The geometrical axis of the talocrural joint—Suggestions for a new measurement of the talocrural joint axis

• Published in: Foot and ankle surgery 2019-06, Vol.25 (3), p.371-377
• Main Authors: Claassen, Leif, Luedtke, Philipp, Yao, Daiwei, Ettinger, Sarah, Daniilidis, Kiriakos, Nowakowski, Andrej M., Mueller-Gerbl, Magdalena, Stukenborg-Colsman, Christina, Plaass, Christian
• Format: Article
• Language: English
• Subjects: Ankle joint; CT-scan; Joint axis; Talocrural joint; Total ankle replacement
• ISSN: 1268-7731; 1460-9584
• DOI: 10.1016/j.fas.2018.02.003

•Study shows a system for estimating the geometrical talocrural joint axis.•High number of 98 CT scans analyzed.•High interindividual variations highlight the potential need of patient specific implantation techniques for total ankle replacement. Despite intensive research there is no consensus about the talocrural joint axis. The aim of the present study is a new method to determinate the geometric rotational axis of the talocrural joint. We analyzed 98 CT-scans of full cadaver Caucasian legs. We generated three-dimensional reconstruction models of the talus. A best fitting cone was orientated to the talar articular surface. The geometric rotational axis was defined to be the axis of this cone. The geometric rotational axis of the talocrural joint is orientated from lateral–distal to medial–proximal (85.6°±10 compared to anatomical tibial axis in torsional plane), from posterior–distal to anterior–proximal (81.43°±44.35 compared to anatomical tibial axis in sagittal plane) and from posterior–medial to anterior–lateral (169.2°±5.91 compared to intermalleolar axis in axial plane). The consideration of our results might be helpful for better understanding of ankle biomechanics.