From the Guidelines
The radial nerve courses from the posterior cord of the brachial plexus, down the arm, and around the shaft of the humerus, supplying the extensor muscles of the wrist and fingers, and its injury can lead to significant morbidity and impact on quality of life. The course of the radial nerve is complex, originating from the posterior cord of the brachial plexus, then descending down the arm, passing through the triangular interval, and wrapping around the shaft of the humerus in the radial groove, where it is particularly susceptible to injury 1. Key points about the radial nerve's course include:
- It runs down the back of the humerus in the radial groove
- It passes through the supinator muscle
- It divides into the posterior interosseous nerve and the superficial sensory branch
- It supplies the extensor muscles of the wrist and fingers, as well as providing sensory innervation to the back of the arm, forearm, and hand. Injury to the radial nerve can occur due to various mechanisms, including trauma, compression, or iatrogenic causes during surgery, especially in the lateral position where the dependent radial nerve is at risk 1. Treatment of radial nerve injury depends on the severity and location of the injury, ranging from conservative management for mild cases to surgical intervention for more severe cases, with the goal of restoring function and minimizing morbidity and impact on quality of life.
From the Research
Course of Radial Nerve
- The radial nerve is a branch of the posterior cord of the brachial plexus and runs down the back of the humerus (upper arm bone) in the radial groove 2.
- It then passes through the supinator muscle in the forearm, where it can be compressed, leading to radial tunnel syndrome or posterior interosseous nerve syndrome 2.
- The radial nerve supplies the extensor muscles of the wrist and fingers, as well as the supinator muscle, and provides sensation to the back of the hand and fingers 3.
Treatment of Radial Nerve Injury
- Treatment of radial nerve injury depends on the location and severity of the injury, and may include physical therapy, splinting, or surgery 4.
- Nerve transfers, such as the transfer of the triceps branch of the radial nerve, can be an effective treatment option for axillary nerve injuries, with a success rate of 80% 5.
- Imaging studies, such as high-resolution ultrasonography or magnetic resonance neurography (MRN), can be used to evaluate nerve continuity and detect reactive soft tissue alterations, such as constrictive scarring or neuroma formation 6.
- Surgical techniques, such as nerve release, can be used to treat entrapments of the radial nerve, and a clinical triad of muscle testing, scratch-collapse test, and pain at the level of nerve compression can be used to diagnose nerve compressions 3.