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1

Model stabilizacji złamania kręgu kręgosłupa odcinka szyjnego

Słowiński J. J.

Inżynier i Fizyk Medyczny

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2018

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Vol. 7, nr 2

116--120

PL

Złamanie trzonu kręgu kręgosłupa stanowi poważny problem natury ortopedycznej ze względu na bliskie sąsiedztwo struktur nerwowych oraz krytyczną rolę w łańcuchu kinematycznym. Z tego powodu jednym ze sposobów odtwarzania uszkodzonej struktury są inwazyjne metody polegające na operacyjnym dojściu do miejsca urazu i wprowadzeniu implantu. Jego dostarczenie powinno pomóc w odtworzeniu anatomicznego ukształtowania struktury kostnej i możliwie wiernie odwzorowaniu utraconej stabilności. Zapewnienie tych biomechanicznych warunków jest krytyczne dla prawidłowego funkcjonowania kręgosłupa i eliminacji ryzyka uszkodzenia struktur nerwowych. Obecnie stosowane metody i techniki operacyjne umożliwiają szeroki dostęp do miejsca przyszłej implantacji i sprzyjają przeprowadzeniu wielu działań dodatkowych, celem których będzie zapewnienie możliwie dobrych warunków pracy zastosowanego systemu stabilizacji. Jedną z metod stabilizacji złamania kręgów w odcinku szyjnym jest tzw. stabilizacja płytkowa. Implantom tego typu, podobnie jak wszystkim innym, stawia się określone wymagania dotyczące ich właściwości fizyko-chemicznych czy biomechanicznych. Z tego względu jednym z decydujących kryteriów jest materiał, z jakiego wykonane są implanty. Jego właściwości będą bezpośrednio rzutowały na możliwości zastosowania oraz bezpieczeństwo i czas eksploatacji.

2

Loading rate effect on mechanical properties of cervical spine ligaments

Trajkovski A., Omerovic S., Krasna S., Prebil I.

Acta of Bioengineering and Biomechanics

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2014

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Vol. 16, no. 3

13--20

EN

Mechanical properties of cervical spine ligaments are of great importance for an accurate finite element model when analyzing the injury mechanism. However, there is still little experimental data in literature regarding fresh human cervical spine ligaments under physiological conditions. The focus of the presented study is placed on three cervical spine ligaments that stabilize the spine and protect the spinal cord: the anterior longitudinal ligament, the posterior longitudinal ligament and the ligamentum flavum. The ligaments were tested within 24-48 hours after death, under two different loading rates. An increase trend in failure load, failure stress, stiffness and modulus was observed, but proved not to be significant for all ligament types. The loading rate had the highest impact on failure forces for all three ligaments (a 39.1 % average increase was found). The observed increase trend, compared to the existing increase trends reported in literature, indicates the importance of carefully applying the existing experimental data, especially when creating scaling factors. A better understanding of the loading rate effect on ligaments properties would enable better case-specific human modelling.

3

Determining of stresses in unpropperly curved cervical spine

Walczak T., Buśkiewicz J., Jankowski R.

Vibrations in Physical Systems

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2008

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Vol. 23

389--394

EN

The paper presents the method of determining the stresses in cervical spine vertebrae. It is based on techniques known from strength of materials – the theory of strongly curved beams. It allows to determine normal stresses in vertebrae of cervical part of spine with known characteristic dimensions. The method was tested on three different cases of cervical spine conformation: one properly and two improperly curved spinal line. Obtained information about influence of spine geometry on character and value of stresses could be useful in clinical practice.

4

Experimental investigation of the lumbar spine – influence of destabilization on the stiffness characteristic

Szust A.

Acta of Bioengineering and Biomechanics

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2006

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Vol. 8, nr 2

127-133

EN

The lumbar spine region is most often affected by disorders. These disorders lead to instability in the motion segments. Many surgical procedures have been undertaken to reduce instability and restore the function of the spine. Spinal fusion is most commonly used to stabilise unstable motion segments. Consequently, immediate stability is provided by instrumentation just after surgery. The segment is being kept aligned until the fusion process is completed. This study was undertaken to evaluate the influence of posterior instrumentation on the stabilisation of lumbar motion segment. The author measured and compared the stiffness of human lumbar spine destabilized in two ways and stabilised with two posterior stabilisers.

5

Application of miniature pressure transducers to the investigation of intradiscal pressure in the cervical spine

Pezowicz C., Kaczmarek B., Będziński R.

Acta of Bioengineering and Biomechanics

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2004

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Vol. 6, nr 2

23-32

EN

The method developed and used by the authors to measure intradiscal pressure is presented. We constructed 'needle* indicators lilted with miniature pressure transducers. Our analysis assessed the impact of stabilisation on pressure in intervcrtcbral discs adjacent to the stabilisation area under compression and bending loads. The research was carried out on the post-mortem specimens of the cervical spine. The results showed that during axial compression there is a small increase in pressure following the introduction of bone graft when compared to the intact spine. On the other hand, bending has a major influence on the resultant pressure, depending on spinal level and the type of bending (flexion/extension). We have also concluded that, regardless of the type of load, in the discs above (the planned and then implemented) stabilisation area, the pressure is lower than in discs located below.

6

Motion analysis of upper parts of human body under dynamical loading

Gzik M., Tejszerska D.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2002

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z. 19

51-54

EN

The mathematical model of the head and seven cervical vertebrae describing dynamics during car collision is presented in this paper. Article included the numerical simulation data of dynamical forces into human cervical spine. On the basis this model is creating extended model included movable trunk and taking into consideration contact human body with armchair, wheel and seat belts.

7

Modelling of dynamic interactions in cervical spine during car collision

Gzik M., Tejszerewska D.

Acta of Bioengineering and Biomechanics

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2000

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Vol. 2, nr 2

33-40

EN

The paper presents a dynamic spatial mathematical model in which a head, two cervical vertebrae, a group of neck muscles, an intervertebral disc, ligaments and intervertebral joints are taken into consideration. The behaviour of modelled body exposed to action of a force corresponding to the real enforcement, which occurred at a head-on collision during the road accident, was simulated, and the model was verified on the basis of data obtained from published experiments.