The sensate fibula osteocutaneous flap: neurosomal anatomy

Rapid return of oral sensation enhances quality of life following oromandibular reconstruction. For predictable reinnervation of flaps, a detailed knowledge of their nerve supply is required. This study was designed to investigate the cutaneous nerve supply of the fibula osteocutaneous flap.

We dissected thirty-seven fresh cadaveric specimens to better understand the cutaneous innervation of the typical fibula flap that would be used in oromandibular reconstruction. In addition, ten volunteers were enlisted for nerve blocks testing the cutaneous innervation of the lateral aspect of the lower leg.

The lateral sural cutaneous nerve (LSCN) is generally considered to be sole cutaneous innervation to the lateral aspect of the lower leg; however, our analysis of the cadaveric specimens revealed dual innervation to this region. We identified a previously unnamed distal branch of the superficial peroneal nerve, which we have termed the recurrent superficial peroneal nerve (RSPN). Given the cadaveric findings, both the LSCN and the RSPN were tested using sequential nerve blocks in 10 volunteers. An overlapping pattern of innervation was demonstrated.

The lateral aspect of the lower leg has an overlapping innervation from the LSCN and the newly described RSPN. The overlap zone lies in the region of the skin paddle of the fibula flap. The exact position of the neurosomal overlap zone (N.O.Z.E.) may be an important factor in reestablishing sensation in the fibula's skin paddle following free tissue transfer.