Consideration in Using the LSCN in Sural Flap Sensory Reconstruction: An Anatomic Evaluation

Abstract

The distally based or the reverse pedicle sural flap (abbreviated as the sural flap) is widely used for the coverage of soft-tissue defects in the lower leg, ankle, and foot. Clinical studies have tended to confirm that almost all the cases receiving the sural nerve (SN) anastomosed to the recipient nerve had sensory reconstruction for the weight-bearing heel in past decades. However, these results were incompletely consistent with the published anatomic literature about the variations of the SN branches in the lower legs. We conducted a clinical anatomic study to clarify some ambiguous view points in the sensory reconstruction of sural flap. Thirty-two lower legs of Chinese cadavers were dissected, and the data about distribution and variations of the SN branches were collected. The medial sural cutaneous nerve (MSCN) and the peroneal communicating branch (PCB) had no sensory subbranches to the upper and middle posterolateral surface of the lower leg except that the PCB had sensory subbranches in one leg. The lateral sural cutaneous nerve (LSCN) ramified 1 to 8 sensory subbranches to above the area in 24 of 32 (75%) legs. The LSCN is the nerve of choice for sensory reconstruction of the sural flap, anatomically; at most, about two-thirds to three-fourths (65%–75%) of the sural flap could have the sensate reconstruction via anastomosis. In contrast, the PCB nerve offers a very low possibility of reinnervation. The MSCN cannot neurotize the sural flap, although protective sensation recovery may be obtained.