The femoral nerve (L2-L4) may be injured during inguinal lymph node dissection or psoas haematoma. A complete femoral nerve lesion would produce all of the following EXCEPT:

• A Weakness of knee extension (quadriceps)
• B Loss of knee jerk
• C Sensory loss on the medial side of leg and foot (saphenous nerve territory)
• D Weakness of knee flexion (hamstrings) ✓

Explanation

The femoral nerve (L2-L4) supplies the anterior compartment of the thigh: quadriceps femoris, sartorius, and pectineus. Its terminal sensory branch, the saphenous nerve, supplies the medial leg and foot. Knee jerk (L3-L4) is mediated via the femoral nerve. Femoral nerve palsy causes quadriceps weakness (knee extension loss), absent knee jerk, and medial leg sensory loss. Knee flexion (hamstrings) is supplied by the sciatic nerve (L4-S3), not the femoral nerve, so hamstring function is PRESERVED.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.