title: Technique for drilling instrument monitoring electrical conductivity in pediatric cervical spine screw insertion: a preliminary report.
abstract: BACKGROUND
  To detail a technique of assisted screw placement in pediatric patients with cervical spine disorders. The use of a recently produced wireless electronic freehand drilling instrument is documented.
  
  
  METHODS
  We performed fixation of the cervical spine using different screws in 5 consecutive patients with various cervical spine disorders (posttraumatic, neoplastic or metabolic). Clinical and radiologic features of all cases are reported. The surgical technique is described.
  
  
  RESULTS
  Twenty-six cervical screws (lateral mass, pars, and/or laminar) were placed with the use of the same pedicle screw pilot hole preparation device, and by the same surgical team. The average age of this patient group was 13.4 years (range: 6 to 16 y). Average follow-up was 10 months (range: 5 to 14 mo). All screws were inserted after the correct trajectory was identified. No breaches were detected. No screw failure was encountered. However, 8 of 26 (30.8%) screws were, on average, 1.3 mm longer that expected (range: 0.5 to 2.4 mm). None of the patients developed neurologic or vascular complications as a result of screw placement.
  
  
  CONCLUSIONS
  Cervical screws placement, although safe, is not free of complications: neurovascular injuries, dural tears, and paraplegia have been described. The use of a wireless electronic handheld pedicle screw pilot hole preparation instrument is a useful tool in the armamentarium of the spinal surgeon dealing with patients with complex spinal deformities or difficult anatomy. Our experience outlines the applicability of this technique at different cervical levels. However, this device is not satisfactory in predicting the length of the screws. The device should be modified or a preoperative computed tomography scan should be used to estimate safe the length of the screws.
  
  
  METHODS
  Level IV (case series).
authors.affiliation: Department of Orthopedic Surgery , The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Zeller
authors.forename: Federico
authors.initials: F
authors.lastname: Canavese
authors.forename: Abahaya V
authors.initials: AV
authors.lastname: Kulkarni
authors.forename: James
authors.initials: J
authors.lastname: Drake
mesh_terms: D000293:Adolescent; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000601:surgery*; D002648:Child; D004553:Electric Conductivity; D005260:Female; D006801:Humans; D008297:Male; D019637:Orthopedic Procedures / Q000295:instrumentation*; D013122:Spinal Diseases / Q000601:surgery*; D013523:Surgical Equipment; D016896:Treatment Outcome