经伤椎与跨节段固定治疗无脊髓损伤的胸腰段A3型骨折

Additional screws fixation on fractured vertebrae versus only short-segment posterior instrumentation for thoracolumbar A3 fracture without neurologic deficit

目的比较经伤椎固定与跨节段固定治疗无脊髓损伤胸腰段A3型骨折的疗效。方法回顾性分析无脊髓损伤的AO分型为A3型的52例胸腰段单椎体爆裂性骨折患者的临床资料，并按固定方法不同分为A、B两组。A组23例为2005年1月至2006年12月采用后路经伤椎椎弓根钉固定的患者，其中男性18例，女性5例；平均年龄（35．3±8．3）岁；伤椎分布：T111例、T129例、L111例、L22例。B组29例为1999年1月至2004年12月采用传统后路跨节段经椎弓根固定的患者，其中男性20例，女性9例；平均年龄（37．3±6．8）岁；伤椎分布：T111例、T127例、L120例、L21例。分别于术前、术后即刻、术后2年对患者临床疗效与影像学指标进行对比分析。结果患者均获随访，随访时间24～84个月，平均（37．4±10．9）个月。A、B两组比较，术前、术后即刻、术后2年JOA、VAS平均评分差异均无统计学意义；术后即刻Cobb角平均矫正度分别为13．7°±7．7°、8．8°±5．0°，术后2年平均矫正丢失度分别为2．9°±1．5°、5．0°±2．9°，差异均有统计学意义（P〈0．01）；术后即刻伤椎前缘高度平均矫正度分别为（29．4±6．0）％、（21．7±6．9）％，术后2年平均矫正丢失度分别为（3．1±0．8）％、（6．6±3．0）％，而术后即刻伤椎后缘高度平均矫正度分别为（8．5±3．2）％、（6．1±1．8）％，术后2年平均矫正丢失度分别为（2．0±0．8）％、（3．4±1．0）％，两组伤椎前、后缘高度术后即刻平均矫正度及术后2年平均丢失度差异均有统计学意义（P〈0．01）。A组术后即刻CT显示11例（47．8％）椎管内骨折块完全复位、12例（52．2％）复位后矢状径狭窄〈1／3，复位效果优于B组（P〈0．01）。术后未出现神经损伤及与伤椎置钉有关的并发症。B组出现2例螺钉断裂。结论经伤椎固定治疗胸腰段A3型骨折能获得更好的初期复位，术后2年矫正丢失较跨节段固定少。

Objective To compare the clinical results of additional screws fixation on fractured vertebrae versus only short-segment posterior transpedicular instrumentation for A3 thoracolumbar fracture without neurologic deficit. Methods Clinical data of 52 cases of thoracolumbar burst fracture without neurologic deficit were retrospectively analyzed. All patients were divided into 2 groups due to different instrumentation and all fractures were classified as type A3 according to AO Classification. From January 2005 to December 2006, 23 cases in group A were treated by short-segment posterior instrumentation combined with additional screws fixation on fractured vertebrae. There were 18 male and 5 female with a mean age of （35.3 ±8.3） years. The fracture segment included 1 in T11, 9 in T12, 11 in L1 and 2 in L2. From January 1999 to December 2004, 29 cases in group B were treated only by conventional short-segment posterior transpedicular instrumentation. There were 20 male and 9 female with a mean age of （37. 3± 6. 8 ） years. The fracture segment included 1 in Tll, 7 in T12, 20 in L1 and 1 in L2. The clinical effect and radiographic measurements were respectively compared preoperatively, immediate and 2 years postoperatively. Results All patients were followed up and the mean follow-up time was （37.4 ± 10. 9 ） months （from 24 to 48 months）. There was no statistic difference of mean JOA and VAS score between 2 groups preoperatively, immediate and 2 years postoperatively （P 〉 0. 05 ） . The average immediate postoperative correction of Cobb＇s angle was 13.7° ± 7.7° in group A, which was statistically significantly higher than that of 8. 8° ±5.0° in group B （P 〈0. 01 ）. The mean kyphosis correction loss of 2.9° ＋ 1.5° in group A was statistically significantly lower than that of 5. 0° ＋ 2.9° in group B 2 years postoperatively （P 〈 O. O1 ）. The average restoration of anterior height of fractured vertebral body immediate postoperatively was （29.4 ±6. 0）% and （21.7 ±6. 9）% respectively. The mean correction loss of anterior height 2 years postoperatively was （3. 1 ±0. 8）% and （6. 6 ± 3.0）% respectively. The average restoration of posterior height of fractured vertebral body immediate postoperatively was （ 8.5 ± 3.2 ） % and （ 6. 1 ± 1.8 ） % respectively. The mean correction loss of posterior height 2 years postoperatively was （ 2. 0 ± 0. 8 ） % and （3.4 ±1.0） % respectively. There were significant differences in average restoration of anterior/posterior height immediate postoperatively and correction loss of anterior/posterior height 2 years postoperatively between the 2 groups （ P 〈 0. 01 ）. According to fracture fragments protruted into the spinal canal on immediate postoperative CT image, there were complete reduction in 11 cases （47. 8% ） and partial reduction in 12 cases （52. 2% ） in group A, which was statistically significantly better than those in group B （P 〈0.01 ）. There was no severe neurologic complications and no other complications related to additional screws fixation postoperatively. Pedicle screw breakage occurred in 2 cases in group B and none in group A. Conclusions Better initial kyphosis correction and less loss of correction 2 years after operation can be obtained by using additional screws fixation on fractured vertebra for thoracolumbar A3 fracture without neurologic deficit.