Effect of compressive follower preload on the flexion-extension response of the human lumbar spine.

Traditional experimental methods are unable to study the kinematics of whole lumbar spine specimens under physiologic compressive preloads because the spine without active musculature buckles under just 120 N of vertical load. However, the lumbar spine can support a compressive load of physiologic magnitude (up to 1200 N) without collapsing if the load is applied along a follower load path. This study tested the hypothesis that the load-displacement response of the lumbar spine in flexion-extension is affected by the magnitude of the follower preload and the follower preload path. Twenty-one fresh human cadaveric lumbar spines were tested in flexion-extension under increasing compressive follower preload applied along two distinctly different optimized preload paths. The first (neutral) preload path was considered optimum if the specimen underwent the least angular change in its lordosis when the full range of preload (0-1200 N) was applied in its neutral posture. The second (flexed) preload path was optimized for an intermediate specimen posture between neutral and full flexion. A twofold increase in flexion stiffness occurred around the neutral posture as the preload was increased from 0 to 1200 N. The preload magnitude (400 N and larger) significantly affected the range of motion (ROM), with a 25% decrease at 1200 N preload applied along the neutral path. When the preload was applied along a path optimized for an intermediate forward-flexed posture, only a 15% decrease in ROM occurred at 1200 N. The results demonstrate that whole lumbar spine specimens can be subjected to compressive follower preloads of in vivo magnitudes while allowing physiologic mobility under flexion-extension moments. The optimized follower preload provides a method to simulate the resultant vector of the muscles that allow the spine to support physiologic compressive loads induced during flexion-extension activities.     

撑开式椎板成形术治疗伴有马尾神经损害的腰椎间盘突出症

目的总结分析伴有马尾神经损害的腰椎间盘突出症的临床特点,并对手术方法进行探讨.方法对采用撑开式椎板成形术治疗的26例伴有马尾神经损害的腰椎间盘突出症患者的临床资料进行回顾性分析.结果获得随访资料26例平均随访6年5个月,根据Macnab疗效标准,优17例,良7例,可1例,差1例.优良率92.3%.结论伴有马尾神经损害的腰椎间盘突出症的临床症状重,手术治疗需要彻底减压方能取得优良效果.采用撑开式椎板成形术显露,除具有全椎板切除的优点,还不破坏腰椎后柱的稳定性,最大限度地保留了脊柱的完整性,减小了手术创伤,是行之有效的手术方法.     

体重对腰椎后路开窗减压手术疗效的影响

目的对不同体重老年腰椎管狭窄患者行单纯腰椎后路开窗减压手术,并评价其治疗效果。方法回顾性分析1996年12月～2002年12月间145例因老年腰椎管狭窄而采用单纯腰椎后路开窗减压手术治疗患者的病例资料,结合问卷调查患者对手术的满意程度,比较不同体重患者住院期间及术后症状改善情况,评估手术疗效。结果不同体重患者术后腰腿疼痛明显缓解、日常生活质量改善,患者对手术的满意率达67.59%。而且患者的各种统计数据表明,不同体重组之间差异无显著性意义(P>0.05)。结论体重在一定程度上影响老年腰椎管狭窄患者的手术治疗结果。单纯腰椎后路开窗减压手术,可以达到较为理想的治疗效果。     

三种颈前路钢板重建对维持颈椎曲度和高度的比较

目的对3种不同颈椎前路钢板系统重建并维持颈椎融合节段曲度和高度的作用进行比较.方法 2002年1月～2004年6月,行颈前路减压,自体髂骨植骨,钢板内固定术122例;男85例,女37例,年龄14～70岁.根据采用Orion、Zephir、Codman 3种颈椎前路钢板系统分为A组37例、B组39例及C组46例.于术前、术后1周和随访时摄颈椎侧位X线片,测量融合节段的曲度和高度,并比较其变化及3组间差异.结果术后患者均获随访6～35个月,平均17.3个月.术后6个月3组患者术段颈椎均获骨性融合.且术后1周时颈椎融合节段曲度和高度较术前明显改善(P＜0.05),但最后1次随访时和术后1周比较,差异无统计学意义(P＞0.05),3组间比较差异无统计学意义(P＞0.05).结论 3种钢板系统均能有效重建并维持颈椎融合节段曲度和高度,近期效果优良.     

下腰椎失稳合并椎管狭窄症的手术治疗

目的：观察下腰椎失稳合并椎管狭窄症患者经椎弓根螺钉系统及椎体融合器治疗的效果。方法：采用后路减压，椎弓根螺钉系统内固定，椎体间融合器BAK融合。结果：术后随访1年一4年3个月(平均2年4个月)，椎体间骨性融合率1年89．6％，2年2个月100％，临床症状消失满意率92％。结论：采用椎管减压、椎弓根螺钉系统加椎间融合器固定，可使滑脱失稳的椎体部分或全部复位，保证脊柱骨性融合，达到脊柱稳定、解除症状的目的。     

Role of technetium-99m planar bone scanning in the evaluation of low back pain

The records of 1018 patients with low back pain in a tertiary spine referral practice were reviewed. One hundred thirty-nine out of 1018 (13.6%) underwent technetium-99m planar bone scanning as part of their investigation. Seventy-three out of 139 scans (52%) showed increased uptake in some area, but only 27 out of 139 (19.4%) showed increased uptake specifically in the low back. Scans consistently yielded no findings with reference to the back when the prescan diagnosis was spinal stenosis, lumbar pain syndrome, herniated nucleus pulposus, or postlaminectomy syndrome. Some scans gave positive findings in patients with a diagnosis of degenerative disc disease, pseudarthrosis, spondylolisthesis, fracture, infection, metabolic disorder, or tumor. Positive scans were generally obtained early after presentation (within 3 months) and negative scans obtained later (after 6 months), suggesting that clinical suspicion is still the main indication for early scanning. Planar bone scanning was helpful in both diagnosis and therapeutic decisionmaking in many conditions.     

伴上肢局部水肿的颈椎病与颈椎减压术的关系

[目的]探讨伴有上肢局部水肿的颈椎病患者的发病机理和与手术颈椎减压的关系。[方法]总结分析4a来收治的10例伴有上肢局部水肿的颈椎病人，其中脊髓型颈椎病7例，神经根型颈椎病2例，后纵韧带骨化型1例，7例行前路椎体次全切减压植骨内固定，1例行前路椎体次全切＋单间隙间盘摘除植骨内固定，2例行后路减压植骨内固定，术后观察患者水肿消退情况。[结果]10例病人上肢局部水肿不同程度消退，前路手术者较后路手术者消退快。[结论]颈椎病患者上肢水肿的发生与颈交感神经受激惹有关，通过前路或后路颈椎管减压，去除颈椎不稳、椎间盘突出、骨赘等交感神经受激惹因素，水肿可逐步消退。     

肌电图对腰神经后根节段定位作用的实验研究

目的:探讨应用肌电图行大鼠腰神经后根节段定位的方法。方法:通过电生理的方法,依次电刺激L3￣L5脊神经后根,分别记录大鼠双侧下肢主要肌肉的肌电图像,测量最早出现的感觉神经动作电位(SNAP)最大波幅值。结果:刺激L3脊神经后根,于股四头肌记录到的波幅峰值(480.8±255.9μV)显著高于其它各组肌肉(P<0.01)。刺激L4脊神经后根,于下肢四组肌肉记录到的CMAP最大波幅平均值均>100μV,其中在股四头肌(305.2±131.5μV)、胫骨前肌(340.2±310.4μV)记录到的波幅峰值显著高于在股二头肌(142.4±144.7μV)、腓肠肌(138.2±127.6μV)记录到的波幅峰值(P<0.01)。刺激L5脊神经后根,于股二头肌(377.5±264.4μV)、腓肠肌(168.4±126.7μV)记录到的波幅峰值显著高于其它各肌群记录到的波幅峰值(P<0.01)。结论:电刺激不同脊神经后根,在大鼠下肢不同肌肉记录到的SNAP的波幅峰值存在差异,综合分析记录到的SNAP的波幅峰值,可作为腰神经后根节段定位的参考。     

计算机体层成像多平面重建在评价椎间融合中的作用

目的 探讨计算机体层成像多平面重建(CTMPR)在评价椎间融合中的作用,寻找定量评价椎间融合的新方法.方法 13例行腰椎间融合的患者术后1周、3个月、6个月行CTMPR,行椎间融合器(Cage)内植骨CT值定量测量.结果 术后1周Cage内植骨CT值为(619.52±26.97)Hu,术后3个月为(628.69±42.60)Hu,术后6个月为(657.77±37.43)Hu.术后1周与术后3个月相比无显著性差异,与术后6个月相比有显著性差异.结论 CT值的测量在椎间融合的判断中具有高准确性.