The presence of an aberrant anterior tibial artery does not depend on the patient's morphotype

Purpose: The aberrant anterior tibial artery (ATA) runs along the posterior surface of the tibial cortex making it, particularly, at risk during high tibial osteotomy (HTO). This study aimed to analyze the prevalence of the ATA according to global morphotype and its anatomical features in consideration of knee surgery. Methods: This retrospective study included 1589 knees on magnetic resonance imaging (MRI) studies with long-leg radiographs. The anatomical characteristics of the ATA, its distance in surgical areas at risk and its lumen were defined on MRI. Its presence according to the patient's morphotype (varus, valgus or neutral) was assessed using a chi(2) test. Results: The ATA was present in 33 of 1589 knees, resulting in a prevalence of 2.1%. The anteroposterior distance of the ATA to the tibial head was 6.6 +/- 2.5 mm at the height of the tibial plateau, 2.7 +/- 1.6 mm at the footprint of the posterior cruciate ligament and 1.0 +/- 0.6 mm under the top of the fibula (p < 0.01). For these three levels, the ratio between the distance from the ATA to the lateral tibial border and the total tibial width decreases progressively (p < 0.001). The mean lumen area of the ATA was 4.2 +/- 2.5 mm(2), and the lumen of the popliteal artery was 9.2 +/- 3.6 mm(2), representing a ratio of 49.4 +/- 27.0%. The prevalence of ATA was similar between varus and valgus patients (n.s). Conclusion: The presence of an ATA is rare, found in one out of 50 cases, but can be easily identified on MRI in patients before knee surgery, especially before HTO. The patient's morphotype did not influence its presence, the lumen diameter is highly variable and its clinical impact has yet to be determined.