Fractures at the thoracolumbar junction are the most common traumatic spinal injuries. Advances in instrumentation for vertebral body replacement have significantly improved surgical techniques.However, the biomechanical characteristics of stabilizing surgeries have been insufficiently studied. Objective. To investigate the stressstrain state (SSS) of a mathematical finite element model of the humanthoracolumbar spine during trunk backward bending after ТhХІІ vertebra resection, considering different transpedicular fixation options. Methods. A mathematical finite element model of the humanthoracolumbar spine — ThIX‒LV vertebrae — was developed. The ТhХІІ vertebra was removed, and an interbody support and transpedicularsystem with 8 screws were implanted to simulate the postsurgical state after a ТhХІІ burst fracture with wide laminectomy, facetectomy, and corpectomy. The influence of transpedicular screw length and the presence of cross-links on the SSS of the model wasexamined. Results. The use of bicortical screws reduced stress levels in the bone elements of the model, except in the regions around the screws in the lumbar vertebrae, when compared to short screws.Installing cross-links decreased stress levels at all control points compared to models without cross-links. Specifically, in the presence of cross-links, the SSS values at the entry points of the short screwsinto the vertebral bodies of ThX, ThXI, LI, and LII were 2.3, 1.8, 1.2, and 5.0MPa, respectively, compared to 2.7, 2.0, 1.5, and 6.1 MPa in the models without cross-links. In the case of bicortical screwswithout cross-links, the stress values at the screw entry points into the pedicles of the corresponding vertebrae were 2.9, 1.5, 8.2, and 11.2 MPa, respectively, compared to 2.7, 1.5, 7.5, and 10.2 MPa in the models with cross-links. Conclusions. When the trunk is tilted backward, the use of cross-links reduces stress levels at all control points in the models, regardless of the screw length used. Bicortical transpedicular screws increase stress levels on the screws themselves and in the lumbar vertebral bodies surrounding them.

Introduction. The thoracolumbar junction is one of the most frequently damaged parts of the human spine when exposed to a traumatic factor. Corpectomy in combination with posterior decompression and restoration of the spinal support function is often performed using an interbody implant and posterior transpedicular stabilization to achieve adequate decompression and stabilization in severe traumatic injuries of this level. The surgery of this type is characterized by significant instability of the operated segment and determines increased requirements for the rigidity and reliability of posterior fixation. We have modeled the situation of a two-level corpectomy with subsequent replacement of bodies with a mesh implant and posterior transpedicular stabilization with 8 screws. Objective. To study the stress-strain state of the thoracolumbar spine model after resection of the Th12-L1 vertebrae with different variants of transpedicular fixation under the influence of a compressive load. Materials and methods. A mathematical finite element model of the human thoracolumbar spine has been developed, the components of which are the Th9 ‒ Th11 and L2-L5 vertebrae (vertebrae Th12-L1 are removed), as well as elements of hardware - interbody support and transpedicular system. Four variants of transpedicular fixation were modeled: using short screws and long screws passing through the cortical layer of anterior wall of vertebral body, as well as two cross links and without them. The stress-strain state of the models was studied under the influence of a vertical compressive distributed load, which was applied to the body of the Th9 vertebra and its articular surfaces. The load value was 350 N, corresponding to the weight of the upper body. Results. d It was found that transpedicular fixation of the thoracolumbar vertebrae with the use of long screws reduces the level of tension in the bone elements of the models. In the area of screw entry into the pedicle of the T10, T11, L2 and L3 vertebral arch, the load when using short screws was 3.1, 1.7, 3.9 and 12.1 MPa, respectively, when using bicortically installed screws - 2.9, 1.8, 3.8 and 10.6 MPa. The addition of two cross-links also reduces the maximum load values in critical areas of the model to a certain extent. In case of short screws combination and two cross-links, the load in these areas was 2.8, 1.7, 3.6 and 11.5 MPa, when using bicortical screws and cross-links - 2.8, 1.6, 3.3 and 9.3 MPa. The study of the stress-strain state of other parts of the model revealed a similar trend. Conclusions. The use of long screws with fixation in the cortical bone of anterior part of the vertebral bodies reduces the level of tension in the bone elements of the models. The use of cross links provides greater rigidity to the transpedicular system, that also reduces the tension in the bone tissue.

The anterior decompression-fusion surgery is currently the most effective treatment method for number of pathological conditions and traumatic injuries of the cervical spine. The study is devoted to the surgery and implant optimization, to achieve the optimal state of sagittal kyphosis in patients after anterior subaxial cervical fusion. The retrospective analysis of 151 clinical cases was held; the nonlinear dependence of the final results of treatment on the degree of correction was revealed using regression analysis, the finite element analysis of the cervical spine models with different parameters of segmental kyphosis of the operated segment was carried out. As a result, the optimal parameters of sagittal contour correction of the operated cervical spine were determined.

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Актуальність. Механічна компресія вмісту хребетного каналу, що виникає при травматичному пошкодженні хребта, має основоположне значення при визначенні тактики терапії і прогнозів регресу неврологічних розладів у постраждалих. Аналіз даних літератури демонструє відсутність критерію, який дозволяє характеризувати морфологічно гетерогенний субстрат, що викликає компресію спинного мозку. Мета: сформулювати визначення, розробити і виконати перевірку вірогідності рентгенограмметричного методу оцінки сагітального розміру різних за морфологічним типом вентрально-інтраканально розташованих травматичних субстратів. Матеріали та методи. Інформаційний пошук дозволив виявити існуючі індекси і методи вимірювання ступеня компресії хребетного каналу, а також клінічну значимість характеру і ступеня компресії спинного мозку травматичним субстратом. Для первинної перевірки вірогідності методу оцінювання вентрально розташованого травматичного субстрату був проведений ретроспективний аналіз даних нейровізуалізації 150 пацієнтів із травматичними змінами шийного відділу хребта. Були проаналізовані дані спондилограм, комп’ютерних та магнітно-резонансних томограм. Вимірювання проводились трьома незалежними експертами. Результати. Розроблений термін «компримуючий фактор», що становить собою збірне поняття і відображає загальну характеристику патологічних анатомічних субстратів, які виникають при ушкодженнях хребетного рухового сегмента, що призводять до деформації стінок хребетного каналу і, як наслідок, викликають здавлення структур хребетного каналу. Для кількісної характеристики виконувалось вимірювання сагітального розміру компримуючого фактора, що має абсолютну метричну величину і характеризує відносний ступінь зміщення субстрату в просвіт хребетного каналу. Отримані при статистичній обробці результати виявляють високу відтворюваність результатів вимірювань. Коефіцієнт конкордації становив 0,85 при р = 0,00025. Висновки. Наведену радіологічну ознаку доцільно використовувати для загальної характеристики клінічного випадку, а також при статистичній обробці даних із метою уніфікації уявлення про ступінь компресії вмісту хребетного каналу.

Objective. To determine the dynamics and state of neurosurgical care for tumors of the spinal cord and spine (TSCS) in Ukraine. Materials and methods. The work is based on the analysis of hospitalizations and surgical treatment of patients with TSCS in neurosurgical departments of Ukraine in 2000-2019. Results. In 2019, 1,325 patients with TSCS were hospitalized in neurosurgical departments of Ukraine, which is 2,3 times more than in 2000 (567), per 1 million population - almost 3 times (34,7 vs. 11, 6 ). Over 20 years, the number of operated patients increased 2,8 times (from 385 to 1079), per 1 million population - 3,6 times (from 7,9 to 28,3), there was an increase in surgical activity by 20% (from 67,9 to 81,4%), a decrease in the general and postoperative mortality - twice (from 2,6 to 1,2% and from 2,6 to 1,3% respectively). Patients with TSCS account for 1,5% of all patients hospitalized in neurosurgical departments of Ukraine, 12,8% of all CNS neoplasms and 5,2% of all spinal pathology. Vertebral tumors account for 42,64% of all TSCS and extramedullary tumors have an incidence rate similar to vertebral tumors (42,64%), intramedullary tumors account for 14,72%. In 2019, 74.4% more patients with extramedullary tumors were hospitalized than in 2000 (565 and 324 respectively), and 84.5% more were operated on (463 and 251 respectively). The rate of increase is even higher per 1 million population. In 2019, there were 14.8 hospitalizations per 1 million population for extramedullary tumors, which is 2.2 times greater than in 2000 (6,6 hospitalizations), and 12,1 operations, which is 2,4 times greater than in 2000 (5,1 operations). In 2019, patients with intramedullary tumors were hospitalized 2,2 times more than in 2000. (195 and 89 respectively), were operated 2,5 times more (151 and 61 respectively). The rate of increase is even 4higher per 1 million population. In 2019, there were 5,1 hospitalizations for intramedullary tumors per 1 million population, which is 2,8 times greater than in 2000 (1,8 hospitalizations), and 4,0 operations, which is 3,2 times greater than in 2000 (1,2 operations). In 2019, patients with vertebral tumors were hospitalized 3.7 times more than in 2000 (565 and 154 respectively), were operated 6,4 times more (465 and 73 respectively). The rate of increase is even higher per 1 million population. In 2019, there were 14,8 hospitalizations per 1 million population for vertebral tumors, which is 4,7 greater than in 2000 (3,1 hospitalizations), and 12,2 surgeries, which is 8,2 greater than in 2000 (1,5 operations). Сonclusions. The introduction of modern neuroimaging methods and advanced treatment methods into clinical practice has contributed to an increase in the number of hospitalizations and surgical interventions in TSCS.

Introduction. The thoracolumbar junction is the most common location of traumatic spinal injuries. It accounts for 50-60% of all thoracic and lumbar spine injuries. Spondyloptosis is rather rare, but one of the most severe types of traumatic injury, that is characterized by a severe damage of spinal axis in one or more planes. Traumatic spondyloptosis is classified as reducible and irreducible, depending on the possibility of intraoperative restoration of the spinal axis without resection of the damaged vertebra. Objective. To determine the optimal surgical technique for traumatic irreducible spondyloptosis of thoracolumbar junction. Materials and methods. A retrospective analysis of the patients’ database treated at the Romodanov Neurosurgery Institute, Ukraine was performed over the past 4 years (2017 to 2020) to identify all cases with traumatic irreducible spondyloptosis of the thoracolumbar junction. Results. Treatment outcomes of five patients aged 18 to 52 years (mean age 31.2 years) were analyzed. The minimum period from the moment of injury to surgery was 14 days, the maximum was 3 months and 2 days (on average 42.2 days). At the time of admission all patients had a neurological deficit that corresponds to the functional class A on the American spine injury associatin ASIA scale of severity of spinal cord injury. The TLICS (Thoracolumbar injury classification and severity) score was 8 points. All the patients had the injury of lateral spondyloptosis: in three cases as an isolated displacement only in the coronal plane, in two – as a combined one - in the coronal and sagittal plane. Surgical intervention in all cases was performed from the posterior approach. As a body replacement system in 2 patients, a vertical cylindrical implant (Mesh) was used, in 3 patients - a telescopic body replacing implant. The method of bicortical implantation of pedicle screws was applied. The transpedicular system was strengthened by two cross links of the rod-to-rod type. In all cases the restoration of spinal axis was achieved in both the coronal and sagittal planes. Follow-up examinations were carried out 2, 6 and 12-18 months of the postoperative period. Regression of neurological disorders was registered in two patients, in one case to ASIA B, in the other to ASIA C. Conclusions. Isolated posterior approach has demonstrated high efficacy in the surgical management of traumatic irreducible spondyloptosis of the thoracolumbar junction both in restoring the axis of the spine and in ensuring the stability of fusion.

Traumatic injury to the cervical spine accompanied by a wide range of possible changes in its osteo-ligamentous apparatus. One of the basic criteria to determine the treatment strategy is the assessment of injury stability which depends on the condition of the spine supporting columns. Most of the modern and widely used classifications of subaxial cervical spine traumatic injuries quite sufficiently characterize the state of the anterior support column. At the same time, much less attention is paid to the assessment of the degree and nature of traumatic changes in lateral masses, facet joints, as well as possible dislocations. Literature analysis reveals the absence of a generally accepted scheme that would allow one to unambiguously and comprehensively characterize the damage to the facets / lateral masses and choose the optimal surgical or conservative treatment method. This review provides well known assessment schemes: classification of traumatic changes of facet joints by Marcel F. Dvorak et al., variants of traumatic displacement of the cervical vertebrae by V.P. Selivanov, variants of lateral mass traumatic injury by Y. Kotani et al. and Posterior Ligament-Bone Injury Classification and Severity Score. The advantages and disadvantages of anterior, posterior or combined approach for the treatment of traumatic injuries of posterior support complex are considered that is of critical importance for obtaining better clinical results. It is noted that the choice of the optimal treatment method is currently a controversial issue. Although good surgical results can be obtained using a variety of methods, there are certain situations in which one technique may be better than others. The accumulated clinical experience and current research on the injured spine biomechanics demonstrate the advantage of surgical treatment in most patients, since such injuries are usually unstable or potentially unstable.