Department of Orthopaedic Surgery, Washington University School of Medicine, One Barnes-Jewish Hospital Plaza, 11300 West Pavilion, Campus Box 8233, St Louis, MO 63110, USA.
Clin Orthop Relat Res. 2012 Mar;470(3):895-902. doi: 10.1007/s11999-011-2222-2. Epub 2011 Dec 20.
Coronal alignment may impact clinical outcome and survivorship in TKA. Patient-specific instrumentation has been developed to restore mechanical or kinematic axis and potentially reduce component malpositioning. Although it is clear these instruments add cost, it is unclear whether they improve alignment.
QUESTIONS/PURPOSES: We determined whether the mean coronal alignment after TKA performed with conventional versus patient-specific instrumentation better restored the mechanical and kinematic axes and whether there were more outliers with one of the two methods.
We retrospectively evaluated 150 primary TKAs performed for osteoarthritis: Group 1 (n = 50) conventional instrumentation; Group 2 (n = 50) patient-specific instrumentation restoring the mechanical axis; Group 3 (n = 50) patient-specific instrumentation restoring the kinematic axis, and measured femorotibial angle, hip-knee-ankle angle, and the zone of the mechanical axis from scout CT images taken 0 to 6 weeks postoperatively.
The mean femorotibial angle differed between the groups: Group 1 had the greatest varus mean alignment and most varus outliers. The mean hip-knee angle was similar between Groups 1 and 2, with Group 3 having greater valgus mean alignment and the most valgus outliers. For the zone of the mechanical axis, Groups 1 and 2 had similar percentages of outliers (40% versus 32%), whereas Group 3 had a greater number of outliers (64%) that were valgus.
TKAs with patient-specific instrumentation restoring the mechanical axis had a similar number of outliers as conventional instrumentation with both groups having more varus outliers than TKAs with patient-specific instrumentation restoring kinematic axis, which had more valgus outliers. Therefore, additional studies are needed to determine whether patient-specific instrumentation improves clinical function or patient satisfaction and whether their routine use can be justified in primary TKA.
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
冠状面对线可能会影响 TKA 的临床结果和生存率。为了恢复机械或运动学轴并可能减少组件错位，已经开发了患者特异性器械。尽管很明显这些器械增加了成本，但尚不清楚它们是否能改善对线。
问题/目的：我们确定了在 TKA 中使用传统器械与患者特异性器械进行手术时，哪种方法能更好地恢复机械和运动学轴，以及两种方法中的哪一种方法有更多的离群值。
我们回顾性评估了 150 例因骨关节炎行初次 TKA 的患者：组 1（n = 50）采用传统器械；组 2（n = 50）采用患者特异性器械恢复机械轴；组 3（n = 50）采用患者特异性器械恢复运动学轴，并在术后 0 至 6 周时从 CT 扫描图像上测量股胫角、髋膝踝角和机械轴的区域。
各组之间的平均股胫角存在差异：组 1 的平均对线有最大的内翻偏差，且内翻离群值最多。组 1 和组 2 的平均髋膝角相似，组 3 的平均对线有更大的外翻偏差，且外翻离群值最多。对于机械轴的区域，组 1 和组 2 的离群值百分比相似（40%比 32%），而组 3 的离群值（64%）更多为外翻。
恢复机械轴的患者特异性器械的 TKA 与传统器械的 TKA 有相似数量的离群值，这两组的内翻离群值比恢复运动学轴的患者特异性器械的 TKA 多，后者的外翻离群值更多。因此，需要进一步研究以确定患者特异性器械是否能改善临床功能或患者满意度，以及它们在初次 TKA 中的常规使用是否合理。
III 级，治疗性研究。详见作者指南，了解完整的证据水平描述。
