The differential diagnosis of groin pain must consider problems of the ilioinguinal and/or genitofemoral nerve. These nerves may become injured during hernia surgery or lower quadrant surgical procedures. To treat injury to these nerves, it is critical to understand their anatomic variability. In the present study the pattern of cutaneous nerve branches in the inguinal region was investigated through dissection in 64 halves of 32 human embalmed anatomic specimens. In contrast to usual textual descriptions, four different types of cutaneous branching patterns are identified: type A, with a dominance of genitofemoral nerve in the scrotal/labial and the ventromedial thigh region. In type A, the ilioinguinal nerve gives no sensory contribution to these regions (43.7 percent). In type B, with a dominance of ilioinguinal nerve, the genitofemoral nerve shares a branch with the ilioinguinal and gives motor fibers to cremaster muscle in the inguinal canal, but has no sensory branch to the groin (28.1 percent). In type C, with a dominance of genitofemoral nerve, the ilioinguinal nerve has sensory branches to the mons pubis and inguinal crease together with an anteroproximal part of the root of the penis or labia majora. The nerve was found to share a branch with the iliohypogastric nerve (20.3 percent). In type D, cutaneous branches emerge from both the ilioinguinal and the genitofemoral nerves. Additionally, the ilioinguinal nerve innervates the mons pubis and inguinal crease together with a very anteroproximal part of the root of the penis or labia majora (7.8 percent). The described patterns of innervation were bilaterally symmetric in 40.6 percent of the cadavers. The anatomic variability of both nerves has implications for all surgeons operating in the groin region and for those caring for the patient with groin pain.

Peroneal nerve decompression at the fibular head may be anticipated to be performed more often because lower extremity peripheral nerve surgery is used to restore sensation to the feet of diabetic patients. Although the basic concept of releasing the fascia of the peroneus longus is well-known, anatomic variants related to the peroneus muscle have been identified that must be included in the technique for decompression of this nerve. A comparison of these anatomic variants was done between a random selection of 29 cadavers (bilateral) and 65 patients who underwent unilateral peroneal decompression to treat symptoms of that compression. A fibrous band on the undersurface of the superficial head of the peroneus longus was found in 30% of the cadavers and it was found in 78.5% of the patients. The mean width of the band in cadavers was 9.1 mm and in patients it was 10.1 mm. A fibrous band on the superficial surface of the deep head of the peroneus longus was found in 43% of cadavers, and it was found in 20% of the patients. The soleus muscle origin was joined to the peroneus muscle origin in 9% of cadavers and it was noted in 6% of the patients. It is suggested that during surgical decompression of the common peroneal nerve at the fibular head, the surgeon be aware of these anatomic variants so that they may be released appropriately.

The pudendal nerve is located topographically in areas in which plastic surgeon reconstruct the penis, the vagina, the perineum, and the rectum. This nerve is at risk for either compression or direct injury with neuroma formation from obstetrical, urogynecologic, and rectal surgery as well as pelvic fracture and blunt trauma. The purpose of this study was to create a 3-dimensional representation based on magnetic resonance imaging of the pelvis supplemented with new anatomic dissections in men and women to delineate the location of the pudendal nerve and its branches, providing educational information both for surgical intervention and patient education. The results of this study demonstrated that most often there are at least 2, not 1, "pudendal nerves trunks" as they leave the pelvis to transverse the sacrotuberous ligament, and that there are most often 2, not 1, exit(s) from Alcock canal, one for the dorsal branch and one for the perineal branch of the pudendal nerve.