title: Factors Influencing Outcomes after Ulnar Nerve Stability-Based Surgery for Cubital Tunnel Syndrome: A Prospective Cohort Study.
abstract: OBJECTIVE
  Simple decompression of the ulnar nerve has outcomes similar to anterior transposition for cubital tunnel syndrome; however, there is no consensus on the proper technique for patients with an unstable ulnar nerve. We hypothesized that 1) simple decompression or anterior ulnar nerve transposition, depending on nerve stability, would be effective for cubital tunnel syndrome and that 2) there would be determining factors of the clinical outcome at two years.
  
  
  METHODS
  Forty-one patients with cubital tunnel syndrome underwent simple decompression (n=30) or anterior transposition (n=11) according to an assessment of intra-operative ulnar nerve stability. Clinical outcome was assessed using grip and pinch strength, two-point discrimination, the mean of the disabilities of arm, shoulder, and hand (DASH) survey, and the modified Bishop Scale.
  
  
  RESULTS
  Preoperatively, two patients were rated as mild, another 20 as moderate, and the remaining 19 as severe according to the Dellon Scale. At 2 years after operation, mean grip/pinch strength increased significantly from 19.4/3.2 kg to 31.1/4.1 kg, respectively. Two-point discrimination improved from 6.0 mm to 3.2 mm. The DASH score improved from 31.0 to 14.5. All but one patient scored good or excellent according to the modified Bishop Scale. Correlations were found between the DASH score at two years and age, pre-operative grip strength, and two-point discrimination.
  
  
  CONCLUSIONS
  An ulnar nerve stability-based approach to surgery selection for cubital tunnel syndrome was effective based on 2-year follow-up data. Older age, worse preoperative grip strength, and worse two-point discrimination were associated with worse outcomes at 2 years.
authors: Department of Orthopedic Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Ho Jung
authors: HJ
authors: Kang
authors: Department of Orthopedic Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Won Taek
authors: WT
authors: Oh
authors: Department of Orthopedic Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Il Hyun
authors: IH
authors: Koh
authors: Department of Orthopedic Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Sungmin
authors: S
authors: Kim
authors: Department of Orthopedic Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. yrchoi@yuhs.ac.
authors: Yun Rak
authors: YR
authors: Choi
mesh_terms: D000328:Adult; D020430:Cubital Tunnel Syndrome / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006225:Hand / Q000601:surgery; D018737:Hand Strength; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D011446:Prospective Studies; D020127:Recovery of Function; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014459:Ulnar Nerve / Q000503:physiopathology / Q000601:surgery*; D055815:Young Adult
keywords: Cubital tunnel syndrome; anterior transposition; prognostic factor; simple decompression; ulnar nerve stability-based surgery