Analysis of the pulmonary function in patients undergoing vertebral body tethering for adolescent idiopathic scoliosis

Purpose The literature concerning the effects of scoliosis correction on pulmonary function (PF) is scarce and solely related to spinal fusion. Vertebral body tethering (VBT) represents a new option for scoliosis correction; however, its effects on PF have not yet been investigated. As VBT is a fusion-less technique that does not limit the dynamics of the chest wall, it is expected not to have a negative impact on PF despite the anterior surgical approach. Methods We analyzed the PF preoperatively and compared it with the PF at 6-weeks, 6-months and 12-monthts postoperatively. Considered parameters were total lung capacity (TLC), forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) expressed as percentages. A change of more than 10% was considered clinically significant. Results Before VBT, overall TLC, FEV1 and FVC measured 98 ± 15%, 85 ± 16% and 91 ± 17%, respectively. Six weeks after surgery, all parameters were comparable to the preoperative values (TLC 96 ± 17%, FEV1 84 ± 14%, FVC 90 ± 16%) and remained so at the last follow-up (TLC 99 ± 15%, FEV1 89 ± 9%, FVC 86 ± 9). While a reduction in FEV1 and FVC was observed at 6-weeks and 6-months in patients with thoracic or double curves compared to thoracolumbar curves, no significant differences were observed at the 12-months follow-up. Conclusions VBT does not cause a reduction in PF values at a short-term follow-up.