Anatomic variability of the ilioinguinal and genitofemoral nerve: Implications for the treatment of groin pain

The differential diagnosis of groin pain must consider problems of the ilio inguinal and/or genitofemoral nerve. These nerves may become injured during hernia surgery or lower quadrant surgical procedures. To treat injury to t hese nerves, it is critical to understand their anatomic variability. In th e present study the pattern of cutaneous nerve branches in the inguinal reg ion was investigated through dissection in 64 halves of 32 human embalmed a natomic specimens. In contrast to usual textual descriptions, four differen t types Of cutaneous branching patterns are identified: type A, with a domi nance of genitofemoral nerve in the scrotal/labial and the ventromedial thi gh region. In type A, the ilioinguinal nerve gives no sensory contribution to these regions (43.7 percent). In type B, with a dominance of ilioinguina l nerve, the genitofemoral nerve shares a branch with the ilioinguinal and gives motor Fibers to cremaster muscle in the inguinal canal, but has no se nsory branch to the groin (28.1 percent). In type C, with a dominance of ge nitofemoral nerve, the ilioinguinal nerve has sensory branches to the mons pubis and inguinal crease together with air anteroproximal part of the root of the penis or labia majora. The nerve was found to share a branch with t he iliohypogastric nerve (20.3 percent). In type D, Cutaneous branches emer ge from both the ilioinguinal and the genitofemoral nerves. Additionally, t he ilioinguinal nerve innervates the mons pubis and inguinal crease togethe r with a very anteroproximal part of the root of the penis or labia majora (7.8 percent). The described patterns of innervation were bilaterally symme tric in 40.6 percent of the cadavers. The anatomic variability of both nerv es has implications for all surgeons operating in tire groin region and for those caring for the patient with groin pain.