[Restoration of thoracic kyphosis with multilevel Ponte osteotomies in thoracic idiopathic scoliosis surgery].

OBJECTIVE

To investigate the effectiveness of multilevel Ponte osteotomies on maintenance and restoration of thoracic kyphosis in idiopathic scoliosis (IS) surgery.

METHODS

Between March 2008 and February 2010, 42 patients with thoracic IS (Lenke type 1 curves) were corrected with posterior pedicle screw system. Multilevel Ponte osteostomies for posterior release was performed in 17 cases (group A), and the 3 segments near the apical vertebrae were selected as the osteotomy site; simple posterior soft tissue release was given in 25 cases (group B). There was no significant difference in sex, age, disease duration, lesion segments, coronary Cobb angle, thoracic kyphosis, Risser index, and bending flexibility between 2 groups (P > 0.05). The anteroposterior and lateral standing radiographs of the spine were taken to compare the effectiveness between 2 groups.

RESULTS

Operation was successfully completed in all patients. The operation time and blood loss in group A were significantly greater than those in group B (P < 0.05). Spine dural injury and leakage of cerebrospinal fluid occurred in 1 case of group A, which was cured after compression on local area of the wound; the other patients had no intraoperative complications. The patients were followed up 2-4 years (mean, 2.8 years); no nerve injury, infection, or internal fixation failure occurred. No obvious correction loss was observed and the appearance and trunk balance were significantly improved. The coronal Cobb angles at 1 week and 2 years after operation were significantly improved when compared with preoperative ones in 2 groups (P < 0.05). There was no significant difference in the coronal Cobb angle and correction rate between 2 groups at 1 week and 2 years after operation (P > 0.05). Group A was significantly better than group B in the thoracic kyphotic angle and angle changes at 1 week and 2 years after operation (P < 0.05).

CONCLUSION

The posterior approach surgery with multilevel Ponte osteotomies can restore the thoracic kyphosis in IS, but it has no effect on coronal correction in Lenke type 1 curves.