前路经寰枢关节螺钉内固定术的临床解剖学研究

目的:为前路经寰枢关节螺钉内固定术提供临床解剖学依据。方法:在100对中国成人干燥寰枢椎配对标本上,对与临床前路经寰枢关节螺钉内固定术相关的数据进行解剖学测量。结果:前路经寰枢关节螺钉内固定术冠状面上螺钉植入最小外偏角(5.5±2.0)°(0°～13.0°),最大外偏角(23.6±2.1)°(17.5°～32.5°),矢状面上螺钉植入最小后倾角(14.9±2.6)°(9.0°～27.0°),最大后倾角(25.6±2.5)°(17.5°～33.5°),内侧钉道距离(16.58±1.49)mm(13.78～21.86mm),外侧钉道距离(26.44±1.75)mm(21.81～33.78mm)。结论:前路经寰枢关节螺钉内固定术,16～26mm长度的螺钉,外倾5°～23°、后倾15°～26°方向拧入是安全的。     

标准位X线片上胸腰椎椎弓根轴线的放射学研究

目的:研究标准正位X线片上T9～L5椎弓根轴线的放射学表现。方法:10具T9～L5脊柱标本,解剖成单个椎体。直视下沿椎弓根轴线置入导针。测量分析下列数据:标准侧位X线片显示导针达到椎体后壁及椎弓根中段时,标准正位X线片导针在椎弓根投影内的距离与椎弓根投影最大横径的百分比。另选4具T9～L5脊柱标本,根据上述数据,X线分步监测椎弓根螺钉植入。结果:标准正位X线片导针位于椎弓根中段时的百分比为(49.16±1.84)%～(51.83±2.53)%,各节段及左右侧椎弓根差异无统计学意义(P>0.05);导针位于椎体后壁时的百分比为(61.13±6.09)%～(74.68±6.13)%,左右椎弓根之间、T10￣T12之间、T9与L1￣L5之间差异分别无统计学意义(P>0.05),T10￣12与T9、L1￣5差异有统计学意义(P<0.001)。植入72枚螺钉,68枚位于椎弓根中心,4枚穿破椎弓根,穿破率5.56%。结论:标准正位X线片导针在椎弓根投影内的比值能间接表达椎弓根轴线,可为经椎弓根手术确定正确的进针轨道提供一种参考。     

股骨远端骨折两种固定方法对比研究

目的 对比应用逆行交锁髓内钉(GSH)和动力髁螺钉(DCS)内固定治疗股骨远端骨折的效果.方法 采用回顾性研究方法对我院自2000年8月～2004年10月治疗的54例股骨远端骨折病例进行对照研究,按A0分类:A1型17例,A2型14例,A3型11例,B1型2例,C1型6例,C2型3例,C3型1例.其中,DCS内固定30例,GSH固定24例.分组统计手术时间,出血量,骨折愈合时间,并发症,膝关节功能.结果 所有病例经5月～2年随访,平均9个月;骨折愈合时间为4.6月(4～9月).DCS固定组平均手术时间1.5小时(1～2.5小时).出血量105 ml(50～200 ml),骨折愈合时间平均4.7月(4～8月),并发症发生5例(发生率16.7%),根据Kolmert膝关节功能评分,优20例,良6例,可4例,优良率为86.6%.GSH固定组手术时间1.8小时(1.5～3.5小时).术中出血量平均120 ml(100～250 ml),平均骨折愈合时间5.1个月(4.5～9个月),并发症发生5例(发生率28%),根据Kolmert膝关节功能评分标准,优15例,良7例,可2例,优良率为91.7%.两组比较,结果无显著差异(P＞0.05) 结论 逆行带锁髓内钉(GSH)及动力髁螺钉(DCS)均是治疗股骨远端骨折的较好方法,但各有其最佳适应症.选择好适应症以及术者技术熟练有利于骨折愈合及关节功能恢复.     

皮质骨圈在椎弓根钉固定系统中支撑作用的生物力学评价

目的：了解脊椎椎弓根钉固定系统在人体皮质骨圈（allograft fusion cage,AFC)植入椎间隙前后对脊柱稳定性的影响。方法：在8具新鲜成年猪离体腰椎标上，以L2－3，L3－R，L4－5节段为实验对象，测试各节段在正常状态下（正常组）、椎间盘切除并Steffee钢板固定（内固定组）、椎间盘切除AFC植入Steffee钢板固定（AFC组）等三种种状态下的轴向压缩刚度。结果：（1）内固定组节段轴向压缩刚度为正常组的14．0％；（2）AFC组节段的轴向压缩刚度明显增加，达到了正常椎间的轴向压缩刚度；（3）在相同轴向压缩载荷作用下，AFC给椎弓根钉受力移位较内固定组明显减小。结论：脊椎椎弓根钉固定系统在AFC椎间植入后，对脊椎稳定性较无AFC植入显著增强，其受力移位明显减小，即可显著减少临床断钉。钢板折弯的机会。     

选择腰椎椎弓根螺钉长度的放射解剖学研究

目的 :探讨在腰椎侧位片及CT片上推算椎弓根螺钉长度的方法 ,为临床提供参考。方法 :随机在 3 0个腰椎骨标本上用 1mm软钢丝在椎弓根最狭窄处缠绕 ,按人字嵴进钉方法打入椎弓根直钢丝 ,拍正侧位片、横断面片及椎弓根CT扫描 ,分别在标本、CT及侧位片上测量椎弓根螺钉长度 ,三组数据比较。结果 :腰椎侧位片上测量的自关节突关节间隙下缘至椎体前缘距离乘以 0 .83即是螺钉长度 ,椎弓根CT扫描测量其长度更为准确。结论 :正常拍照条件下 ,用腰椎侧位片和椎弓根CT片可准确地推算螺钉长度 ,具有临床实用意义。     

椎弓根螺钉在胸腰椎骨折治疗中体会

目的探讨椎弓根螺钉（PS）在胸腰椎骨折治疗中的疗效。方法回顾性分析应用PS治疗胸腰椎骨折的68例病例资料。全部病例均采用分离显露损伤椎体及上下各一个椎体行后路减压,椎弓根螺钉复位内固定,小关节突及横突间和椎间植骨融合的治疗方法。结果随访2-52个月,68例骨折均愈合,58例椎体高度完全恢复,压缩性骨折中6例残留10%-30%的压缩未能恢复,65例植骨融合良好,无内固定松动现象。结论椎弓根是脊柱中最坚强的部位,椎弓根螺钉经椎弓根至椎体固定胸腰椎骨折操作简便、固定可靠、骨折复位和恢复胸腰椎正常弧度可以分步骤完成,重建的脊椎稳定性好,可早期下床活动,为目前胸腰椎骨折治疗中较好的方法之一。     

Radiology of postnatal skeletal development

The development of the second cervical vertebra is complex. The dens (odontoid process) develops two primary ossification centers that usually coalesce within three months following birth. These centers are separated from the primary ossification center of the vertebral centrum by a cartilaginous region—the dentocentral synchondrosis. This synchondrosis is a slow growing, bipolar physis similar to the triradiate catilage of the acetabulum. It contributes to the overall heights of both the dens as well as the vertebral body. Anatomically the dentocentral synchondrosis is below the level of the C1–C2 articulations. This cartilaginous structure is continuous throughout the vertebral body with similar cartilage in both the facet regions as well as the neurocentral synchondroses. These various carulaginous continuities progressively close—first, the connections to the facet regions, next the neurocentral synchondroses, and finally the dentocentral synchondrosis. Remnants of the incompletely closed dentocentral synchondrosis must be distinguished from a fracture, which usually propagates along this structure as a physeal injury in infants and children. The cartilaginous epiphysis at the tip of the dens may be transverse or may form a cleft (V) shape. At eight to ten years, a secondary ossification center—the ossiculum terminale—develops in this proximal dens epiphysis. Fusion of the ossiculum terminale with the rest of the dens occurs between ten and thirteen years.     

Risk Factor Analysis of Facet Fusion Following Cervical Lateral Mass Screw Fixation with a Minimum 1-Year Follow-up: Assessment of Maximal Insertional Screw Torque and Incidence of Loosening

Posterior stabilization is a common surgical procedure, which aims for rigid stabilization by facet fusion. Facet non-union has a potential risk of the screw loosening and malalignment. Although some authors have reported the influencing factors about screw loosening in the lumbar spine, there are few reports about the risk factor contributing to the facet non-union in the cervical spine. In all, 22 patients (78 facets and 122 screws) with degenerative cervical kyphosis or spondylolisthesis who underwent decompression and lateral mass screw (LMS) fixation were analyzed. Age, gender, smoking, bone mineral density (BMD), the degree of facet decortication with bone packing, and screw loosening were investigated as risk factors contributing to the facet non-union at each segmental fused level. Facet fusion rate was 85.9% (67/78 facets) and the incidence of loosening was 4.9% (6/122 screws, 4 patients). Insufficient facet decortication with bone packing is a significant risk factor of facet non-union (p <0.05, odds ratio: 26.5). All six loosened screws were associated with bony non-union of the facet and were located in the uppermost or lowermost vertebrae. Comparing loosened screws and stable screws, the average maximal insertional screw torque (MIT) was 9.8 cNm and 39.5 cNm, respectively (p <0.05). Additionally, the length of the stable screws was significantly longer versus the loosened screws (p <0.05). Lower MIT and shorter screw length located near the ends of the lateral mass may predict loosening, which can lead to facet non-union. Sufficient facet decortication with bone packing is one of the important factors contributing to the facet fusion.