Posterior Cutaneous Nerve of the Forearm

nervus cutaneus antebrachii posterior

The posterior cutaneous nerve of the forearm is a sensory branch of the radial nerve arising in the radial groove of the humerus (C5-C8). It emerges between the lateral head of triceps and brachioradialis, pierces the lateral arm fascia, and descends to supply a broad strip of skin over the posterior and posterolateral forearm from the elbow to the wrist.

Region: Forearm

Clinical Relevance

Clinical Notes

This nerve is most commonly damaged during lateral elbow surgery, including extensor tendon release for lateral epicondylopathy, radial head procedures, and lateral epicondylectomy. The nerve's exit point from the fascia near the lateral intermuscular septum places it at risk with any incision in this region. The resulting posterior forearm numbness or painful neuroma can produce a more troublesome outcome than the original condition. Identifying the nerve during surgical approach planning and skin incision placement significantly reduces this risk.

Pathology

Common Injuries & Conditions

Lateral Elbow Surgery Injury

Transection of the posterior cutaneous nerve of the forearm during lateral epicondyle release or radial head surgery causes posterior forearm numbness and a painful cutaneous neuroma at the incision site, which can be managed by neuroma excision and nerve burial if symptoms are disabling.