Nervus suralis
The sural nerve is a sensory nerve of the lower limb formed by the union of sural branch of the tibial nerve and the communicating sural branch of the common fibular nerve supplying sensation to the lower lateral aspect of the calf and foot.
Gross anatomy
It travels within subcutaneous tissue adjacent to the small saphenous vein in the lower posterolateral calf. The nerve descends and curls forward behind the lateral malleolus and becomes the lateral dorsal cutaneous nerve. Usually comprising the nerve roots S1 and S2 it provides sensation to the lower lateral calf, lateral ankle, lateral foot and some of the 5 digit.
Variant anatomy
The nerve has a variable anatomical formation. The most common of which is via the union of the medial sural cutaneous nerve (a branch of the proximal tibial nerve) and the peroneal communicating nerve from the lateral sural cutaneous nerve (a branch of the common peroneal nerve). The nerve may be formed solely from either of these branches.
Related pathology
Iatrogenic injury to the sural nerve can occur with operative procedures involving the ankle, calcaneal tendon and the small saphenous vein. Injury to the nerve is well tolerated, and for this reason, the is often used for nerve grafting or biopsy.