顶椎凹侧置钉类型对青少年特发性脊柱侧凸患者矫形效果的影响

Effect of different type of pedicle screws placement in concavity side of apical vertebrae on the treatment of adolescent idiopathic scoliosis

目的:探讨顶椎凹侧置钉类型对青少年特发性脊柱侧凸(AIS)患者矫形效果的影响。方法:2002年1月～2007年10月采用全节段椎弓根螺钉固定技术治疗83例单结构弯的AIS患者,年龄13.5～17岁,平均15.5岁。根据顶椎凹侧置钉种类不同分为:顶椎单轴向螺钉固定组(A组,38例)和多轴向螺钉固定组(B组,45例)。两组术前Cobb角、柔韧性、顶椎旋转度无明显统计学差异。比较两组的Cobb角矫正率和顶椎去旋转率(RAsag角矫正率),并根据CT上螺钉长轴与钉帽轴线的夹角大小和方向来判断B组顶椎钉口成角程度和方向。结果:两组Cobb角矫正率无明显统计学差异(69%、68%,P>0.05),A组顶椎去旋转率高于B组(42%、34%,P<0.05)。术后CT证实B组的顶椎凹侧有37枚螺钉(82%)出现钉口成角(平均-13.5°)。结论:单轴向螺钉的顶椎去旋转率明显高于多轴向螺钉。对于单结构弯,在提高置钉准确性、后方结构充分松解的同时,顶椎凹侧应尽量选择单轴向螺钉固定。

Objective：To study the effect of monoaxial and muhiaxial pedicle screws in the correction of adolescent idiopathic scoliosis（AIS）.Method：From Jan 2002 to Oct 2007,83 cases with single structural curve had been analyzed retrospectively,the mean age at time of surgery was 15.5 years old.According to the type of pedicle screws on apex concavity side,all cases were divided into monoaxial （group A） and muhiaxial （group B） pedicle screw fixation.There was no statistical difference on Cobb angle,flexibility and rotation degree preoperatively between two groups.The correction rate in Cobb angle and derotation degree between two groups were analyzed statistically,and the direction and degree of the screw junction on apex concavity side in group B were determined.Result：There was no statistical difference in the Cobb angle correction rate between two groups （69% vs 68%,P〉0.05）.However,the correction rate of derotation degree was much higher in group A（42%） than that in group B（34%）（P〈0.05）.In group B,There were 37 screws（82%） with confirmed angulation on the junction （average -13.5^o ）.Condusion：Monoaxial rather than muhiaxial pedicle screw,can provide much stronger derotation force during the correction of rotational vertebral.As for the single structrual carve,the concavity side of apical vertebrae should be fixed with monoaxial pedicle screw.