title: Anatomic comparison of transarticular screws with lateral mass screws in cervical vertebrae.
abstract: OBJECTIVE
  To compare the potential incidence of nerve root (ventral and dorsal ramus) injury caused by cervical transarticular screws and Roy-Camille lateral mass screws.
  
  
  METHODS
  Insertion techniques with Klekamp transarticular screws and Roy-Camille lateral mass screws were respectively performed in this study. Each technique involved four specimens and 40 screws, which were inserted from C(3) to C(7). And 20-mm-long screws were used to overpenetrate the ventral cortex. The anterolateral aspect of the cervical spine was carefully dissected to allow observation of the screw-ramus relationship.
  
  
  RESULTS
  The overall percentage of nerve invasion was significantly lower with Klekamp (45%) technique than with Roy-Camille (85%) technique (P less than 0.05). The largest percentage of nerve invasion for Klekamp transarticular screws was found at the dorsal ramus (25%), followed by the ventral ramus (15%) and the bifurcation of the ventral dorsal ramus (5%). The largest percentage of nerve invasion for Roy-Camille lateral mass screws was found at the ventral ramus (80%).
  
  
  CONCLUSIONS
  The potential risk of nerve root invasion is lower with Klekamp transarticular screws than with Roy-Camille lateral mass screws.
authors: Department of Orthopedics, Ningbo Sixth People's Hospital, Ningbo 315040, China. lgysimon@yahoo.com.cn
authors: Guan-yi
authors: GY
authors: Liu
authors: Rong-ming
authors: RM
authors: Xu
authors: Wei-hu
authors: WH
authors: Ma
authors: Yong-ping
authors: YP
authors: Ruan
authors: Shao-hua
authors: SH
authors: Sun
authors: Lei
authors: L
authors: Huang
mesh_terms: D000328:Adult; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000293:injuries*; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000601:surgery*