Lateral Calcaneal Artery: Pertinent Anatomy for Sinus Tarsi Approach and Calcaneal Osteotomy

CATEGORY: Trauma INTRODUCTION/PURPOSE: The lateral calcaneal artery provides critical arterial supply for healing of the extensile lateral approach to the calcaneus. A recent study has shown that preoperative doppler ultrasound showing non-patency of the lateral calcaneal artery is strongly correlated with wound complications when using this approach. Plate and screw fixation of calcaneus fractures through the sinus tarsi approach has gained popularity, including techniques involving percutaneous screw placement into a plate. Avoidance of lateral calcaneal artery injury may be improved with further quantification of its anatomy and associated variation. Finally, while the lateral approach to the calcaneus for osteotomy is routinely performed with minimal wound complications, the relationship of the lateral calcaneal artery to this approach was studied as well. METHODS: This is a cadaveric anatomic study performed using six fresh frozen cadaver specimens. The specimens were treated with intra-arterial injection of latex and dye. The specimens were first utilized in a separate study in which an orthopedic resident, blinded to the present study, performed a standard, oblique osteotomy of the calcaneal body. The cadavers were then examined for the relationship of the lateral calcaneal artery to the previous dissections. Finally, an extended sinus tarsi approach was made, and the relationship of the lateral calcaneal artery was quantified relative to the posterior facet and the posterior most point of the tuberosity, and relative to screw holes in a percutaneous calcaneal plate. RESULTS: Lateral calcaneal artery injury was observed in six out of six cadavers in which calcaneal osteotomy had been performed. The lateral calcaneal artery was encountered when performing the extended sinus tarsi approach at a mean ratio of 0.4 (standard deviation 0.11) of the distance from the posterior facet to the posterior aspect of the tuberosity. It crossed the posterior-most hole in the posterior facet portion of the plate in two cadavers. It also passed within 2 mm of the posterior most hole in the tuberosity portion of the plate in one cadaver. CONCLUSION: Careful dissection is warranted when extending the sinus tarsi approach beyond the posterior facet to preserve the lateral calcaneal artery. Injury is also possible with percutaneous tuberosity screw placement into a plate, and the consequences for sinus tarsi approach healing are unknown. Lateral calcaneal artery injury is difficult to avoid with the traditional lateral approach for calcaneal osteotomy, and while it has no implications for that approach which heals reliably, it indicates that preoperative doppler would be warranted if extensile lateral approach were considered in a patient who has previously undergone calcaneal osteotomy.