Cubital Tunnel Syndrome (Ulnar Nerve Entrapment)

Understanding Cubital Tunnel Syndrome (Ulnar Nerve Entrapment)

The ulnar nerve runs behind the inner bump of the elbow through a channel called the cubital tunnel, the spot known as the "funny bone." It provides feeling to the small finger and half of the ring finger and controls many of the small muscles of the hand.

In cubital tunnel syndrome the nerve is compressed or stretched at the elbow. Bending the elbow increases pressure on the nerve, so symptoms are often worse at night or with long phone calls and desk work. Other causes include leaning on the elbow, a nerve that snaps over the bony bump, and changes from prior injury or arthritis.

Mild cases often improve with avoiding elbow bending and pressure and wearing a splint at night. Numbness that persists beyond about six weeks of nonsurgical care, or weakness of the hand muscles, is treated with surgery to release the nerve and sometimes move it to the front of the elbow (transposition) before permanent damage occurs.

Causes & Risk Factors

• Prolonged elbow bending, including sleeping with the arm bent
• Leaning on the elbow
• A nerve that snaps over the medial epicondyle
• Prior elbow fractures, dislocations or arthritis

Symptoms

Common signs and symptoms of Cubital Tunnel Syndrome include:

• Numbness and tingling in the ring and small fingers
• Symptoms that worsen with the elbow bent or at night
• Weak grip and clumsiness
• Difficulty with fine finger movements
• Muscle wasting in the hand in advanced cases

Treatment Options

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

• Avoiding prolonged elbow bending and direct pressure
• A night splint to keep the elbow straighter
• Anti-inflammatory medications and nerve gliding exercises
• Cubital tunnel release
• Anterior transposition of the ulnar nerve