Twente spine model: A complete and coherent dataset for musculo-skeletal modeling of the lumbar region of the human spine

Musculo-skeletal modeling can greatly help in understanding normal and pathological functioning of the spine. For such models to produce reliable muscle and joint force estimations, an adequate set of musculo-skeletal data is necessary. In this study, we present a complete and coherent dataset for the lumbar spine, based on medical images and dissection measurements from one embalmed human cadaver. We divided muscles into muscle-tendon elements, digitized their attachments at the bones and measured morphological parameters. In total, we measured 11 muscles from one body side, using 96 elements. For every muscle element, we measured three-dimensional coordinates of its attachments, fiber length, tendon length, sarcomere length, optimal fiber length, pennation angle, mass, and physiological cross-sectional area together with the geometry of the lumbar spine. Results were consistent with other anatomical studies and included new data for the serratus posterior inferior muscle. The dataset presented in this paper enables a complete and coherent musculo-skeletal model for the lumbar spine and will improve the current state-of-the art in predicting spinal loading.     

S100A9 induces nucleus pulposus cell degeneration through activation of the NF-κB signaling pathway

Oxidative stress in the lumbar disc leads to the degeneration of nucleus pulposus (NP). However, the molecular mechanisms underlying this process remain unclear. In this study, we delineated a key calcium-binding protein, S100A9, which was induced by oxidative stress and was highly expressed in the degenerative NP. Immunofluorescence staining and Western blotting revealed that S100A9 induced NP cell apoptosis in vitro by up-regulating the expression of pro-apoptotic markers, including cleaved caspase-3, cytochrome c and Bax. Moreover, RT-PCR analyses revealed that the expression of S100A9 caused NP matrix degradation by up-regulating the expression of matrix degradation enzymes and increased the inflammatory response by up-regulating cytokine expression. Therefore, S100A9 induced NP cell degeneration by exerting pro-apoptotic, pro-degradation and pro-inflammatory effects. The detailed mechanism underlying S100A9-induced NP degeneration was explored by administering SC75741, a specific NF-κB inhibitor in vitro. We concluded that S100A9 induced NP cell apoptosis, caused matrix degradation and amplified the inflammatory response through the activation of the NF-κB signalling pathway. Inhibition of these pro-apoptotic, pro-degradation and pro-inflammatory effects induced by S100A9 in NP may be a favourable therapeutic strategy to slow lumbar disc degeneration.     

Trunk muscle contributions of to L4–5 joint rotational stiffness following sudden trunk lateral bend perturbations

The purpose of this research was to investigate the contributions of individual muscles to joint rotational stiffness and total joint rotational stiffness about the lumbar spine’s L_4–5 joint prior to, and following, sudden dynamic lateral perturbations to the trunk. Kinematic and surface EMG data were collected while subjects maintained a kneeling posture on a robotic platform, while restrained so that motions caused by the perturbation were transferred to the pelvis, causing motion of the trunk and head. The robotic platform caused sudden inertial trunk lateral perturbations to the right or left, with or without timing and direction knowledge. An EMG-driven model of the lumbar spine was used to calculate the muscle forces and contributions to joint rotational stiffness during the perturbations. Data showed 95% and 106% increases in total joint rotational stiffness_, about the lateral bend and axial twist axes, when subjects had knowledge of the timing of the perturbation. Also, the contralateral muscles exhibited a significantly larger total joint rotational stiffness about the lateral bend axis, and earlier surface EMG responses, than the ipsilateral muscles. The results indicate that, when the timing of the perturbation was unknown, subjects relied more on delayed muscle forces following the perturbation to stiffen the L_4–5 joint.     

Effect of microgravity on the biomechanical properties of lumbar and caudal intervertebral discs in mice

Prolonged exposure to microgravity has shown to have deleterious effects on the human spine, indicated by low back pain during spaceflight and increased incidence of post-spaceflight herniated nucleus pulposus. We examined the effect of microgravity on biomechanical properties of lumbar and caudal discs from mice having been on 15-day shuttle mission STS-131. Sixteen C57BL/C mice (spaceflight group, n=8; ground-based control group, n=8) were sacrificed immediately after spaceflight. Physiological disc height (PDH) was measured in situ, and compressive creep tests were performed to parameterize biomechanical properties into endplate permeability (k), nuclear swelling pressure strain dependence (D), and annular viscoelasticity (G). For caudal discs, the spaceflight group exhibited 32% lower PDH, 70% lower D and crept more compared to the control mice (p=0.03). For lumbar discs, neither PDH nor D was significantly different between murine groups. Initial modulus, osmotic pressure, k and G for lumbar and caudal discs did not appear influenced by microgravity (p>0.05). Decreases in both PDH and D suggest prolonged microgravity effectively diminished biomechanical properties of caudal discs. By contrast, differences were not noted for lumbar discs. This potentially deleterious interaction between prolonged weightlessness and differential ranges of motion along the spine may underlie the increased cervical versus lumbar disc herniation rates observed among astronauts.     

The use of intermittent trunk flexion to alleviate low back pain during prolonged standing

The current study examined of the effect of intermittent, short-term periods of full trunk flexion on the development of low back pain (LBP) during two hours of standing. Sixteen participants completed two 2-h standing protocols, separated by one week. On one day, participants stood statically for 2 h (control day); on the other day participants bent forward to full spine flexion (termed flexion trials) to elicit the flexion relaxation (FR) phenomenon for 5 s every 15 min (experimental day). The order of the control and experimental day was randomized. During both protocols, participants reported LBP using a 100 mm visual analogue scale every 15 min. During the flexion trials, lumbar spine posture, erector spinae and gluteus medius muscle activation was monitored. Ultimately, intermittent trunk flexion reduced LBP by 36% (10 mm) at the end of a 2-h period of standing. Further, erector spinae and gluteus medius muscle quietening during FR was observed in 91% and 65% of the flexion trials respectively, indicating that periods of rest did occurred possibly contributing to the reduction in LBP observed. Since flexion periods do not require any aids, they can be performed in most workplaces thereby increasing applicability.     

腰椎间盘突出症阶梯式手术治疗方案的临床疗效和患者心理状况调查

目的:探讨阶梯式手术治疗方案对腰椎间盘突出的临床疗效和患者对临床疗效的心理接受情况。方法:回顾性分析2014年至2016年本院骨科确诊为腰椎间盘突出症的50例患者,经椎间孔镜下行髓核摘除微创手术(Percutaneous transforaminal endoscopic discectomy,PTED),术后1天和3个月采用视觉疼痛模拟评分(VAS)和改良Mac Nab疗效评定、术后3个月采用Oswestry功能障碍指数(ODI)评价手术效果,以及相应调查时间点患者对手术效果心理接受程度调查;对于7例微创手术疗效不佳患者进一步采用传统的开窗髓核摘除术(Fenestration discectomy,FD),采用同样方法评价手术效果和调查患者心理接受情况。结果:50例微创术后1天及术后3个月的VAS评分和ODI指数均显著低于术前,差异具有显著性(P均0.05);改良Mac Nab疗效评定:术后1天优良率为84%,术后3个月为86%;患者对术后疗效心理满意度调查:术后1天,满意并接受为84%,不满意但接受为16%,不满意难接受为0;术后3个月,满意并接受为86%,不满意但接受为14%,不满意难接受为0。对于微创术后效果欠佳7例患者行FD手术,术后1天及3个月的VAS评分和ODI指数均显著低于术前,差异具有显著性(P均0.05);改良Mac Nab疗效评定:术后1天优良率为71%,术后3个月为100%;患者对开窗术后疗效心理满意度调查:术后1天,满意并接受为71%,不满意但接受为0,不满意难接受为29%;术后3个月,满意并接受为100%,不满意但接受为0,不满意难接受为0。结论:腰椎间盘突出症阶梯式手术治疗方案临床效果和患者心理接受情况均值得临床推荐。     

MIS-TLIF结合钉棒系统治疗极外侧型腰椎间盘突出症的临床研究

目的:观察和比较使用通道下经椎间孔腰椎融合术(Minimally Invasive Transforaminal Lumbar Interbody Fusion;MIS-TLIF)与常规开放手术治疗极外侧型腰椎间盘突出症的临床疗效。方法:回顾性分析2012.01至2016.01经纳入及排除标准筛选后的共计61例腰椎间盘突出症患者。根据不同的手术方法,将上述患者分别纳入实验组(MIS-TLIF组)与对照组(常规开放手术组)。对患者手术前后的疼痛程度(VAS),功能障碍程度(JOA)及各围手术期指标(出血量,手术时间,透视次数,卧床时间,花费,并发症)进行统计学比较。结果:MIS-TLIF组与对照组患者在术前的VAS评分及JOA评分的比较中无显著性差异,经外科手术后,都有显著性改善(P0.05)且两组间无显著统计学差异(P0.05)。但MIS-TLIF组在出血量,卧床时间,并发症等指标中都显著优于对照组(P0.05)。结论:通道下经椎间孔腰椎融合术作为一种微创术式,能够显著改善极外侧型腰椎间盘突出症患者的临床症状,并具有其独有的优势和长处,在临床工作中可以进行进一步的使用和推广。     

经骨折椎体椎弓根螺钉短节段固定治疗胸腰段骨折疗效

目的:评估和分析经骨折椎体椎弓根螺钉短节段固定治疗胸腰段单椎体粉碎性骨折的临床疗效。方法:选取胸腰段单椎体粉碎性骨折30例患者,分为两组,甲组20例,采用经骨折椎体椎弓根螺钉短节段固定治疗,均行骨折椎体及骨折椎体上下相邻椎体的椎弓根螺钉+双侧连接杆固定;乙组10例,只行骨折椎体的上下相邻椎体的椎弓根螺钉+连接杆固定术。术后随访。测定两组患者手术前后的椎体后凸畸形角和骨折椎体前方高度,评估其临床疗效。结果:术前平均后凸畸形角纠正:甲组15°,乙组11°,P0.05。术后骨折椎体前方的平均高度(和正常椎体前方高度比):甲组89%,乙组81%,P0.05;术后3个月随访:平均后凸畸形角纠正丢失,甲组2°,乙组6°,P0.05;骨折椎体前方的平均高度(和正常椎体前方高度比):甲组87%,乙组73%,P0.05。结论:经骨折椎体椎弓根螺钉短节段固定治疗胸腰段单椎体粉碎性骨折能提供更好的生物力学稳定性,更有利于骨折的复位和后凸畸形的纠正。