title: Maintenance of spontaneous lumbar curve correction following thoracic fusion of main thoracic curves in adolescent idiopathic scoliosis.
abstract: OBJECTIVE
  The aims of our study were to provide long-term information on the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic anterior correction and fusion (ASF) and to determine the impact of ASF on pulmonary function.
  
  
  METHODS
  A total of 41 patients (four males, 37 females) with main thoracic (MT) adolescent idiopathic scoliosis (AIS) treated with ASF were included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up period was 13.5 years (10 to 18).
  
  
  RESULTS
  For the TL/L curve, the mean curve flexibility evaluated with supine pre-operative bending radiographs was 78.6% (standard deviation 16.5%), with no significant loss of correction observed. On comparing patients with an increase of the TL/L curve increase (> 4º, n = 9, 22%) to those without, significant differences were observed in the correction rate of the MT curve at the final follow-up (p = 0.011), correction loss of the MT curve (p = 0.003) and the proportion of patients who had semi-rigid instrumentation (p = 0.003). Pre-operative percentage predicted forced vital capacity (%FVC) was 80%, dropping to 72% at final follow-up (p < 0.001). The Scoliosis Research Society questionnaire score was not significantly different between patients with and without a TL/L curve increase (p = 0.606). Spontaneous lumbar curve correction (SLCC) was maintained up to 18 years following selective ASF in most patients and demonstrated significant correlation with maintenance of MT curve correction.
  
  
  CONCLUSIONS
  Maintenance of MT curve correction using rigid instrumentation provided stable SLCC over time. An observed 8% decrease in %FVC indicates that ASF should be reserved for patients with no or only mild pulmonary impairment. Cite this article: Bone Joint J 2016;98-B:997-1002.
authors.affiliation: Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo, Hokkaido, 0608638, Japan.
authors.forename: H S
authors.initials: HS
authors.lastname: Sudo
authors.affiliation: Schoen-Clinic Vogtareuth, Krankenhausstr. 20, 83569 Vogtareuth, Germany.
authors.forename: M M
authors.initials: MM
authors.lastname: Mayer
authors.affiliation: Orthopaedic Hokushin Hospital, Kikusuimotomachi 3-3, Sapporo, Hokkaido 003-0823, Japan.
authors.forename: K K
authors.initials: KK
authors.lastname: Kaneda
authors.affiliation: St Franziskus Hospital, Schönsteinstr 63, 50825 Cologne, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Núñez-Pereira
authors.affiliation: Japan Community Health Care Organization Hokkaido Hospital, Nakanoshima 1-8, Sapporo, Hokkaido 062-8618, Japan.
authors.forename: S Y
authors.initials: SY
authors.lastname: Shono
authors.affiliation: Paracelsus Medical University Salzburg, Research Office, Strubergasse 21, A-5020 Salzburg, Austria.
authors.forename: W H
authors.initials: WH
authors.lastname: Hitzl
authors.affiliation: Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo, Hokkaido, 0608638, Japan.
authors.forename: N I
authors.initials: NI
authors.lastname: Iwasaki
authors.affiliation: Werner-Wicker-Clinic Bad Wildungen, Im Kreuzfeld 4, D-34537 Bad Wildungen, Germany.
authors.forename: H K
authors.initials: HK
authors.lastname: Koller
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008297:Male; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D014797:Vital Capacity; D055815:Young Adult
keywords: Adolescent idiopathic scoliosis; Anterior spinal fusion; Main thoracic curve; Spontaneous lumbar curve correction