联合单向及万向椎弓根螺钉经伤椎经皮内固定治疗胸腰椎骨折

Percutaneous transvertebral fixation of thoracolumbar fractures with monoaxial and polyaxial pedicle screws

目的探讨联合应用单向椎弓根螺钉和万向椎弓根螺钉经伤椎经皮内固定治疗胸腰椎骨折的效果。方法选择2010年1月＋2011年12月收治的无神经功能损伤的胸腰椎单节段骨折患者，随机分为两组：对照组（伤椎及伤椎上、下位椎体使用万向钉）和研究组（伤椎上位椎使用单向钉，伤椎及伤椎下位椎使用万向钉），行微创Longitude经皮椎弓根螺钉3椎6钉内固定术。对比分析两组患者的基本情况、术后伤椎高度及Gardner节段后凸畸形（Gardner segmental ky—photie deformity，GSKD）及伤椎后凸角等的变化，评估后凸畸形矫正能力。应用视觉模拟评分（vis—ual analogue scale，VAS）和Oswestry功能障碍指数（Oswestry disability index，ODI）量表等评价手术前后患者疼痛、功能等变化。并分析两组术后断钉发生率变化。结果两组共入选30例患者，术后随访6～18个月，平均10．5个月。两组在性别、年龄、骨折节段、骨折分型等一般资料和手术时间、失血量、止痛药使用以及住院时间等围术期资料差异无统计学意义。术后GSKD和伤椎后凸角研究组分别为（15．0±5．4）°和（16．0±6．5）°，对照组分别为（8．8±5．4）°和（9．0±5．5）°（P〈0．01）。术后GSKD和伤椎后凸角丢失度研究组分别为（2．6±1．3）°和（1．9±1．5）°，对照组分别为（3．7±2．1）°和（2．7±2．2）°（P〉0．05）。伤椎前缘矫正度和后缘的丢失度研究组分别为（33．0±11．4）％和（1．2±1．2）％，对照组分别为（22．7±11．4）％和（2．5±2．1）％（P〈0．05），研究组优于对照组。伤椎前缘的丢失度和后缘的矫正度研究组分别为（2．8±2．7）％和（5．0±4．8）％，对照组分别为（5．4±4．7）％和（3．1±2．9）％（P〉0．05）。两组术后相同时期VAS和ODI评分差异无统计学意义。结论联合应用单向和万向椎弓根螺钉的微创经皮内固定可提高胸腰椎骨折后凸畸形和伤椎椎体前缘高度的矫正能力，同时降低术后伤椎椎体后缘高度的丢失率。

Objective To evaluate effect of percutaneous transvertebral fixation of thoracolumbar fractures using both monoaxial and polyaxial pedicle screws. Methods The study involved single-level thoracolumbar fracture patients without neurological deficits undergone minimally invasive percutaneous fixation with CD-Horizon Longitude system from January 2010 to December 2011. Three level vertebras were immobilized by six pedicle screws. They were randomized into two groups： control group fixed with polyaxial screws for the fractured vertebra as well as the upper and lower adjacent vertebras and study group fixed with monoaxial screws for the superior adjacent vertebra and polyaxial screws for the injured vertebra and inferior adjacent vertebra. General information, height of fracture vertebral body, Gardner segmental kyphotie deformity, GSKD） and local kyphosis angle were assessed and compared between groups after operation so as to estimate correction ability of kyphosis deformity. Visual analogue scale （VAS） and Oswestry disability index （ODI） were used to evaluate alteration of back pain and lower limb function. Incidence of screw breakage was also compared between groups. Results Totally, 30 patients were enrolled in the trial and received an average follow-up of 10.5 months （ range, 6-18 months）. Two groups were similar in general information （sex, age, fracture levels, and fracture types） and perioperative information （operation time, intraoperative blood loss, proportion of antalgic supplement and hospital stay）. GSKD and local kyphosis angle were significantly higher in study group than in control group after operation [ （ 15.0 ± 5.4） °vs （8.8 ± 5.4） o, （ 16.0 ± 6.5 ） ° vs （9.0 ± 5.5 ） ° respectively, P 〈 0.01 ]. While, correction loss of GSKD and local kyphosis was similar between study and control groups [ （2.6 ± 1.3 ） °vs （ 1.9 ± 1.5） o, （3.7 ± 2.1 ） ° vs （2.7 ± 2.2） o respectively, P 〉 0.05 ]. Correction of anterior vertebral body height and correction loss of posterior vertebral body height were superior in study group to control group [ （33.0 ± 11.4） % vs （22.7 ± 11.4） %, （ 1.2 ± 1.2） % vs （2.5 ± 2.1 ） % respectively, P 〈 0.05 ]. Correction loss of anterior vertebral body height and correction of posterior vertebral body height were similar between study and control groups [ （ 2.8 ± 2.7 ） % vs （ 5.4 ± 4.7 ） %, （ 5.0 ± 4.8） % vs （3.1 ± 2.9） % respectively, P 〉 0.05 ]. Besides, there were no significant differences of VAS and ODI between the two groups in the same period after operation. Conclusion Combined use of monoaxial and polyaxial pedicle screws in minimally invasive percutaneous fixation improves kyphosis deformity and correction ability of anterior height and decreases correction loss of posterior height of the fractured vertebral body.