title: Comparison of the effects of subcutaneous anterior transposition and in situ decompression on the histologic and electrophysiologic properties of the ulnar nerve: an experimental study in a rabbit model.
abstract: OBJECTIVE
  Although anterior transposition of the ulnar nerve is a commonly performed procedure for treatment of cubital tunnel syndrome, there are concerns that surgical mobilization puts blood supply to the nerve at risk. The purpose of this study was to compare the effects of subcutaneous anterior transposition (SAT) and in situ decompression (ISD) on the ulnar nerve's histologic and electrophysiologic properties in a rabbit model.
  
  
  METHODS
  We assigned 30 male, young adult New Zealand white rabbits to 1 of 3 groups (each group, n = 10). The extensive dissection-SAT group underwent complete neurolysis of the right ulnar nerve from brachial plexus to wrist and a subsequent SAT, the ISD group underwent ISD with 4-cm-long exposure of the ulnar nerve, and the SAT group underwent SAT with 4-cm-long circumferential neurolysis of the ulnar nerve. We killed the animals 7 days after the operation. We assessed electrophysiologic changes by finding the percentage of compound motor action potential of the surgical limb compared with the contralateral limb, and histologic changes by ischemic fiber degeneration.
  
  
  RESULTS
  The extensive dissection-SAT group showed a significantly lower percentage of compound motor action potential and higher grade of ischemic fiber degeneration than the ISD and SAT groups. On the other hand, the percentage of compound motor action potential and the grade of ischemic fiber degeneration were similar between the latter 2 groups without a statistically significant difference.
  
  
  CONCLUSIONS
  This study demonstrated that surgical mobilization of the ulnar nerve during SAT has an effect similar to ISD on the nerve's histologic and electrophysiologic properties at the 7th postoperative day in a rabbit model.
  
  
  CONCLUSIONS
  In a rabbit model, ISD and SAT appear to affect histologic and electrophysiologic findings of the ulnar nerve equally at postoperative day 7, which suggests that they would have the same relative safety in a clinical setting.
authors.affiliation: Department of Orthopedic Surgery and Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yoo Joon
authors.initials: YJ
authors.lastname: Sur
authors.forename: Jung Soo
authors.initials: JS
authors.lastname: Lee
authors.forename: Seok Whan
authors.initials: SW
authors.lastname: Song
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001707:Biopsy, Needle; D020430:Cubital Tunnel Syndrome / Q000175:diagnosis / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods*; D004195:Disease Models, Animal; D004576:Electromyography / Q000379:methods; D007150:Immunohistochemistry; D008297:Male; D016067:Nerve Transfer / Q000379:methods*; D009431:Neural Conduction / Q000502:physiology; D011817:Rabbits; D011897:Random Allocation; D020127:Recovery of Function; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D040521:Subcutaneous Tissue / Q000601:surgery; D014459:Ulnar Nerve / Q000473:pathology* / Q000601:surgery*