An intelligent system for improving the process of hydromechanical extrusion

An intelligent software system is developed for improving the process of hydromechanical extrusion enabling semi-fluid friction of the bar on the container walls and on the die mouth to be created, thus providing a favorable action of friction forces due to the fact that the velocity of the lubricant layer exceeds that of the bar. Herewith, extrusion pressure and the degree of strain inhomogeneity decrease significantly, and the bar-tool contact decreases, this being particularly relevant for metals adhering to the tool. © 2019 Author(s)

A RARE CASE OF SUCCESSFUL STAGED SURGERY IN THE PATIENT WITH JOINED STENOSIS OF THE VERTEBRAL CANAL AT THE CERVICAL, THORACIC AND LUMBAR LEVELS

In the present article we describe a clinical example of a successful staged surgical treatment in the patient with rare joined stenosis of the vertebral canal at the cervical, thoracic and lumbar levels, surgical rehabilitation was 24 weeks. In connection with clinical data the first stage included ventral decompression of the cervical department of the spinal cord and spondylodesis by a telescopic prosthesis of a vertebral body, during the second stage through a minithoracotomy with an endovideo-assistance we performed anterolateral decompression of the spinal cord and spondylodesis by a telescopic prosthesis of a vertebral body with a lateral plate, and the third stage consisted of dorsal decompression of a dural bag and roots of the spinal cord, transpedicular fixation with an interbody spondylodesis in a lumbar department of the spine. Applying low-traumatic techniques for decompression and spondylodesis with specialized devices we could decrease level of pain syndrome, degree of neurologic deficiency, improve life quality and carry out effective fixation of three operated on vertebral aspects. Mini-invasive staged microsurgical decompressive stabilizing techniques can be used for successful treatment in patients with joined stenoses in the vertebral canal and also allow to reduce considerable risks for life and to cause full rehabilitation in the shortest possible time

Analysis of the influence parameters spine-pelvic balance on the risk of development degeneration and degenerative disease of adjacent segments after lumbar spine rigid fixation

Introduction An increase in the load on adjacent segments causes changes in the parameters of the spinal-pelvic balance and, as a consequence, the development of the so-called biomechanical «stress». Such pressures are a key link in the pathogenesis of degeneration, and in the presence of clinical and neurological manifestations of the latter and adjacent segment degenerative disease (ASD/ASDd).Objective of this study was to assess the effect of the parameters of the spinal pelvic balance on the risk of developing ASD/ASDd after dorsal decompression-stabilizing interventions (DDSI).Material and Methods The study included medical records of patients who underwent DDSI for lumbar spine degenerative diseases. Clinical and instrumental parameters were assessed.Results Based on the inclusion criteria, 98 patients (48 with signs of ASD/ASDd and 50 without) were included in the study. The average postoperative follow-up period for the respondents was 46.6 ± 9.8 months. If PI/ LL parameters were <10 and the ratio of segmental and global lumbar lordosis (LIV-SI/LI-SI) was 50% or more, the incidence of ASD/ASDd was significantly lower in patients who underwent rigid lumbar stabilization surgery.Conclusion The values of PI/LL parameters and the ratio of segmental and global lumbar lordosis are obvious risk factors for the development of ASD/ASDd after rigid lumbar spine DDSI

Analysis of the results of staging decompression / stabilization interventions in the treatment of patients with tandem stenosis of cervical and lumbar spine

The concept of "tandem stenosis" comprises combination of degenerative stenosis in both cervical and lumbar spine. At the moment, there is no consistent approach to the surgical procedures in this group of patients, as well as the researchers do not pay much attention in their papers to the sequence and stage-by-stage approach to the procedures and to the analysis of combined surgical procedures. The aim of the research was to analyze the results of staging decompression/ stabilization interventions in the treatment of patients with tandem stenosis of cervical and lumbar spine. We performed a retrospective analysis of prospectively collected results of treatment of 46 patients with combined (tandem) stenosis of cervical and lumbar spine. The patients were operated in four neurosurgical clinical units of Vladivostok, Irkutsk and Novosibirsk. We assessed clinical data: level of pain syndrome - using visual analog scale (VAS), neck disability index (NDI), Oswestry disability index (ODI), MacNab and Nurick clinical outcomes, as well as the results of plain spine radiography and neuroimaging studies (MRI, MSCT). Multicenter study of the results of staging surgical procedures with the use of specialized microsurgical instruments in the treatment of patients with tandem stenosis of cervical and lumbar spine allowed us to confirm their high clinical and radiological effectiveness

Peritumoral edema at brain meningiomas

Among edema-producing neoplasms of central neural system, the meningiomas are unique. Meningiomas are histologically benign, slow growing and originate extracerebrally. The development of accompanying peritumoral brain edema (PBE) occurs in 40-60 % of meningiomas and often with a high degree of PBE with no obvious relation to the size and histologic features of the meningioma. The aim of our study was to determine the correlation between such parameters as gender, age of the patient, localization of the tumor tissue and the presence/severity of PBE. At meningiomas PBE was present in 70,1 % of patients. Meningioma with the presence of PBE occur more often than tumors without PBE. Olfactory groove tumors have more pronounced degree of PBE, unlike meningiomas of parasagittal localization and the region of the wings of the sphenoid bone. Mixed meningiomas had a greater degree of PBE unlike meningotheliomatozic and fibroblastic variants

Bone morphogenetic protein-2 influence on metabolic activity and proteoglycan synthesis by intervertebral disc cells

Modern therapeutic strategies for intervertebral disc repair mainly focus on targeting molecular pathways of extracellular matrix degeneration. Anabolic strategies for regeneration are aimed to increase production of major extracellular molecules. Members of TGF-b superfamily proteins, particularly the bone morphogenetic proteins (BMP) have a high regenerative potential regarding the mesenchymal cells. The goal of this study is to study production of proteoglycans by the intervertebral disc cells under the influence of bone morphogenetic protein 2. Material and methods. The experiment was carried out on the cell cultures derived from the annulus fibrosis cells and nucleus pulposus cells of the human intervertebral disc. We studied cell livability, metabolic activity and proteoglycan expression. Cell livability was assessed using the trypan blue staining. Alamar blue test was used for the estimation of metabolic activity. Amount of sulfated glycosaminoglycans was assessed using the assay based on the reaction with 1,9-Dimethylmethylene Blue. Results. Cultivation with bone morphogenetic protein 2 in different concentrations did not decrease livability of the cells. Study cell cultures with application of bone morphogenetic protein 2 in different concentrations showed significant increase in metabolic activity and proteoglycan synthesis by the annulus fibrosis cells. Despite the relative increase in the number of the nucleus pulposus cells treated with the bone morphogenetic protein 2, the differences in metabolic and synthetic activity compared with control group was not significant. Conclusion. The bone morphogenetic protein 2 has an anabolic effect towards the intervertebral disc cells, particularly in the production of proteoglycans by the annulus fibrosis cells

PERIARTICULAR CYSTS OF FACET JOINTS: ETIOPATHOGENESIS, DIAGNOSIS, METHODS OF SURGICAL TREATMENT. A CLINICAL EXAMPLE

Background. Periarticular cysts (PC) of facet joints is a rare pathology in neurosurgical practice. The concept of PC is applicable for all cysts that are located either pararticularly in the region of facet joints, or start from them.Material and methods. A systematic search was performed in medical databases: Medline, RINC, EMedicine, UMKB, Pubmed on the relevant topic in Russian and English. The search query includes  words: arcuate joint, periarticular cyst, clinic, diagnosis, surgical  treatment. One of the significant factors of PC development is the  instability of the vertebralmotor segment of both degenerative and post-traumatic character.Results. The result of the literature review was the writing of a clinical lecture, the current state of the issue of etiopathogenesis, diagnosis and management of patients with  periarticular cysts of facet joints was studied. The article gives a  clinical example of surgical treatment of a patient with a periarticular cyst at the level of LIV-LV on the right.Conclusion. Periarticular cysts of facet joints are one of the factors of compression of cauda equina roots, with surgical treatment being  a radical and effective way of treatment. A detailed study of this  pathology is a promising direction in spinal neurosurgery. Further  research is required on comparative analysis of clinical and  instrumental efficacy of various methods of surgical treatment of periarticular cysts of facet joints

Histological and immunohistochemical characteristics of brain meningiomas

Meningiomas are among the most common primary intracranial tumors. They arise from meningothelial cells of the arachnoid layer that forms the external lining of the brain and occur primarily at the base of the skull in the parasellar regions as well as over the cerebral convexities. Of particular difficulty are anaplastic meningiomas, having similarities with malignant soft tissue tumors. Immunostaining allows to define not only the source of cytogenetic, tumor grade, but detect abnormal proteins - transcription products damaged DNA regions and make recommendations for the appointment of targeted therapy. Targeted effect on the meningioma will allow to achieve a significant increase in patient survival

Posttraumatic pneumacephalus: etiopathogenesis, diagnostics, methods of surgical treatment. Clinical case

Studying an opportunity to optimize the treatment of the patients with severe traumatic brain injuries is a topical issue in modern neurosurgery. Traumatic tension pneumocephalus is one of life-threatening conditions which accompanies severe TB1 and is often complicated with posttraumatic liquorrhea and mass effect. Materials and methods. We carried out systematic search in Russian and foreign medical databases (Medline, Russian Science Citation Index, EMedicine, UMKB) concerning our theme. We included the following words in our search request: tension pneumocephalus, mass effect, valve mechanism, treatment. The result of conducted review of literature was writing the clinic lecture, studying current status of the problem of etiopathogenesis, diagnostics and surveillance of the patients with tension pneumocephalus. The article presenas clinical case of successful surgical treatment of a patient with traumatic tension pneumocephalus. Conclusion. There are no uniform standards of urveillance of the patients with tension pneumocephalus. Based on our own experience, we determined that minimally invasive surgery is a method of choice among reconstructive craniofacial surgeries in the treatment of patients with traumatic tension pneumocephalus. It decreases the risks of intra- and postoperative complication. Compliance, using external ventricular drainage and repeated lumbar punctures with prevention of inflammatory complications helped stopping nasal liquorrhea and eliminating mass effect which caused absolute regression of neurological signs

Development of an algorithm for the clinical and instrumental diagnosis of non-compression lumbar pain syndromes to optimize the use of puncture surgical techniques

Background. Pain syndromes developing as a result of degeneration of the lumbar segments of the spine constitute a significant problem in modern vertebrology. The results of the application of preoperative diagnostic provocative tests are contradictory, and therefore the mixed effectiveness of puncture surgical techniques is recorded.Objective. To develop an algorithm for the clinical and instrumental diagnosis of non-compression lumbar pain syndromes to optimize the use of puncture surgical techniques.Material and Methods. The study included 923 patients who underwent provocative diagnostic techniques on the intervertebral disk (IVD) and the arched joints (AJ) between 2012 and 2017. Taking into account clinical and instrumental data, the following are made: in group I (n=246) – laser IVD nucleoplasty, in group II (n = 287) – laser denervation of FJ, in group III (n = 390) – simultaneous use of laser exposure to IVD and AJ. We analyzed the dynamics of the level of pain in the lumbar spine and lower extremities according to The Visual Analogue Scale and quality of life according to The Short Form-36 (SF-36) questionnaire.Results. When performing provocative diagnostic tests, the minimum number of adverse effects was recorded: 3.2% in group I, 2.4% in group II, and 2.1% in group III. After puncture methods of surgical treatment, a significant persistent decrease in the severity of preoperative pain was observed both in the lumbar spine (p = 0.002, p = 0.005 and p = 0.004, respectively) and in the lower extremities (p = 0.003, p = 0.001 and p = 0.005, respectively) A significant improvement in the physical and psychological components of health was also established in group I (p = 0.02 and p = 0.01, respectively), in group II (p = 0.01 and p = 0.03, respectively) and group III (p = 0.03 and p = 0.02, respectively).Conclusion. In the presence of neuroimaging parameters of IVD according to C. Pfirrmann III–IV and protrusion size 4–6 mm, minimal degenerative changes in the AJ according to A. Fujiwara I–II and D. Weishaupt I–II, as well as a positive disruption test, it is possible to perform laser nucleoplasty. In case of detection of neuroimaging data of IVD according to C. Pfirrmann I–II and protrusion size less than 4 mm, moderately pronounced degenerative changes in the AJ according to A. Fujiwara II–III and D. Weishaupt II–III, as well as positive paraarticular stimulation of AJ, laser denervation of AJ is recommended. When determining, according to neuroimaging data, moderate degenerative changes in IVD according to C. Pfirrmann over III and protrusion size 4–6 mm, as well as degeneration of AJ according to A. Fujiwara more than II and D. Weishaupt more than II, positive of samples and paraarticular stimulation of AJ, it is advisable to perform simultaneous surgical intervention in the volume of laser IVD nucleoplasty and laser denervation of AJ