title: Posterior cervical fixation with a nitinol shape memory loop for primary surgical stabilization of atlantoaxial instability: a preliminary report.
abstract: OBJECTIVE
  To evaluate a new posterior atlantoaxial fixation technique using a nitinol shape memory loop as a simple method that avoids the risk of vertebral artery or nerve injury.
  
  
  METHODS
  We retrospectively evaluated 14 patients with atlantoaxial instability who had undergone posterior C1-2 fusion using a nitinol shape memory loop. The success of fusion was determined clinically and radiologically. We reviewed patients' neurologic outcomes, neck disability index (NDI), solid bone fusion on cervical spine films, changes in posterior atlantodental interval (PADI), and surgical complications.
  
  
  RESULTS
  Solid bone fusion was documented radiologically in all cases, and PADI increased after surgery (p<0.05). All patients remained neurologically intact and showed improvement in NDI score (p<0.05). There were no surgical complications such as neural tissue or vertebral artery injury or instrument failure in the follow-up period.
  
  
  CONCLUSIONS
  Posterior C1-2 fixation with a nitinol shape memory loop is a simple, less technically demanding method compared to the conventional technique and may avoid the instrument-related complications of posterior C1-2 screw and rod fixation. We introduce this technique as one of the treatment options for atlantoaxial instability.
authors.affiliation: Department of Neurosurgery, Research Institute of Clinical Medicine, Institute for Medical Sciences, Chonbuk National University Medical School and Hospital, Jeonju, Korea.
authors.forename: Duk-Gyu
authors.initials: DG
authors.lastname: Kim
authors.forename: Jong-Pil
authors.initials: JP
authors.lastname: Eun
authors.forename: Jung-Soo
authors.initials: JS
authors.lastname: Park