Does thoracic hypokyphosis matter in lenke type 1 adolescent idiopathic scoliosis?

Steven D. Glassman, Daniel J. Sucato, Leah Y. Carreon, James O. Sanders, Michael G. Vitale, Lawrence G. Lenke

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Study Design: We analyzed a prospective cohort of Lenke 1ABC adolescent idiopathic scoliosis (AIS) patients based on differences in T5eT12 sagittal alignment. Objective: Our objective was to determine whether patients with hypokyphotic scoliosis demonstrate unique characteristics in terms of baseline health status and response to surgery. Background Summary: Right thoracic AIS often presents as a hypokyphotic scoliosis, with rotatory deformity resulting in a diminution of the normal thoracic kyphosis. The perceived importance is indicated by the inclusion of a sagittal plane modifier within Lenke's classification system for AIS and studies examining reduction strategies to restore thoracic kyphosis. Methods: We grouped patients based on thoracic kyphosis, measured from T5 to T12, as either less than 10° (hypokyphotic) or greater than or equal to 10° (normal/kyphotic). We used Student t test for independent samples to compare continuous variables between the hypokyphotic and normal/kyphotic groups. Results: There was a significant difference in age between groups (mean age, 14.9 years in the hypokyphotic group versus 13.4 years in the normal/kyphotic group; p = .007). Differences in baseline health status measures were statistically significant but small. Hypokyphotic patients reported less pain than normal/kyphotic patients, with a mean Scoliosis Research Society (SRS) Pain score of 4.15 versus 4.03 (p = .044), better SRS Mental Domain scores (4.06 vs. 3.92; p = .026), and better SRS Total scores (3.92 vs. 3.83, p = .027). The hypokyphotic group also had better SRS Appearance (3.36 vs. 3.30) and Activity scores (4.20 vs. 4.13), but these differences did not reach statistical significance. Conclusions: There were no differences in baseline or 2-year postoperative outcome scores in Lenke 1 AIS patients with hypokyphosis compared with patients with normal sagittal alignment. Maintenance of or restoration to normal kyphosis in hypokyphotic patients with Lenke 1 AIS may not improve clinical outcome compared with patients who remain lordotic after surgical correction.

Original languageEnglish (US)
Pages (from-to)40-45
Number of pages6
JournalSpine Deformity
Issue number1
StatePublished - Jan 2013


  • Adolescent idiopathic scoliosis
  • Health status
  • SRS-22
  • Sagittal alignment
  • Thoracic hypokyphosis
  • Thoracic lordosis

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine


Dive into the research topics of 'Does thoracic hypokyphosis matter in lenke type 1 adolescent idiopathic scoliosis?'. Together they form a unique fingerprint.

Cite this