Biomechanical characteristics of the porcine denticulate ligament in different vertebral levels of the cervical spine-preliminary results of an experimental study.

Background: Few studies exist on the mechanical properties of denticulate ligaments and none report the variation in these properties at different levels of the spine. The aim of this study was to perform an experimental determination of load-extension and stress-strain characteristics of the denticulate ligament and to establish if their properties change at different vertebral levels of the cervical spine.

Method: The study was carried out on a total of 98 porcine denticulate ligament samples dissected from seven fresh porcine cervical spinal cord specimens.

Biomechanics of distal femoral fracture fixed with an angular stable LISS plate.

Fractures of the distal end of the femur are infrequent and constitute less than 1% of all fractures. Only 3% to 6% of femoral fractures occur at the distal end. The two groups most at risk of the said fractures are young men and older women.

Analysis of the influence of a metha-type metaphysical stem on biomechanical parameters.

The full postoperative loading of the limb is possible if patients are properly selected and qualified for hip arthroplasty and the requirements as to the proper position of the metaphysial stem are met. The lack of precision, and patient qualification which does not satisfy the fixed criteria may result in stem setting inconsistent with the assumptions. An analysis based on the finite element method (FEM) will enable one to find out how to plan the magnitude of operated joint loading on the basis of the position of the stem in the postoperative radiograph.

Finite element modelling of the cervical spinal cord injury -- clinical assessment.

The aim of the study was to evaluate the efficiency of Finite Element Method (FEM) modelling of the clinical cases of traumatic cervical spinal cord injury (SCI). The study population consisted of 28 patients suffering from traumatic cervical spine injury with (study group) and without (control) neurological deficits. A numerical simulation of the trauma event was performed, based on validated 3D FEM model.

Mechanical properties of cervical dura mater.

The aim of the study was to determine experimentally the stress as strain function as well as the orthotropy and heterogeneity of porcine dura mater of the cervical spinal cord. Material was divided into groups based on the place of collection, considering the dorsal side and ventral side, specifying the number of cervical vertebra, and the direction of tension of the sample - longitudinal or circumferential. Experimental studies were conducted with the MTS Synergie 100 testing machine.

Numerical model of the human cervical spinal cord--the development and validation.

The influence of mechanical load on the extent of nervous tissue damage in the spinal cord at the time of trauma is presently incontestable. Although numerical modelling cannot fully replace physical testing, it seems to be the perfect complement to experiments in terms of the analysis of such a complex phenomenon as traumatic spinal cord injury. Previous numerical models of the human cervical spinal cord have been limited by several factors: two-dimensional modelling, spinal cord geometry simplification and incomplete reflection of specific anatomical and biomechanical relations of the objects being modelled.

Impact of some external factors on the values of mechanical parameters determined in tests on bone tissue.

The knowledge of the mechanical characteristics of bone structures is a prerequisite for theoretical, numerical, and experimental analyses describing the functioning of bone, which is a living organ. The description of the mechanical properties of bone tissue, such as conventional Young's modulus or strength, will enable the assessment of the degree of tissue degeneration through a comparison of the material properties of the examined bones to the properties determined for physiologically normal bones. However, the mechanical parameters published by different research centres often differ from each other by up to several hundred percent.

The biomechanical analysis of the traumatic cervical spinal cord injury using finite element approach.

According to up-to-date knowledge only mathematical modelling of the spinal cord injury (SCI) may provide real insight into a spatial location of the fields of the spinal cord mechanical strain generated by the injury. The purpose of our research was to correlate the results of Finite Element Analysis of SCI with the patient's neurological state and the injured spinal cord MR imaging. The 3D Finite Element Model of the cervical spinal cord and vertebral canal of a 21-year-old male patient was created.

Computerized tomography evaluation of cortical bone properties in the tibia.

Background: Tibia shaft fractures are among the most common fractures. However, the incidence of tibia fractures does not increase in the elderly. Osteoporotic bone resorption is possibly compensated for by periosteal apposition, which improves the mechanical properties of the bone.