Saphenous neuralgia of the knee.

The saphenous nerve is the longest branch of the femoral nerve and is a purely sensory nerve. It arises from the 3rd and 4th lumbar roots. As mentioned it is an exclusively sensory. It supplies the medial articulation of the knee and cutaneous sensation of the medial aspect of the knee, leg and ankle. The nerve travels in close proximity to the femoral vessels subsartorial. This hunter canal is formed by a fibrous band spanning between the vastus medialis and the adductor magnus. At this point the nerve is most susceptible to entrapment. The nerve enters the adductor canal and then cross the adductor muscle. The adductor canal or hunter ́s canal is a muscular tunnel in the thigh. It is boundered by the sartorius muscle anteriorly; the vastus medialis muscle laterally as well as the adductor longus and adductor magnus muscles postero-medially and contains the femoral artery, vein and the saphenous nerve. The roof of the hunter ́s canal is a fibrous band bridging the vastus medialis and adductor magnus (Figure 1) [18]. Within the canal the nerve is vulnerable to entrapment. It descends along the medial side of the knee and exits the adductor canal. Medial of the knee the infrapatellar branch divides from the nerve