The anatomy of ulnar nerve branches in anterior transposition.

Cubital tunnel syndrome is the second most common nerve entrapment neuropathy. When non-operative treatments fail, surgical intervention is indicated. Although there remains no consensus between simple decompression and anterior transposition, there is a growing recognition of improved clinical outcomes in the latter. Few details of ulnar nerve branches around the elbow are available however and their sacrifice may be necessary to facilitate anterior transposition. Therefore, ten cadaveric upper extremities were dissected to delineate the course and branching pattern of the ulnar nerve around the elbow joint; anterior transposition was also performed in the cadaveric specimens. Digital photographs of the dissection study were analyzed using the Image J package. Results show that distal ulnar nerve branches are distributed more laterally towards the olecranon and may potentially restrict transposition more than has been recognized; proximal branches may also overlap incision lines of such transposition procedures.