Effect of anterior versus posterior in situ decompression on ulnar nerve subluxation

We sought to determine the effect anterior versus posterior in situ decompression with 360° external neurolysis on ulnar nerve subluxation. Ten cadaveric specimens were used, with anterior release performed on 5 specimens and posterior release the other 5 specimens. Each specimen was released for 4 cm centered over the cubital tunnel followed by 12 cm, 20 cm, and 20 cm with 360° external neurolysis. After release, the elbow was brought through a range of motion from 0° to 140° of flexion. Compared with posterior release, anterior release demonstrated significantly more total subluxation of the ulnar nerve for all release types from 80° to 120° of flexion (P<.05). At 140° of flexion, the 4-cm release, the 12-cm release, and the 20-cm release with 360° external neurolysis also demonstrated significantly more total subluxation with anterior release (P<.05). Ulnar nerve subluxation was significantly lower with posterior release, compared with anterior release for limited and complete in situ decompression.