Anatomic considerations for safe placement of calcaneal pins

Placement of a Steinmann pin in the calcaneus is indicated in various orthopaedic conditions. Planning the point of entry and the direction of transcalcaneal pin insertion is crucial for avoidance of neurovascular injury, tendon injury, and subtalar joint violation. Fifteen cadaveric feet were studied in which transfixing calcaneal pins were inserted in posteromedial and anteromedial sites. The posteromedial site was at a point 3/4 the distance between the palpable tip of the medial malleolus and the heel, with the pin inserted transversely. The anteromedial site was at the sustentaculum tali with the pin inserted transversely angled 25 degrees to 30 degrees inferolaterally. Radiographs were then taken and the specimens were dissected to determine the path of each pin and the safe and danger zones for transcalcaneal pin placement. It was concluded that the posteromedial calcaneal pin site is safer and easier to determine.