椎弓根螺钉系统固定对椎体生长发育的影响

Influence of pedicle screw instrumentation on growth potential of the immature vertebra

中文关键词:  椎弓根螺钉  中央神经骺板  椎体  椎管  生长发育

英文关键词:Pedicle screw  Neurocentral synchondrosis  Vertebral body  Spinal canal  Growth

中文摘要:

  【摘要】 目的：探讨椎弓根螺钉系统固定对5岁以下婴幼儿椎体生长发育的影响。方法：回顾性分析2000年1月～2016年12月在我院行双侧椎弓根螺钉固定的先天性脊柱侧凸患儿，年龄≤5岁，随访时间至少5年。在术前与末次随访时，于CT轴位图像上测量患者固定椎和邻近非固定椎的椎体及椎管相关参数（椎体及椎管前后径和横径、椎管面积及双侧椎弓根长度）。计算各项参数的生长值（末次随访数值-术前数值）和生长百分比（增长值除以末次随访值）。将胸椎和腰椎的参数进行分组比较。采用统计学的方法比较组间差异。结果：本研究共纳入13例患者，接受手术时的平均年龄为3.4±1.1岁（2~5岁），平均随访7.2±2.2年（5~11年）。所有患者均接受半椎体切除、椎弓根螺钉固定、短节段融合。研究共纳入69个椎体，包括43个固定椎以及26个非固定椎。在末次随访时，所有椎体的各项参数均得到明显增加。固定椎椎管前后径的生长值（2.2±1.7mm）与椎管面积（72.8±48.5mm2）明显大于非固定椎（1.1±1.3mm，39.2±26.3mm2），固定椎椎管前后径的生长百分比[（11.2±7.1）%]与椎管面积生长百分比[（21.3±11.6）%]明显大于非固定椎[（6.0±6.0）%，（13.4±8.1）%]，固定椎椎体前后径的生长值（3.8±2.5mm）明显小于非固定椎（6.1±3.0mm），生长百分比[（20.5±12.1）%]也明显小于非固定椎[（28.1±11.0）%]，差异均具有统计学意义（P＜0.05）。在腰椎椎体中，结果类似。在随访过程中，非固定腰椎椎管形状发生了明显的变化，而在固定腰椎体中此形状变化不明显。结论：椎弓根螺钉系统固定可能会减缓椎体的生长发育，间接加速椎管的生长发育，可能阻止或减缓腰椎椎管形状的演变。但其影响较小，椎弓根螺钉固定的椎体较术前均有明显的生长。所以，在小于5岁的婴幼儿中应用椎弓根螺钉系统固定对椎体生长发育并无严重影响。

英文摘要:

  【Abstract】 Objectives: To explore the influence of pedicle screw instrumentation on the growth of immature spine at a very young age. Methods: Between January 2000 and December 2016, individuals who had bilateral pedicle screw instrumentation were reviewed. Patients younger than 5 years old with a minimal follow-up of 5 years were included. Anteroposterior diameter of vertebral body, pedicle length of both sides, anteroposterior diameter, transverse diameter and area of spinal canal were measured on CT images before surgery and at final follow-up. Parameters of instrumented vertebrae and adjacent non-instrumented vertebrae were compared. Growth value was calculated as: preoperative value - postoperative value, and growth percentage were calculated as: growth value divided by the final follow-up value. Subgroups of thoracic vertebrae and lumbar vertebrae were compared, respectively. Statistical analyses were performed. Results: 13 patients with congenital spinal deformity were enrolled. The average age at surgery was 3.4±1.1(range, 2-5) years old, and the average follow-up was 7.2±2.2(range, 5-11) years. Osteotomy and short instrumentation with pedicle screws were performed on each case. A total of 69 segments was measured, including 43 instrumented vertebrae and 26 adjacent non-instrumented vertebrae. Significant increases of all parameters were noted at final follow-up. The growth value(2.2±1.7mm vs 1.1±1.3mm), the area of spinal canal(72.8±48.5mm2 vs 39.2±26.3mm2), the growth percentage of anteroposterior diameter[(11.2±7.1)% vs (6.0±6.0)%] and area of the spinal canal[(21.3±11.6)% vs (13.4±8.1)%], the anteroposterior diameter of vertebral body(3.8±2.5mm vs 6.1±3.0mm) and its growth percentage[(20.5±12.1)% vs (28.1±11.0)%] had significant differences between instrumented vertebrae and non-instrumented vertebrae(P＜0.05). Similar results were noted in lumbar region. Shape-change phenomenon was found in non-instrumented vertebrae and not apparent in instrumented vertebrae. Conclusions: Pedicle screw instrumentation may slow down the growth of vertebral body, indirectly speed up the growth of spinal canal and hinder the shape-change phenomenon of lumbar spinal canal. But the influence is quite slight and the significant development occurs in instrumented vertebrae. So pedicle screw instrumentation may not make a great difference on the growth of immature vertebrae in children younger than 5 years old.