What is a nerve transfer?

A functioning donor nerve or motor branch is connected without tension to a denervated recipient through one coaptation. The connection is placed close to the target muscle to shorten regeneration distance. The donor is selected to minimize functional cost.

A transfer may be considered when direct repair or a short graft is not possible or is expected to be limited, when the target muscle remains receptive to reinnervation, and when the donor has adequate strength and axon supply.

Timing and patient selection

Time from injury, level of damage, target-muscle status, recipient-nerve quality, age, associated tissue injury and rehabilitation capacity all influence selection. Serial examination, EMG and selected imaging help determine whether recovery is occurring and the target remains reconstructable.

Foot drop and the deep peroneal nerve

Functioning donorSuitable tibial branch or fasciclesDistal coaptationTo a deep peroneal targetReinnervation and therapyTraining the new dorsiflexion command

For common or deep peroneal injury, one or several tibial motor branches—such as branches to soleus, gastrocnemius, flexor hallucis longus or flexor digitorum longus—or superficial peroneal fascicles can be connected to a dorsiflexion target.

The review included 16 reports and 154 patients before exclusions. MRC≥3 was reported in 58% when multiple branches or an SPN donor were used versus 43% with a single tibial branch. This was not a randomized comparison and the groups differed, so the percentages should not be treated as a guaranteed advantage.

Potential transfer routes for dorsiflexion reconstruction, from the supplied paper figures.

Femoral nerve and knee extension

Donor branchOften from the obturator nerveFemoral recipientSelected functional targetReconstructive goalImproved activation of knee extension

Anterior obturator branches are frequent donors for femoral targets and knee-extension recovery. Tensor fascia lata, sartorius and other branches have also been described. The review found many favourable reports, but cohorts were generally very small and sometimes single cases.

Anatomical transfer options around the thigh and femoral nerve, from the paper figures.

Sciatic, tibial and obturator targets

For sciatic or tibial injury, obturator or femoral branches have been transferred to gastrocnemius or other tibial targets. Femoral donors have been described for restoration of thigh adduction after obturator injury. Evidence is particularly sparse, so planning must be individualized.

Sensory nerve transfers

The goal is protective sensation in a vulnerable region, particularly the foot. Described examples include superficial peroneal to deep peroneal and saphenous to tibial or plantar targets. Only seven sensory-transfer reports were included, with different tests and follow-up.

Sensory recovery is slow and may remain incomplete. Insensate skin still requires protection from pressure, heat and injury during regeneration.

Rehabilitation and evidence limits

Rehabilitation teaches the donor command within the new action, preserves joint range and strengthens the target as reinnervation appears. An orthosis may remain necessary, and tendon or muscle transfer may be more appropriate in some cases.

All included clinical studies were OCEBM level-IV case series with substantial heterogeneity. MRC strength does not fully capture walking, endurance or quality of life, so larger studies and consistent functional outcomes are needed.

Source article

Duraku LS, Buijnsters ZA, Power DM, George S, Walbeehm ET, de Jong T. Motor and sensory nerve transfers in the lower extremity: Systematic review of current reconstructive possibilities. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2023;84:323–333. doi:10.1016/j.bjps.2023.06.011

The anatomical figures on this page are taken from the paper supplied for the project and are shown for medical explanation.

Motor and Sensory Nerve Transfers in the Lower Extremity