- 期刊
Rotational Alignment of the Tibia
脛骨之旋轉性排列
摘要
全人工膝關節置換術在現今是相當普遍的手術，但手術的成功與否須賴優良的技術，對膝關節之解剖構造、生物力學有深入的瞭解，且須考慮到膝關節的正面、側面和額面(forntal)之排列。且前所使用的各種全人工膝關節系統對於如何切割股骨及使用骨髓內導引器已有良好的發展，但對於脛骨之切害及人工關節之放置排列則無較好之導引。。 本研究得到三個結論：(1)證實膝關節在彎曲時確有脛骨內轉現象，即所謂的螺旋迴轉機制(screw-home mechanism), (2)膝關節彎曲90度，脛骨正面軸線通過踝關節處，位在此踝關節表面中心點較靠內側處。(3)脛關節伸直時，正常之力學軸線與脛骨棘突之距離為1.3公分。 全人工膝關節置換術，行脛骨切害時，膝關節需彎曲90°，此時切割之導引標識可參考本研究之結論二；將Trial prosthesis置入後，膝關節伸直，再以本研究之結論三加以校正，可得到合手正常的Trial component之旋轉排列位置。
關鍵字
無資料並列摘要
Roentgenological study of the lower limb was performed in the normal subjects and the osteoarthritic patients to determine the rotational alignment of the tibia. In the normal subjects, the angle formed by the center of the patella, the tibial tuberosity and the center of the ankle (P-T-A angle) is 14.8 (14.0-15.4) degrees in extension and 7.5 (7.0-7.9) degrees in 90 degrees flexion of the knee. The distance between the tibial tuberosity and the mechanical axis of the limb in 1.3 (0.9-1.8) cm in the normal subjects and 4.0 (2.6-6.8) cm in the osteoarthritic knee patients. The center of the ankle shown on the radiograph was medially located to the surface midpoint between two malleoli. The three conclusions are useful as a guideline during total knee arthroplasty to obtain a correct rotational placement of the tibial component.