Kendoff D, Citak M, Pearle A, Gardner M J, Hankemeier S, Krettek C, Hüfner T
Trauma Department, Hannover Medical School, Carl Neubergstrasse 1, 30625, Hannover, Germany, and Orthopaedic Department, Hospital for Special Surgery, New York, NY, USA.
Knee Surg Sports Traumatol Arthrosc. 2007 Aug;15(8):1003-8. doi: 10.1007/s00167-007-0308-x. Epub 2007 Mar 16.
Inaccurate coronal plane realignment is a common problem after high tibial osteotomy. It has been shown that lower limb rotation has an effect on the two-dimensional measurement of lower limb alignment. Although alignment errors are known to occur due to limb rotation, the magnitude of this effect is unknown. Navigation systems allow for the measurements of coronal plane alignment and dynamically rotational and sagittal plane. Our study evaluated the effect of rotational leg movements on coronal plane alignment as determined by image-free navigation. We hypothesized that a linear relationship exists between rotation and angular measurements. Eight cadavers were used, while three test conditions of the complete lower limbs were established: (1) solid knee arthrodesis, (2) provisional knee arthrodesis and (3) unconstrained knee conditions. Navigated measurements of coronal and sagittal lower limb axis were done initially without knee flexion for defined internal/external rotations of 5 degrees, 10 degrees and maximal values for all test series. Repeated test for the unconstrained knee included stepwise knee flexion of 5 degrees, 10 degrees and 20 degrees. Statistical analysis comparing the test conditions 1, 2 and 3 and comparison between flexion movements of the unconstrained knee were done. Results revealed no significant differences between the different rotations of test condition 1 (mean 0.34 degrees, SD 0.23, range, 0 degrees-0.8 degrees). Condition 2 similarly did not result in significant deviations (mean 0.51 degrees, SD 0.24, range 0.1 degrees-0.9 degrees). Measurement deviations ranging from 0.4 degrees to 4.3 degrees were found for condition 3, the unconstrained knee. However, no statistically different testings from the arthrodesed knee were found (P=0.099-0.410). Knee flexion from 5 degrees, 10 degrees or 20 degrees, showed significant deviations (P<0.05) for all rotations at all degrees of flexion. Rotation and flexion of 5 degrees led to significant alignment errors of 3.4 degrees and 2.8 degrees, respectively, for internal and external rotations. Measurement failures due to the rotational movements of 1 degree-4 degrees might add to additional sources of errors causing relevant under- or over-corrections of the mechanical leg axis. Discrepancies of the axis due to rotational movements as well as flexion of the knee joint can be avoided and corrected immediately with the help of navigation.
胫骨高位截骨术后冠状面复位不准确是一个常见问题。研究表明，下肢旋转会影响下肢对线的二维测量。尽管已知肢体旋转会导致对线误差，但其影响程度尚不清楚。导航系统可用于测量冠状面的对线以及动态的旋转和矢状面。我们的研究评估了无影像导航确定的下肢旋转运动对冠状面对线的影响。我们假设旋转与角度测量之间存在线性关系。使用了8具尸体，同时建立了完整下肢的三种测试条件：（1）坚固的膝关节融合，（2）临时膝关节融合和（3）无约束膝关节条件。最初在膝关节不屈曲的情况下，对所有测试系列进行5度、10度的定义内/外旋转以及最大值时的冠状面和矢状面下肢轴线的导航测量。对无约束膝关节的重复测试包括逐步进行5度、10度和20度的膝关节屈曲。对测试条件1、2和3进行了统计分析比较，以及对无约束膝关节的屈曲运动进行了比较。结果显示，测试条件1的不同旋转之间无显著差异（平均值0.34度，标准差0.23，范围0度 - 0.8度）。条件2同样未导致显著偏差（平均值0.51度，标准差0.24，范围0.1度 - 0.9度）。在条件3（无约束膝关节）中发现测量偏差范围为0.4度至4.3度。然而，与融合膝关节相比，未发现统计学上的显著差异（P = 0.099 - 0.410）。在所有屈曲角度下，5度、10度或20度的膝关节屈曲在所有旋转角度下均显示出显著偏差（P < 0.05）。5度的旋转和屈曲分别导致内旋和外旋时显著的对线误差3.4度和2.8度。1度 - 4度的旋转运动导致的测量失败可能会增加额外的误差来源，从而导致机械下肢轴线的相关矫正不足或过度矫正。借助导航可以避免并立即纠正由于旋转运动以及膝关节屈曲导致的轴线差异。
