Ulnar Nerve Transposition

About Ulnar Nerve Transposition

Ulnar nerve transposition is an operation for cubital tunnel syndrome, compression of the ulnar nerve at the elbow, which is the second most common nerve entrapment in the upper limb after carpal tunnel syndrome. At the elbow the nerve runs in a groove behind the medial epicondyle, the funny bone, where it is vulnerable to pressure and to stretching when the elbow is bent. Symptoms include numbness and tingling in the ring and little fingers and, in more advanced cases, weakness and wasting of the small muscles of the hand. Surgery is considered when symptoms persist despite activity modification and night splinting, or when there is muscle weakness. Options include simple decompression in situ, which releases the tissues compressing the nerve without moving it; medial epicondylectomy, which removes part of the bony prominence; and anterior transposition, which moves the nerve in front of the elbow so that it is no longer stretched during flexion. Transposition may place the nerve under the skin, within the muscle or beneath the flexor pronator muscle mass. Randomized trials have found simple decompression and transposition to give broadly similar results in typical cases, and simple decompression has fewer complications, so transposition is often reserved for nerves that slip over the epicondyle or for revision surgery. Endoscopic decompression is an alternative at some centers. Sensory symptoms often improve, while recovery of muscle strength is slower and may be incomplete when wasting has been long standing.