Department of Joint Surgery, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.
Chin Med J (Engl). 2010 Oct;123(19):2666-70.
Severe valgus deformity often has bone defect and laxity of the medial ligamentous, and total knee arthroplasty in severe valgus knee is, in most cases, more challenging for surgeons. The usefulness of a computer assisted navigation system in reestablishing the mechanical axis has been well established. Hence, the interest for surgeons is how the navigation system makes the procedure of total knee arthroplasty with severe valgus knee easier.
From June 2006 to March 2008 in Department of Joint Surgery, Shanghai Sixth People's Hospital, 6 patients (7 knees) with severe valgus knee underwent total knee arthroplasty using the Stryker Navigation system, which is an active wireless and imageless system. All the patients were followed up for 12 to 18 months after surgery. The X-ray radiographs for whole limbs were obtained on all patients to determine preoperative and postoperative alignments.
A primary, posterior stabilized prosthesis was utilized in all cases. The average preoperative overall mechanical axis of the seven knees was 19.6° ± 4.6° of valgus (range 16° to 29°), and the average postoperative mechanical axis was 0.4° ± 0.7° (range 0.8° varus to 1.4° valgus).
The navigation system is a very effective and useful tool for accurate intraoperative restoration of alignment in the face of significant deformity with valgus knee. To prevent component malposition, we did not reduce the knee before solidification of bone cement but controlled alignment using the navigation system up to implantation of the final component.
严重的内翻畸形常伴有骨缺损和内侧韧带松弛，对于大多数外科医生来说，严重内翻膝的全膝关节置换术更具挑战性。计算机辅助导航系统在重建机械轴方面的有效性已得到充分证实。因此，外科医生感兴趣的是导航系统如何使严重内翻膝的全膝关节置换术更容易进行。
2006 年 6 月至 2008 年 3 月，上海第六人民医院关节外科对 6 例（7 膝）严重内翻膝患者采用史赛克导航系统（一种主动无线无图像系统）行全膝关节置换术。所有患者均获得随访，随访时间为术后 12 至 18 个月。所有患者均拍摄全下肢 X 线片，以确定术前和术后的对线情况。
所有病例均采用后稳定型假体。7 膝的平均术前整体机械轴为 19.6°±4.6°外翻（范围 16°至 29°），平均术后机械轴为 0.4°±0.7°（范围 0.8°内翻至 1.4°外翻）。
在面对严重的内翻畸形时，导航系统是一种非常有效和有用的工具，可实现术中对线的精确重建。为了防止假体位置不当，我们在骨水泥凝固前不进行膝关节的复位，而是使用导航系统控制对线，直到最后安装组件。
