[Anatomic characteristics and clinic significance of the lateral femoral cutaneous nerve].

OBJECTIVE: To explore the reasons of poor sensation recovery after anterolateral thigh flap (ALTF) transplantation and to improve the design and sensation reconstruction of ALTF. METHODS: Lower limbs from 21 adult cadavers were chosen, and the lateral femoral cutaneous nerves (LFCN) were dissected. Their courses, shape, distribution and anatomic variation were observed, the distance from original sites of LFCN's posterior and anterior branches to the anterior superior iliac spine (ASIS) were measured, and the external diameter of their main trunks,after piercing out from the inferior margin of inguinal ligament or sending out their posterior branches and their anterior branches, were measured. RESULTS: The plane which the posterior branches sent out from the LFCN located at 4.8 (0~16.9) cm below the ASIS. The plane which the anterior branches sent out from the LFCN located at 14.2 (6.7~24.1) cm below the ASIS. There were 6 branches of the LFCN, namely ordinary three branches (9/21), high-level posterior branch (5/21), posterior branch absent (3/21), anterior branch absent (1/21), tiny branch, (2/21) and LFCN absent (1/21). The section of the LFCN was oblate, the external diameter of the LFCN,s main trunk after piercing out from the inferior margin of inguinal ligament or sending out its posterior branch and its anterior branch was 2.68 (1.18-4.52) mm, 2.18 (0.80-4.10) mm and 1.63 (0.44-2.60) mm, respectively. CONCLUSION: Poor sensation recovery after ALTF transplantation is due to anatomic variation of the posterior branch of the LFCN. The sensory recovery of ALTF may be improved if the 2/3 low to median part of the anterolateral thigh and the main trunk of the LFCN or its plane before sending out the anterior branch is chosen for anastomosis.