Definition
Compression of the ulnar nerve near the elbow that causes numbness and tingling in the ring and small finger. Tenderness near the "funny bone" (inner elbow) and the occasional electrical shock down the forearm into the small finger can occur. More advanced cases cause hand weakness and atrophy of the hand muscles. Symptoms are often worse during the night or when repetitively flexing the elbow. The nerve is irritated where it is vulnerable behind the elbow, or between the forearm muscles just below the elbow. In most patients, the reason for this type of compression remains uncertain.
Diagnosis
Diagnosis is made by a history and physical examination by your physician. It is then confirmed with electrical studies done in the office. Rarely, ulnar nerve compression at the elbow may be confused with nerve compression in the neck. Therefore it is important to be evaluated by a specialist in neurological disorders. MRI is usually not required.
Treatment Options
Avoidance of repetitive strain and wearing an elbow splint at night are both initially prescribed. It is also very important to avoid pressure on the ulnar nerve at the elbow-sometimes an elbow pad is recommended. Steroid injections near the ulnar nerve at the elbow help some patients, but recurrences are common. If the above options have not helped, then surgical release of the carpal tunnel may be indicated. Surgery should be strongly considered if symptoms are present throughout the day, or if hand weakness is present.
Surgery
There are multiple surgical options (from the simplest to most complex):
- Simple decompression: a small 1.5-inch incision is used and all points of nerve compression are released. The nerve is not manipulated or moved somewhere else. This procedure takes about 30 minutes and is performed under sedation with the elbow numbed with lidocaine. Recent studies have shown that this procedure is optimal for most patients.
- Simple decompression with epicondylectomy: The nerve is once again released from any points of compression, but a portion of the "funny bone" (medial epicondyle) is also removed. Some perform this procedure if the ulnar nerve "dislocates" from its normal position with flexion of the arm. Although this "dislocation" may be evident before surgery, it often needs to be confirmed at surgery.
- Subcutaneous transposition: A longer 3-4 inch incision is used and the ulnar nerve is released from compression and then moved under the skin to the front of the elbow. Although commonly performed, this procedure may leave the nerve vulnerable to external trauma, especially in thin patients.
- Submuscular transposition: An approximate 4-6 inch incision under general anesthesia is used to expose the ulnar nerve as well as the muscles near the elbow. The muscles are cut and the ulnar nerve is placed below them. The muscles are then re-attached. Although this is considered the most definitive procedure available, one must remember that a simple decompression may be as effective in most patients. Submuscular transposition is commonly used in patients who failed a previous, simpler decompression. Some immobilization and a longer recovery is required.
For all surgeries, the skin is closed with sutures that absorb under the skin. Therefore, suture removal is not required. The type of surgery recommended depends on each individual; sometimes multiple options are available.
Simple decompression of the ulnar nerve at the elbow.
Complications
Ulnar nerve decompression at the elbow is both safe and effective. Therefore, it is commonly performed. Risks include about a 1% chance of infection, which may be treated with antibiotics or even re-operation. For the more complex surgeries listed above, the risk of infection is slightly higher. A patch of numbness near the elbow occurs in some patients following this procedure, which is secondary to cutting small nerves in the skin to make the incision. Fortunately, it resolves in most patients over many months. Nevertheless, it can be permanent and bothersome in a small percentage of people. With the smaller incision used for a simple decompression, the chance of this numbness is minimized. Wound tenderness can be problematic in a small percentage of patients, but this often resolves in a few months after surgery. In advanced cases of ulnar nerve compression at the elbow, the surgery may only partially improve the patient's symptoms; this is because permanent nerve damage may have already occurred before surgery. A final risk of surgery is nerve damage that may cause hand weakness or numbness-this is quite rare, occurring much less than 1%.
Day of Surgery
Ulnar nerve release at the elbow is performed in day surgery. Since sedation or general anesthesia is used, you must not eat or drink after midnight the night before surgery. Your medications can be taken the morning of surgery with a sip of water. You arrive one hour before the procedure and meet the anesthesiologist and the surgeon once again. Although a simple decompression takes about 30 minutes, you will be in the operating room for about an hour for cleaning, positioning, and dressing the wound. After the procedure, you are observed in the recovery room for about one hour and then are allowed to leave with a friend or family member taking you home.
Discharge Instructions
For simple decompressions, an occlusive dressing is applied to your elbow, which should be kept in place for three days. You may shower. On the third day, the dressing is removed revealing small stickers covering the wound. These are left alone until you visit the surgeon a week after surgery. You may shower and these stickers can get wet. You are encouraged to use the operated arm for daily activity and some light work. Pain is usually minimal after a simple release, but the occasional Tylenol is often required. If you experience severe or progressive pain or bleeding, you should call the surgeon. Some spotting of the dressing with blood is normal. For submuscular transpositions, the wound is covered with a light ace bandage and the arm is placed in a sling for two weeks. You may shower, but for the first week a plastic bag should keep the dressing dry. The dressing is changed when you visit the surgeon a week after surgery.
Recovery
The operated arm should be only used for occasional light work during the first two weeks after surgery. This is so the wound heals well. For patients who only do light work in an office setting, they can return to work a few days after surgery. Following this initial two-week period, occupational/physical therapy is prescribed by the surgeon or physiatrist, which is performed on a progressive basis for about six weeks. Although you may visit the physical therapist three times per week in the beginning, once the exercises are learned they can often be performed at home. By eight weeks after surgery you should have no restrictions with use of the hand and arm. You will see the surgeon a second time 6-8 weeks after the procedure. Submuscular transposition has a longer recovery with most patients performing physical therapy for about 3 months.
