Jefferson骨折复位钢板的设计、改良及初步临床应用

Design, modification and clinical application of Jefferson-fracture reduction plate

目的 介绍Jefferson骨折复位钢板系统（Jefferson-fracture reduction plate,JeRP）及其相关参数,评估其改良前后的临床疗效.方法 对Jefferson骨折患者应用螺旋CT三维重建排除寰椎横韧带断裂后,采用原型JeRP系统进行手术治疗,分析其初步临床应用的疗效及出现的问题.根据应用中的不足,通过寰椎三维重建模型,进行应用解剖学研究并测量相关解剖数据,重新确定寰椎侧块上、下位螺钉的最佳进钉点和长度,根据该数据设计、改良JeRP钢板并予以临床应用.术后采用颈椎过伸、过屈位X线片评估是否存在寰枢椎不稳,应用CT扫描观察骨折愈合情况.结果 8例Jefferson骨折患者行经口咽寰椎骨折复位、原型JeRP钢板内固定术,术后平均随访6.3个月,所有患者术后枕颈部疼痛逐渐改善,咽后壁切口愈合良好,未见感染,骨折均达到解剖复位及骨性愈合,术后随访未见寰枢椎失稳,但其中3例患者因寰椎侧块上位螺钉穿破寰枕关节而导致颈椎活动受限.针对此问题,并通过应用解剖学测量,模拟置钉显示寰椎侧块外1/3平分线与寰椎上、下关节面交点所形成线段的中点作为寰椎侧块上位螺钉的进钉点,可保证JeRP钢板侧块上位螺钉不穿透上关节面,同时可保证足够空间置入下位螺钉,具备临床可行性.根据此结果设计出改良JeRP钢板,应用于4例Jefferson骨折患者,术后影像学检查证实所有螺钉均位于寰椎的侧块中.结论 原型JeRP初步应用显示较好的疗效,但仍存在寰椎侧块上位螺钉穿透寰枕关节的可能;改良后钢板的设计更加符合寰椎的解剖结构,基本可以保证螺钉位于侧块中.

Objective To introduce the design,modification and clinical application of Jefferson-fracture reduction plate （JeRP）,which was designed for the surgical treatment of Jefferson-fracture of the atlas,and evaluate the clinical effects.Methods JeRP system was designed for the treatment of patients with Jefferson fractures without rupture of the transverse ligament.Eight patients were treated operatively with the JeRP system for reduction and fixation of the fracture.Three-dimensional spiral CT was used to determine the integrity of the transverse ligament.During the preliminary clinical application,the clinical results were satisfied.But there were some disadvantages.The entry point of the superior screw of the mass was much too high,causing the screw penetrate into the atlantooccipital joint.Three-dimension Computed tomography images were used to analyze the anatomic characters of atlas.The relative anatomic parameter of the atlas was obtained.According to it,the Jefferson-fracture reduction plate was modified.The modified JeRP was applied clinically in another 4 patients.Extension and flexion X-ray were used to determine whether there was atlatoaxial dislocation after the operation.CT was used to determine whether there was bony fusion.Results Eight patients with Jefferson fractures without rupture of the transverse ligament were treated with the original JeRP.The mean follow-up time was 6.3 months.Neck pain was significantly alleviated after surgery in all patients.There was no infection or wound breakage.The reduction of the fracture was satisfied in all patients.Bony fusion was achieved in 3 months.No atlantoaxial dislocation was found in all patients during follow-up.Of the 8 patients,three complained about the movement restriction of the neck.The radiological examination found the upper screw of lateral mass breaking into the atlas-occipital joint.Anatomic structure of C1 lateral mass was measured using 1 mm CT scans.The optimal entry points and other parameters for the screws of the mass were determined.According to the anatomic parameters,we modified the JeRP.Another 4 patients with Jefferson fractures without rupture of the transverse ligament were treated operatively using this modified JeRP system.The preliminary clinical results were satisfactory.No screw penetrating into the atlas-occipital joint happened.Conclusion Although the preliminary results of the application of JeRP were satisfactory,there was a high ratio of atlas-occipital joint violated during lateral mass screw insertion.The modified JeRP can avoid this complication.