胸腰椎爆裂骨折去除内固定后后凸畸形发生原因分析

目的 回顾分析胸腰椎爆裂骨折去除内固定后是否继发后凸畸形.方法 18例胸腰椎爆裂骨折(T11～L2)采用短节段椎弓根钉固定术,术后1年取出内固定物,测量内固定取出术后0.5～2年Cobb角度变化及伤椎椎体高度的变化.结果 18例患者(35～68岁)术后随访6～24个月(平均18.7个月),无术中、术后并发症发生,无椎弓根钉断裂或松动现象.与取内固定钉前相比,16例无骨质疏松患者取钉后6个月Cobb角平均丢失0.7°,椎体高度丢失0.8 mm;取钉后1年Cobb角平均丢失1.9°,椎体高度丢失1.1 mm(P＞0.05);取钉后2年Cobb角平均丢失2.4°,椎体高度丢失1.3mm(P＞0.05).合并骨质疏松的2例患者,取钉后6个月Cobb角丢失6°、8°,椎体高度丢失3mm、5 mm;取钉后1年Cobb角丢失13°、17°,椎体高度丢失5 mm、7 mm;取钉后2年Cobb角丢失15°、19°,椎体高度丢失6 mm、7.5 mm.结论 胸腰椎爆裂骨折内固定术后脊柱后凸畸形会有轻度发展,但椎体高度丢失并不明显.若合并骨质疏松,胸腰椎爆裂骨折内固定术后脊柱后凸畸形会明显发展.

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.

Causes for kyphosis after removal of internal fixators for thoracolumbar vertebrae burst fractures

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.