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Radial Tunnel Syndrome

(Posterior Interosseous Nerve Syndrome)

by David R. Steinberg, MD

Radial tunnel syndrome is a disorder resulting from compression of a branch of the radial nerve in the forearm or back of the arm or at the elbow.

Causes of compression of the radial nerve at the elbow include injury, ganglia, lipomas (noncancerous fatty tumors), bone tumors, and inflammation of the surrounding bursa or muscles.

Compression of the radial nerve results in cutting, piercing, or stabbing pain affecting the top of the forearm and back of the hand and side of the elbow. Pain results when the person tries to straighten the wrist and fingers. There is no numbness because the radial nerve principally connects to muscles.

Doctors base the diagnosis on an examination.

To reduce pressure on the nerve, the person should wear a splint on the wrist and/or the elbow and avoid rotating the wrist and bending the arm at the elbow. If the wrist becomes weak and tends to droop (wristdrop) or if symptoms are not relieved after 3 months of nonsurgical treatment, surgery may be needed to relieve pressure on the nerve.