Preliminary findings on the effect of load-carrying to the structural integrity of the cervical spine

Summary Carrying loads on the head is a common practice in rural Zimbabwe. Headloading imposes a considerable amount of strain to the axial skeleton. The cervical spine, being the most cranial and mobile part of the vertebral column, may be susceptible to spondylosis or disc degeneration in headloading. Age as well as the effects of intrinsic factors on cervical spondylosis have been well documented. However, studies on the effect of extrinsic weight bearing to spondylosis on the cervical spine are lacking. In this study, the effect of headloading on the pattern of spondylosis attributed to aging was examined. Results indicated that age led to significant degeneration of the fifth intervertebral disc space (P<0.05) as well as significant straightening of the lordotic curve (P<0.01). Load carrying seems to accentuate the straightening of the curve (P<0.001). The results also suggest that headloading creates a shift in the degeneration from the fifth intervertebral disc space to higher levels. It is concluded that carrying heavy loads on the head alters the pattern of degenerative changes of the cervical spine.

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Etude préliminaire des effets des charges lourdes sur l'intégrité structurale de la colonne cervicale

Résumé Porter de lourdes charges sur la tête est une pratique habituelle au Zimbabwe dans les zones rurales. Le port céphalique de charge impose des contraintes considérables au squelette axial. La colonne cervicale, portion crâniale et mobile de la colonne vertébrale, peut présenter une cervicarthrose ou une altération discale en raison du port de charges sur la tête. L'âge et les facteurs intrinsèques déterminant une cervicarthrose ont été bien étudiés. Cependant, l'action éventuelle d'un poids supplémentaire contribuant à la genèse d'une cervicarthrose n'a pas été étudiée. Dans cette étude, les effets du port céphalique de charge sur l'importance d'une cervicarthrose attribuée au vieillissement, sont examinés. Les résultats indiquent que le vieillissement aboutit à une altération significative du 5ème espace intervertébral (P<0,05) ainsi qu'à un redressement significatif de la lordose (P<0.01). Le port de charge semble accentuer le redressement de la courbe (P<0,001). Les résultats suggèrent également que le port de charge sur la tête réalise un transfert des lésions du 5ème espace intervertébral vers des niveaux sujacents. On en déduit que le port de lourdes charges sur la tête modifie l'aspect des atteintes dégénératives de la colonne cervicale.

     

Antenatal differentiation of the human intervertebral disc

Summary To study the antenatal differentiation of the human intervertebral disc, the columns of forty eight embryos and fetuses were examined histologically. The primitive disc is composed of two structures: the notochord which shows a progressive expansion into the disc, and the fibrocartilaginous perinotochordal disc. No histological sign of interaction between notochordal and perinotochordal cells, which may explain the notochordal expansion into the discs, was seen. On the other hand, the notochordal intervention in the cartilaginous differentiation of the inner zone is probable.

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Différenciation anténatale du disque intervertébral humain

Résumé Cette étude de la différenciation anténatale du disque intervertébral humain repose sur l'examen de coupes histologiques de quarante huit colonnes vertébrales d'embryons et de foetus. Le disque primitif est composé de deux structures : la notochorde, qui présente une expansion progressive de son diamètre au sein du disque, et le disque périnotochordal, d'abord mésenchymateux puis fibrocartilagineux. Il n'a pas été mis en évidence de signe histologique témoignant d'une interaction entre les cellules notochordales et les cellules périnotochordales qui puisse expliquer l'expansion de la notochorde au sein des disques. Le rôle de la notochorde dans la différenciation cartilagineuse de la zone centrale est par contre probable.

     

Design Characteristics for the Tissue Engineering of Cartilaginous Tissues

Tissues like the temporomandibular joint (TMJ) disc and the knee meniscus are often mistakenly viewed as a tantamount to hyaline cartilage, largely due to the absence of a comprehensive understanding of the distinguishing properties of cartilaginous tissues. Because of this confusion, fibrocartilaginous tissue engineering attempts may not be based on suitable experimental designs. Fibrocartilaginous tissues are markedly different than hyaline cartilage; however, the dearth of knowledge related to their cellular and biochemical composition, as well as their biomechanical characteristics, is stunning. Hyaline articular cartilage is exclusively composed of chondrocytes that produce primarily type II collagen, whereas the TMJ disc and the knee meniscus have a mixed cell population of fibroblasts and cells similar to chondrocytes, which predominantly secrete type I collagen. Additionally, fibrocartilaginous tissues have a low glycosaminoglycan content, a low compressive modulus, and a high tensile modulus when compared to hyaline cartilage. Therefore, it is crucial for fibrocartilaginous tissue engineering attempts to be tissue-specific, utilizing the knowledge of the distinct and unique properties of these tissues. At the same time, advances and insights related to the science and engineering aspect of hyaline cartilage regeneration must be carefully considered for the in vitro engineering of fibrocartilaginous tissues.     

椎间盘退变的腰椎活动节段力学模型

椎间盘是人体组织中最早发生退行性改变的部位。本文报告采用三维有限元方法建立的椎间盘退变腰椎活动节段的力学模型,着重分析其在直立时的应力分布与载荷传递情况。模型共有388个节点,组成293个单元,所得结构较为合理可靠。作者认为,本模型具有其独特的优点。可望用于进一步的研究。     

Current understanding of cellular and molecular events in intervertebral disc degeneration: implications for therapy

Until recently, material removed from the intervertebral disc (IVD) at surgery consisted either of 'loose bodies' from the centre of the IVD or discal tissue displaced (prolapsed) into the intervertebral root or spinal canals. This material is best regarded as a by-product of disc degeneration and therefore not representative of the disease process itself. Recent advances in surgical techniques, particularly anterior fusion, in which large segments of the anterior part of the IVD are excised with the anatomical relationships between different components intact, have generated material that can be investigated with modern molecular and cell biological techniques. This is an important area of study because degeneration of the lumbar IVDs is associated, perhaps causally, with low back pain, one of the most common and debilitating conditions in the West. 'Degeneration' carries implications of inevitable progression of wear-and-tear associated conditions. Modern research on human IVD tissue has shown that this is far from the case and that disruption of the micro-anatomy described as degeneration is an active process, regulated by locally produced molecules. The exciting consequence of this observation is the possibility of being able to inhibit or even reverse the processes of degeneration using targeted therapy.     

Microsurgical cordotomy in 20 patients with epi-/intradural fibrosis following operation for lumbar disc herniation

Summary Using an improved microsurgical technique, cordotomy was carried out by the cervicothoracic route in 20 patients with persistent radicular pain due to epi-/intradural fibrosis following operation for lumbar disc herniation. 65% of them had good long-term results with respect to radicular pain (follow-up period 6–132 months; mean 66 months). Permanent severe motor impairment was not observed. In patients with severe pain of benign organic origin microsurgical cordotomy can be considered as a last resort.     

The R-zero line: a new kinematic concept of the lumbar spine

Summary A new kinematic concept is described that relates to the notion that the lumbar spine behaves as a complete structure. This concept is called the R-zero line and represents kinematically the neutral position of the lumbar spine between anteflexion and retroflexion. The clinical significance of this parameter is evaluated in normal individuals and in patients with a symptomatic herniated disc at L4–5, with a symptomatic herniated disc at L5–S1, and with spondylolysis/spondylolisthesis. The results of this study show that the R-zero line has a characteristic configuration in all four test groups.     

骶管阻滞配用周围神经阻滞治疗腰椎间盘突出症的疗效

[目的 ]探讨非手术方法治疗腰椎间盘突出症的疗效 .[方法 ]将 98例腰椎间盘突出症患者分成腰痛组和腿痛组 ,前者采用骶管阻滞加严氏椎间隙阻滞法 ,后者采用骶管阻滞加腰大肌肌沟阻滞法 .[结果 ]两组治疗前后分值相比较均有显著性差异 ,其优良率分别为 88%和 84% .[结论 ]采用骶管阻滞加严氏椎间隙阻滞或腰大肌肌沟阻滞法治疗腰椎间盘突出症具有疗效     

多节段颈椎间盘脱出的脊髓型颈椎病治疗的回顾性分析

目的：研究多节段颈间盘脱出症术式选择、减压范围及植骨的处理。方法：对48例患者的发病因素、病程及影像学表现特征进行分析。本组均采用颈椎前路减压自体髂骨植骨融合术,术后随访最平均4．7年。结果：治疗效果优：28例（58．3％）良：11例（22．9％）。可：6例（12．5％）,差：3例（6．3％）。结论多节段间盘脱出症减压手术应首先考虑前路手术。如临床症状不缓解,可待植骨愈合后再后后路减压手术。一般两个节段的间盘摘除基本可以解决多间盘脱出的颈椎病。有的原则是务必保持椎间高度。     

腰椎间盘突出症继发马尾神经综合征手术治疗的疗效

目的：研究腰椎间盘突出症继发马尾神经综合征手术治疗的疗效。方法：对６７例腰椎间盘突出症并发马尾神经综合征的患者发病因素、病程、影像学的表现特征、手术时机的选择同其治疗的随访结果进行综合分析。随访时间３个月至３．５年,平均１年４个月。结果：急性发病的患者其手术时机的选择同患者功能恢复的优良率有关,发病１周、２周、１个月、１个月以上疗效优良率分别为７２．２２％,６３．６４％,５０．００％,３３．３３％