Analysis of Clinical and Radiological Predictive Factors for Moderate and Severe Pulmonary Impairment in 102 Adolescent Idiopathic Scoliosis (AIS) Patients With Major Cobb Angle ≥45°: A Study of an Asian Population.

Abstract

Study DesignRetrospective cohort study.ObjectiveTo investigate the independent predictive factors for moderate-severe pulmonary impairment (MSPI) among adolescent idiopathic scoliosis (AIS) patients.MethodsThe preoperative pulmonary function tests (PFTs) of 102 AIS patients (<i>major Cobb angle ≥45</i>°) operated between 2015 and 2020 were retrospectively reviewed. Patients were divided into 2 groups based on the predicted <i>forced vital capacity (FVC)</i> and <i>forced expiratory volume in one second (FEV</i>_<i>1</i><i>)</i>, respectively. Group 1 had normal/ mild pulmonary impairment (<i>FVC or FEV</i>_<i>1</i> <i>>65% predicted</i>) whereas Group 2 had MSPI (<i>FVC or FEV</i>_<i>1</i> <i>≤65% predicted)</i>. Multivariate logistic regression analysis was performed to determine the predictive factors for MSPI.Results41.2% (N = 42) and 52.0% (N = 53) of the total patients were categorised into Group 2 (MSPI) based on predicted FVC and FEV₁, respectively. In general, Group 2 had more patients with a major main thoracic (MT) curve, larger MT curve with lower MT flexibility, a larger MT apical vertebra translation (MT-AVT), and a smaller thoracolumbar-lumbar (TL/L) AVT than Group 1 (<i>P <</i> .<i>05</i>). When analyzing the MT Cobb angle for every 10<i>°</i> increment, patients with MT Cobb angle ≥70° had MSPI (N = 31.4%). Body mass index (BMI) (FVC: aOR .8; FEV₁: aOR .9) and MT Cobb angle (<i>for every 10° increment</i>, FVC: aOR 1.7; FEV₁: aOR 1.8) were the significant independent predictive factors for MSPI.ConclusionMSPI was evident in patients with MT Cobb angle ≥70°, with MT Cobb angle and BMI being the significant independent predictive factors.