The authors studied the course of the infrapatellar branch of the saphenous nerve in 36 cadaver legs, with particular reference to its relationship to the sartorius muscle. In 19 (52.8%) the infrapatellar nerve passed through the sartorius, in 15 (41.7%) it passed over the sartorius before distributing to the antero-medial aspect of the knee. In two the nerve branched: in one both branches penetrated the sartorius and in the other, one branch penetrated and the other passed over the sartorius. The authors could not find any case in which the nerve passed through the tendon of the sartorius or passed under the sartorius. These findings explain why few cases of entrapment neuropathy of the infrapatellar branch clinically need surgical treatment.
