Geisbüsch Andreas, Auer Christoph, Dickhaus Hartmut, Niklasch Mirjam, Dreher Thomas
Department of Orthopaedic and Trauma Surgery, University Hospital Heidelberg, Schlierbacher Landstraße 200a, Heidelberg 69117, Baden-Württemberg, Germany.
Department of Medical Biometrics and Computer Sciences, University Hospital Heidelberg, Heidelberg 69117, Baden-Württemberg, Germany.
J Orthop Res. 2017 May;35(5):1106-1112. doi: 10.1002/jor.23348. Epub 2016 Jul 4.
Correction of rotational gait abnormalities is common practice in pediatric orthopaedics such as in children with cerebral palsy. Femoral derotation osteotomy is established as a standard treatment, however, different authors reported substantial variability in outcomes following surgery with patients showing over- or under-correction. Only 60% of the applied correction is observed postoperatively, which strongly suggests intraoperative measurement error or loss of correction during surgery. This study was conducted to verify the impact of error sources in the derotation procedure and assess the utility of a newly developed, instrumented measurement system based on electromagnetic tracking aiming to improve the accuracy of rotational correction. A supracondylar derotation osteotomy was performed in 21 artificial femur sawbones and the amount of derotation was quantified during the procedure by the tracking system and by nine raters using a conventional goniometer. Accuracy of both measurement devices was determined by repeated computer tomography scans. Average derotation measured by the tracking system differed by 0.1° ± 1.6° from the defined reference measurement . In contrast, a high inter-rater variability was found in goniometric measurements (range: 10.8° ± 6.9°, mean interquartile distance: 6.6°). During fixation of the osteosynthesis, the tracking system reliably detected unintentional manipulation of the correction angle with a mean absolute change of 4.0° ± 3.2°. Our findings show that conventional control of femoral derotation is subject to relevant observer bias whereas instrumental tracking yields accuracy better than ±2°. The tracking system is a step towards more reliable and safe implementation of femoral correction, promising substantial improvements of patient safety in the future. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1106-1112, 2017.
矫正旋转步态异常在小儿骨科中很常见，比如在脑瘫患儿中。股骨去旋转截骨术已成为一种标准治疗方法，然而，不同作者报道术后结果存在很大差异，患者出现过度矫正或矫正不足。术后仅观察到60%的预期矫正效果，这强烈提示术中存在测量误差或手术过程中矫正效果丢失。本研究旨在验证去旋转手术中误差来源的影响，并评估一种新开发的基于电磁跟踪的仪器测量系统的实用性，旨在提高旋转矫正的准确性。对21个人造股骨锯骨标本进行髁上截骨术，并在手术过程中通过跟踪系统和九名评估者使用传统角度计对去旋转量进行量化。通过重复计算机断层扫描确定两种测量设备的准确性。跟踪系统测量的平均去旋转角度与定义的参考测量值相差0.1°±1.6°。相比之下，角度测量中发现评估者间的变异性很大（范围：10.8°±6.9°，平均四分位数间距：6.6°）。在骨固定过程中，跟踪系统可靠地检测到矫正角度的意外操作，平均绝对变化为4.0°±3.2°。我们的研究结果表明，传统的股骨去旋转控制存在相关的观察者偏差，而仪器跟踪的准确性优于±2°。跟踪系统朝着更可靠、更安全地实施股骨矫正迈出了一步，有望在未来大幅提高患者安全性。©2016骨科研究协会。由威利期刊公司出版。《矫形外科学研究》35:1106 - 1112, 2017年。
