title: Complications of pedicle screw fixation in scoliosis surgery: a systematic review.
abstract: METHODS
  Systematic review.
  
  
  OBJECTIVE
  To review the published literature on the use of pedicle screws in pediatric spinal deformity to quantify the risks and complications associated with pedicle screw instrumentation, particularly in the thoracic spine.
  
  
  BACKGROUND
  The use of pedicle screws in adolescent scoliosis surgery is common. Although many reports have been published regarding the use of pedicle screws in pediatric patients, there has been no systematic review on the risks of complications.
  
  
  METHODS
  PubMed, Ovid Medline, and Cochrane databases were searched for studies reporting the use of thoracic pedicle screws in pediatric deformity. We excluded articles dealing with neuromuscular scoliosis or bone dysplasia to focus mostly on adolescent thoracic idiopathic scoliosis and the likes. We then searched for cases reports dealing with thoracic pedicle screws complications.
  
  
  RESULTS
  This systematic review retrieved 21 studies with a total of 4570 pedicle screws in 1666 patients. The mean age of the patients was 17.6 years; 812 patients were women and 252 were men, and 5 studies did not identify sex. Overall, 518 (4.2%) screws were reported as malpositioned. However, in studies in which postoperative computed tomography scans were done systematically, the rate of screw malpositioning was as high as 15.7%. The reported percentage of patients with screw malpositioned is around 11%. Eleven patients underwent revision surgery for instrumentation malposition. Other complications reported include loss of curve correction, intraoperative pedicle fracture or loosening, dural laceration, deep infection, pseudarthrosis, and transient neurologic injury. There were no major vascular complications reported in these 21 studies. We could identify 9 case report articles dealing with complications of pedicle screws. Such complications were mostly either vascular (10 cases) or neurologic (4 cases), without any irreversible complications.
  
  
  CONCLUSIONS
  Malposition is the most commonly reported complication of thoracic pedicle screw placement, at a rate of 15.7% per screw inserted with postoperative computed tomography scans. The use of pedicle screws in the thoracic spine for the treatment of pediatric deformity has been reported to be safe despite the high rate of patients with malpositioned screws (11%). Major complications, such as neurologic or vascular injury, were almost never reported in this literature review of case series. Cases reports on the other hand have started to identify such complications.
authors.affiliation: Department of Orthopaedic Surgery, University of Virginia, Charlottesville, VA 22908, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Hicks
authors.forename: Amit
authors.initials: A
authors.lastname: Singla
authors.forename: Francis H
authors.initials: FH
authors.lastname: Shen
authors.forename: Vincent
authors.initials: V
authors.lastname: Arlet
mesh_terms: D000293:Adolescent; D001863:Bone Screws / Q000009:adverse effects*; D005260:Female; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects; D008297:Male; D011475:Prosthesis Failure; D012086:Reoperation; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation; D013904:Thoracic Vertebrae / Q000601:surgery*