Determining the Insertion Site for Retrograde Intramedullary Nail Fixation of Tibiotalocalcaneal Arthrodesis: A Radiographic and Intraoperative Anatomical Landmark Analysis

Literature regarding the optimal entry point at the plantar aspect of the heel for performing tibiotalocalcaneal arthrodesis with a locked retrograde intramedullary nail is plentiful, but fails to provide meaningful guidance beyond broad generalizations. Because of the complex nature of the procedure, which requires precise alignment of multiple joints, difficulties in guide-wire placement frequently arise. Furthermore, proper guide-wire placement is usually performed under image intensification, placing the patient, surgeon, and operating room personnel at risk of ionizing radiation. This study evaluates weight-bearing lateral radiographic and anatomical landmarks to determine the optimal guide-wire entry point at the plantar heel fat pad, as well as a prospective intraoperative evaluation of the efficacy of using these landmarks to properly seat the guide wire. Radiographic and anatomical landmark portions of the study revealed that the calcaneocuboid joint was located 18.5 ± 3.4 mm anterior to the tibia mid-diaphyseal line, and that the lower leg soft tissue outline approximated the calcaneocuboid joint to within 0.3 ± 1.2 mm. The intraoperative portion of the study revealed that by first aligning the guide wire with the lower leg soft tissue outline, which approximated the location of the calcaneocuboid joint, and then translating the wire approximately 2.0 cm posteriorly, the increase in the efficacy of properly seating the guide wire was statistically significant (P ≤ .0001). The author proposes that this technique improves the accuracy of guide-wire placement and decreases dependency on intraoperative image intensification.