Evaluation of the horizontal approach to the medial malleolar facet in sagittal talar fractures through dorsiflexion and plantarflexion positions

Background 
Talar fractures often require osteotomy during surgery to achieve reduction and screw fixation of the fractured fragments due to limited visualization and operating space of the talar articular surface. The objective of this study was to evaluate the horizontal approach to the medial malleolus facet by maximizing exposure through dorsiflexion and plantarflexion positions.
Methods 
In dorsiflexion, plantarflexion, and functional foot positions, we respectively obtained the anterior and posterior edge lines of the projection of the medial malleolus on the medial malleolar facet. The talar model from Mimics was imported into Geomagic software for image refinement. Then Solidworks software was used to segment the medial surface of the talus and extend the edge lines from the three positions to project them onto the \"semicircular\" base for 2D projection. The exposed area in different positions, the percentage of total area it represents, and the anatomic location of the insertion..., DICOM-formatted CT-scan images of each patient were imported into Mimics software (21.0 ; Materialise, Leuven, Belgium). We removed the soft tissue and affected bones by the function of image segmentation, region growth and multiple slice editing of Mimics software, respectively. A total of 273 virtual foot and ankle models were created. In dorsiflexion, plantarflexion, and functional foot positions, we respectively obtained the anterior and posterior edge lines of the projection of the medial malleolus on the medial malleolar facet (Fig. 1). At the same time, we found that the medial malleolar facet had a shape resembling a “semicircle”, and regardless of whether the foot was in the functional position, dorsiflexed, or plantarflexed, the movement of the medial malleolus occurred within this \"semicircular\" region (Fig. 2A). Tracing the outline of the foot in the three positions on the talus, it is not difficult to observe that plantarflexion and dorsiflexion expand the exposure area on ..., , # Evaluation of the horizontal approach to the medial malleolar facet in sagittal talar fractures through dorsiflexion and plantarflexion positions

In the positions of foot dorsiflexion, plantarflexion, and functional, we respectively obtained the anterior and posterior edge lines of the projection of the medial malleolus on the medial malleolar facet. The talar model from Mimics was imported into Geomagic software for image refinement. Then Solidworks software was used to segment the medial surface of the talus and extend the edge lines from the three positions to project them onto the \"semicircular\" base for 2D projection. The exposed area in different positions, the percentage of total area it represents, and the anatomic location of the insertion point at the groove between the anteroposternal protrusions of the medial malleolus were calculated. The mean total area of the \"semicircular\" region on the medial malleolus surface of the talus was 542.10 ± 80.05 mm2. In the functional ...