Ulnar Nerve Transposition
This outpatient procedure, performed under general or regional anesthesia, repositions the ulnar nerve to prevent it from sliding against or becoming pinched by the medial epicondyle (the bony bump on the inner side of the elbow). Ulnar nerve transposition is used to treat cubital tunnel syndrome.
The ulnar nerve branches off from a group of nerves known as the brachial plexus. The ulnar nerve runs through the inner arm to the back of a bony protrusion on the inner part of the elbow, known as the medial epicondyle, before extending down into the hand. This nerve is primarily responsible for providing the muscles of the forearms and hands with sensation.
When the ulnar nerve becomes compressed or irritated, pain and numbness may occur in the elbow, wrist or hand. Ulnar nerve transposition is a surgical procedure performed to relocate the ulnar nerve from its position behind the medial epicondyle to a location at the front of the elbow where it will no longer be pinched or compressed.
Causes of Ulnar Nerve Compression
Compression of the ulnar nerve may be caused by a variety of factors that generally involve placing extensive pressure on the area where the ulnar nerve is located. This compression may be caused by leaning the elbow on a hard surface, such as a desk, for hours at a time, or fracturing the medial epicondyle. Patients with certain inflammatory joint conditions, such as rheumatoid arthritis or cubital tunnel syndrome, are also at risk for developing ulnar nerve compression. The condition commonly occurs in individuals who perform certain repetitive motions that involve a frequent bending of the elbow as well.
Candidates for Ulnar Nerve Transposition
Whenever the ulnar nerve is compressed or irritated, its function becomes limited. Some patients suffer from weakness in the muscles that are attached to the ulnar nerve, while others may experience a tingling or numbness that radiates into the fingers. More severe cases of ulnar nerve compression are usually characterized by difficulties with finger coordination, which may lead to difficulty with everyday tasks such as typing on a computer.
If conservative treatment methods such as the use of anti-inflammatory medication or wearing a splint or brace are not effective or the symptoms of ulnar nerve compression last for more than 6 weeks, surgery may be necessary to reposition the ulnar nerve.
The Ulnar Nerve Transposition Procedure
Ulnar nerve transposition is an outpatient procedure that is performed under either general or regional anesthesia. The main purpose of the surgery is to reposition the ulnar nerve, relieving it from compression or damage.
To begin the procedure, an incision will be made along the inner area of the elbow. This provides the surgeon with access to the ulnar nerve and medial epicondyle. The ulnar nerve is relocated from behind the medial epicondyle to a new position toward the front of the elbow. The new location of the ulnar nerve may be directly under the skin, within a muscle or just beneath a muscle.
Risks of Ulnar Nerve Transposition
Ulnar nerve transposition is a very common procedure that is generally considered to be safe and effective. There is little risk of post-surgical infection, which can be treated with antibiotics should it occur. Wound tenderness may occur in some patients, but that usually resolves on its own within a few months of surgery. Nerve damage, which causes hand weakness or numbness, is a possible complication of the surgery, but it is rare.
Recovery from Ulnar Nerve Transposition
After an ulnar nerve transposition, a splint or cast will be worn around the elbow to help it maintain a bent position. If the ulnar nerve has been placed within a muscle, the elbow will be bent at a 90-degree angle. If the ulnar nerve has instead been placed directly under the skin, the elbow will be bent at a 45-degree angle. Keeping the elbow at these positions enables the incision to heal properly and allows the ulnar nerve to become secure in its new location. The position will be maintained for approximately 2 to 4 weeks.
Once the cast or splint has been removed, patients usually begin a physical therapy program. This regimen will focus on restoring the patient's full range of motion in the elbow joint through muscle stretching and toning exercises. In most cases, a full recovery following ulnar nerve transposition will take 3 to 6 months. However, a number of factors may influence the length of a patient’s recovery period, including overall health prior to surgery, the severity of the condition and how well the patient responds to physical therapy.