frames of non-fractured and fractured femur defined by anatomic characteristics of the femurs. An optical tracker is applied to real-time measure the anatomic dimensions of fractured femur. Utilizing the dimension difference between non-fractured and fractured femur, diaphyseal femoral fracture reduction can be completed.
An experiment of two different femoral fracture models is applied to verify the performance of image-guided navigation system for diaphyseal femoral fracture reduction surgery. The results show that the distance error of the origin of target frame is about 4mm, axial direction error is less than 6 degrees, and the femoral length error is less than 3mm after reduction.

並列關鍵字

C-arm ； surgical navigation ； computer-assisted surgery ； fracture reduction ； software verification

參考文獻

[1] B. R. Bolhofner, B. Carmen, and P. Clifford, "The results of open reduction and Internal fixation of distal femur fractures using a biologic (indirect) reduction technique," J Orthop Trauma, vol. 10, pp. 372-7, 1996.

[2] T. P. Ruedi, C. Sommer, and A. Leutenegger, "New techniques in indirect reduction of long bone fractures," Clin Orthop Relat Res, pp. 27-34, Feb 1998.

[3] M. Leunig, R. Hertel, K. A. Siebenrock, F. T. Ballmer, J. W. Mast, and R. Ganz, "The evolution of indirect reduction techniques for the treatment of fractures," Clin Orthop Relat Res, pp. 7-14, Jun 2000.

[4] R. Hofstetter, M. Slomczykowski, C. Krettek, G. Koppen, M. Sati, and L. P. Nolte, "Computer-assisted fluoroscopy-based reduction of femoral fractures and antetorsion correction," Comput Aided Surg, vol. 5, pp. 311-25, 2000.

[5] K. T. Foley, D. A. Simon, and Y. R. Rampersaud, "Virtual Fluoroscopy: Computer-Assisted Fluoroscopic Navigation," Spine, vol. 26, pp. 347-351, 2001.