ARTIFICIAL NUCLEUS PULPOSUS FOR DEGENERATIVE LUMBAR SPINE

人工髓核治疗退变性腰椎

• 批准号: 07671573
• 负责人: OKAWA Atsushi
• 金额: $ 1.34万
• 依托单位: TOKYO MEDICAL AND DENTAL UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07671573/
• 关键词: LUMBAR SPINE; DEGENERATION; INSTABILTY; INTRADISCAL PRESSURE; BIOMECHANICS; ARTIFICIAL DISC; 変性腰椎; 腰椎不安定性; バイオメカニクス

The altered stiffness of the degenerated intervertebral disc (IVD) would affect a motion of the whole lumbar spine and be a cause of low back problems. An artificial intervertebral disc, being developed these days, will solve this problem, but the required surgery is as invasive as anterior interbody fusion operation. A substitute for nucleus pulposus can be an alternative treatment of degenerative lumbar disease. To obtain a basic information of the mechanical status of the degenerative lumbar spine, in this study, we examined the motion pattern of the whole lumbar spine using videofluoroscopy and measured intradiscal pressure during bending motion to know how much force is applied to the intervertebral disc in an actual motion.Lumbar sagittal motion videos were recorded under a fluoroscope in volunteers (n=14 ; age 22.4) and patients with CLBP (n=13 ; age 46.3) and degenerative spondylolisthesis (n=8 ; age 63.5), while the subjects bent forward from a standing neutral position and th … More en returned to the original position. The videos were converted to still images at 5 frames per second. Disk angles from L2-3 to L5-S1 were measured to estimate sagittal rotation. Disk degeneration was evaluated on T2 mid-sagittal MR image.In the control group (volunteers), 9 exhibited sequentially spreading motion, one exhibited simultaneous motion, and 3 showed confused starting points. the anterior bending motion is usually spread from the upper segment to the lower one, but six of the patients with degenerative spondylolisthesis showed disordered patterns. Decreased motion, persistent flexion, and earlier extension in a certain segment were more frequently seen in the patients than in controls. The decreased stiffness of one segment would affect the segmental motion pattern, resulting in the altered motion pattern of the whole lumbar spine.Before measuring the actual motion and the simulataneous change of the intradiscal pressure, we studied a validity of a transducer catheter. Five humane L3-L4 spinal unit obtained at autopsy was used. The intradiscal pressures did not change statistically at any site (anterior, posterior, lateral portion of the IVD) where the tip of the catheter was located. The pressure measured did not also change according to the direction of the tip of the catheter.In vivo we measured the intradiscal pressure in three segments to be fused at an operation. The subject moved from the neutral standing position, bending forward, and bent backward cyclically. The pressure on standing was 600-1000mmHg. Just after beginning to bend forward, the pressure raised steeply up to 2000mmHg, while the angular motion was only 0.6 degrees. This increased pressure was thought to be from paravertebral muscle contraction. When the subject continued to bend backward, the intradiscal pressure got lower around the neutral position than that of the beginning.Hydrogel is thought to be a ideal type of a high density polymer for a substitute of nucleus pulposus. However, materials with strong mechanical property did not exist as a hydrogel, and should be developed newly. This needs further advanced research. Less

退化的椎间盘（IVD）的刚度改变会影响整个腰椎的运动，并成为下背部问题的原因。如今开发的人造椎间盘将解决此问题，但是所需的手术与前室内融合手术一样具有侵入性。牙髓核的替代品可以是退化腰部疾病的替代治疗方法。为了获得退化的腰椎机械状态的基本信息，在这项研究中，我们使用视频荧光镜检查了整个腰椎的运动模式，并在弯曲运动过程中测量了在弯曲运动过程中测量的疗程内压力，以了解在实际运动中对椎间盘施加了多少力量。 CLBP（n = 13;年龄46.3）和退化性赞助（n = 8; 63.5岁），而受试者从站立的中立位置向前弯曲，并且更多的EN返回到原始位置。视频以每秒5帧的速度转换为静止图像。测量从L2-3到L5-S1的磁盘角以估计矢状旋转。在对照组（志愿者），9个暴露的依次扩散运动，一个同时曝光的同时运动和3个显示困惑的起点。前弯曲运动通常从上部扩展到下部，但六名具有退化性赞助的患者显示出无序的模式。与对照组相比，患者的运动减少，持续的屈曲和一定段的早期延伸比在患者中更常见。一个片段的刚度降低会影响分段运动模式，从而导致整个腰椎的运动模式改变。在测量验证内压力的实际运动和模拟变化之前，我们研究了换能器导管的有效性。使用尸检时获得的五个人L3-L4脊柱。在任何位点（前，后部，侧面，IVD的前，后部，侧面）所在的任何位点（前，后部，外侧部分）都没有统计上的扫描压力。测得的压力也没有根据导管尖端的方向变化。在体内，我们测量了在操作时融合的三个部分中的验证内压力。受试者从中立的站立位置移动，向前弯曲，并循环向后弯曲。站立的压力为600-1000mmhg。刚开始向前弯曲后，压力升高到2000mmHg，而角运动仅为0.6度。这种增加的压力被认为来自副肌肉收缩。当受试者继续向后弯曲时，在中性位置周围的内部压力低于开始的位置。水凝胶被认为是高密度聚合物的理想类型。但是，具有强大机械性能的材料并不作为水凝胶存在，应新开发。这需要进一步的高级研究。较少的