title: Preoperative curves of greater magnitude (>70°) in adolescent idiopathic scoliosis are associated with increased surgical complexity, higher cost of surgical treatment and a delayed return to function.
abstract: BACKGROUND
  Surgical procedures to correct larger curve magnitudes >70° in patients with adolescent idiopathic scoliosis (AIS) are still common; despite their increased complexity, limited research has assessed the effect of preoperative curve severity on outcomes.
  
  
  OBJECTIVE
  This study aimed to examine the impact of preoperative curves >70° vs. those ≤70° on perioperative, functional and financial outcomes in patients with AIS undergoing posterior spinal fusion (PSF).
  
  
  METHODS
  Seventy seven eligible AIS patients who underwent PSF were prospectively followed-up, until return to preoperative function was reported. Preoperative curves >70° vs. ≤70° were analysed in relation to surgical duration, estimated blood loss, perioperative complications, length of hospitalisation, return to function and cost of surgical treatment per patient.
  
  
  RESULTS
  Severe preoperative curves >70°, identified in 21 patients (27.3 %), were associated with significantly longer surgical duration (median 6.5 vs. 5 h, p = 0.001) and increased blood loss (median 1250 vs. 1000 ml, p = 0.005)-these patients were 2.1 times more likely to receive a perioperative blood product transfusion (Relative Risk 2.1, CI 1.4-2.7, p = 0.004). Curves >70° were also associated with a significantly delayed return to school/college, and an increased cost of surgical treatment (€33,730 vs. €28,620, p < 0.0001).
  
  
  CONCLUSIONS
  Surgeons can expect a longer surgical duration, greater intraoperative blood loss and double the blood product transfusion risk when performing PSF procedures on AIS patients with curves greater than 70° vs. those ≤70°. Surgical correction for curves >70°, often as a result of lengthy surgical waiting lists, also incurs added expense and results in a partial delay in early functional recovery.
authors.affiliation: Department of Orthopaedic Surgery, Our Lady's Children's Hospital, Crumlin, Dublin, 12, Ireland. roslyn.tarrant@olchc.ie.|The National Children's Research Centre, Crumlin, Dublin, 12, Ireland. roslyn.tarrant@olchc.ie.
authors.forename: R C
authors.initials: RC
authors.lastname: Tarrant
authors.affiliation: Department of Orthopaedic Surgery, Our Lady's Children's Hospital, Crumlin, Dublin, 12, Ireland.
authors.forename: J M
authors.initials: JM
authors.lastname: Queally
authors.affiliation: Department of Orthopaedic Surgery, Our Lady's Children's Hospital, Crumlin, Dublin, 12, Ireland.
authors.forename: P F
authors.initials: PF
authors.lastname: O'Loughlin
authors.affiliation: Department of Anaesthetics, Our Lady's Children's Hospital, Crumlin, Dublin, 12, Ireland.|Blackrock Clinic, Blackrock, Co, Dublin, Ireland.
authors.forename: P
authors.initials: P
authors.lastname: Sheeran
authors.affiliation: Department of Orthopaedic Surgery, Our Lady's Children's Hospital, Crumlin, Dublin, 12, Ireland.|Blackrock Clinic, Blackrock, Co, Dublin, Ireland.
authors.forename: D P
authors.initials: DP
authors.lastname: Moore
authors.affiliation: Department of Orthopaedic Surgery, Our Lady's Children's Hospital, Crumlin, Dublin, 12, Ireland.|Blackrock Clinic, Blackrock, Co, Dublin, Ireland.
authors.forename: P J
authors.initials: PJ
authors.lastname: Kiely
mesh_terms: D000293:Adolescent; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
keywords: Adolescent idiopathic scoliosis; Cost of surgical treatment; Functional outcomes; Large deformity magnitude; Perioperative outcomes; Posterior spinal fusion; Surgical waiting times