Objective. To analyze variants of post-traumatic spinal canal narrowing in burst fractures accompanied by fragment displacement of critical values, and to determine the effectiveness of surgical remodeling of the spinal canal.

Material and Methods. Medical records of 136 patients with burst fractures of thoracic and lumbar vertebrae involving displacement of fragments into spinal canal on critical values were analyzed. Fragments were classified by their quantity, width, displacement type, and connection with the rest of vertebral body.

Results. Three types of fragments displaced into spinal canal were identified: Type I – a large free fragment occupying all interpedicular space in the cranial part of the spinal canal with linear and angular displacement; Type II – a large fragment impacted into the central and posterior parts of the vertebral body and occupying the whole interpedicular space with linear displacement; and Type III – several fragments connected with the central part of the vertebral body and occupying the space less than interpedicular one with linear displacement.

Conclusion. Type I fragments are most favorable for application of indirect reduction, while Types II and III fragments are less likely reduced by transpedicular fusion and ligamentotaxis than by anterior spinal canal remodeling. Accounting for a type of fragment displacement into the spinal canal is important in preoperative planning for burst fracture surgery.

Objective. To specify techniques of transcutaneous transpedicular vertebroplasty for lumbar vertebra injury in patients with osteoporosis.

Material and Methods. Ninety five patents aged 55 to 82 years with uncomplicated injuries to lumbar vertebrae associated with osteoporosis were operated on. Specific features of surgery depended on radiological morphological parameters of the injured vertebra revealed by preoperative X-ray examination. Standard radiography and computer-aided tomography were used.

Results. Persistent antalgic effect was observed in 96.3 % of operated patients. In 7 (7.3 %) cases conventional transcutaneous vertebroplasty was associated with cement extravasation beyond vertebra limits. Patients having such X-ray picture of injury underwent a modified technique of vertebroplasty with bilateral transpedicular injections of precalculated bone cement volume into posterior and anterior fragments of the injured vertebra.

Conclusion. The choice of vertebroplasty technique should be made with account for radiological morphometric parameters of the injured vertebra optimally based on CT findings.

Objective. To study possible combinations of severity of physiological spinal curvatures (lumbar lordosis and thoracic kyphosis) evidenced by computer optical topography (COMOT), and to elaborate specified classification of sagittal plane posture disorders based on statistically valid topographic norms and criteria.

Material and Methods. Results of the COMOT screening of children and adolescents in six cities formed a clinical database including more than 33,000 patients approximately evenly distributed through ages: ranged from 4.5 to 17.5 years.

Results. A new classification of sagittal plane posture disorders was elaborated based on the COMOT method findings. This classification differentiates posture disorders on manifestation of deviations into mild, moderate, and marked considering all possible relations of severity of physiological curvatures. It contains 21 posture types: a harmonic, 8 types of mild disorders, 7 types of moderate disorders, and 5 types of marked disorders.

Conclusion. In 2011, the proposed classification of sagittal plane posture disorders was introduced into the TODP software system (WTOPO version 3.8-11), that would allow for more accurate differentiation of sagittal plane posture based on topography survey results. This is important for both clinical practice and scientific research.

Objective. Neurophysiological assessment of brainstem structures in patients with cervical spine injury using short latency auditory evoked potentials (SLAEP).

Material and Methods. Study group included 48 patients aged 18 to 50 years with early and intermediate periods of cervical spine injury. Patients were grouped according to anatomic features of the cervical spine, which determine peculiarities of injury and its effect on the spinal cord.

Results. Changes in SLAEP were observed in 14 patients (87.5 %) with injury to craniovertebral junction. Brainstem structures were involved in 7 (38.8 %) patients with uncomplicated injury of the lower cervical spine. Patients with complicated injury of the cervical spine had SLAEP abnormalities in 100 % of cases including elongation of latencies and interpeak intervals, distortion of peak-to-peak amplitude ratios, and peak deformations and asymmetries.

Conclusion. Complicated and uncomplicated cervical spine injuries are characterized by signs of dysfunction of brainstem structures, predominantly at pontomedullar and pontomesencephal levels. It was found that degree of SLAEP changes depends on severity of the cervical spine injury.

Objective. To assess the efficacy of neurological complication prevention by multimodal intraoperative monitoring of spinal cord functioning.

Material and Methods. Results of intraoperative spinal cord monitoring in 457 patients during spine correction surgery for grade IV scoliosis with application of the third-generation segmental instrumentation were analyzed. The magnitude of scoliotic curvature exceeded 80 degrees in 353 patients. All patients underwent continuous intraoperative monitoring of lower extremity skin temperature. Out of them, in 45 patients somatosensory evoked potentials were recorded, and in 41 patients intraoperative Stagnara wake-up test was performed.

Results. Neurological complications were registered in 4 patients as lower atonic paraplegia which accompanied with rapid rise in lower extremity skin temperature more than by 1 °C during spinal deformity correction. In two of them SSEP recording showed a sharp decrease in the amplitude of potential waves up to their complete disappearance. Skin temperature monitoring of lower extremities did not revealed significant changes in patients without neurological complications.

Conclusion. Multimodal intraoperative monitoring of the spinal cord function should be performed in patients with high risk of neurological complications after surgical correction of spinal deformity.

Objective. To compare the strength resistance of seriesproduced and modified spinal systems to continuous cyclic loading.

Material and Methods. Assembled transpedicular four-screw systems with monoaxial screws of equal configuration were tested. The study group included modified fixation system, and the control group – series-produced domestic fixation systems. All devices were fixed in textolite vertebra models with the account for average pedicle angle and interpedicular distance, with equal interval between vertebrae, and using one transverse connector. The models were exposed to axial cyclic loading.

Results. In dynamic loading conditions with 150 kg load (1,500 Newton) and the frequency of 6 cycles per second, the maximum strength of transpedicular fixation system from the study group was at average statistically reliably 22.1 % higher than that from the control group (p ≤ 0,05).

Conclusion. The performed study appeared to be a scientific rationale for transpedicular screw modification. Suggested modification statistically reliably increases the maximum strength of fixation system, which reduces complication rate after transpedicular fixation and allows extending indications for transpedicular spinal fusion alone.

Objective. To assess spinal mobility with different extents of intervertebral disc resection, strength of screw fixation in vertebral bodies depending on placement techniques, and potentials for augmentation of screw fixation with bone cement.

Material and Methods. Eighteen young human cadaveric models of thoracolumbar spines were used. Discs with different extents of discectomy were exposed to rapture and torsion load. Mechanical stability of screw fixation using different placement techniques and augmentation with bone cement was assessed.

Results. The highest spinal mobility was observed after total discectomy with posterior longitudinal ligament dissection. Two-rod fixation system proved to be the most stable one, and bicortical screw placement – the most preferable. Bone cement augmentation increases mechanical stability of screws inserted into vertebral bodies.

Objective. Analysis of morphological criteria of formation of secondary growth plate and vertebral body torsion in scoliosis.

Material and Methods. Specimens of vertebral body growth plates from convex and concave sides of deformity, intervertebral discs, and bone tissue were obtained during surgical correction of spinal deformity in 60 patients age 6–14 with II–IV grade idiopathic scoliosis. Structural components of the spine of children age 10–14 obtained from the Department of Forensic Medicine were used as controls. Specimens were analyzed using morphological, histochemical, and immunohistochemical methods and ultrastructural analysis.

Results. Proliferative activity of chondrocytes in the concave zone of the growth plate and in loose areolar tissue of the disc with isogenous groups and columnar structures, which repeat the stages of growth plate chondroblast differentiation, is specified as a secondary growth plate. Secondary growth zone is a biomechanical adaptive mechanism of congruency formation type. Second process of vertebral body torsion also may be characterized as adaptive mechanism. A change in the structural organization of the growth plate is observed at early stages of scoliotic spinal deformity (Grade II). Formation of columnar structures is disturbed; isogenic groups of cells are at the angle of 45° to the axis of the spine.

Conclusion. The formation of bone structures in accordance with the violation of the chondroblast architectonics in the growth plate is a morphological substrate of the torsion, and explains the interdependence or the priority of the torsion in the formation of wedge-shaped vertebrae.