Submuscular transposition of the ulnar nerve.

Anterior submuscular transposition by the Learmonth technique is more demanding technically than other procedures described to treat cubital tunnel syndrome. I generally reserve submuscular transposition for patients who have failed previous anterior subcutaneous transposition and those who are very thin, in which case the nerve may be prominent immediately beneath the skin, resulting in an area of uncomfortable sensitivity. In patients who are candidates for reoperation following failed anterior submuscular transposition, it is common to find an area of compression that was not released during the initial operation. Most importantly, failure to release the arcade of Struthers, the arcuate ligament, and the flexor carpi ulnaris muscle fascia; excise the medial intermuscular septum; or provide ample room for the ulnar nerve beneath the flexor-pronator muscles will result in failure of surgical treatment. Range-of-motion exercises and hand strengthening facilitate early return of function.