What is the Cubital Tunnel?

The cubital tunnel is a part of the anatomy of the arm. It is a tunnel surrounded by ligament, muscle, and bone, through which the unlar nerve passes at the elbow. The ulnar nerve actually begins at the neck and travels down the arm through the cubital tunnel at the elbow and the carpal tunnel at the wrist. The unlar nerve supplies the pinky finger and part of the ring finger.

The point at which the ulnar nerve passes through the cubital tunnel is almost directly at the bend of the elbow, or the part of the elbow most people refer to as the “funny bone.” When you hit that part of the elbow against something and experience a painful sensation, it is a response caused by the impact and vibration of the ulnar nerve. While this impact causes temporary discomfort and pain, it is a common occurrence and rarely causes complications.

On the other hand, if the cubital tunnel should become inflamed due to trauma or repetitive stress injury (RSI), the ulnar nerve can become compressed, causing pain in the shoulder, arm, elbow, and even the two fingers supplied by the ulnar nerve. This condition is called cubital tunnel syndrome.

Cubital tunnel syndrome is marked by a tingling pain that begins in the elbow, but can sometimes be felt in the neck and shoulder, as well as in the fourth and fifth fingers. Cubital tunnel syndrome can occur alone, or in conjunction with carpal tunnel syndrome, in which case, all five fingers would feel numb and tingly at times. Diagnosis is typically made by a hand surgeon after performing a physical exam and a series of tests.

Tests for diagnosing cubital tunnel syndrome include a nerve conduction velocity test to measure nerve function. An electromyogram (EMG) is also a common test for diagnosing the problem. An EMG helps determine the functionality of the muscles controlled by the ulnar nerve and to assess the extent of the damage caused by the nerve compression.

Treatment may vary depending on the extent of the damage to the ulnar nerve. In some cases, a combination of cortisone injection to relieve swelling in the cubital tunnel and a change in physical habits followed by anti-inflammatory medications may relieve the problem. For some people, the problem is merely caused by their sleeping positions, in which case their doctor may provide a splint to use at night. The splint is designed to keep the arm straight, rather than bent, while sleeping.

If the pain and discomfort is not relieved with non-surgical treatment, surgery may be necessary. The goal of surgery is to eliminate the compression of the nerve to relieve the pain. This is typically done with a surgical procedure called ulnar nerve transposition, which means that a surgeon essentially creates a new tunnel and moves the ulnar nerve into it. This is typically a simple outpatient surgery that requires two to three follow-up appointments and may require either at-home exercises or brief physical therapy to recover full use of the arm and elbow. It typically relieves the pain in the long term, if not permanently.

If you experience pain, tingling, or similar symptoms in the arm, elbow, and hand, you should consult your family doctor or a hand surgeon. Nerve compression that is left untreated for a long period of time can result in permanent nerve damage and possibly even loss of use of the fingers or arm.