短节段DRFS脊柱内固定术后即刻刚度的变化及其意义

目的测试短节段猪脊柱标本在完整、失稳后及内固定后的刚度变化。方法选择12节段猪脊柱标本12具,测定其前屈、后伸、侧屈及旋转时的刚度;切除椎间盘、小关节及前后纵韧带松解脊柱,测定其各项运动刚度;用DRFS脊柱内固定系统进行短节段内固定后重复测试各项运动刚度。结果与完整脊柱的刚度（前屈、后伸、侧屈及旋转的刚度分别为0.389±0.305,1.090±0.355,1.012±0.301,1.232±0.441,1.103±0.414,1.013±0.402）相比,失稳后脊柱各项运动的刚度（前屈、后伸、侧屈及旋转的刚度分别为0.216±0.218,0.278±0.204,0.255±0.124,0.409±0.169,0.633±0.218,0.626±0.216）均明显减少（P〈0.05）,而内固定后脊柱各项运动的刚度（前屈、后伸、侧屈及旋转的刚度分别为（0.568±0.351,0.679±0.151,0.759±0.314,0.729±0.311,1.006±0.304,0.975±0.218）均明显高于失稳后脊柱,与完整脊柱前屈、侧屈及旋转运动无明显差异,后伸运动的刚度明显高于完整脊柱（P〈0.01）。结论短节段脊柱内固定后各项运动的刚度明显高于脊柱失稳后,与完整标本相比除后伸运动的刚度明显增高外,其余各方向的运动刚度相近。     

滑动椎弓根钉系统稳定性体外生物力学测试

[目的]对滑动椎弓根钉系统(SPSS)与通用椎弓根钉系统(USS)在脊柱侧凸固定强度、刚度和稳定性等方面进行生物力学比较,以测试滑动椎弓根螺钉内固定系统稳定性的生物力学性能.[方法]采用12具猪新鲜脊柱标本,随机分成两组分别测量不同工况下T12椎体的位移,并计算其强度和刚度进行比较.[结果]滑动组和通用组无论在轴向压缩、前屈、后伸、侧屈情况下,主应变、位移变化及固定强度、刚度均无显著性差异(P>0.05).[结论]滑动椎弓根钉系统治疗脊柱侧凸同样能够达到通用椎弓根钉系统相同的矫形效果及生物力学稳定性,同时它不影响青少年生长发育.     

脊柱前中柱稳定性对椎弓根螺钉内固定器前屈压缩刚度的影响及其意义

目的 分析脊柱前中柱稳定性对椎弓根螺钉内固定器固定后前屈压缩刚度的影响,并探讨其临床意义。方法 收集7具新鲜猪T_(10)～L_4节段胸腰椎脊柱标本,“Ⅴ”形切除L_1椎体并压缩至闭合,造成前中柱不稳,模拟L_1骨折后安放AF椎弓根内固定器,进行前屈-压缩测试,分别计算完整标本、损伤标本和内固定后标本的前屈-压缩刚度。结果 完整标本、损伤标本和固定后标本的前屈-压缩刚度分别为413.9±118.6N/mm、136.6±31.6N/mm、240.5±51.4N/mm。相互间差异显著 (P<0.001)。结论 脊柱前中柱失稳后,经椎弓根螺钉内固定器械固定不能使其恢复到正常的机械力学性质,特别是前屈-压缩方向上。胸腰椎脊柱骨折经椎弓根螺钉系统固定后恢复前中柱的机械力学性质,减少其载荷分享是防止术后角度丢失,避免内固定器械固定失败的关键。     

胸腰椎爆裂性骨折伤椎固定的生物力学研究

目的 比较跨节段椎弓根钉固定与三椎体六枚椎弓根钉固定术固定胸腰椎骨折的生物力学效果。方法 采用8具新鲜小牛椎体标本（T11-L3）,MTS机压缩制作L1椎体爆裂性骨折模型。实验分完整状态组、骨折组、跨节段椎弓根钉固定组、三椎体六枚椎弓根钉固定组。应用脊柱三维运动试验机对标本进行前屈,后伸,左、右侧弯及左、右旋转6个方位的运动范围（ROM）测试并计算刚度值,所得数据进行统计学处理,比较各组间差异。结果 脊柱骨折状态6个方向ROM均显著增加（P〈0．05）,椎间刚度值明显降低（P〈0．05）;固定状态的ROM均较完整状态、骨折状态显著减小（P〈0．01）,而刚度值均较完整状态、骨折状态增大,差异有显著性意义（P〈0．05）;跨节段椎弓根钉固定组与三椎体六枚椎弓根钉固定组之间的ROM、刚度值差异均无显著性意义（P〉0．05）。结论 跨节段椎弓根固定与三椎体六枚椎弓根钉固定术在重建脊柱骨折稳定性方面,效果无明显差异。     

脊柱失稳节段经椎弓根螺钉内固定器固定后对邻近节段三维运动的影响

目的研究经椎弓根螺钉内固定器固定脊柱失稳节段后对邻近节段三维运动范围的影响.方法在7例新鲜成人尸体T10～L4脊柱标本上,模拟L1骨折后安放经椎弓根螺钉内固定器,在10.0N@m载荷下进行三维运动测试.分析脊柱固定阶段(T12～L2)、邻近节段(T11～T12、L2～L3)和总节段(T11～L3)的前屈、后伸、轴向旋转和侧弯运动范围.结果经椎弓根螺钉内固定器固定后能使固定节段屈伸、侧弯运动方向上运动范围减少,轴线旋转运动恢复至正常完整节段运动范围.但同时邻近节段屈伸、侧弯运动运动范围增加,轴向旋转运动范围无明显变化.固定后总节段比正常完整总节段屈伸、侧弯运动运动范围增加,轴向旋转运动范围无明显变化.结论经椎弓根螺钉内固定器固定使邻近节段屈伸和侧弯运动范围代偿性增加,但不能代偿丢失的运动范围,对邻近节段的轴向旋转无明显影响.     

颈椎分离损伤内固定的抗旋转和前屈强度测试

目的：比较四种颈椎内固定方法的旋转和前屈强度。方法：成年新鲜猪第２７颈椎标本５具，每具切取３个脊柱功能单位试件，切断椎间连接造成三柱分离性损伤，采用椎弓根钉、关节突钉、棘突钢丝、椎体钢板将椎骨两两固定，测试它们的旋转和前屈强度及位移大小。结果：椎弓根固定试件的旋转和前屈破坏力最大，加载过程的旋转位移大于正常，前屈位移小于正常，固定最牢。椎体钢板固定的旋转破坏力大于关节突和棘突钢丝试件，前屈破坏力小，位移大。关节突固定的旋转破坏力大于棘突钢丝，角位移小。结论：颈椎严重损伤在选用内固定后，由于抗旋转和前屈强度及位移差异，可适当辅以外固定     

单节段与双节段椎弓根螺钉固定胸腰椎单椎体骨折的生物力学比较

目的:比较单节段与双节段椎弓根螺钉固定术固定胸腰椎单椎体骨折的生物力学效果。方法:在16具新鲜小牛胸腰椎标本(T11-L3)的L1椎体上制作不完全爆裂骨折模型,分为两组,分别行单节段与双节段椎弓根螺钉固定,对固定后的标本施加扭矩为4Nm的疲劳载荷共2000次,加载频率为0.5Hz,经脊柱三维运动测量系统测量正常、损伤、固定和周期性加载后固定节段前屈/后伸、左/右侧弯和左/右旋转运动时固定节段的运动范围。结果:单节段固定组前屈、后伸、侧屈、旋转稳定指数(SPI)分别为0.78、0.80、0.92、0.83,双节段固定组SPI分别为0.88、0.89、0.95、0.85,在前屈方向单节段固定组明显小于双节段固定组(P<0.01);疲劳后,单节段固定组SPI在前屈、后伸、侧屈、旋转方向分别降低0.05、0.03、0.05、0.11,降低值均大于双节段固定组,且在旋转和侧屈方向有显著性差异(旋转:P<0.01;侧屈:P<0.05)。结论:两种术式均可重建脊柱骨折即刻稳定性,效果无明显差异。在旋转、侧屈方向,双节段椎弓根螺钉固定术抗疲劳载荷效果优于单节段固定术。     

脊柱骨折经伤椎椎弓根置钉附加横连短节段固定的稳定性测试

目的:探讨脊柱骨折经伤椎椎弓根置钉附加横连短节段钉棒固定的稳定性.方法:5具新鲜冰冻小牛腰椎标本(L1～L5)制备成L3椎体爆裂骨折模型,依次进行单纯经伤椎和上下相邻椎体椎弓根置钉短节段6钉固定(单纯经伤椎6钉固定组)和附加横连经伤椎和上下相邻椎体椎弓根置钉短节段6钉固定(附加横连经伤椎6钉固定组),测试L2～L4损伤前(对照组)、损伤后(骨折组)及单纯经伤椎6钉固定组和附加横连经伤椎6钉固定组的三维6个方向的运动范围(ROM),比较各组间的差异.结果:L3椎体爆裂骨折后L2～L4各方向的ROM明显增加,与损伤前比较均有显著性差异(P<0.05);单纯经伤椎6钉固定组与附加横连接经伤椎6钉固定组各方向的ROM均明显减小,与骨折组相比均有显著性差异(P<0.05),在前屈、后伸、侧弯运动方向的ROM小于对照组,差异有显著性(P<0.05),旋转方向上大于对照组(P<0.05).两种固定方式在前屈、后伸、侧弯方向上的ROM无显著性差异(P>0.05),附加横连经伤椎6钉固定组较单纯经伤椎6钉固定组在旋转方向上的ROM小,差异有显著性(P<0.05).结论:经伤椎椎弓根置钉短节段钉棒固定可提高骨折模型各个运动方向上的生物力学稳定性,附加横连经伤椎6钉固定技术较单纯经伤椎6钉固定技术在轴向旋转运动方向上可提供更强的力学稳定性.     

胸腰椎骨折伤椎短椎弓根钉固定的生物力学研究

[目的]通过生物力学测试对胸腰椎爆裂性骨折伤椎单侧短椎弓根钉固定的稳定性及刚度进行评价.[方法]取18具新鲜小牛胸腰段(T11 ～L3)标本,制作成胸腰椎爆裂性骨折模型,测试跨节段4枚椎弓根钉固定(4钉组)、伤椎单侧短椎弓根钉固定(5钉组)、伤椎双侧椎弓根钉固定(6钉组)标本模型的轴向压缩刚度及三维6个方向的运动范围(ROM).[结果]4钉组、5钉组、6钉组三种固定方式,均能提高骨折模型的稳定性及刚度;5钉组、6钉组模型刚度均明显高于4钉组,差异有统计学意义(P＜0.05),5钉组、6钉组模型在屈伸、侧弯、旋转6个方向的运动范围(ROM)均明显低于4钉组,差异有统计学意义(P＜0.05);而5钉组与6钉组模型之间的刚度比较差异无统计学意义(P＞0.05),5钉组与6钉组模型在屈伸、侧弯、旋转6个方向的运动范围(ROM)的比较差异无统计学意义(P＞0.05).[结论]对于胸腰椎爆裂性骨折,伤椎置钉固定能明显提高脊柱的刚度及稳定性,经伤椎单侧短椎弓根钉固定与伤椎双侧椎弓根钉固定对脊柱刚度及稳定性的影响无明显差异.     

腰椎横突间入路椎体间融合术的生物力学评价

目的 观察腰椎横突间入路椎体间融合术(ILIF)及附加椎弓根钉固定后的生物力学稳定性.方法 采用小牛脊柱运动节段标本12具,依序进行不同处理后分为以下7组:(1)正常对照组(IS);(2)左侧小关节切除+椎间融合器植入组(TLIF);(3)TLIF附加同侧椎弓根钉固定组;(4)TLIF附加双侧椎弓根钉固定组;(5)左侧横突间入路椎间融合器植入组(ILIF);(6)ILIF附加同侧椎弓根钉固定组;(7)ILIF附加双侧椎弓根钉固定组.分别测试各组在轴向压缩、前屈、后伸、左右侧屈时的载荷-应变、载荷-位移变化以及轴向刚度和双向扭转稳定性等生物力学指标,并进行统计学比较.结果 所有生物力学指标中ILIF组稳定性均大于TLIF组(P<0.05),在定量扭矩扭角方面差距最大达72%.ILIF+BPSF的稳定性最高,在前屈载荷应变方面较IS组差异最大达53%,而ILIF+HPSF组与ILIF+BPSF组比较差异无统计学意义(P>0.05). 结论 ILIF手术生物力学稳定性优于TLIF手术;ILIF附加同侧椎弓根钉固定与附加双侧椎弓根钉固定生物力学稳定性相当,使用ILIF术式附加侧同椎弓根螺钉固定,可提供较好的即刻稳定性.     

Lumbar lateral interbody cage with plate augmentation: in vitro biomechanical analysis

Many studies have concluded that stand alone cages provide limited stabilization to the spine, and this primary stabilization decreases postoperatively due to various factors. A supplemental fixation may, therefore, be needed to improve the stability. Extensive biomechanical analysis was performed in the present study to further evaluate the stabilization achieved by a laterally inserted cage and the role of an anterior lateral supplemental fixation. Eight human cadaver functional spinal units were subjected sequentially to four different test conditions: (1) intact, (2) instrumented laterally with a long cylindrical threaded cage, (3) the same cage supplemented with a lateral fixation plate, the plate being firmly connected to the cage, and (4) removal of the connection between the plate and the cage. Pure moments were applied to each specimen in a quasi static manner, ranging from -7 Nm to 7 Nm in flexion/extension, lateral bending and axial rotation. Three-dimensional segmental motions were simultaneously recorded under each loading condition. Statistical analysis was carried out on the motion parameters, including the range of motion (ROM) and the neutral zone (NZ). Inter-group comparisons were made using the Friedman test and the Wilcoxon test. The results showed that the stand alone lateral cage provided stabilization by increasing segmental stiffness above that of the intact spine. The stiffness increase ratios were: 1.6 in flexion/extension ( P=0.07), 1.3 in lateral bending ( P=0.4) and 1.0 in axial rotation ( P=0.67). A supplemental plate provided significant reinforcement of the stabilization. The stiffness increase ratios relative to the intact spine were: 3.1 in flexion/extension ( P=0.012), 5.0 in lateral bending ( P=0.012) and 2.3 in axial rotation ( P=0.012). After removal of the connection between the cage and the plate, the stiffness ratios were: 2.7 in flexion/extension ( P=0.027), 4.6 in lateral bending ( P=0.027) and 2.1 in axial rotation ( P=0.027). Globally, the cage alone increased the segmental stiffness above that of the intact spine by a factor of 1.1 ( P=0.39), with the supplemental plate, segmental stiffness increased by a factor of 3.1 ( P<0.01), and the unconnected cage/plate increased stiffness by a factor of 3.0 ( P=0.02). Supplementation of the lateral cage with an anterolateral plate was thus shown to provide significant additional stabilization in all directions, which may potentially compensate for the postoperative decrease in segmental stability.     

不同类型前路钢板固定应用于颈椎屈曲牵张型损伤的生物力学研究

目的探讨采用前路钢板固定颈椎屈曲牵张型损伤治疗的可靠性,并比较静力化固定和动力化固定等不同设计类型钢板在恢复损伤节段稳定性方面的差异。方法采用12具小牛颈椎标本,在C_(4,5)节段制作屈曲牵张损伤模型,切除椎间盘、植骨后随机分为3组,分别采用Orion、Codman、Window钢板、螺钉固定,测试手术固定各组在颈椎前屈、后伸、侧屈及旋转运动时的稳定性并与正常标本比较。结果颈椎屈曲损伤后,无论采用哪种钢板固定,其术后运动范围(ROM值)均比正常颈椎要大。Orion固定最接近正常标本,但在旋转运动时有明显差异。Codman固定仅在侧曲时的稳定性接近正常和Orion固定组。Window固定最弱,在各运动状态下的刚度均明显低于正常组。结论在颈椎屈曲牵张型损伤时,前路静力化固定相对稳定,动力化固定可能牺牲一定的固定强度,尤其是选择平移类设计的钢板固定更要谨慎。     

The development of a dynamic,six-axis spine simulator

Background contextAlthough a great deal of research has been completed to characterize the stiffness of spinal specimens, there remains a limited understanding of the spine in 6 df and there is a lack of data from dynamic testing in six axes.PurposeThis study details the development and validation of a dynamic six-axis spine simulator.Study designBiomechanical study.MethodsA synthetic spinal specimen was used for the purpose of tuning the simulator, completing positional accuracy tests, and measuring frequency response under physiological conditions. The spine simulator was used to complete stiffness matrix tests of an L3–L4 lumbar porcine functional spinal unit. Five testing frequencies were used, ranging from quasistatic (0.00575 Hz) to dynamic (0.5 Hz). Tests were performed without an axial preload and with an axial preload of 500 N.ResultsThe validation tests demonstrated that the simulator is capable of producing accurate positioning under loading at frequencies up to 0.5 Hz using both sine and triangle waveforms. The porcine stiffness matrix tests demonstrated that the stiffness matrix is not symmetrical about the principal stiffness diagonal. It was also shown that while an increase in test frequency generally increased the principal stiffness terms, axial preload had a much greater effect.ConclusionsThe spine simulator is capable of characterizing the dynamic biomechanics of the spine in six axes and provides a means to better understand the complex behavior of the spine under physiological conditions.     

Bioactive bone cement as a principal fixture for spinal burst fracture: an in vitro biomechanical and morphologic study

STUDY DESIGN: An in vitro biomechanical and radiographic study to evaluate the properties of a newly developed bioactive bone cement for stabilization of the fractured spine, suitable for minimally invasive application. OBJECTIVES: To determine the mechanical stability of the fractured spine after injection of the newly developed bioactive bone cement under quasi-static and cyclic loading regimens. SUMMARY OF BACKGROUND DATA: Bone cement injection has been reported as a potentially useful, minimally invasive technique for treating vertebral body fracture or stabilizing osteoporosis. However, potential problems associated with the use of polymethylmethacrylate (PMMA) have prompted the search for alternative solutions. The use of bioactive bone cement as a potential replacement for PMMA has been reported. METHODS: Biomechanical and radiographic analyses were used to test the mechanical stability of the fractured spine. The cement used was formed from hydroxyapatite powder containing strontium and bisphenol A diglycidylether dimethacrylate (D-GMA) resin. Twenty-six fresh porcine spine specimens (T10-L1) were divided into three groups: pilot, intact, and cemented. Spinal stiffness and failure strength were recorded in the intact group with the specimens flexed at 10 degrees. Uniform injuries were created in all specimens of the cemented group, and compressive loading was applied with 10 degrees of flexion until a fracture occurred. The bone cement was injected into the fractured spine, and stiffness was evaluated after 1 hour. Failure strength was also recorded after 3000 and 20,000 fatigue load cycles. Morphology of the specimens was observed and evaluated. RESULTS: Results from a cell biocompatibility test indicated that the new bioactive bone cement was favorable for cell growth. Spinal stiffness significantly decreased after fracture (47.5% of intact condition). Instant stiffness of the spine recovered to 107.8% of the intact condition after bone cement injection. After 3000 and 20,000 cycles of fatigue loading, stiffness of the cemented spine was found to be 93.5% and 94.4% of intact stiffness, respectively (P < 0.05). Average failure strength of the spine was 5056 N (after 3000 cycles) and 5301 N (after 20,000 cycles) after bone cement injection and fatigue loading. Radiographs and cross-sectional observations indicated a good cement-bone bonding and fracture fill. CONCLUSIONS: A new bioactive bone cement without cytotoxic effect has been developed. Results show that minimally invasive techniques to apply this cement to porcine spines results in augmentation of mild burst fractures such that the original stiffness and strength of the vertebra are recovered. This new cement therefore shows potential as an augmentation to traditional instrumentation in the surgical management of vertebral fractures. The potential for further clinical applications is currently under investigation.     

Kinematics of the chest cage and spine during breathing in healthy individuals and in patients with adolescent idiopathic scoliosis.

STUDY DESIGN: The lung function test by a Plethysmograph enabled calculations to be made of the total lung capacity and vital capacity. A Motion Analysis System (Elite, BTS Inc., Milano, Italy) was used to observe and record chest cage and spinal movements and as to correlate lung function with the chest cage and spine kinematics. OBJECTIVES: To determine the three-dimensional kinematics and the shape and size changes of the chest cage and thoracic spine motion during deep breathing in healthy and scoliotic individuals. SUMMARY OF BACKGROUND DATA: Lateral flexion plus rotation of the involved vertebrae around a vertical axis causing a decrease in lung function is the main disfigurement of scoliosis. Reports show that even after spinal fusion, reduced vital capacity associated with an increased residual volume are detected. Factors such as angle of scoliosis, length of the spinal column involved, and duration of the deformity influence pulmonary function but do not significantly affect its reduction. Mechanical inefficiency during breathing has not been studied. METHODS: Three-dimensional kinematics of the chest cage and spine during breathing were studied in 41 scoliotic patients and in 20 healthy individuals. Three-dimensional chest cage motions relative to the spine and thoracic spine motions relative to T12 were calculated. To examine stiffness of the spine, lateral bending angles were calculated. The lung function test, which including spirometry and lung subdivision, also was performed for the scoliotic patients. RESULTS: Significant differences (P < 0.05) were found in the movements of the upper level of the chest cage in anteroposterior and vertical directions, ranging from 16.7 to 28.6 mm in healthy individuals and from 12.1 to 24.2 mm in scoliotic patients. The thoracic spine displayed two-dimensional movements posteriorly and vertically during breathing, whereas less movement was seen in scoliotic patients. In addition, overall the scoliotic spine showed signs of stiffness in lateral bending. CONCLUSIONS: The range of movement of the chest cage and spine is more limited in the scoliotic cases. This overall stiffness of the chest cage and the spine may contribute to the mechanical inefficiency and impairment of pulmonary function found in scoliotic patients.     

脊柱刚度测试系统信度研究

目的:通过动物实验,检测脊柱刚度测试系统(spine stiffness test system,SSTS)的信度。方法:将100只350～450g雄性SD大鼠随机分为5组,分别饲养1、2、4、8、12周,每只大鼠均使用棘突外部连接固定系统对其L4、L5和L6进行外部连接固定。在各自饲养期结束时,使用SSTS进行固定节段的刚度检测,并观察连接时间对大鼠造模节段刚度的影响;为保证SSTS压力测量的准确性,使用前对其压力探头进行标定。结果:SSTS加载探头的实际误差小于0.04%,其误差范围符合实际测试要求;刚度检测结果显示SSTS具有较好的可靠性,组内相关系数ICC=0.948(P<0.01),且大鼠造模节段的刚度随连接时间的延长而增加。结论:SSTS具有较好的准确性和可靠性,其控制软件操作简单、易于掌握,可准确采集各点的压力载荷和脊柱运动节段产生的微小位移参数,但在固定辅件的选择、测量范围的确定、干扰变量的区分等方面仍需改进,以便SSTS适用于更多脊柱伤病模型。     

Comparison of lumbosacral fixation devices

Fusion of L4 and L5 to the sacrum has a high incidence of success. Using conventional methods, nonunion is common when long scoliosis fusions are extended to the sacrum. Three methods of instrumentation for fusing the lumbar spine to the sacrum were compared on a spine simulator test stand. Harrington distraction rods from the sacral ala to L1, Luque rods from L1 to the sacrum, and Harrington compression rods from L1 to the sacrum were tested. The use of a spine instrumentation test stand discounted biologic variation in spinal structure. Sequential loading of each test stand-instrumentation construct in torsion, flexion, extension, and lateral bending gave stiffness constants (Ks) for each test mode. Test values had reproducibility of greater than 94%. Ks illustrates the inability of Harrington distraction rods to the sacrum to resist flexion and torsion, but the ability to resist lateral bend and extension. Harrington compression rod and Luque rod constructs have equivalent stiffness in flexion and torsion. Harrington compression rods efficiently resist extension, and Luque rods resist lateral bending. Harrington distraction rods have limited use in lumbosacral junction fixation other than to correct and resist lateral bending.     

颈椎后路单开门手术对颈椎三维运动及刚性的影响

目的研究颈椎后路单开门椎管扩大成形术对颈椎三维运动及刚性的影响。方法脊髓型颈椎病单开门手术后病例 55例,平均随访 35.9个月,对手术前后的颈部轴性症状、神经功能变化 (JOA评分 )和颈椎动态侧位片进行比较。运用 ZMS－ 1型人体颈椎三维运动及刚度测试仪对颈椎单开门术后组 (12例 )和术前对照组 (10例 )进行活体力学测试。测试内容包括 :(1)颈椎主动及被动运动范围; (2)载荷－位移关系和颈椎刚度; (3)颈椎伸、屈肌群主动等长收缩力矩。结果术后 JOA评分平均改善率 66.2％,优良率 78.2％。术后出现明显或严重颈部轴性症状的病例较术前增加 (P< 0.01);术后颈部轴性症状明显者颈椎弧度较小 (P< 0.01);颈部轴性症状分级与 JOA评分改善率两者差异无显著性意义 (P >0.05)。手术后颈椎区域主动及被动伸屈、旋转和侧屈运动范围减小 (P< 0.05),主要影响中下颈椎。颈椎载荷－位移关系可拟合为指数方程 T=b0e。在颈椎各向运动中侧屈刚度最大,其次为后伸与前屈,旋转刚度最小。术后组颈椎刚度大于术前组。结论单开门手术损害颈椎矢状面的静态力学平衡,并使颈椎运动范围减小、柔韧性下降。颈椎弧度改变同颈部轴性症状轻重相关,而与 JOA评分改善率无关。     

Comparison of motion restriction and trunk stiffness provided by three thoracolumbosacral orthoses (TLSOs)

The amounts of thoracic and lumbar spine motion restriction and passive trunk stiffness provided by three thoracolumbosacral orthoses (TLSOs) (Aspen TLSO, Boston Body Jacket, and CAMP TLSO) were compared. Ten subjects executed maximum trunk flexion, extension, and lateral bending motions. The spine motion was measured noninvasively with a thin strain gauge device (Flexducer), and passive trunk stiffness around the neutral posture was estimated from an electromyography-assisted biomechanical model. No significant differences in either the restriction of motion or the amount of added passive trunk stiffness were found between the three orthoses. The subjects also did not perceive any difference in the restriction of motion but rated the Aspen TLSO significantly more comfortable than the other two orthoses. The rigid custom orthosis design may not be important for restricting the spine motion and providing passive trunk stiffness, or there may be other measures that reflect better the function of orthoses.