Superficial peroneal and sural nerve transfer to tibial nerve for restoration of plantar sensation after complex injuries of the tibial nerve: cadaver feasibility study.

BACKGROUND

Nerve reconstruction following lower-extremity nerve injuries usually leads to worse outcomes in comparison with upper-extremity injuries due to the long distances of nerve regeneration. This study was performed to consider the clinical application of distal nerve transfer for the treatment of long gaps of the tibial nerve (TN) and in established compartment syndrome. It aimed to determine the anatomic suitability of transferring the sural nerve (SN) in combination with the superficial peroneal nerve (SPN) to the TN at the level of the tarsal tunnel for restoration of plantar sensation.

METHODS

Nine fresh above-knee amputated limbs were dissected with the aid of loupe magnification. We focussed on the detailed anatomy of the course of the SN and the SPN from its emergence proximally at the knee level to the foot. Two different regions, suprafascial and subfascial, were described for each nerve. The maximum length of dissection and the length of the nerves in each region were measured. In all dissections, we assessed the feasibility of directly transferring the SN and SPN to the TN at the level of the tarsal tunnel.

RESULTS

The average length of the course of the SN was 20.6 cm (SD ± 2.3 cm) subfascially and 16.4 cm (SD ± 0.9 cm) suprafascially. For the SPN, the average length was 19.4 cm (SD ± 1.9 cm) subfascially and 18 cm (SD ± 2.5 cm) suprafascially. The point of emergence of the nerve from the subfascial course to the suprafascial course was defined as the pivot point for its transfer to the TN. Both the SN and the SPN reached the TN comfortably at the level of the tarsal tunnel, allowing direct co-aptation.

CONCLUSION

Distal nerve transfer using the SN in combination with the SPN is an anatomically reliable procedure, being a potential alternative to the use of nerve grafts in reconstruction of long gaps of the TN. In addition, selected patients with compartment syndrome may also benefit from this transfer to restore plantar sensation.