Abstract
The extended lateral approach offers a safe surgical approach in the fixation of calcaneal fractures. Lateral plating of the calcaneum could put structures on the medial side at risk. The aim was to identify structures at risk on the medial side of the calcaneum from wires, drills or screws passed from lateral to medial.
Ten embalmed cadaveric feet were dissected. A standard extended lateral approach was performed. The DePuy perimeter plate was first applied and 2mm K-wires were drilled through each of the holes. The medial side was now examined to determine the structures at risk through each hole. The process was repeated with the Stryker plate. The calcaneum was divided into 6 zones, by two vertical lines, from the margins of the posterior facet and a transverse line along the axis of the bone through the highest point of the peroneal tubercle.
The DePuy and the Stryker plates have 12 screw positions, 5 of which are common. With both systems, screw positions in zone 1 risk injury to the medial plantar nerve and zone 3 the lateral plantar nerve. A screw through zone 2 compromises the medial plantar in both. Screws through zone 4 risk the lateral plantar nerve with the DePuy plate. Screws through zone 5 of the DePuy plate risk the medial calcaneal nerve. Zone 5 of the Stryker plate and Zone 6 of both are safe.
There is significant risk to medial structures from laterally placed wires, drills or screws. Subtalar screws have the highest risk and have to be carefully measured and placed. The Stryker plating system is relatively safer than the DePuy perimeter plate with three safe zones out of six.
