The thigh

Key Points

• The lateral thigh dermatomes are L4, L5 and S1. Posteriorly S1 and S2 are the main dermatomes. The dermatome map below shows the distribution. Remember for the exam knowledge of individual nerves are not required - you are expected to be familiar with dermatomal patterns however.
• For arterial supply you need to be aware that cutaneous supply is via branches of the femoral artery. Again for the exam individual branches are not expected to be named.
• The great saphenous vein passes posteriorly to the medial epicondyle of the femur. Candidates should be aware of the course of the great saphenous from the SFJ just below the inguinal ligament running in the anteromedial thigh past the medial epicondyle of the knee where it descends towards the medial malleolus.