Following a car accident in which the patient received a deep laceration on the medial side of his right knee, she notices numbness along the medial side of his right leg and foot. There is no motor deficit. The nerve which appears to have been injured is?
The saphenous nerve travels with the great saphenous vein, running along the medial side of the leg and thigh. It provides cutaneous innervation to the medial leg and foot and does not provide motor innervation to any muscles. So, both the case history and the symptoms point to a saphenous nerve injury. Branches of the femoral nerve provide cutaneous innervation to the skin of the anterior thigh--these nerves would not have been involved with this accident. The sural nerve runs with the lesser saphenous vein, posterior to the lateral malleolus and up the back of the leg. It provides cutaneous innervation to the skin of the posterior surface of the lower leg and the skin of the lateral side of the foot. The superficial fibular nerve provides sensory innervation to the distal third of the leg and the dorsal surface of the foot.
Femoral nerve
Saphenous nerve
Sural nerve
Superficial fibular nerve