Moewis P, Boeth H, Heller M O, Yntema C, Jung T, Doyscher R, Ehrig R M, Zhong Y, Taylor W R
Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Center for Sports Science and Sports Medicine Berlin, Germany.
Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Center for Sports Science and Sports Medicine Berlin, Germany; Bioengineering Research Group, University of Southampton, United Kingdom.
Med Eng Phys. 2014 Jul;36(7):889-95. doi: 10.1016/j.medengphy.2014.03.017. Epub 2014 Apr 26.
The in vivo quantification of rotational laxity of the knee joint is of importance for monitoring changes in joint stability or the outcome of therapies. While invasive assessments have been used to study rotational laxity, non-invasive methods are attractive particularly for assessing young cohorts. This study aimed to determine the conditions under which tibio-femoral rotational laxity can be assessed reliably and accurately in a non-invasive manner. The reliability and error of non-invasive examinations of rotational joint laxity were determined by comparing the artefact associated with surface mounted markers against simultaneous measurements using fluoroscopy in five knees including healthy and ACL deficient joints. The knees were examined at 0°, 30°, 60° and 90° flexion using a device that allows manual axial rotation of the joint. With a mean RMS error of 9.6°, the largest inaccuracy using non-invasive assessment was present at 0° knee flexion, whereas at 90° knee flexion, a smaller RMS error of 5.7° was found. A Bland and Altman assessment indicated that a proportional bias exists between the non-invasive and fluoroscopic approaches, with limits of agreement that exceeded 20°. Correction using average linear regression functions resulted in a reduction of the RMS error to below 1° and limits of agreement to less than ±1° across all knees and flexion angles. Given the excellent reliability and the fact that a correction of the surface mounted marker based rotation values can be achieved, non-invasive evaluation of tibio-femoral rotation could offer opportunities for simplified devices for use in clinical settings in cases where invasive assessments are not justified. Although surface mounted marker based measurements tend to overestimate joint rotation, and therefore joint laxity, our results indicate that it is possible to correct for this error.
膝关节旋转松弛度的体内定量对于监测关节稳定性变化或治疗效果具有重要意义。虽然侵入性评估已被用于研究旋转松弛度，但非侵入性方法尤其对于评估年轻人群具有吸引力。本研究旨在确定能够以非侵入性方式可靠且准确地评估胫股旋转松弛度的条件。通过将与表面安装标记相关的伪影与使用荧光透视法对五个膝关节（包括健康关节和前交叉韧带损伤关节）进行同步测量的结果进行比较，确定了旋转关节松弛度非侵入性检查的可靠性和误差。使用允许手动轴向旋转关节的设备在0°、30°、60°和90°屈膝位对膝关节进行检查。非侵入性评估的最大误差出现在膝关节0°屈曲位，平均均方根误差为9.6°，而在膝关节90°屈曲位时，均方根误差较小，为5.7°。布兰德-奥特曼评估表明，非侵入性方法和荧光透视法之间存在比例偏差，一致性界限超过20°。使用平均线性回归函数进行校正后，所有膝关节和屈曲角度的均方根误差降低至1°以下，一致性界限小于±1°。鉴于其出色的可靠性以及基于表面安装标记的旋转值能够实现校正这一事实，在侵入性评估不合理的情况下，胫股旋转的非侵入性评估可为临床环境中使用的简化设备提供机会。虽然基于表面安装标记的测量往往会高估关节旋转，进而高估关节松弛度，但我们的结果表明可以校正这种误差。
