Razi Journal of Medical Sciences

    Background and Aim: The present studies on kyphoscoliosis operation demonstrate different results on lung volume changes. Some observations show increased, some show decreased and other studies show no changes in the dynamic respiratory flows.

In this study we evaluated lung volumes before and after surgery. We also evaluated the correlation of repiratory lung volume changes with mean of Cobb's angle.

Patients and Methods: In this observational descriptive study, 18 non smoker patients with idiopathic scoliosis were included. Cobb's angle, lung volume and flow were measured before and after surgery with spirometer. Paired t-test was used for statistical analysis. To consider height and weight changes during the follow ups, we used percentage relative to normal instead of absolute volumes.

Results: From 30 patients included in this study we followed 18. Mean follow up duration was 34.5±19.6 months (SD=19.6) Dynamic volume changes were: VC=13.4 SD=8.6 (P<0.005), FVC=9.22 SD=14 (p<0.001) and FEV1=9.8 SD=15 (p<0.001). There was no significant correlation between lung volume changes and Cobb's angle changes. There was weak inverse correlation between mean value of dynamic volume changes and mean changes in Cobb's angle after surgery the greater the cobb's angle changes, the lesser the lung volume changes.

Conclusion: In this study there was significant decrement of dynamic lung volumes after corrective surgery for thoracic curve scoliosis. There was no correlation between the degree of corrective angle and the amount of lung volume changes. There was a weak linear correlation between cobb's angle and lung volumes before surgery. Greater the angle changes, lesser the lung volume changes.There was a weak inverse correlation between the mean value of Cobb's angle and changes in dynamic lung volume after surgery.