What is cubital tunnel syndrome?

What is cubital tunnel syndrome?

Cubital tunnel syndrome is a nerve entrapment at the elbow involving the ulnar nerve within the "cubital tunnel". Like carpal tunnel or tarsal tunnel it may have to be surgically corrected. The information from Bermant Plastic Surgery is easy to read and clear so let's follow it. Dr. Bermant is Board Certified by the American Board of Plastic Surgery and is located in Richmond, Virginia.

The Problem
Nerve compression problems behind the elbow are called cubital tunnel syndrome. The ulnar nerve passes through the cubital tunnel which is a bony passageway. When you "hit your funny bone" and have tingling in the small and ring fingers, you are hitting the ulnar nerve at the cubital tunnel.

The tunnel has a bone passageway on both sides and the base. A ligament holds the nerve into the tunnel by crossing from one bone to the other. The ulnar nerve controls muscles used for gripping, primarily of the little, ring, and sometimes middle fingers. It also controls muscles in the hand used for strong pinch, and other muscles that coordinate fine movements. This includes most of the muscles in the hand except two muscles that lift the thumb up and out of your palm, turning the thumb into a better position for pinching. The ulnar nerve also receives feeling from the small and ring fingers from both the palm and backside of your hand.

Your complaints may result from either sensory or motor (muscle) nerve compression. For example, your symptoms may primarily involve numbness and tingling in the little and ring fingers, the side and back of the hand. These complaints occur or worsen when the elbow is bent, as when: 1) holding a telephone in the hand, 2) resting the head on the hand, 3) crossing the arms over the chest, 4) curling the arm under the body during the night. Your hand may also become cold or numb when it is on top of a steering wheel. The other group of symptoms involves motor functions of the nerve. You may be aware that the hand has become weaker, resulting in trouble opening jars. You may drop things, or your hand may not perform quite as easily as it did before. For example, you may have difficulty coordinating your fingers while typing or playing the violin, guitar, or piano. The problems usually worsen with extended activities. Frequently there are both sensory and motor symptoms present. Often we do not know the cause of this problem. Often, the patient experienced some injury to the region of the elbow: Examples include fractures, dislocations, direct blows, and severe twisting of the elbow. The nerve can also be injured with a sudden forceful flexion and extension of the elbow as may occur when the hands are on the wheel of a car in a rear ended automobile accident. Occupations requiring significant elbow flexion throughout the day, such as typing, computer data or assembly line work may contribute toward problems with pressure on this nerve. Nerve compressions are more common in people with arthritis, diabetes, thyroid problems, and those who consume a great deal of alcohol.

Nonoperative Treatment
With elbow bending, the nerve is pulled up between bones into the bony groove, causing increased pressure on the nerve. Every time the elbow is bent the nerve is tightened and the blood supply to the nerve is reduced. A straight elbow has less pressure on the nerve. You may be able to avoid surgery by keeping the elbow straight as often as possible. Clearly this cannot be done throughout the day because you need to bend your elbow to do many tasks. Regular daily activities must be altered. Avoid crossing your arms across your chest. When talking on the telephone, watch how much your elbow is bent. Those who need to use the telephone frequently should get a cradle attachment or headset. You may have to alter your sleeping position with pillows. Adjust your chair and desk so that when writing, working at a typewriter or a computer keyboard, the elbow is flexed no more that 30 degrees and the wrist is in a neutral position. You may need a night stand for bedtime reading so that the book is not always held with the elbow bent. Most of these changes are common sense and require you to pay attention to your daily activities. We can make a splint to keep the elbow straight or slightly (30 degrees) flexed. I often suggest that you fabricate your own elbow extension splint with soft toweling or use hockey elbow pads, which prevent elbow flexion. In addition before considering surgery, we will need to manage contributing medical conditions such as arthritis and diabetes.

The Operation
The operation is designed not only to take pressure off the nerve, but also to move the nerve to a position to reduce compression during common daily activities. There are many operations for compression of the ulnar nerve at the elbow. We will concentrate on the procedure to move the ulnar nerve to the front of the elbow. The nerve will no longer have the added pressure of being pulled into the bony groove when bending the elbow. Placing the nerve beneath a muscle layer prevents it from slipping back in the bony groove and provides an increased blood supply to help heal the nerve. The placement under the muscle also protects the nerve from injury. With a new location, The nerve can become compressed or pinched by the new anatomic structures the nerve must pass through. The operation is also designed to remove these potential sites.

This operation is called an anterior submuscular transposition of the ulnar nerve. The incision is made behind the elbow. The length of the incision varies, depending on the thickness of the arm, the size of the arm, the amount of fat tissue, and the presence of any unusual anatomic arrangements. A longer incision gives a better view of the delicate structures Dr. Bermant is trying to protect. A nerve crosses the area of the incision. This is a small nerve that supplies the skin behind the elbow and in part of the forearm. This nerve and others may become injured during the operative procedure. After surgery, pain in the scar and loss of sensation are possible despite Dr. Bermant's care to protect these nerves at the time of surgery. Magnifying glasses (operating microscope or loupes) show detail during the operation to reduce the chances of injury. The ulnar nerve is identified in the bony tunnel and the bands causing pressure on it are released. The muscles that start from the elbow and cross down the forearm are called the flexor - pronator muscle mass. They turn the forearm, bend the wrist, and bend some of the fingers. These muscles are lifted from the bone. The strong tissue that covers this mass is lengthened to reduce compression in the nerve's new position. The areas above and below the elbow that the nerve passes through are treated to diminish future nerve compression. Patients who have constant numbness, severe weakness, or muscle wasting may have scar tissue inside the nerve. In these cases, microsurgical release of scar tissue in the nerve is performed with magnifying glasses or microscope. The outer wrapping of the nerve is opened and the scar tissue within the nerve is freed. Care is taken to limit any injury to the small connections between the nerve fibers.

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For more information about tunnel syndromes see:

• Carpal tunnel syndrome
• Tarsal tunnel syndrome
• Cubital tunnel syndrome