The Anatomy of the Tibial Nutrient Artery Canal—An Investigation of 106 Patients Using Multi-Detector Computed Tomography

Abstract

Radiologic evaluation of the tibial nutrient artery is clinically important as disruption of tibial blood supply is a risk factor for delayed or non-union of tibial fractures. Damage to the tibial nutrient artery canal (TNAC) may occur by a traversing fracture or iatrogenic cause in the context of pin/screw placement. Furthermore, TNAC could be misdiagnosed as a stress fracture. The aim of this study was to characterize the normal anatomy of TNAC and to delineate its gender and side-specific differences. Patients who underwent contrast-enhanced computed-tomography encompassing the pelvis and lower extremities were included. TNAC was identified with an external and internal foramen and a traversing intercortical canal. Various anatomical morphometrics were evaluated: total number of nutrient canals, angular position of the outer and inner nutrient foramina, absolute and relative position of the nutrient foramina, as well as the intercortical canal length with respect to tibial length. The majority of patients of both genders had only one tibial nutrient canal, multiple canals or complete absence were rare. In most cases, the outer nutrient foramen was found on the posterolateral aspect of the upper-third of tibia at about 32% of tibial length; the inner foramen was found at the middle third of the tibia (41% of tibial length). The course of nutrient canal was mostly cranio-caudal with a small, but significant difference in relative canal length: 8.5% vs. 10% of tibial length for females and males, respectively. The angular location of the outer and inner foramen was between 20–30° and did not reveal a statistically significant difference between genders. No statistically significant side specific differences were found for all analyzed parameters and both genders. The clinical relevance of this anatomical study pertains to establishing “safe corridors” of pin/screw insertion in the context of surgical management of tibial fractures in order to avoid iatrogenic disruption of tibial blood supply.