Radial tunnel syndrome, much like the more common and well-known carpal tunnel syndrome, is a painful condition caused by nerve entrapment.
The radial nerve runs from the side of the neck, along the back of the upper arm and down through the forearm and hand. At the elbow, the nerve goes through a passage formed by bone and muscles called the radial tunnel.
Nerve entrapment can occur at five parts of the radial tunnel. In some patients, the nerve becomes pinched because the tunnel is too small. In others, entrapment is related to repetitive twisting, pushing or pulling movements, bending at the wrist or repeated gripping and pinching motions.
Symptoms of Radial Nerve Entrapment
Radial nerve entrapment symptoms include pain and tenderness on the outside of the arm. The pain typically starts near the bony part of the elbow joint and radiates through the forearm.
In many patients, pain worsens when the wrist is flexed or the palm is turned upward, and when holding an object with the wrist and elbow in a stiff, straight position. Fatigue and weakness in the forearm muscles may accompany the pain, and it may become difficult to keep the wrist steady with grasping and lifting.
Diagnosing Radial Tunnel Syndrome
Diagnosis of radial nerve entrapment begins with a detailed medical history and physical examination to pinpoint the source of the patient’s pain. But because the symptoms of radial nerve entrapment mimic those of several other hand, wrist and elbow conditions and injuries, diagnosis may require more than a consultation.
Often, diagnostic imaging tests — such as ultrasound, magnetic resonance imaging (MRI) and electromyography — are ordered to rule out lateral epicondylitis, osteoarthritis, elbow joint synovitis, muscle tears and other pathologies that cause forearm and elbow pain.
Treatment for Radial Tunnel Syndrome
Nonsurgical treatments are nearly always the recommended initial course of action for entrapment of the radial nerve. Options that can help relieve pain include:
- Splinting or casting to immobilize the wrist
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Physical therapy exercises
- Ultrasound massage
- Nerve block to inject a local anesthetic
Many patients are able to alleviate their symptoms through these conservative measures. However, activity modifications — avoiding prolonged wrist flexion, forearm pronation and elbow extension — are crucial for successful nonsurgical treatment.
Although surgery may be an option for relieving persistent pain, it usually isn’t necessary or recommended. Surgical treatment is a last resort, considered only when symptoms don’t improve after several months of conservative care.
For more information on diagnosing and treating radial tunnel syndrome, consult with an experienced physical medicine and rehabilitation physician.