Structure-Respiration Function Relationships Before and After Surgical Treatment of Early-onset Scoliosis

Abstract

Spine and chest wall deformities in children with early onset scoliosis (EOS) frequently impair respiratory function and postnatal growth of the lung. While a relationship between deformity and such impairment has been reported in children with adolescent idiopathic scoliosis it is not well understood in children with early-onset scoliosis (EOS). We therefore describe (1) the preoperative relation between Cobb angle and forced vital capacity (FVC) in infants with EOS; (2) how changes in Cobb angle before and after surgery relate to changes in lung ventilation and perfusion in the right and left lungs. We measured FVC in 10 children with EOS<3years old using the raised volume rapid thoracic compression (RVRTC) technique and correlated them with Cobb angles. We then measured right lung contributions to total lung ventilation and perfusion using lung scans before and 4 to 57months after placement of vertical expandable prosthetic titanium ribs (VEPTRs) in 15 children with EOS and correlated changes in right lung function with postoperative changes in Cobb angles. In children 4 to 57months of age, preoperative FVC (mean value, 83%; range, 63%-109% of predicted values) did not correlate with Cobb angles (mean value, 56º; range, 14°-120º). In children 1.8 to 11.5years old, right lung ventilation and perfusion were abnormal in eight and seven children, respectively, but neither ventilation nor perfusion predictably normalized despite reductions in Cobb angle postoperatively. The data extend the age range of children with EOS whose Cobb angles correlate poorly with FVC preoperatively. The data are also consistent with reports that reduced Cobb angles after VEPTR insertion do not correlate with postoperative changes in respiratory function.