title: Comparison of outcomes after atlantoaxial fusion with transarticular screws and screw-rod constructs.
abstract: OBJECTIVE
  The purpose of this study was to compare the radiological and neurological outcomes between two atlantoaxial fusion method for atlantoaxial stabilization; C1 lateral mass-C2 pedicle screws (screw-rod constructs, SRC) versus C1-2 transarticular screws (TAS).
  
  
  METHODS
  Forty-one patients in whom atlantoaxial instability was treated with atlantoaxial fixation by SRC group (27 patients, from March 2005 to May 2011) or TAS group (14 patients, from May 2000 to December 2005) were retrospectively reviewed. Numeric rating scale (NRS) for pain assessment, Oswestry disability index (ODI), and Frankel grade were also checked for neurological outcome. In radiologic outcome assessment, proper screw position and fusion rate were checked. Perioperative parameters such as blood loss during operation, operation time, and radiation exposure time were also reviewed.
  
  
  RESULTS
  The improvement of NRS and ODI were not different between both groups significantly. Good to excellent response in Frankel grade is shown similarly in both groups. Proper screw position and fusion rate were also observed similarly between two groups. Total bleeding amount during operation is lesser in SRC group than TAS group, but not significantly (p=0.06). Operation time and X-ray exposure time were shorter in SRC group than in TAS group (all p<0.001).
  
  
  CONCLUSIONS
  Both TAS and SRC could be selected as safe and effective treatment options for C1-2 instability. But the perioperative result, which is technical demanding and X-ray exposure might be expected better in SRC group compared to TAS group.
authors.affiliation: Department of Neurosurgery, Korean Armed Forces Busan Hospital, Busan, Korea.
authors.forename: Ji Yong
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Spine and Joint Research Institute, Guro Teun Teun Hospital, Seoul, Korea.
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Oh
authors.affiliation: Department of Neurosurgery, Inha University College of Medicine, Incheon, Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Yoon
authors.affiliation: Department of Neurosurgery, Inha University College of Medicine, Incheon, Korea.
authors.forename: Hyeong-Chun
authors.initials: HC
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Inha University College of Medicine, Incheon, Korea.
authors.forename: Hyun Sung
authors.initials: HS
authors.lastname: Seo
keywords: Atlantoaxial fixation; C-1 lateral mass screw; C-2 pedicle screw; Complications; Fusion; Transarticular screw