[Radiological factors influencing pulmonary function test in severe spinal deformity]

To investigate the pulmonary dysfunction patterns in severe spinal deformity and to identify radiological factors affecting the pulmonary function.

From September 2009 to December 2014, a total of 66 patients were involved in this Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University. Preoperative pulmonary function testing (PFTs) and radiographic examination were performed on all of the involved patients. Correlation analysis and subsequent stepwise multiple regression analysis were carried out to assess the associations between radiographic measurements of deformity and the results of pulmonary function testing.

Fifty-seven out of 66 patients had impaired pulmonary dysfunction, and more than half of were ≤59% predicted forced expiratory volume in 1 second (FEV1). Most of the patients with severe spinal deformity demonstrated a restrictive pattern of pulmonary function. The magnitude of the major curve, the number of involved thoracic vertebrae had significant effect on pulmonary function. While these 2 factors were associated with an increased risk of pulmonary impairment, they explained only 46.2%-55.1% of the observed variability in vital capacity, forced vital capacity, and forced expiratory volume in one second.

Preoperative PFTs are clinically impaired in 86% of patients with severe spinal deformity, and more than half of that were moderate and severe pulmonary dysfunction. The magnitude of the major curve and the number of involved thoracic vertebrae are the main risk factors influencing the pulmonary dysfunction.