腰椎间盘突出人工髓核置换术的生物力学测试

目的 对腰椎间盘人工髓核置换术进行生物力学评价，为临床应用提供理论依据。方法 取6具新鲜成人尸体腰椎标本（L1～S1），制成三种L4～L5运动节段的试验模型：正常腰椎，椎间盘髓核切除术后，人工髓核植人术后，分别对其进行生物力学测试，记录不同运动状态下脊柱节段运动范围（ROM）的改变情况。结果 与正常脊柱组比较，去髓核组运动节段活动明显增大（P〈0．05），稳定性下降，人工髓核植入组与去髓核组比较运动节段活动明显减小（P〈O．05），与正常脊柱组相比较，运动节段活动差异无显著性（P〉0．05）。结论 腰椎椎间盘人工髓核的植人能较好地恢复腰椎间盘髓核摘除后运动节段的生物力学稳定性。     

腰椎间盘突出症髓核的组织学研究及其临床意义

作者自１９９０年８月～１９９４年１２月间，将１２８例腰椎间盘突出症摘除的髓核组织，与对照组共５６个髓核组织制成ＨＥ标本进行组织学观察．结果发现：腰椎间盘突出症组（１）７４例（５７．８１％）的髓核中有脊索细胞（Ｐ值＜０．０５），其中３０岁、４０岁年龄组髓核中的脊索细胞所占比率明显高于其他年龄组；（２）１０４例（８１．２５％）的髓核中有退变的脊索样细胞（Ｐ值＜０．００５）；（３）２８例破裂型腰椎间盘突出症的髓核中２４例（８５．７１％）有脊索细胞，较其他类型明显增高．而对照组５具胎儿和新生儿尸体的２０个髓核中均有脊索细胞；５例胸腰段外伤性骨折病人的１０个髓核及９具成人尸体的５６个髓核中均未见到脊索细胞．本结果提示：如脊索细胞性髓核向纤维软骨性髓核移行过程发生障碍，仍保留为脊索细胞或脊索样细胞是发生腰椎间盘退变的因素之一．     

新型可注射性人工髓核的生物力学测试

目的:对自行研制的新型可注射性人工髓核进行体外生物力学测试,为其应用于临床提供实验依据.方法:将用聚碳酸酯聚氨酯(PCU)被囊和硅橡胶填充物制备而成的人工髓核在生物力学测试机上进行压缩模量试验、静刚度试验、动刚度试验、屈服极限试验,记录相关数据,并进行相关分析.结果:以10N/s的速度对假体纵向缓慢加载到150N、250N、350N、500N、1000N时人工髓核的应力和应变成非线性关系,弹性模量约为2.5MPa:以10N/s的速度纵向加载到1000N过程中静刚度逐渐增大,且为非线性;以10N/s的速度缓慢纵向加载到400N时,动刚度在0.5～3Hz激振频率范围内其应力滞后于应变的相位角约为13°,在激振频率为3Hz时,动刚度约为静刚度的3.5倍:以10N/s的速度从500N～2000N范围内缓慢加载,填充物没有塑性变形;在1200N时,1个假体发生屈服.结论:新型可注射性人工髓核具有良好的粘弹性,抗形变能力强,可试用于动物体内研究,但材料尚需进一步改进.     

聚乙烯醇水凝胶人工髓核置入对腰椎运动影响的生物力学研究

目的：研究髓核摘除后聚乙烯醇水凝胶人工髓核置入对腰椎活动度和椎间隙高度的影响.方法：对7具新鲜成人尸体L4/5正常椎间隙、髓核摘除后和置入人工髓核后在8.0Nm扭矩下的屈伸、侧弯和旋转的活动度（ROM）、中性区（NZ）和椎间隙高度变化进行测试、比较.结果：髓核摘除后,L4/5椎间屈伸、侧弯、旋转的ROM和NZ较正常组显著增加（P＜0.05或0.01）,在0和200N的负荷下椎间隙高度较相同情况下正常组分别下降1.2mm和1.7mm;置入人工髓核后,相对于正常椎间隙,L4/5椎间屈伸、侧弯、旋转的ROM和NZ无明显差异,较髓核摘除组明显下降（P＜0.05或0.01）,在0N和200N的负荷下椎间隙高度较相同情况下髓核摘除组分别增加1.6mm和2.0mm.结论：聚乙烯醇水凝胶人工髓核置入椎间盘切除后的椎间隙可有效恢复椎间隙高度,维持腰椎节段正常的三维运动功能稳定性.     

等离子髓核低温消融叠加经皮髓核切除术治疗腰椎间盘突出症

目的 探讨应用等离子髓核低温消融叠加经皮髓核切除术治疗腰椎间盘突出症的疗效.方法 2004年11月-2005年11月间,对60例腰椎间盘突出症患者行等离子髓核低温消融叠加经皮髓核切除术并作术后随访分析.结果 全部病例术后随访3-11月,优44例、良13例、可2例、差1例,优良率达到95%.结论 应用等离子髓核低温消融叠加经皮髓核切除术的优势互补技术是一种行之有效的微创治疗,相对应地拓宽了适应症,扩大了微创技术在腰椎间盘突出症治疗中的应用空间.     

正常髓核细胞的黏弹性研究

目的 观察正常髓核细胞的黏弹性。方法 髓核组织取材于3例脊柱侧凸矫形手术者术中取出废弃的髓核组织,用胰蛋白酶和Ⅱ型胶原酶消化分离细胞,Ⅱ型胶原免疫荧光组化和蕃红染色进行细胞鉴定,测量细胞直径,采用微管吸吮技术分析髓核细胞的黏弹性特性。结果 髓核细胞直径为(15.40±1.83)μm,正常髓核细胞的黏弹性参数k1(0.101 ±0.052) kPn、k2(0.353±0.199) kPa和μ(3.034±1.843) kPa·s。直线相关性分析表明,仅k1与髓核细胞直径明显相关(r=-0.389,P＜0.05)。结论 正常髓核细胞表现为典型的黏弹性固体蠕变特征;微管吸吮技术可以作为测量髓核细胞生物力学特性的可靠方法。     

皮肤伸展术后生物力学和组织学的实验研究

目的：观察皮肤伸展作用后生物力学特性和组织学的改变。方法：取４只体重２０ｋｇ左右的猪为实验动物,采用自身对照方式进行,对伸展作用侧及对照侧皮肤标本分别进行拉伸断裂强度,拉伸断裂伸长百分率、皮肤本构关系等生物力学指标的测定及组织学的检查。结果：伸展皮肤的粘弹性下降,组织学观察可见伸展后表皮细胞层次增多,真皮层稍变薄。结论：皮肤伸展作用后,其生物力学性质及组织学均有明显变化。临床上可采用皮肤伸展术,以     

腰椎髓核摘除后小关节应力分析

[目的]研究L4、5正常腰椎节段、髓核摘除术后腰椎节段小关节的应力大小和分布情况.[方法]利用有限元软件Ansys,建立L4、5正常节段和髓核摘除术后三维有限元模型.固定模型L5椎体下终板,在L4椎体上终板施加400 N的轴向压缩载荷,并在L4椎体上终板分别向模型施加前屈、后伸和右旋转力,力矩大小均为6 Nm.分析各个状态下腰椎小关节的应力分布情况.[结果]建立了L4、5腰椎节段正常、髓核摘除术后的三维有限元模型.小关节处理为三维接触模型,线性、面接触单元,无摩擦,由上下关节突关节面及韧带结构组成.正常模型两侧小关节在右旋转时均产生较大应力,而以左侧小关节产生应力更大.髓核摘除模型在前屈、后伸、旋转时小关节的应力均增加.[结论]在腰椎不同的运动状态下,两侧小关节面各个部位的接触情况是不同的,应力大小和分布也是变化的.髓核摘除后腰椎前柱的承载功能减弱,小关节等后柱结构分担载荷增大.     

人工髓核假体置换术的研究进展

退行性椎间盘病变(degenerative disc disease,DDD)引起的腰腿痛越来越普遍，传统的椎间盘髓核摘除和(或)脊柱融合术在缓解疼痛及维持脊柱节段稳定性方面疗效肯定。但随着对椎间盘结构和生物力学性能研究的深入，由椎间盘髓核摘除所导致的脊柱生物力学和结构紊乱已经引起骨科医师的广泛关注。     

全椎板切除髓核摘除术治疗腰椎间盘突出症失败的原因分析

1．1 一般资料 本组755例：男386例,女369例;年龄17～55岁,平均41岁;发病时间2h～5年,平均1年2个月;根据腰椎间盘突出的位置分类：双侧型540例,中央型162例,极外侧型53例;根据腰椎间盘突出的程度分类：突出物挤出432例,突出物游离323例;发病原因：无外伤史442例,跌伤162例,扭伤151例;合并其他脊柱病变：合并腰椎管狭窄405例,合并腰椎滑脱216例,     

Effects of a high fat-sucrose diet on cortical bone morphology and biomechanics

Summary High fat-sucrose (HFS) diets can reportedly produce glucose intolerance and hyperinsulinemia that may indirectly have deleterious effects on bone. The effects of a high-fat diet on calcium absorption, bone calcium content, and bone mechanical properties, however, remain controversial. Thus, we examined the morphological and biomechanical adaptations in limb bones of rats that were fed a HFS diet. Female Sprague-Dawley rats (8 weeks old) were randomly assigned to two groups, either a control group (n=9) fed a standard diet (low-fat complex-carbohydrate) or an experimental group (n=9) fed a HFS diet for 10 weeks. The right tibia and second metatarsus (MT) were fractured in three-point bending, and contralateral bones were used for morphological and histological analyses. HFS tibias had significantly lower maximum load and failure energy, and tensile stress at the proportional limit for both HFS tibia and MT was significantly less than controls. In addition, the elastic modulus and density of the HFS MT was significantly lower than controls. Geometry of the tibial mid-diaphysial cross section did not differ for the two diets, but the cortical cross-sectional area of HFS MT increased significantly compared to control MT. The total number of osteons in the middiaphysis of HFS MT decreased, but tibial and MT porosities did not change with the HFS diet. Our results suggest that the deleterious effects of the HFS diet may be more related to changes in the material properties of the cortical bone rather than to osteoporotic changes in the bone.     

Evaluation of standard nucleotomy for lumbar disc herniation using the Love method: results of follow-up studies after more than 10 years

A retrospective analysis of long-term follow-up results more than 10 years after a standard nucleotomy for lumbar disc herniation with the Love method was done to determine the effectiveness of this procedure. Nucleotomy according to Love was the standard treatment for lumbar disc herniation before the various minimally invasive alternatives were recently introduced. Without long-term follow-up analysis of Love operations, evidence-based evaluation of those new methods is impossible. We believe that the standard nucleotomy procedure should now be evaluated precisely. In this study we present a comparison of 1-year follow-up results to the results more than 10 years after lumbar nucleotomy. Seventy-six consecutive patients who had undergone lumbar nucleotomy were identified. It was possible to assess 54 (71.1%) of the cases more than 10 years after surgery. The initial and final outcomes were assessed using the MacNab classification and the Japanese Orthopaedic Association (JOA) score. With the MacNab classification a successful outcome 1 year after surgery was achieved in 87.0% of the cases. At the final follow-up, this result was reduced to 74.1%. Seven patients required a second operation and patients under 21 years of age were at risk for reoperation. Patient overall satisfaction with the results of the standard nucleotomy was high. The disc height of the operation site significantly decreased after surgery; nevertheless, this did not affect the clinical outcome. A standard lumbar nucleotomy according to Love is a safe and reliable method of treating selected patients with lumbar disc herniations.     

肺气肿兔单侧肺减容术后的肺功能及组织结构变化

目的　评价阻塞性肺气肿兔单侧肺减容术 (LVRS)后的肺功能和组织结构变化 ,并与肺叶切除术比较。方法　 4 0只新西兰大白兔采用烟熏和气管内滴注弹性蛋白酶制成阻塞性肺气肿模型 ,随机分为肺气肿组 (A组 )、单侧LVRS组 (B组 )、肺叶切除组 (C组 )和假手术组 (D组 ) ,每组 10只。 8周后进行肺功能和肺组织学检查。结果　与A组比较 ,B组和C组的潮气量、0 3秒用力呼气容积 (FEV0 3)、FEV0 3 FVC(用力肺活量 )、PaO2 、平均肺泡数和肺泡隔面密度增加 ,功能残气量、PaCO2 、肺总容积和肺泡直径降低 (P <0 0 5 ) ,而D组变化不明显 (P >0 0 5 )。B组和C组肉眼及光镜下可见肺气肿改善 ,而D组无明显变化。B组和C组之间上述各指标差异无显著性 (P >0 0 5 )。结论　单侧LVRS和肺叶切除术均可有效改善阻塞性肺气肿兔的肺功能和组织结构     

The effects of initial end contact on medial collateral ligament healing: a morphological and biomechanical study in a rabbit model

In this investigation, the effect of initial end contact on medial collateral ligament (MCL) healing was studied in the rabbit model. Sixty-eight 1-year-old New Zealand white rabbits were separated into two groups. In one group, a 4 mm saggital Z-plasty was performed in the right MCL midsubstance (contact group), and in the other group, an analogous 4 mm midsubstance segment was removed (gap group). Left knees were unoperated to serve as internal contralateral MCL controls. Animals had unrestricted cage activity until sacrifice in groups of eight at 3, 6, 14, and 40 weeks postoperatively. Early results demonstrated that contact and gap injuries healed with what appeared to be scar tissue both morphologically and biomechanically. In both groups, laxities recovered to their contralateral values within 6 weeks and biomechanical viscoelastic behaviors recovered to 68-92% of contralaterals by 14-40 weeks. Despite these similarities, contacts showed morphological and biomechanical evidence of improved healing over gaps. Contact scars remodeled more quickly, recovered laxity more quickly, and were generally closer to contralaterals than gaps in terms of their structural strength, stiffness, and material behaviors, after 40 weeks of healing. With the exception of appearances and failure stress, all measured properties of contact healing MCLs were statistically indistinguishable from contralateral MCLs at 40 weeks of healing. These advantages of contact healing in this model support speculations that there are differences in the early rate and possibly in the later quality of ligament healing when cut rabbit MCL ends are in proximity. Longer-term studies to define end points and mechanisms of healing are required.     

Local and global subaxial cervical spine biomechanics after single-level fusion or cervical arthroplasty

An experimental in vitro biomechanical study was conducted on human cadaveric spines to evaluate the motion segment (C4–C5) and global subaxial cervical spine motion after placement of a cervical arthroplasty device (Altia TDI™,Amedica, Salt Lake City, UT) as compared to both the intact spine and a single-level fusion. Six specimens (C2–C7) were tested in flexion/extension, lateral bending, and axial rotation under a ± 1.5 Nm moment with a 100 N axial follower load. Following the intact spine was tested; the cervical arthroplasty device was implanted at C4–C5 and tested. Then, a fusion using lateral mass fixation and an anterior plate was simulated and tested. Stiffness and range of motion (ROM) data were calculated. The ROM of the C4–C5 motion segment with the arthroplasty device was similar to that of the intact spine in flexion/extension and slightly less in lateral bending and rotation, while the fusion construct allowed significantly less motion in all directions. The fusion construct caused broader effects of increasing motion in the remaining segments of the subaxial cervical spine, whereas the TDI did not alter the adjacent and remote motion segments. The fusion construct was also far stiffer in all motion planes than the intact motion segment and the TDI, while the artificial disc treated level was slightly stiffer than the intact segment. The Altia TDI allows for a magnitude of motion similar to that of the intact spine at the treated and adjacent levels in the in vitro setting.     

中药胶剂修复半月板损伤的实验研究

目的 观察中药胶剂促进半月板损伤修复的效果,并探讨其作用机理。方法 选用同样条件饲养,体重３ｋｇ左右的健康成年日本大耳白兔８０只,雌雄不拘,每组４０只,均采用左右侧自身对照,侧别由掷币法随机决定。一组动物为空白对照,即一侧半月板裂伤植入中药胶剂,另一侧裂伤不做任何处理;另一组动物为实验对照,即一侧裂伤植入中药胶剂,另一侧裂伤植入物理性状与该中药胶剂相似的明胶。在日本大耳白兔双侧下肢内侧半月板前１／     

Effect of flexor sheath integrity on tendon gliding: a biomechanical and histologic study

The effect on tendon gliding of flexor sheath excision versus incision/closure following primary flexor tendon repair was examined biomechanically and histologically in forty-one chickens. There was no significant difference in either the tendon excursion required to fully flex the digit or in the work of flexion (the integration of the forces that resist tendon gliding during excursion) between the sheath excised and sheath closed groups. The results were unaffected by postoperative immobilization or intermittent passive motion. Histologically, it was noted that at 3 weeks the healing tendon was surrounded by a layer of granulation tissue that was nearly identical in both the sheath excised and the sheath closed digits. Of note was the finding that a synovial lining could not be identified in those digits that had previously undergone sheath closure. However, at 6 weeks postoperatively, a new gliding surface could be identified surrounding the tendon in both the sheath excised and the sheath closed digits. This study indicates that closure of the flexor sheath after primary tendon repair does not improve tendon gliding as measured biomechanically. Despite its repair, the flexor sheath does not maintain its synovial characteristics as demonstrated histologically, and a new sheath must subsequently be formed.     

乙型肝炎患者抗病毒前后肝组织病理检查的变化与意义

目的：通过对慢性乙型肝炎患者抗病毒治疗前后肝组织病理检查的差异性比较,初步探讨干扰素与核苷（酸）类似物抗病毒治疗效果。方法对29例单独应用干扰素或核苷（酸）类似物治疗的慢性乙型肝炎患者,于治疗前和治疗后48周进行肝组织活检,用半定量系统计分方案对治疗前后肝组织学进行评分,比较治疗前后变化并分析其意义。结果治疗前后相比,HBV DNA完全应答组获得显著的组织学改善。抗病毒治疗48周干扰素与核苷（酸）类似物两种抗病毒方式相比较无差异。结论无论是干扰素或是核苷（酸）类似物抗病毒,获得病毒学完全应答均可明显改善肝脏炎症、纤维化程度,不同机制的抗病毒药物治疗在48周时肝脏组织学变化无明显差异。     

松质骨螺钉骨水泥强化的生物力学和组织学研究

目的通过动物实验观察不同骨水泥强化松质骨螺钉的生物力学和组织学变化动态,为骨质疏松骨折患者内固定提供理论基础。方法在10只杂种犬胫骨近端制作松质骨螺钉植入的动物模型,分别采用碳酸化羟基磷灰石水泥(CHC)和聚甲基丙烯酸甲酯(PMMA)强化,分别于术后5d、4、8、12和16周处死动物,观察螺钉拔出的生物力学和组织学变化。结果CHC强化的螺钉拔出力随手术后时间的延长而逐渐升高,16周时达到(512.5 14.5)N,而PMMA强化组螺钉拔出力则随手术后时间的延长而逐渐降低。CHC-骨界面结合紧密,并且随时间延长出现CHC降解和骨长入,而PMMA-骨界面形成一层纤维组织。结论CHC强化能够提高松质骨螺钉植入体内的稳定性,并且随植入时间延长而逐渐升高。     

雄性大鼠肾上腺大部切除后骨质疏松生物力学研究

目的 研究雄性大鼠骨质疏松的骨生物力学特性.方法 基于切除肾上腺雄性大鼠骨质疏松模型,研究其股骨生物力学指标.结果 骨质疏松大鼠弯曲弹性模量、弯曲刚性系数及最大弯曲应力降低,弯曲韧性系数雄性大鼠升高.结论 骨质疏松雄性大鼠骨质综合生物力学水平降低,骨质抗应力性能降低,骨质韧性损失慢于或小于抗应力性能.