title: Selective thoracic fusion in Lenke 1C curves: prevalence and criteria.
abstract: METHODS
  Multicenter retrospective analysis of prospectively collected data.
  
  
  OBJECTIVE
  Evaluate radiographical and clinical characteristics of patients undergoing a selective thoracic fusion (STF) for Lenke 1C curves.
  
  
  BACKGROUND
  STF of adolescent idiopathic scoliosis has been advocated for the so-called "false double major" curve (Lenke 1C/King type II). Despite these recommendations, many surgeons continue to perform nonselective fusions for this curve type. It is unknown to what extent other factors influence the surgeon's fusion-level selection.
  
  
  METHODS
  A prospective multicenter database included 264 patients with surgically treated Lenke 1C curves and were divided into 2 groups. The STF group included patients with the lowest instrumented vertebra at or cephalad to L1, whereas the nonselective fusion group included patients with the lowest instrumented vertebra at or caudal to L3. Preoperative radiographical, clinical (scoliometer), Scoliosis Appearance Questionnaire (SAQ), and Scoliosis Research Society (SRS) questionnaires were analyzed and compared.
  
  
  RESULTS
  Only 138 of 264 patients (49%) underwent an STF. Sex ratio (90% vs. 86% female), average age (14.7 vs. 14.8 yr), and preoperative main thoracic Cobb angles (56.0° ± 9.9° vs. 55.3° ± 11.4°) were not significantly different (STF vs. nonselective fusion). However, the average thoracolumbar/lumbar (TL/L) preoperative Cobb angle was significantly smaller in the STF group (42.1° ± 8.6° vs. 47.0° ± 9.0°; P < 0.001), whereas the main thoracic: TL/L Cobb ratio (1.35 ± 0.20 vs. 1.18 ± 0.15; P < 0.001), apical vertebral translation, and rotation (1.82 ± 0.59 vs. 1.31 ± 0.53; P < 0.001), (1.16 vs. 0.98; P < 0.001) ratios were significantly greater in the STF group. Preoperative coronal balance, sagittal Cobb angles (including T10-L2 kyphosis) and Risser Grade were not significantly different. Preoperative TL/L scoliometer measures were significantly less in the STF group (8.1° ± 3.7° vs. 10.3° ± 5.4°; P = 0.001). On the SAQ, the STF group had less desire for an appearance change.
  
  
  CONCLUSIONS
  Despite the recommendation to fuse only the structural thoracic curve in a 1C curve, only 49% of patients were treated with an STF. Those undergoing an STF had smaller TL/L Cobb angles, less TL/L clinical deformity, larger main thoracic: TL/L ratios, and less desire for an appearance change.
  
  
  METHODS
  3.
authors: Norton Leatherman Spine Center, Louisville, KY, USA.
authors: Charles H
authors: CH
authors: Crawford
authors: Lawrence G
authors: LG
authors: Lenke
authors: Daniel J
authors: DJ
authors: Sucato
authors: B Stephens
authors: BS
authors: Richards
authors: John B
authors: JB
authors: Emans
authors: Michael G
authors: MG
authors: Vitale
authors: Mark A
authors: MA
authors: Erickson
authors: James O
authors: JO
authors: Sanders
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012189:Retrospective Studies; D012600:Scoliosis / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D011795:Surveys and Questionnaires; D013904:Thoracic Vertebrae / Q000601:surgery*; D016896:Treatment Outcome