Feeling wall tension in an interactive demonstration of Laplace's law

Letić, Milorad

doi:10.1152/advan.00034.2012

Cited by 11 publications

(10 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Harrington et al [ 46 ] found a positive correlation between lumbar vertebral size and “classical” disc herniation. They suggested that the diameters of the vertebral disc influence its ability to withstand tension during compression according to LaPlace's law [ 47 ]. We believe that bigger vertebral body sizes are weaker to resist vertical stress, i.e., SN.…”

Section: Discussionmentioning

confidence: 99%

Lumbar Schmorl’s Nodes and Their Correlation with Spine Configuration and Degeneration

Abbas

Hamoud

Peled

et al. 2018

BioMed Research International

View full text Add to dashboard Cite

The aim of this study was to reveal whether demographic aspect, vertebral morphometry, and spine degeneration are associated with lumbar Schmorl's nodes (SNs). A retrospective cross-sectional study was performed using data from the Department of Radiology (Carmel, Medical Center, Israel) for 180 individuals: age range between 40 and 99 years; 90 males and 90 females. All participants had undergone high-resolution CT scans for abdominal diagnostic purposes in the same supine position prior to our study, which enabled the processing of the scans in all planes and allowed a 3D reconstruction of the lower lumbar region. Eighty individuals (44.4%) had at least one SN along the lumbar spine, particularly at L3-4 level (30%). Vertebral body length (L1 to L3) and width (L1 and L4) were significantly greater in the SNs group compared to non-SNs group. On contrast, disc height (L3-4 and L4-5) was significantly lesser in SNs group than non-SNs group. SNs was significantly associated with smoking (X2= 4.436, P=0.02) and degenerative lumbar spinal stenosis (X2= 5.197, P=0.038). Moreover, the prevalence of SN was significantly greater in individuals with vacuum phenomenon and osteophytes formation (L1-2 to L4-5 levels). This study indicates that vacuum phenomenon on L3-4 (OR: 4.7, P=0.034), smoking habit (OR: 3.2, P=0.003), disc height loss of L4-5 (OR: 0.798, P=0.008), vertebral body length of L1 (OR: 1.37, P<0.001), and age (OR: 1.05, P=0.002) increase the probability of developing lumbar SNs.

show abstract

Section: Discussionmentioning

confidence: 99%

Lumbar Schmorl’s Nodes and Their Correlation with Spine Configuration and Degeneration

Abbas

Hamoud

Peled

et al. 2018

BioMed Research International

View full text Add to dashboard Cite

show abstract

“…Harrington et al [40] suggested that the diameters of the vertebral disc influence its ability to withstand tension during compression. Their argument rests on LaPlace’s law [42] which states that the ability of a fluid-filled tube wall to withstand tension decreases with increasing radius. We can assume that rounded (cylindrical) vertebral bodies possess larger diameters than the more “kidney-shaped” vertebral bodies, making the vertebral disc more vulnerable to stress, hence the higher rate of disc herniation among individuals with large vertebral bodies.…”

Section: Discussionmentioning

confidence: 99%

In the quest for degenerative lumbar spinal stenosis etiology: the Schmorl’s nodes model

Abbas

Slon

Stein

et al. 2017

BMC Musculoskelet Disord

View full text Add to dashboard Cite

BackgroundDegenerative lumbar spinal stenosis (DLSS) is a common health problem in the elderly and usually associated with three-joint complex degeneration. Schmorl’s nodes (SNs) are described as vertical herniation of the disc into the vertebral body through a weakened part of the end plate that can lead to disc degeneration. Since SNs can harm the spine unit stability, the association between DLSS and SNs is expected. The aim of this study is to shed light on the relationship between degenerative lumbar spinal stenosis and SNs.MethodsTwo groups of individuals were studied: the first included 165 individuals with DLSS (age range: 40–88, sex ratio: 80 M/85 F) and the second 180 individuals without spinal stenosis related symptoms (age range: 40–99, sex ratio: 90 M/90 F). The presence or absence of SNs on the cranial and caudal end plate surfaces at the lumbosacral region (from L1 to S1 vertebra) was recorded, using CT images (Brilliance 64 Philips Medical System, Cleveland Ohio, thickness of the sections was 1–3 mm and MAS, 80–250). Chi-Square test was taken to compare the prevalence of SNs between the study groups (control and stenosis) by lumbar disc level, for each gender separately. Multivariable logistic regression analysis was also used to determine the association between DLSS and SNs.ResultsThe prevalence rate of SNs was significantly greater in the stenosis males (L1-2 to L5-S1) and females (L4-5 and L4-S1) compared to their counterparts in the control (P < 0.001). In addition, the presence of SNs in both males and females was found to increase the likelihood for DLSS.ConclusionsOur results indicate that SNs prevalence is significantly greater in the DLSS group compared to the control. Furthermore, SNs are strongly associated with DLSS.

show abstract

“…We also found that pathological vertebrae have shorter pedicles compared to healthy vertebrae. The pedicles act as structural buttresses for the vertebral body and play an important role in load bearing during axial compression [ 63 - 68 ]. It has been hypothesized that the shorter pedicles identified in vertebrae with Schmorl’s nodes may be less able to withstand physical strain placed on the spine [ 25 , 45 ].…”

Section: Discussionmentioning

confidence: 99%

The ancestral shape hypothesis: an evolutionary explanation for the occurrence of intervertebral disc herniation in humans

et al. 2015

View full text Add to dashboard Cite

BackgroundRecent studies suggest there is a relationship between intervertebral disc herniation and vertebral shape. The nature of this relationship is unclear, however. Humans are more commonly afflicted with spinal disease than are non-human primates and one suggested explanation for this is the stress placed on the spine by bipedalism. With this in mind, we carried out a study of human, chimpanzee, and orangutan vertebrae to examine the links between vertebral shape, locomotion, and Schmorl’s nodes, which are bony indicators of vertical intervertebral disc herniation. We tested the hypothesis that vertical disc herniation preferentially affects individuals with vertebrae that are towards the ancestral end of the range of shape variation within Homo sapiens and therefore are less well adapted for bipedalism.ResultsThe study employed geometric morphometric techniques. Two-dimensional landmarks were used to capture the shapes of the superior aspect of the body and posterior elements of the last thoracic and first lumbar vertebrae of chimpanzees, orangutans, and humans with and without Schmorl’s nodes. These data were subjected to multivariate statistical analyses.Canonical Variates Analysis indicated that the last thoracic and first lumbar vertebrae of healthy humans, chimpanzees, and orangutans can be distinguished from each other (p<0.028), but vertebrae of pathological humans and chimpanzees cannot (p>0.4590). The Procrustes distance between pathological humans and chimpanzees was found to be smaller than the one between pathological and healthy humans. This was the case for both vertebrae. Pair-wise MANOVAs of Principal Component scores for both the thoracic and lumbar vertebrae found significant differences between all pairs of taxa (p<0.029), except pathological humans vs chimpanzees (p>0.367). Together, these results suggest that human vertebrae with Schmorl’s nodes are closer in shape to chimpanzee vertebrae than are healthy human vertebrae.ConclusionsThe results support the hypothesis that intervertebral disc herniation preferentially affects individuals with vertebrae that are towards the ancestral end of the range of shape variation within H. sapiens and therefore are less well adapted for bipedalism. This finding not only has clinical implications but also illustrates the benefits of bringing the tools of evolutionary biology to bear on problems in medicine and public health.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0336-y) contains supplementary material, which is available to authorized users.

show abstract

Feeling wall tension in an interactive demonstration of Laplace's law

Abstract: LAPLACE'S LAW plays a mayor role in explanations of the wall tension of structures like blood vessels, the bladder, the uterus in pregnancy, bronchioles, eyeballs, and the behavior of aneurisms or the enlarged heart.

Cited by 11 publications

References 2 publications

Lumbar Schmorl’s Nodes and Their Correlation with Spine Configuration and Degeneration

Lumbar Schmorl’s Nodes and Their Correlation with Spine Configuration and Degeneration

In the quest for degenerative lumbar spinal stenosis etiology: the Schmorl’s nodes model

The ancestral shape hypothesis: an evolutionary explanation for the occurrence of intervertebral disc herniation in humans

Contact Info

Product

Resources

About