title: A biomechanical comparison of a novel thoracic screw fixation method: transarticular screw fixation vs traditional pedicle screw fixation.
abstract: BACKGROUND
  Transarticular screw fixation is used in the upper cervical and lumbar spine to achieve posterior spinal stability, and its biomechanical performance has been proven to be similar to that of pedicle screw fixation. However, few studies have reported the use of transarticular screw fixation in the upper thoracic spine.
  
  
  OBJECTIVE
  To biomechanically compare transarticular screws with pedicle screws in short-term cyclic loading in the upper thoracic spine.
  
  
  METHODS
  Eight fresh human cadaveric spine specimens (T1-T3) were harvested and tested for 6 cycles in flexion, extension, lateral bending, and torsion in their intact condition. Each specimen was then destabilized and restabilized with 3 fixation methods: the pedicle screw/rod construct, the transarticular screw/rod construct, and transarticular screws alone. The instrumented specimens were reteted with the same protocol.
  
  
  RESULTS
  All fixation systems reduced the range of motion significantly with respect to flexion, extension, lateral bending, and axial rotation (P < .01). However, no significant difference was observed between the 3 instrumented groups.
  
  
  CONCLUSIONS
  This biomechanical study demonstrates in vitro that transarticular screws and pedicle screws have statistically similar biomechanical stability in a noncorpectomy model. Posterior transarticular screws may be an alternative for internal fixation in the upper thoracic spine.
authors: Department of Orthopedics, Changzheng Hospital, the Second Military Medical University, Shanghai, PR China.
authors: Yang
authors: Y
authors: Yu
authors: Ning
authors: N
authors: Xie
authors: Shaohua
authors: S
authors: Song
authors: Wei
authors: W
authors: Zhang
authors: Qunfeng
authors: Q
authors: Guo
authors: Bin
authors: B
authors: Ni
authors: Junsheng
authors: J
authors: Luo
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001863:Bone Screws; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D013123:Spinal Fusion / Q000295:instrumentation*; D013904:Thoracic Vertebrae / Q000601:surgery*