The cutaneous nerves of the front of the thigh are derived from segments L. 1, 2, 3, 4. The lateral, intermediate, and medial cutaneous nerves of the thigh and the (long) saphenous nerve are derived from the femoral nerve. They pierce the deep fascia along an oblique line that roughly marks the Sartorius.
Source: Boileau Grant JC. A Method of Anatomy: Descriptive and Deductive. 5th ed. Baltimore, Md: Williams & Wilkins Co; 1952:382.
January 2004. Arch Surg. 2004;139(1):72. doi:10.1001/archsurg.139.1.72