Study design: A prospective evaluation of cardiorespiratory function following spinal fusion in adolescent idiopathic scoliosis (AIS).
Objective: To evaluate the cardiopulmonary function during exercise in patients with severe AIS, before and 2 years after undergoing a posterior spinal fusion.
Summary of background data: After surgical correction of scoliosis, a greater cardiorespiratory adaptation to exercise would be expected from correction of the rib cage associated with the spine deformity. However, there is no clear evidence regarding whether tolerance to maximum exercise improves in the medium term after surgery in patients with severe curves.
Methods: We include patients with AIS proposed for posterior surgical correction aging between 12 and 17 years. Every patient had a Cobb angle >45° and a Lenke type 1A scoliosis. Cardiac and respiratory functional measures, such as heart rate and blood pressure, maximum oxygen consumption (VO2max), eliminated volume of carbon dioxide (VCO2), quotient between ventilation and volume of exhaled carbon dioxide (VE/CO2), respiratory exchange rate, ventilatory capacity at maximal exercise (VEmax), were recorded before and 2 years after surgery.
Results: Twenty patients were included in our study, 15 girls and 5 boys, with an average age of 13 years. The main scoliotic curve was corrected in the coronal plane in an average of 71.9%. The maximal aerobic power expressed by body weight normalized VO2max was found preoperatively to have an average of 30.9 ± 6.2 mL/kg/minute, indicating a poor aerobic capacity, which did not improve at final follow-up, decreasing to a mean value of 29.3 ± 5.7 but without statistical significance. However, the percentages of curve correction showed a statistically significant correlation with VO2max (r = 0.534; P < 0.05).
Conclusion: Patients with severe adolescent idiopathic scoliosis Lenke type 1A showed limited cardiorespiratory tolerance to maximum exercise that did not improve 2 years after surgery.
Level of evidence: 3.