title: All-pedicle screw versus hybrid instrumentation in adolescent idiopathic scoliosis surgery: a comparative radiographical study with a minimum 2-Year follow-up.
abstract: METHODS
  Comparative analysis of 2 groups of patients who underwent surgical treatment of adolescent idiopathic scoliosis (AIS).
  
  
  OBJECTIVE
  To compare a segmental pedicle screw only system with a hybrid system for the treatment of Lenke type 1 AIS curves.
  
  
  BACKGROUND
  Although previous AIS studies have tried to compare various constructs with the all-pedicle screw fixation, all have failed to address important confounding variables, such as skeletal maturity, preoperative flexibility of the curve, and factors associated with a multicenter or multisurgeon analysis.
  
  
  METHODS
  The medical records and spinal radiographs of patients with AIS treated surgically by a single surgeon between 2000 and 2009 were retrospectively reviewed. Patients with Lenke type 1 curves and minimum follow-up of 2 years were divided into 2 groups that were meticulously matched: group 1 consisted of patients in whom the all-pedicle screw construct was used, whereas group 2 included patients who were treated with the hybrid hook-screw system.
  
  
  RESULTS
  Group 1 included 34 patients and group 2 included 29 patients. At the last follow-up, thoracic curve correction averaged 70.4% for the all-pedicle screw group and 60% for the hybrid group (P = 0.19). The all-pedicle screw group showed a significantly greater increase in thoracic kyphosis than the hybrid group system (P = 0.04). Global sagittal balance showed greater improvement in the all-pedicle screw group during the immediate postoperative that was lost by the last follow-up. The all-pedicle screw system revealed less intraoperative blood loss but greater operating time than the hybrid construct. After controlling for length of follow-up, no statistical difference in any of the radiographical parameters measured was recorded.
  
  
  CONCLUSIONS
  With the exception of global sagittal balance, the pedicle screw system provided better maintenance of its corrective parameters when followed for greater than two years.
  
  
  METHODS
  3.
authors: Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
authors: Alvin H
authors: AH
authors: Crawford
authors: Marios G
authors: MG
authors: Lykissas
authors: Xu
authors: X
authors: Gao
authors: Emily
authors: E
authors: Eismann
authors: Jennifer
authors: J
authors: Anadio
mesh_terms: D000293:Adolescent; D001863:Bone Screws; D016009:Chi-Square Distribution; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D019637:Orthopedic Procedures / Q000295:instrumentation* / Q000379:methods; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome