[The influence of thoracic kyphosis on sagittal balance of the lumbosacral spine in thoracic idiopathic scoliosis patients].
OBJECTIVE
To evaluate the influence of thoracic kyphosis to sagittal alignment and balance of the lumbosacral vertebrae in thoracic adolescent idiopathic scoliosis patients.


METHODS
Standing posteroanterior and lateral x-rays of a cohort of 55 patients with thoracic adolescent idiopathic scoliosis were obtained. The patients were classified according to their thoracic kyphosis, the first group TK < 10 degrees and the second group 10 degrees < or = TK < or = 40 degrees . The following parameters were measured: lumbar lordosis (LL), upper and lower arc of lumbar lordosis, sagittal vertical axis, sacral slope (SS), pelvic incidence (PI), pelvic tilt (PT). Sagittal plane parameters were analyzed using t-test between two groups, with significance set at P < 0.05. Linear correlations between parameters were calculated using Pearson correlation coefficients, with significance set at P < 0.01.


RESULTS
There were smaller LL and upper arc of lumbar lordosis in the first group. Significant linear correlations were found between each single adjacent shape parameter. Significant correlations were also found between TK, LL and upper arc of lumbar lordosis, as well as between PT, SS and PI.


CONCLUSIONS
Sagittal alignment and balance of the lumbosacral vertebrae may influence the thoracic kyphosis in AIS patients. The mechanism of this influence may through the adaptation of upper arc of lumbar lordosis. This influence must be considered in thoracic adolescent idiopathic scoliosis patients who undergo selective posterior thoracic fusion.
Qiu
Yong
Y
Department of Orthopaedics, the Affiliated Drum Tower Hospital of Medical School, Nanjing University, Nanjing 210008, China. scoliosis2002@sina.com
Yin
Gang
G
Cao
Xing-Bing
XB
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000150:complications / Q000473:pathology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D011859:Radiography; D012447:Sacrum / Q000000981:diagnostic imaging / Q000473:pathology*; D012600:Scoliosis / Q000150:complications / Q000473:pathology*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*