侧块螺钉置入治疗颈椎骨折对颈椎曲度的影响

Influence of lateral mass screw fixation on the cervical alignment in patients with cervical fracture

目的:恢复颈椎的生理曲度对维持颈椎的远期稳定性及恢复颈椎本身的生物力学环境有重要意义。将侧块螺钉内固定系统应用于颈椎骨折,探讨其对颈椎曲度的远期影响。方法:①回顾分析河北医科大学第三医院脊柱外科于2002-06/2004-08应用后路侧块螺钉置入治疗颈椎骨折不稳或骨折脱位的78例患者。78例患者中67例(85.9%)获得随访。其中1个节段固定9例,2个节段固定14例,3个节段固定25例,4个节段固定14例,5个节段固定5例。②固定材料:Sofamor公司的Axis颈椎后路固定系统。板及螺钉为钛合金材料,具有MRI兼容性。钛板按孔径分为11、13和15mm3种不同规格。螺钉分松质骨螺钉和皮质骨螺钉。松质骨螺钉有直径3.5mm和4.0mm、长度6～24mm两种规格,皮质骨螺钉直径4.0mm、长度26～54mm。③患者分别在术后3个月、12个月、24个月进行随访,每一次随访均拍颈椎正、侧位X射线片,部分患者行颈椎动力位X射线检查,分析患者颈椎生理曲度的改变情况。结果:①颈椎生理曲度:67例中有65例从术后到随访结束时生理曲度的改变平均为2°(0°～6°)。有2例术后3个月固定失败,生理曲度丢失。②并发症:5例患者术后有并发症,其中1例单侧C5神经根损伤(患者是屈曲牵张损伤),3例患者伤口浅表感染,1例糖尿病患者深部伤口感染。③材料与组织的生物相容性反应:术中所用材料均为钛合金体内植入物,与人体组织的生物相容性好,到随访结束时,无血液、免疫、组织等反应,无囊膜形成及细胞质的转变;亦无钛合金腐蚀、磨损等材料反应的发生。结论:颈椎外伤患者应用后路侧块螺钉可以有效矫正并保持颈椎的生理曲度,并发症少。

AIM： The recovery of cervical alignment is significant for the long-term stability and biomechanics of cervical vertebra. This study evaluated the effect of lateral mass screw placement on alignment maintenance in a long term. METHODS： ①From June 2002 to August 2004, 78 patients with unstable cervical vertebral fracture or a fracture-dislocation undergoing posterior spine fusion and lateral mass instrumentation in Department of Spinal Surgery, Third Affiliated Hospital of Hebei Medical University were retrospectively analyzed. Among them, 67 patients were followed up （85.9%）, of whom 9 patients received one level fused, 14 two levels fused, 25 three levels fused, 14 four levels fused and 5 five levels fused. ②The fixed material of Axis cervical posterior fixation system was from Sofamor company. The plate and screw were made of titanium alloy, presenting MRI compatibility. Titanium plates were of 11, 13 and 15 mm in pore diameter; the screws included cancellous bone screws （3.5 mm and 4.0 mm in diameter, 6-24 mm in length） and os integumentale screws （4.0 mm in diameter and 26-54 mm in length）. ③Postoperatively, patients were followed from 3, 12, and 24 months. Anteroposterior and lateral radiographs of the cervical spine were obtained at each visit, and power radiographs of partial patients were examined to investigate the changes in cervical physiological curvature. RESULTS： ①Cervical alignment： In 65 of the 67 patients, the mean change in sagittal alignment from the immediate postoperative to the end of the follow-up was 2°（range, 0° to 6°）. Radiographically, two cases were of instrumentation/fixation failure and loss of sagittal alignment in 3 months postoperatively. ②Complications： Five patients developed complications after operation, including one case of C5 nerve root injury （distractive flexion）, three cases of superficial wound infections and one diabetic patient of deep wound infection. ③Biocompatibility of tissue and material： All the materials used in operation were interstitial implant of titanium alloy. To the end of follow-up, there were no reaction of blood, immunization and tissue, no peplos formation or changes in cytoplasm, and no reaction of materials such as alloy corrosion and worn out. CONCLUSION： Lateral mass screws could effectively correct and maintain the alignment with minimal complications for patients with traumatic injuries in cervical spine.