Anatomical variations of the sural nerve

Abstract

An anatomical study of the formation of the sural nerve (SN) was carried out on 76 Thai cadavers. The results revealed that 67.1% of the SNs were formed by the union of the medial sural cutaneous nerve (MSCN) and the lateral sural cutaneous nerve (LSCN); the MSCN and LSCN are branches of the tibial and the common fibular (peroneal) nerves, respectively. The site of union was variable: 5.9% in the popliteal fossa, 1.9% in the middle third of the leg, 66.7% in the lower third of the leg, and 25.5% at or just below the ankle. One SN (0.7%) was formed by the union of the MSCN and a different branch of the common fibular nerve, running parallel and medial to but not connecting with the LSCN, which joined the MSCN in the lower third of the leg. The remaining 32.2% of the SNs were a direct continuation of the MSCN. The SNs ranged from 6-30 cm (mean = 14.41 cm) in length with a range in diameter of 3.5-3.8 mm (mean = 3.61 mm), and were easily located 1-1.5 cm posterior to the posterior border of the lateral malleolus. The LSCNs were 15-32 cm long (mean = 22.48 cm) with a diameter between 2.7-3.4 mm (mean = 3.22 mm); the MSCNs were 17-31 cm long (mean = 20.42 cm) with a diameter between 2.3-2.5 mm (mean = 2.41 mm). Clinically, the SN is widely used for both diagnostic (biopsy and nerve conduction velocity studies) and therapeutic purposes (nerve grafting) and the LSCN is used for a sensate free flap; thus, a detailed knowledge of the anatomy of the SN and its contributing nerves are important in carrying out these and other procedures.

Anatomical Variations in Formation of Sural Nerve in Adult Indian Cadavers

“…In present study, the site of union of MSCN with PCN (Type A) was more in lower 3 rd of leg (58.3%). Similar observations were made by Mahakkanukrah P et al, [15].…”

“…Mahakkanukrauh P et al, and Pyun SB et al, have told that the formation of sural nerve was by the union of MSCN and LSCN in 67.1% and 76.9% of cases respectively [15,16].…”

“…Authors have explained that bilateral asymmetry in the pattern of sural nerve formation is a rule rather than the exception, occurring in about 80% of cadavers [15].…”

“…Sural nerve is widely used for both diagnostic ( biopsy and nerve conduction velocity studies) and therapeutic purposes(nerve grafting) [11,23,25,26] the consistent location of the sural nerve, 1-1.5 cm behind the posterior border of lateral malleolus provides a precise surgical approach and efficient electrode placement for sensory conduction studies [15]. Sural nerve conduction studies are done in focal neuropathies to know the conduction velocity, action potential and amplitude.…”

Anatomy of the Sural Nerve Related to Calcaneal Tendon, Intermalleolar Line and Small Saphenous Vein

“…Furthermore, the relation to the SSV was investigated (Eid & Hegazy). At the ankle, the position of SN referred to the lateral malleolus (LM) was studied (Lawrence & Botte, 1994;Mahakkanukrauh & Chomsung, 2002;Aktan Ikiz et al, 2005). However, the reference points used in the previous studies are difficult to locate in the living subjects and the comparison with the bone length was not taken into account.…”