Halo pin positioning in the temporal bone; parameters for safe halo gravity traction

Semmelink, K; Hekman, Edsko E.G.; Griethuysen, M van; Bosma, Jesse; Swaan, A; Kruyt, Moyo C.

doi:10.1007/s43390-020-00194-2

Cited by 2 publications

(1 citation statement)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Під час дослідження тракційних способів лікування застосовано переважно експериментальні методи досліджень. Більшість робіт із них присвячено визначенню кількості гвинтів, що застосовуються в системі ГГТ [3], або їх оптимальному розташуванню [11].…”

unclassified

Analysis of mathematical modeling of a biomechanical model of halo-graviеn traction in spinal deformities in children

Rogozinskyi¹,

Levytskyi²,

Dolianytskyi³

et al. 2021

View full text Add to dashboard Cite

Halo-gravity traction (HGT) systems are widely used in leading clinics around the world as a staged method for correcting complex (>100°) scoliotic deformities of the spine in children. Today there is no single approach to the use of this technique, and each doctor makes a decision regarding the treatment regimen empirically, based on his clinical experience. Purpose – to investigate with the help of finite element method the stress-strain state of the spine of various degrees of deformation using HGT. Materials and methods. When constructing the computational model, geometric models of various parts of the spine, developed in the laboratory of biomechanics of the State Institution «IPPS named after I.P. Sitenko of the National Academy of Medical Sciences of Ukraine». The following changes were made to the model, in accordance with the purpose of the study: spinal deformity 70° and 100°; added skull model; added model of HGT and its fixation to the skull. Results. When using the HGT system with fixation, the most loaded part of the spine is the T2-T5 vertebrae. It should be noted that with an increase in the degree of deformity, the T4 and T5 vertebrae become loaded. The HGT system with fixation and load equal to half the body weight does not lead to critical values of bone tissue stress in terms of strength. Results. In the treatment of rigid spinal deformities in children with a deformity angle (>100°) using a HGT system, the first stage mathematically proved the effectiveness of this technique, but the maximum recommended load should not exceed 50% of the patient’s body weight. Modeling the correction of spinal deformities using mathematical models makes it possible to analyze the effect of various treatment methods in several versions without surgery. The maximum von Mises stress value of 40.1 MPa is not critical for bone tissue in terms of strength (ultimate strength for cortical bone is 70 MPa). However, when the load is doubled, i.e. with HGT to a load equal to the body weight, the level of stress will also double and exceed the ultimate strength of the bone tissue. The research was carried out in accordance with the principles of the Helsinki declaration. The study protocol was approved by the Local ethics committee of all participating institutions. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: final element method, spinal deformity, halo-gravity traction.

show abstract

unclassified

Analysis of mathematical modeling of a biomechanical model of halo-graviеn traction in spinal deformities in children

Rogozinskyi¹,

Levytskyi²,

Dolianytskyi³

et al. 2021

View full text Add to dashboard Cite

show abstract

Аналіз Напружено-Деформованого Стану Моделі Хребта Із Заднім Спондилодезом При Лікуванні Сколіотичних Деформацій У Дітей

Levitsky¹,

Rogozinsky²,

Dolyanitsky³

et al. 2022

TRAUMA

View full text Add to dashboard Cite

Background. Mathematical modeling of the correction of scoliotic deformities of the spine makes it possible to analyze the effectiveness of various methods of treatment without surgical intervention. In the study of traction, mainly experimental methods were used. The purpose was to investigate the stress-strain state of the spine models with varying degrees of scoliotic deformity during posterior spinal fusion. Materials and methods. Deformities of the spine of 40, 70 and 100° were modeled, with posterior spondylodesis of the Th1-Th12 vertebrae. A load of 300 N was used. Results. With a deformity of 40°, the most stressed are the areas of frontal plane curve. For the upper vertebrae Th1-Th4, a more even distribution of stress over the vertebral body is observed. For Th5-Th10 vertebrae, the concave side of the vertebral bodies is more stressed. In the thoracic spine, the more stressed vertebrae are Th2 and Th5. The main load is borne by the fixing structure, in which the level of stress is significantly higher than in the bone structures of the vertebrae. In the posterior supporting complex of the vertebrae, the stress concentration areas are located at the points where fixing screws enter the bone. An increase in the magnitude of the scoliotic deformity of the spine up to 70° causes an increase in the level of stresses in all elements of the model, with the exception of Th9-Th10 vertebrae. With a deformity of 100° in the posterior supporting complex of the vertebrae, the stress concentration areas are located at the points where fixing screws enter the bone. The stress level of 116.0 MPa exceeds the ultimate strength of the cortical layer of the bone tissue of the spine, which can lead to microdamage of the bone tissue and loosening of the screws. Conclusions. For all values of scoliotic deformity of the spine, the most stressed are Th4 and Th5 vertebrae. A decrease in the degree of deformity has a significant effect on the stress-strain state of the spinal column. In the Th4 vertebral body, the level of stresses with a deformity of 100° is more than twice as high as with a deformity of 70°, and more than 4 times higher than with a deformity of 40°. In the body of the Th5 vertebra, the stress level with a deformity of 70° is 1.5 times less than with a deformity of 100°, and with a deformity of 40°, it is 3 times less. The level of stress in the Th1-Th5 vertebral bodies is higher than that of Th6-Th12. In the posterior supporting complex, at the points where screws enter the bone, the maximum stress value at a deformity of 40° is 34.0 MPa, which is not critical for the bone tissue. With a deformity of 70°, the stresses are 85.0 MPa, which can exceed the ultimate strength for the cortical bone and lead to microdestruction of the bone tissue in the screw-bone contact area. With a deformity of 100°, the stresses are equal to 116.0 MPa, which exceeds the ultimate strength for the cortical bone and can lead to microfracture in the screw-bone contact area.

show abstract

Halo pin positioning in the temporal bone; parameters for safe halo gravity traction

Cited by 2 publications

References 21 publications

Analysis of mathematical modeling of a biomechanical model of halo-graviеn traction in spinal deformities in children

Analysis of mathematical modeling of a biomechanical model of halo-graviеn traction in spinal deformities in children

Аналіз Напружено-Деформованого Стану Моделі Хребта Із Заднім Спондилодезом При Лікуванні Сколіотичних Деформацій У Дітей

Contact Info

Product

Resources

About