Femoral nerve dimensions at the inguinal ligament and inguinal crease levels: implications for femoral nerve block

Abstract Introduction: Femoral nerve block, when used solely or as a supplement to general anaesthesia, provides anaesthesia and analgesia to the anterior thigh. In spite of its established benefits, femoral nerve block is still underutilized in Nigeria. Our objective was to study the dimensions of femoral nerve at the level of the inguinal ligament and inguinal crease using a cadaveric model; no such data exists in Nigeria. Materials and Methods: Using 7 adult human cadavers (6 males and 1 female), the depth and thickness of the femoral nerve were measured at the levels of inguinal ligament and inguinal crease. The spatial relationship of femoral nerve to the surrounding structures was also observed. Result: The study showed a significantly wider thickness and shorter depth of the femoral nerve at the level of inguinal crease relative to inguinal ligament. Conclusion: We concluded that in centers where ultrasound and neurostimulation techniques for femoral nerve block in Nigerians are unavailable, the inguinal crease level where the femoral nerve is more supericial and wider in thickness would be the landmark of choice compared to the inguinal ligament level.