Unexplored topographic anatomy of obturator nerve in the adductor compartment of thigh, a cadaveric study

Background The objective was to study the topographical location of the obturator nerve after its exit from the obturator foramen and to note the vascular variations in relation to it. Methods This cross-sectional study was performed on 54 lower extremities (27 right-sided and 27 left-sided) available at the Department of Anatomy. A digital Vernier caliper was used to measure anatomical landmarks in relation to the obturator nerve. Results The location of obturator nerve from the femoral artery at the inguinal ligament level was 41 ± 7.3 mm and 46.1 ± 5.4 mm correspondingly over the right and left sides. Its distance from the anterior superior iliac spine was 108.1 ± 9.2 mm and 107.2 ± 5.1 mm on these sides. The shortest distance of obturator nerve from the inguinal ligament on the right and left side was 18.2 ± 2.9 mm and 19.1 ± 3.7 mm respectively. No statistically significant difference was detected (p > 0.05) between the left and right sides in any of the parameters measured in this study. An aberrant obturator artery was detected in eight specimens (14.8%), which branched from the external iliac artery. Accessory obturator veins were observed in 4 cases (7.4%), which were opened into the external iliac vein. Conclusion This study provides important data on the topographical location of the obturator nerve in the inguinal region, which can be used as an anatomical guide for obturator nerve blocks.