Pulmonary function after anterior double thoracotomy approach versus posterior surgery with costectomies in idiopathic thoracic scoliosis

The surgical approach in the treatment of idiopathic thoracic scoliosis depends on the type of curve involved. In anterior correction, the rib hump is corrected by derotating the thoracic spine. In posterior scoliosis surgery, additional rib hump resection is sometimes necessary to achieve an optimal cosmetic result. The aim of this study was to compare pulmonary function in these two patient groups.

Forty patients in the anterior group (A) were treated with standard double thoracotomy, with an anterior derotation spondylodesis and a primary stable dual-rod system. The posterior group (P) included 29 patients who were treated with a pedicle screw-based posterior instrumentation spondylodesis, with additional rib hump resection. Pulmonary function was evaluated preoperatively, on the 12th postoperative day, and at 3, 6, 12 and 24 months during the follow-up.

The patients’ mean age was 15 years in group A and 19 in group P with a standard deviation 8.7 years and a significant difference. With regard to body height or weight there were no significant differences between the two groups. In group A, the deterioration in pulmonary function immediately after the operation (from \( V_{{{\text{c}}_{\max } }} /{\text{FEV}}_{1} \) 75.3 %/71.3 % preoperatively to 38.5 %/36.1 % postoperatively) was clearer than in group P (\( V_{{{\text{c}}_{\max } }} /{\text{FEV}}_{ 1} \) 71.6 %/65.7 % preoperatively to 47.7 %/48.4 % postoperatively). During a follow-up period of 3 months, the values improved in both groups in comparison with the values immediately after the operation. Up to the 2 year follow-up, pulmonary function in the posterior and anterior groups corresponded to the preoperative values, with no significant differences. There was a trend toward moderately increased values in the posterior group and moderately decreased values in the anterior group at the 2-year follow-up examination, in comparison with the preoperative baseline, but without a statistically significant difference. Two major complications occurred in the anterior group, with reintubation and several bronchoscopy examinations due to atelectasis.

The severe deterioration in group A is caused by the substantial trauma with double thoracotomy in contrast to rib hump resection. For patients with severe restrictive pulmonary distress, posterior instrumentation in combination with rib hump resection would be preferable to an anterior procedure involving double thoracotomy. Respiratory physiotherapy exercise should be administered in order to minimise postoperative pulmonary distress. In conclusion opening of the chest wall leads to deterioration of pulmonary function with improvement to the preoperative values after 6 months in the posterior and after 24 months in the anterior group.