Ulnar nerve decompression by transposing the nerve and Z-lengthening the flexor-pronator mass: clinical outcome.

Controversy surrounds the reliability of methods of treating ulnar nerve compression at the elbow. The effectiveness of submuscular anterior nerve transposition was evaluated in 33 limbs of 31 patients. The flexor-pronator Z-lengthening technique, without internal neurolysis, was used. Results were determined by patient chart reviews. Severity of preoperative nerve compression was measured using Dellon's classification. Of the 33 limbs, 6 had mild preoperative nerve compression; 7, moderate; and 20, severe. Overall outcome was evaluated using a modification of the Bishop rating system. At a mean follow-up period of 49 months, 12 limbs (36%) had excellent results, 20 limbs (61%) had good results, and 1 limb (3%) had a poor result. These findings indicate that submuscular ulnar nerve transposition using the flexor-pronator Z-lengthening technique without internal neurolysis is a reliable method of treating ulnar nerve compression at the elbow.