Causes for kyphosis after removal of internal fixators for thoracolumbar vertebrae burst fractures / 中华创伤杂志

ABSTRACT

Objective To retrospectively analyze whether the kyphosis exists after removal of the internal fixators for thoracolumabar vertebrae fractures. Methods A total of 18 patients (35-68 years old) with thoracolumabar vertebrae fractures (T11-L2 ) were fixed with short segment pedical screw. The fixators were removed one year postoperatively to observe the changes of the Cobb' s angle and trauma vertebra'height. Results All the patients were followed up for 6-24 months ( average 18.7 months),which showed no intraoperative or postoperative complication, breakage or loosening of the screws. Compared to the Cobb angle and the vertebra height before removal of the internal fixators, the average loss of the Cobb angle was 0.7° and that of the vertebra height was 0.8 mm six months after removal of the fixators, 1.9° and 1.1 mm respectively one year after removal of the fixators, and 2.4° and 1.3 mm respectively two years after removal of the fixators in 16 patients without osteoporosis (P ＞0. 05). Among two patients with osteoporosis, the average loss of the Cobb angle and the vertebra height was 6° and 8°respectively and 3 mm and 5 mm respectively six months after removal of the fixators; 13° and 17° respectively and 5 mm and 7 mm respectively one year after removal of the fixators; 15° and 19° respectively and 6 mm and 7.5 mm two years after removal of the fixators. Conclusions After the internal fixation for thoracolumbar vertebrae burst fractures, kyphosis develops mildly, with insignificant change of the vertebral height. While the kyphosis becomes worse after removal of the fixators for thoracolumbar vertebrae burst fractures in patients with osteoporosis.