Radial Tunnel Syndrome

Understanding Radial Tunnel Syndrome

The radial nerve crosses the outer elbow and passes through a narrow passage in the forearm muscles called the radial tunnel. In radial tunnel syndrome, the nerve is irritated or compressed there, causing an aching pain in the top of the forearm a few centimeters below the outer elbow.

Because the pain is close to where tennis elbow hurts, the two are often confused, and radial tunnel syndrome was first described as a cause of "resistant tennis elbow" ^[1]. Unlike tennis elbow, the tenderness is further down the forearm, and pain is often worse when turning the palm up or straightening the middle finger against resistance. Numbness is not typical, because the nerve branch involved mainly controls muscles ^[2].

Treatment starts with rest from aggravating activities, splinting, therapy and anti-inflammatory measures, and a diagnostic injection can help confirm the diagnosis. Surgical release of the nerve is considered for symptoms that continue despite several months of nonsurgical care, although results are less predictable than for other nerve compressions and the diagnosis remains debated ^[2].

Causes & Risk Factors

• Repetitive forearm rotation and gripping
• Compression by muscle edges or fibrous bands in the forearm
• Direct injury to the forearm
• Often occurs alongside tennis elbow

Symptoms

Common signs and symptoms of Radial Tunnel Syndrome include:

• Aching pain in the top of the forearm below the outer elbow
• Pain worse with turning the palm up or gripping
• Tenderness further down the forearm than in tennis elbow
• Fatigue of the forearm muscles
• Usually no numbness

Treatment Options

Treatment for Radial Tunnel Syndrome depends on the severity of your condition and may include:

• Rest from aggravating activities
• Wrist splinting
• Physical therapy and nerve gliding
• Diagnostic and therapeutic injection
• Surgical release of the radial tunnel for persistent symptoms

References

1. Roles NC, Maudsley RH. Radial tunnel syndrome: resistant tennis elbow as a nerve entrapment. J Bone Joint Surg Br. 1972;54(3):499-508. pubmed.ncbi.nlm.nih.gov/4340924/
2. Wolf JM, Patel R, Ghosh K. Radial Tunnel Syndrome: Review and Best Evidence. J Am Acad Orthop Surg. 2023;31(15):813-819. doi.org/10.5435/JAAOS-D-23-00314