椎体爆裂骨折环形减压术后椎管再塑形

Remodeling of the spinal canal after circum decompression of burst vertebral fractures

目的通过观察环形减压后椎管的形态学变化，探讨椎管塑形的方式及完成塑形的时间。方法2003年1月至2006年6月，采用椎管环形减压、椎弓根螺钉固定治疗胸腰椎爆裂骨折76例，其中53例获得随访。骨折部位：T11 1例，T12 15例，L1 18例，L2 15例，L3 3例，L4 1例。脊髓损伤程度按ASIA标准评定：A级27例，B级7例，C级6例，D级2例，E级11例。术前及不同随访时间行X线和CT检查，测量伤椎平面的椎管最小矢状径及伤椎相邻的上下椎管矢状径平均值，计算伤椎椎管狭窄率，同时测量塑形后的伤椎椎管矢状径并与理论值进行配对t检验，比较塑形后椎管矢状径的恢复程度。结果53例患者术后获平均24．2个月（12～60个月）随访。15例脊髓不完全损伤患者，ASIA分级分别提高1～3级，27例脊髓完全损伤患者中，8例部分神经根功能有所恢复，术后CT复查显示伤段椎管减压充分、脊髓受压完全解除。术后12个月椎管形态均表现不同程度的再塑形现象。术后24个月同一层面CT示再塑形的椎管管径与伤椎正常椎管矢状径理论值差异无统计学意义（P〉0.05）。结论胸腰椎爆裂骨折环形减压后不规则的椎管出现了明显的再塑形现象，再塑形过程发生于伤后12个月左右，且这一过程不受神经系统损伤程度的影响，即骨折平面和伤后ASIA分级不影响椎管的再塑形过程。塑形后的椎管接近正常形态，椎管矢状径在正常范围内。

Objective To observe the time and pattern of remodeling of the spinal canal after circum decompression of burst vertebral fractures. Methods A total of 76 patients with thoracolumbar burst fracture were treated with eircum decompression and pedicle screw fixation, Of them, 53 eases were followed up for 24. 2 （12 to 60） months averagely. By the ASIA evaluation system, the severity of spinal cord injury was rated as grade A in 27 eases, grade B in 7, grade C in 6, grade D in 2 and grade E in 11. The initial stenosis ratios of the injured spinal canals were calculated. The sagittal diameters of the injured canals were measured pre- and past-operatively and analyzed by paired Student＇s t test at the follow-up time of remodeling. Results The ASIA evaluation improved I to 3 grades in the 15 patients with incomplete injury to the spinal cord, while the nerve root recovered partial function in 8 of the 27 patients with complete injury to the spinal cord. CT scans demonstrated a complete decompression of the canal. Remodeling of the spinal canal developed 12 months after operation. There were no significant differences （ P 〉 0. 05） in the sagittal diameter between the remodeling and normal canals 24 months postoperatively. Conclusions Significant spontaneous remodeling of the spinal canal can develop 12 months after cireum decompression of thoracolumbar burst fracture. This process may not be affected by the fracture location or the severity of neurological deficits. The canal shape after remodeling is close to the normal.