Scoliosis and chest cage deformity measures predicting impairments in pulmonary function: a cross-sectional study of 492 patients with scoliosis to improve the early identification of patients at risk

TY - JOUR

T1 - Scoliosis and chest cage deformity measures predicting impairments in pulmonary function: a cross-sectional study of 492 patients with scoliosis to improve the early identification of patients at risk

AU - Dreimann, Marc

AU - Hoffmann, Michael

AU - Kossow, Kai

AU - Hitzl, Wolfgang

AU - Meier, Oliver

AU - Koller, Heiko

PY - 2014/11/15

Y1 - 2014/11/15

N2 - STUDY DESIGN: This study examines the correlations between pulmonary function tests (PFTs) and radiographical measures of spinal deformities in patients with scoliosis.OBJECTIVE: To define the parameters that enable more accurate predictions of restricted pulmonary function (PF) in patients with scoliosis.SUMMARY OF BACKGROUND DATA: The early identification of patients with scoliosis who are at risk of developing severe curve progression and restricted PF is critical to improving patient care.METHODS: A total of 492 patients with a thoracic/thoracolumbar curve (TC) and preoperative PFTs as well as radiographical analysis of the TC and thoracic kyphosis (TK) were assessed. The forced vital capacity (FVC) was expressed as a percentage of the predicted value (FVC%). According to guidelines for the severity of pulmonary impairments, classifications were used: no impairment (FVC > 80%), mild (65 < FVC ≤ 80%), moderate (50 < FVC ≤ 65), and severe impairment (FVC ≤ 50%). Main radiographical parameters were included and statistical analyses were used to identify radiographical predictors and to develop prediction models.RESULTS: The average age was 17 years, 94% of the patients had adolescent idiopathic scoliosis, 20% had lordoscoliosis (TK <10°). The average FVC% was 75% ± 17%, their average TC was 57° ± 21°, and TK was 26° ± 25°. A total of 38% had no impairment, 37% exhibited mild impairment, 15% had moderate impairments, and 10% were severely impaired. Spinal deformities identified by radiographical analysis (TC, TC-flexibility, apical vertebral rotation, TK, and rib hump) significantly influenced FVC% (P < 0.01). TK logistic regression analysis revealed that 2 factors are predictive for an FVC 50% or less: increased scoliosis with a low TK less than 0° (odds ratio = 7.3) or a high TK more than 60° (odds ratio = 20). A model for predicting FVC values more than 50% was established and shown to achieve a correct classification rate of 94%.CONCLUSION: Patients with increasing coronal and sagittal plane deformities with a high thoracic scoliosis apex are at the highest risk for reduced FVC%. The models developed provided improved estimations of actual PF based on the magnitude of the radiographical deformity.

AB - STUDY DESIGN: This study examines the correlations between pulmonary function tests (PFTs) and radiographical measures of spinal deformities in patients with scoliosis.OBJECTIVE: To define the parameters that enable more accurate predictions of restricted pulmonary function (PF) in patients with scoliosis.SUMMARY OF BACKGROUND DATA: The early identification of patients with scoliosis who are at risk of developing severe curve progression and restricted PF is critical to improving patient care.METHODS: A total of 492 patients with a thoracic/thoracolumbar curve (TC) and preoperative PFTs as well as radiographical analysis of the TC and thoracic kyphosis (TK) were assessed. The forced vital capacity (FVC) was expressed as a percentage of the predicted value (FVC%). According to guidelines for the severity of pulmonary impairments, classifications were used: no impairment (FVC > 80%), mild (65 < FVC ≤ 80%), moderate (50 < FVC ≤ 65), and severe impairment (FVC ≤ 50%). Main radiographical parameters were included and statistical analyses were used to identify radiographical predictors and to develop prediction models.RESULTS: The average age was 17 years, 94% of the patients had adolescent idiopathic scoliosis, 20% had lordoscoliosis (TK <10°). The average FVC% was 75% ± 17%, their average TC was 57° ± 21°, and TK was 26° ± 25°. A total of 38% had no impairment, 37% exhibited mild impairment, 15% had moderate impairments, and 10% were severely impaired. Spinal deformities identified by radiographical analysis (TC, TC-flexibility, apical vertebral rotation, TK, and rib hump) significantly influenced FVC% (P < 0.01). TK logistic regression analysis revealed that 2 factors are predictive for an FVC 50% or less: increased scoliosis with a low TK less than 0° (odds ratio = 7.3) or a high TK more than 60° (odds ratio = 20). A model for predicting FVC values more than 50% was established and shown to achieve a correct classification rate of 94%.CONCLUSION: Patients with increasing coronal and sagittal plane deformities with a high thoracic scoliosis apex are at the highest risk for reduced FVC%. The models developed provided improved estimations of actual PF based on the magnitude of the radiographical deformity.

U2 - 10.1097/BRS.0000000000000601

DO - 10.1097/BRS.0000000000000601

M3 - SCORING: Journal article

C2 - 25202929

VL - 39

SP - 2024

EP - 2033

JO - SPINE

JF - SPINE

SN - 0362-2436

IS - 24

ER -