An analysis of thoracic cage deformities and pulmonary function tests in congenital scoliosis

To determine: (1) the relationship of thoracic cage parameters and preoperative pulmonary function tests (PFTs) in congenital scoliosis (CS) patients. (2) if patients with rib deformity have greater impairment of PFTs than those without rib deformity.

A total of 218 patients with CS and pulmonary dysfunction (FVC < 80 %) were conducted in one spine center between Jan 2009 and Mar 2013. The demographic distribution, medical records, PFTs and radiographs of all patients were collected. The association of PFTs and thoracic cage deformities was analyzed.

In total, 143 patients (65.6 %) had a clinically relevant impairment of pulmonary function. They had smaller BMI, larger thoracic transverse and anteroposterior diameter, more thorax height, scoliotic angle and number of involved vertebra than no clinically impairment. PFTs were negative correlation significantly with scoliotic angle, number of involved vertebra and thoracic sagittal diameter, while thorax height is significant positive. The T1-12 height was significant positive correlation with age, stature, weight, thoracic transverse and sagittal longitudinal diameter, while negative correlation with scoliotic curve, number of involved vertebra, as well as kyphotic angle. PFTs do not correlate with T1-12 height, but significantly associated with the rib anomalies. The FVC and FEV1 were significantly lower in patients with rib anomalies than without rib anomalies. There was no association between the pulmonary function and the location of rib deformities.

PFTs correlate significantly with scoliotic angle, number of involved vertebra, thoracic sagittal diameter, and thorax height. PFTs were significantly lower in patients with rib anomalies, particular to the patients with fused rib.