by Carl Butterfield, M.D., assistant to Dr. Reid
Introduction:
Cubital tunnel syndrome is due to ulnar nerve entrapment at the elbow. The cubital tunnel is found on the inside of the elbow and is made up of fibrous and bony elements. The volume of the tunnel decreases with flexion of the elbow, and diminishes even further with associated wrist flexion. The ulnar nerve may be injured by compression within the narrow cubital tunnel or at its entrance to the tunnel by the sharp fibrous edge of the overlying muscle. This syndrome is the second most common entrapment neuropathy (after carpal tunnel syndrome) and is more frequent in men than women.
Symptoms:
The symptoms are usually gradual in onset with the most common complaint being hand clumsiness and weakness. Pain may also be present, but the difficulty with hand control is more often seen. Very often this syndrome is associated with difficulty doing fine hand and/or finger movements. Sensory examination may reveal loss of light touch, or in milder cases, decrease in two-point discrimination.
Diagnosis:
Cubital tunnel syndrome is diagnosed with a combination of history and physical examination and nerve conduction velocities of the ulnar nerve. Decreased nerve conduction across the compression site (at the elbow) is usually noted. Other diseases that may mimic cubital tunnel syndrome include: Tumor, syrinx, amyotrophic lateral sclerosis, tumors of the lower brachial plexus, diabetes mellitus, or alcoholism.
Treatment:
Patients with only minor symptoms or who have no neurological deficits, should only be treated with conservative measures. These include the treatment of any underlying causes with the elimination of any activities that may be exacerbating the ulnar nerve compression, such as resting the elbow on hard surfaces and repetitive extreme flexion of the elbow. Patients who do not respond to a conservative treatment plan or who present with atrophy, potential permanent nerve damage due to compression, and/or muscular weakness, should be treated surgically. There are five commonly used surgical treatments for the treatment of cubital tunnel syndrome. They include: (1) simple decompression by opening the cubital tunnel. (2) Anterior subcutaneous transposition, (3) intramuscular transposition, (4) submuscular transposition of the ulnar nerve, and (5) medial epicondylectomy.
(1) Simple Decompression of the Cubital Tunnel: This procedure is performed through a 10-cm curvilinear incision (like a flattened "W") centered over the medial aspect of the elbow. And finally, the facial roof of the cubital tunnel is opened.
(2) Anterior Subcutaneous Transposition of the Ulnar Nerve: This procedure is begun in the same way as the simple decompression. In this case, the nerve must be mobilized not only at the level of the cubital tunnel, but also more distally at the deep aponeurosis of the flexor carpi ulnaris muscle and more proximally at the level of the medial intramuscular septum. A subcutaneous sling or facial flap is created around the nerve to prevent it from returning to it's previous position.
(3) Intramuscular Transposition of the Ulnar Nerve: This procedure involves the creation of a groove or trough within the proximal flexor-pronator muscle group for the placement of the transposed nerve. The facia overlying the muscle is then closed over the nerve to prevent relocation to its prior position.
(4) Submuscular Transposition of the Ulnar Nerve: A submuscular transposition involves a complete detachment of the flexor-pronator common tendon origin at the medial epicondyle of the humerus bone. The ulnar nerve is then moved over adjacent to the median nerve, then, the flexor-pronator common tendon is placed over the transposed nerve and sutured to it's epicondyle attachment. A "step-cut" technique of the tendon is performed to allow lengthening of the tendon to prevent compression of the nerve at it's new location.
(5) Medial Epicondylectomy: This technique involves simple nerve decompression and mobilization followed by a subperiosteal resection of the medial epicondyle. Then, the periosteum is closed.
Risks involved with surgical treatments for cubital tunnel syndrome:
Any time a surgical treatment is used, there will always be certain risks that have to be known and considered against the desired benefits. Though they may be very infrequent, they need to be known by the patient so as to permit the making of the most accurate decision about going through with surgery. The risks are as follows: infection, bleeding, loss of life, paralysis, weakness, numbness, nonrelief, recurrence, pain, poor wound healing, or other serious complications.
Benefits from Surgical Treatment for Cubital Tunnel Syndrome:
The benefits are related to the indications for surgery, and include: (1) Decompression of the ulnar nerve to prevent permanent or additional damage to the nerve, (2) To relieve problematic symptoms, and (3) to improve strength and sensation in the affected arm/hand.
Recommendations Following Surgical Treatment for Cubital Tunnel Syndrome:
Immediately after the surgery, the patient is advised to keep the arm above the level of the heart so as to minimize the chances of post-operative bleeding. During the week, or so, after surgery, the incision should be kept clean and dry to prevent infection or opening of the wound. If the bandage should become soiled or wet, it should be removed and replaced with a clean, dry one. Please note that if during the time before the surgical wound heals, the patient should develop a fever, or if the wound should become red, inflamed, start to drain, or if there are any questions, the treating physicians office should be contacted promptly.
Pain Management After Surgery:
During the time of hospitalization, (usually one day) the patient will be provided with either injectable or oral pain medication. As soon as the pain can be controlled with oral medication, the patient should transition to it, because that is how pain will be controlled when the patient goes home. Because most pain medication has the potential to loose its efficacy, or become habit forming, if used in excess, it is suggested that these medications only be used as needed and only as prescribed.
Return to Patient Educational Materials Page