Wangroongsub Yongsak, Cherdtaweesup Sornnarin
Department of Orthopedics, Faculty ofMedicine, Chulalongkorn University, Bangkok, Thailand.
J Med Assoc Thai. 2009 Dec;92 Suppl 6:S1-5.
Postoperative tibiofemoral alignment of the lower extremity is one of the most important factors that will assure a successful long-term outcome of a total knee arthroplasty. In this regard, most surgeons prefer to use an intramedullary guide than an extramedullary one for the femoral cut. However the entry point for the guiding rod is crucial for an appropriate femoral cut and femoral component positioning. The ideal entry point of the guiding rod should be the central axis of the distal femur in both coronal (anterior view) and sagittal planes (lateral view).
The authors studied the proper entry point for the femoral intramedullary guiding rod in total knee arthroplasty by using the top of the femoral intercondylar notch as the referenced point.
A series of radiographs for twenty-nine femurs from thirty-one cadavers, both anterior-posterior and lateral views, were evaluated in this study.
75.8 percent of the entry points in the coronal plane were at least 1 mm medial to the top ofthefemoral intercondylar notch. 82.7 percent of the entry points in the sagittal plane were superior to the top of the femoral intercondylar notch more than 10 mm. The proper entry point at the distal femur should be 1.5 +/- 2.01 mm medial and 12 +/- 2.72 mm superior to the top of the femoral intercondylar notch.
The result of this study could be useful for surgeons who prefer intramedullary guide system in total knee arthroplasty.
下肢术后胫股关节对线是确保全膝关节置换术长期成功的最重要因素之一。在这方面，大多数外科医生在进行股骨截骨时更喜欢使用髓内导向器而非髓外导向器。然而，导向杆的入点对于合适的股骨截骨和股骨组件定位至关重要。导向杆的理想入点在冠状面（前视图）和矢状面（侧视图）均应为股骨远端的中轴线。
作者以股骨髁间切迹顶部为参考点，研究全膝关节置换术中股骨髓内导向杆的合适入点。
本研究评估了来自31具尸体的29根股骨的一系列前后位和侧位X线片。
冠状面75.8%的入点至少在股骨髁间切迹顶部内侧1毫米处。矢状面82.7%的入点高于股骨髁间切迹顶部超过10毫米。股骨远端的合适入点应在股骨髁间切迹顶部内侧1.5±2.01毫米且上方12±2.72毫米处。
本研究结果可能对外科医生有用，这些医生在全膝关节置换术中更喜欢使用髓内导向系统。
