Objective. To perform a non-systematic review of classifications of screw malpositions in transpedicular fixation of thoracic and lumbar
spine deformities and to develop a tactical classification of screw malpositions in instrumental fixation of scoliotic deformities of the spine
with a consensus assessment (kappa coefficient).
Material and Methods. A search of studies was conducted in the Pubmed, eLibrary, and Google databases that evaluated the location
of screws using or justifying the classification. Given the narrow specificity of the topic, publications of any design were included in the
sample. Based on the data obtained, the authors proposed a tactical classification of screw malpositions in instrumental fixation of scoliotic deformities of the spine with an assessment of expert agreement using the Cohen’s kappa coefficient.
Results. A total of 139 articles were found in the databases, including 21 articles from references. Of them, 66 articles did not correspond
to the topic of the study, 12 – did not have the open-text access, and 85 – had open-text access. Twenty articles met the inclusion criteria. The analysis showed that classifications used mainly determine the displacement of screws into the lumen of the spinal canal without
taking into account clinical manifestations and treatment tactics. Five classifications have been proposed to assess the position of screws
in scoliosis, while only one determines the tactics of patient management based on a score assessment.
Conclusion. An objectified method for assessing the accuracy of screw position is needed to provide additional evidence of the safety
of malpositions and to determine the clinical significance of malpositions, risk factors associated with incorrect installation, and further
actions of the surgeon.

Objective. To perform multicomponent assessment of the results of surgical treatment of patients with idiopathic scoliosis of less than 40° according to Cobb and their compliance with patients’ expectations.

Material and Methods. A total of 105 patients (97 women and 8 men) with an average age of 18.8 years, including 51 (48.6%) patients aged 18 years and older, were operated on for idiopathic scoliosis with a primary curve that did not exceed 40° (average 34.9°) at the time of surgery. Surgery was performed using Drummond instrumentation (2 patients), Antares system (4), and CDI (99), including using pedicle screws in 47 cases. The average period of postoperative follow-up was 51.1 months (range 24 to 170 months). Examination methods included clinical and radiological examination, SRS-24 questionnaire, and examination by a clinical psychologist.

Results. In the overall group of 105 patients, the primary curve decreased during the intervention from 34.9° to 11.6° (correction – 66.7%), and at the end of the observation period it was 14.1° (loss of correction – 10.7%). The countercurvature correction was 60.1% with a subsequent loss of correction of 1.1° (7.4% of the achieved correction). Transpedicular fixation resulted in significantly greater correction of the primary curve (24.7° vs. 21.7°) with a smaller loss of correction (0.7° vs. 5.4°). Survey using the SRS-24 questionnaire demonstrated significant positive trends in the overall score (the so-called Grand Total) and in the domains of general and professional activity. Negative trends were noted for the assessment domains of postoperative appearance and satisfaction with treatment results.

Conclusion. Idiopathic scoliosis with a primary curve less than 40° is often treated surgically due to patient’s demand. A significant proportion of patients are not fully satisfied with the outcome. Indications for surgery for such deformities should be formulated strictly on an individual basis, and patients require special preparation, primarily psychological.

Objective. To identify main negative factors influencing the comprehensive assessment of the results of surgical treatment of severe idiopathic scoliosis with a primary thoracic curve.

Material and Methods. A total of 288 patients were operated on for idiopathic scoliosis with main thoracic curve (Lenke types 1, 2, 3 and 4)
measuring 93.0° [85.0°; 105.0°] in 1999–2019. Out of them, 154 patients had the lumbar countercurvature of 62.0° [53.0°; 72.5°]. All patients were operated on using posterior segmental instrumentation with hook fixation, hybrid (hook fixation in the thoracic and transpedicular one in the lumbar and thoracolumbar spine) and transpedicular fixation. The median age of patients at the time of surgery was 15.0 [13.0; 17.0] years, and the median period of postoperative follow-up – 4.3 [3.0; 6.2] years. Clinical and radiological data in the preoperative, postoperative and in long-term postoperative periods, and data of the SRS-24 survey were analyzed. The threshold values of eight clinical parameters were evaluated based on their excess of reference parameters of the physiological norm and data substantiated by previously conducted studies.

Results. The residual thoracic curvature of more than 70° was detected in 32 (11.1%) patients, thoracic kyphosis over 60° – in 22 (7.6%), shoulder girdle tilt more than 5 ° – in 39 (13.5%), correction less than 50% – in 108 (37.5%), clinical frontal imbalance – in 49 (17.0%), hypokyphosis – in 79 (27.4%), hypolordosis – in 37 (12.8%), and total SRS-24 score less than 80 points – in 7 (2.4%) patients. Excellent results were stated in 123 (42.7%) patients, good - in 118 (41%), including 42 (35.6%) with one or more significant negative factors; satisfactory results were stated in 44 (15.3%) patients, including 35 (79.5%) with critical negative factors. Unsatisfactory results were noted in 3 (1.0%) patients.

Conclusion. Identification of statistically significant differences in 398 parameters made it possible to reveal eight negative factors that affect the outcome of treatment of severe thoracic scoliosis, and to determine their threshold values. Three critical negative factors have the greatest impact on the result of surgical treatment: the residual thoracic scoliotic curve more than 70°, thoracic hyperkyphosis more than 60° and shoulder girdle tilt more than 5°.

Objective. To assess the condition and functional parameters of m. erector spinae in patients who underwent dynamic anterior and rigid posterior fixation for thoracic scoliosis, using ultrasound diagnostics (US) and a proprietary methodology.

Materials and Methods. The comparative study involved 95 patients aged 15–55 years with idiopathic right-sided thoracic scoliosis (Cobb angle 35–60°): 33 of them after dynamic fixation, 32 after rigid fixation, and 30 patients awaiting surgery (control group). The follow-up period exceeded 12 months. Ultrasound examination included measuring of the fiber pennation angle, muscle thickness, contractility index, and relative asymmetry at the apex of the scoliotic curve. Measurements were performed in two patient positions: at rest and during maximum extension (30°, controlled by a goniometer).

Results. Statistically significant differences (p ≤ 0.05) between the groups were found. At rest, the pennation angle after dynamic fixation (20.06° ± 0.15°) was 26.5% higher than after rigid fixation (15.85° ± 0.62°), but lower than control values (23.57° ± 0.93°). The thickness of m. erector spinae with dynamic fixation (1.23 cm ± 0.01 cm) was close to the control (1.35 cm ± 0.02 cm), whereas with rigid fixation  a pronounced decrease in thickness was observed (0.89 cm ± 0.01 cm). During extension (30°), the pennation angle in patients operated on with the dynamic system sharply increased to 39.5° (close to the control value of 40.5°), which was 2.4 times higher than the indicator (16.2°) in the group with rigid fixation. The thickness of m. erector spinae (2.15 cm ± 0.05 cm) under load after dynamic fixation corresponded to the control (2.20 cm ± 0.03 cm), while rigid fixation showed thinning (1.21 cm ± 0.14 cm). The mean contractility index after dynamic fixation was significantly lower (p < 0.05) than that (84.65% ± 0.35%) after rigid fixation and close to the control value (53.9%), indicating preservation of muscle contractility. Relative asymmetry was minimal in the dynamic fixation group (1.6%) compared to that in the rigid fixation (2.24%) and control (2.96%) groups.

Conclusion. The ultrasound technique used in the study demonstrated high efficiency in assessing the condition of the paraspinal muscles. Anterior dynamic fixation for thoracic scoliosis provided the preservation of m. erector spinae functional activity, the maintenance of natural contraction and improved muscle symmetry, whereas posterior rigid fixation was accompanied by structural changes, including reduced elasticity and degeneration of muscle fibers.

Objective. To analyze long-term radiological and clinical outcomes of treatment of neurologically intact burst fractures of the thoracolumbar junction and to determine the optimal method of surgical treatment.

Material and Methods. A single-center retrospective cohort study was conducted. Inclusion criteria were: AOSpine type A3 or A4 fracture at the T11–L2 level; absence of spinal cord and its nerve root injury; patient availability for a follow-up examination 12 months or later
after surgery. Surgical treatment methods were divided into six groups depending on surgical approach (posterior, anterior, or combined) and whether decompression was performed. Standard radiological parameters were evaluated at admission, immediately after surgery, and at the final examination. Clinical outcomes were assessed using the Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI).

Results. A total of 57 patients (50.9% female, 49.1% male; mean age 41.1 ± 14.6 years) were included in the study. The median follow-up period was 57.6 months [28.9–110.4]. The study groups were homogeneous in terms of sex, age, and most radiological parameters. The dynamics of radiological parameters did not differ significantly between the groups, with the exception of spinal canal stenosis (SS), which was significantly lower (p = 0.008) in the groups without decompression upon admission. Among patients who underwent stabilization procedures, a separate subgroup of patients with stenosis of more than 30% (n = 10, Me 34.8% [32.6–48.8]) on admission was identified. This subgroup showed the greatest reduction in stenosis over time, with a median decrease of –28.9% [–31.3; –13.6]. The  overall incidence of Grade Ia complications according to Landriel-Ibañez classification was 26.3%. Grades IIb and IIIa were detected in four patients (7.0%), predominantly from groups with decompression (p = 0.025). Bony fusion was detected in the majority of patients (n = 50, 87.7%), including stable pseudarthrosis in four patients (7.0%) and unstable pseudarthrosis in three cases (5.3%). There were no significant differences in radiological outcomes between the groups (χ² test, p = 0.535), however, decompression was found to be a significant risk factor for pseudarthrosis (p = 0.039). Pseudarthrosis developed significantly more often in cases involving bilateral facet joint resection (p = 0.010). When assessing the clinical results, the pain severity at the surgical site did not differ significantly between the groups (p = 0.944). The lowest ODI scores were observed in the group of transpedicular fixation without decompression.

Conclusion. Short-segment posterior pedicle screw fixation without laminectomy could be an effective treatment option for patients with neurologically intact burst fractures of the thoracolumbar junction with kyphotic deformity up to 21.5°, a decrease in the vertebral body anterior height down to 53.2%, and a vertebral body index over 0.53. In cases of spinal canal stenosis up to 49%, spontaneous bone fragment lysis with partial or complete canal remodeling can occur without decompressive surgery, provided rigid internal immobilization of the segment is achieved. Further prospective studies with a high level of evidence are necessary to determine the optimal surgical approach for treating neurologically intact thoracolumbar junction fractures.

Objective. To evaluate the effectiveness of a combination of transpedicular and transforaminal endoscopic approaches for the removal of lumbar spine herniations with a double compressive intracanal component: significant protrusion in the disc plane combined with an extremely high degree of rostral or caudal migration.

Material and Methods. An analysis of two clinical cases and literature data on the use of a combination of transpedicular and transforaminal endoscopic approaches through a single skin incision was performed. The dynamics of pain syndrome according to the Visual Analog Scale (VAS), neurological status and MRI results were assessed.

Results. In both cases, the migrated sequestrated fragments and significant disc plane protrusions were successfully removed, with complete regression of pain syndrome and restoration of function. No complications were reported.

Conclusion. The presented combination of transpedicular and transforaminal endoscopic approaches is a promising and safe surgical method for treating patients with disc herniations, compressing neural structures both in the plane of the disc and in the area of the migrated fragment. Further studies on a larger sample are required.

Objective. To compare the capabilities of the most common open and minimally invasive TLIF techniques in the correction of segmental lordosis in patients with degenerative diseases of the lumbar spine, based on a non-systematic literature review.

Material and Methods. Study design: non-systematic structured literature review. Articles published for the last 5 years were searched using the following keywords: degenerative, lumbar open mis TLIF, segmental restoration, segmental lordosis, degenerative, spine, TLIF.

Results. Seventeen sources that met the inclusion criteria were included in the study. Among the included original studies, a large variability in the corrective capabilities of open and minimal TLIF was revealed - the achieved values of segmental lordosis/amount of correction can differ by more than 4 times among authors.  A number of reasons were identified influencing this but not mentioned in systematic reviews: lack of proper preoperative examination of patients and planning of intervention, ambiguous intraoperative technique for performing correction, different initial values of the segmental angle (kyphosis), and lack of standardized technique for measuring angular parameters.

Conclusion. The corrective possibilities of open and minimally invasive TLIF still need to be clarified. The wide variation of segmental lordosis values in existing articles makes it difficult for an outside observer to correctly interpret the results and requires carefully designed meticulous studies.

Objective. To compare the capabilities of the most common open and minimally invasive TLIF techniques in the correction of segmental lordosis in patients with degenerative diseases of the lumbar spine, based on a non-systematic literature review.

Material and Methods. Study design: non-systematic structured literature review. Articles published for the last 5 years were searched using the following keywords: degenerative, lumbar open mis TLIF, segmental restoration, segmental lordosis, degenerative, spine, TLIF.

Results. Seventeen sources that met the inclusion criteria were included in the study. Among the included original studies, a large variability in the corrective capabilities of open and minimal TLIF was revealed - the achieved values of segmental lordosis/amount of correction can differ by more than 4 times among authors.  A number of reasons were identified influencing this but not mentioned in systematic reviews: lack of proper preoperative examination of patients and planning of intervention, ambiguous intraoperative technique for performing correction, different initial values of the segmental angle (kyphosis), and lack of standardized technique for measuring angular parameters.

Conclusion. The corrective possibilities of open and minimally invasive TLIF still need to be clarified. The wide variation of segmental lordosis values in existing articles makes it difficult for an outside observer to correctly interpret the results and requires carefully designed meticulous studies.

Objective. To conduct a multifactorial assessment of the risks of intraoperative damage to the dura mater (DM) in patients who underwent primary and repeated interventions on the lumbar spine.

Material and Methods. A retrospective comparative analysis of data from two groups of patients who underwent repeated (n = 144) and primary (n = 153) surgery for degenerative diseases of the lumbar spine was conducted. All surgeries were performed by two experienced surgeons using a standard posterior approach, intraoperative fluoroscopy, microsurgical techniques and binocular magnification. Intraoperative (presence of adhesions, damage to the dura mater, duration of surgery, blood loss, approach and stabilization) and clinical and anamnestic data (gender, age, body mass index, diagnosis, blood transfusion and revisions) were analyzed. Damage to the dura mater was assessed intraoperatively, during revision and based on MRI data. Statistical analysis was performed using the binary logistic regression model.

Results. In repeated surgeries, epidural fibrosis was observed in 92.36% of patients, which significantly increased the risk of dura mater injury as compared to primary surgeries (15.2% vs. 1.9%; p < 0.001). According to multivariate analysis, the extent of surgical access does not have a statistically significant effect on dura mater injury. The presence of fibrosis increases the risk of injury by 4 times, while spine stabilization reduces it by 6 times. The effect of surgery duration on the risk of dura mater injury was not statistically proven. The main limitation of the study is the insufficient postoperative MRI screening, which may lead to the underestimation of the incidence of complications.

Conclusion. Epidural fibrosis is a key risk factor for damage to the dura mater during revision surgery. Its prevention is a pressing issue in surgery for lumbar spine dorsopathies.

Objective. To determine the radiation doses of surgeons performing spinal stabilization operations using fluoroscopy and X-ray.

Material and Methods. Design: prospective study and description of a case series. The sample included the most dose-related spine stabilization techniques: percutaneous transpedicular fixation (PTF, n = 11) and puncture kyphoplasty (PKP, n = 10). Effective radiation doses and equivalent radiation doses to the lenses of the eyes and the skin of the hands were evaluated.

Results. In the PTF and PKP groups, the following values were obtained, respectively: effective radiation doses to the surgeon – 0.07 mSv and  0.09 mSv; equivalent radiation doses to the lens of the eye – 1.2 mSv and 2.45 mSv, and to the skin of the hands – 11.96 mSv and 5.59 mSv.

Conclusion. The obtained values of effective radiation doses to the surgeon correspond to the recommended standards for radiation exposure to operating room personnel. The safe level of radiation will be exceeded after approximately 150 transpedicular fixation procedures or 82 PKPs, without taking into account other surgical interventions performed under radiographic guidance.

Objective. To evaluate the biomechanical properties of biodegradable poly-L-lactide cages on a cadaveric model of the cattle cervical spine.

Material and Methods. Prototypes of interbody cervical implants were developed on the Ender 3v2 3D printer. The mechanical characteristics of experimental cage specimens were evaluated, and the orientation of the specimens during 3D-printing was investigated. Single-level cervical discectomy with fixation by a cage made of poly-L-lactide was performed in 12 cadaveric models. Biomechanical tests of  the operated vertebral segment were carried out under cyclic loading conditions.

Results. In this type of testing, the developed cervical cage models demonstrated high deformation stability under compression load, and the  absence of deformation and migration in static and cyclic tests.

Conclusion. The development of biocompatible biodegradable cervical cages is a promising direction in medicine. Given the high rate of postoperative complications associated with migration and subsidence of cages made of non-resorbable materials, biodegradable implants may become a competitive analog for cervical segment fixation.