Wide Decompression May Render the Ulnar Nerve Unstable: A Cadaveric Study.

The purpose of this study was to evaluate for ulnar nerve instability following incrementally widened in situ decompression. A standard release of the ulnar nerve was performed in 16 cadaveric elbows, extending from 7cm distal to the medial epicondyle, and then released proximally for a total of 10 cm in 2-cm increments. Eight of the 16 elbows (50%) displayed subluxation of the ulnar nerve following complete in situ decompression. The rate of subluxation was found to increase with increasing length of proximal decompression. The greatest increase in rate of subluxation was seen beyond 4 cm proximal to the medial epicondyle. Cubital tunnel release should be limited to decompression of only the cubital tunnel if clinical and electrodiagnostic studies indicate that the cubital tunnel is the source of compression.