article editorial

Objective. To evaluate short-term result of selective navigation templates application in idiopathic scoliosis surgery.

Material and Methods. A total of 12 patients aged 14–17 years with idiopathic scoliosis were included in the study. Group A included 6 patients treated with selective application of navigation templates for pedicle screws insertion in the most difficult zones. Group B (control) included 6 patients in whom all the pedicle screws were placed with free-hand technique. Number of screws inserted was 16–20 per patient. There was no significant difference between the groups in sex, age, Cobb angle, number of vertebrae instrumented, number of pedicle screws and laminar hooks. Surgery duration, blood loss, absolute and relative correction were compared. In Group A, duration of the 3D-objects fabrication and printing, as well as pedicle screw accuracy based on 2-mm increment grading system were evaluated.

Results. Selective application of navigation templates as compared with total free hand screws placement significantly reduced surgery duration. Difference in blood loss and deformity correction was not significant. A total of 107 pedicle screws were placed in Group A, 48 of them with navigation templates and 59 by free-hand technique. Average pedicle width in screw installation with navigation templates was 4.28 ± 1.43 mm, and in that with free-hand technique 6.53 ± 1.72 mm, with significant difference. Accurate screw placement with navigation templates and by free-hand technique were 93.7 % and 88.0 %, respectively, with no significant difference. Duration of 3D-objects manufacturing was 1419 ± 190 minutes. Active operator’s involvement was required in about 10 % of the while.

Conclusion. Selective application of a pair of two-level navigation templates for most difficult pedicles in idiopathic scoliosis significantly reduces surgery duration. Difference in blood loss and deformity correction is insignificant. Refusal of total templates usage for combination of navigation templates for selected difficult pedicles and free-hand technique for the rest is an option for shortening the preoperative preparation, but provides screw placement accuracy comparable with total templates usage (92.5–97.6 % as reported).

Objective. To analyze the state of autonomic regulation of the heart rate in patients with adolescent idiopathic scoliosis before the upcoming surgical treatment of spinal deformity.

Material and Methods. The study included 30 patients with adolescent idiopathic scoliosis who were admitted for surgical treatment from January to April 2021. There were 28 female and 2 male patients. The heart rate variability (HRV) registration was carried out on the VNS-micro vegetotester, with Poly-Spectrum.NET software, Neurosoft (Russia). The study was conducted for 5 minutes in the supine position and for 5 minutes after the active orthostatic test. Temporal and spectral indicators of heart rate were analyzed.

Results. When analyzing HRV at rest, an increase in the temporal indicators of the heart rate and the power of high-frequency wave oscillations was recorded, which indicates both an increased activity of autonomic regulation in general and the predominance of the regulatory influence o of the parasympathetic division of the autonomic nervous system. A decrease in all spectral components during an active orthostatic test and an increase in stress index values by 3.5 times indicate  a significant stress of regulatory systems.

Conclusion. Analysis of HRV in patients with adolescent idiopathic scoliosis at rest revealed increased autonomic activity with a predominant effect of the parasympathetic division of the autonomic nervous system. The state of exercise-induced energy deficit, registered after an active orthostatic test, indicates a significant preoperative stress of the regulatory systems and refers this category of patients to a group of increased risk of complications associated with hemodynamic instability.

The objective of this systematic review was to analyze the clinical efficacy of various technical options for surgical treatment of patients with injuries to the lower thoracic and lumbar spine. The review includes 57 studies published in 2001–2022, which were selected from the main medical databases – PubMed, Medline, and The Cochrane Database of Systematic Reviews. In these publications, five options for surgical intervention were identified, the clinical effectiveness of which was determined by the degree of regression of neurological disorders, the quality of the achieved reposition, the amount of loss of correction within two years after surgery, the number of complications, the duration of operations, and the amount of blood loss. For pairwise comparison between groups, the Kruskal – Wallis test was used for several independent samples, based on the initial determination of the normality of data distribution in groups. To determine the differences between the parameters before and after the operation, the Wilcoxon test was used for two dependent samples. Differences were considered statistically significant at p < 0.05. An analysis of the literature data showed that there are no differences in the dynamics of neurological recovery in patients with spinal cord injury in the thoracic or lower lumbar spine when using five different types of surgical treatment. There are also no differences in the quality of correction of kyphotic deformity of injured spinal motion segments between all studied groups. Statistically significant lower loss of deformity correction is noted in patients who underwent one-stage circumferential decompression through posterolateral approach and decompression through combined approaches. Notably, operations performed through isolated posterior or anterior approaches have comparable values of correction loss. Operations with decompression of the dural sac through the posterior approaches are characterized by a significantly shorter time of surgical intervention than operations with decompression through the anterior and combined approaches. The smallest volume of blood loss is observed during surgery with decompression through isolated posterior approaches. The largest volume of blood loss is in the group with posterolateral approach and one-stage circumferential decompression. Surgical interventions through posterior approach have a statistically significant lower complication rate than operations that include the anterior stage.

Objective. To carry out a retrospective analysis of the restoration of the anterior and posterior vertebral body heights and the elimination of deformation of the anterior spinal canal wall caused by thoracic and lumbar spine injury, based on the data of spiral computed tomography (SCT).

Material and Methods. The study analyzed SCT data and case histories of 50 patients with thoracolumbar spinal cord injury operated on at different times after injury: up to 10 days – Group 1 and 11–30 days – Group 2. All patients underwent spinal reposition using a transpedicular device. The preoperative and postoperative SCT parameters were compared with the initial ones, which were calculated. The restoration of vertebral body heights and the elimination of deformation of the anterior spinal canal wall were compared in two groups depending on the distraction of interbody spaces and changes in the angle of segmental deformity.

Results. In Group 1, the anterior and posterior dimensions of the vertebral body were restored, on average, by 95.3 ± 1.9 and 96.9 ± 1.4 % of the initial height; in Group 2 – by 87.4 ± 4.2 and 96.6 ± 1.8 %, respectively. The maximum restoration of the anterior dimensions of the vertebral bodies was achieved with distraction of the anterior interbody spaces closer to 100 % of the original size in the first and second groups. The maximum recovery of the posterior dimensions of the vertebral bodies was obtained by distraction of the posterior interbody spaces by 97 % or more of the original dimensions. The maximum elimination of the displacement of bone fragments from the spinal canal was obtained by distraction of the interbody spaces to a distance close to 100 % of the initial one, and when the obtained angle of segmental deformity coincided with the initial one.

Conclusion. In the first 10 days after the injury, a greater percentage of the restoration of the anterior and posterior vertebral body heights and a decrease in the deformation of the anterior wall of the spinal canal were obtained. It was possible to maximally eliminate the deformation of the anterior wall of the spinal canal and restore the height of the anterior and posterior walls of the damaged vertebra by approaching the obtained dimensions of interbody spaces and the angle of segmental deformity to the initial ones.

Objective. To analyze dynamics of vertebrogenic pain syndrome and quality of life after transpedicular decompression in patients with depressed fractures of the thoracic and lumbar spine.

Material and Methods. An observational prospective pilot study included 10 patients with AO Spine type A1 fractures of the thoracic and lumbar spine operated on in 2020–2021. All patients underwent transpedicular decompression. Severity of pain syndrome according to VAS, ODI score, and the magnitude of apical kyphosis were studied in the preoperative period and at 3 day, 1, 3, 6 and 12 month postoperative follow-up.

Results. The age of patients was 35–70 years (median 46). The ratio of men and women was 1 : 4. By localization, the fractures were distributed as follows: T10 – 1 patient (10 %), T11 – 1 patient (10 %), L2 – 2 patients (20 %), T12 – 3 (30 %) and L1 – 3 patients (30 %). Statistically significant regression of pain syndrome according to VAS from 9.5 (7.3; 10.0) to 2 (1.0; 2.0) scores during the year (χ² = 35.5, df 4, p < 0.001) was observed. Noteworthy was a rapid regression of the pain syndrome 3 days after decompression from 9.5 (7.3; 10.0) to 4.5 (4.0; 6.0) and a decrease of ODI score and improvement in the quality of life of patients from 69.0 (58.5; 82.0) to 9.0 (4.8; 10.8):  χ² = 36.8, df4, p < 0.001. During the follow-up period, an increase in the Cobb segmental angle from 5.3º°(4.1°; 6.7°) to 9.7°(8.4°; 12.5°) (p = 0.005) was observed in all patients. However, this did not affect the intensity of back pain or the quality of life of patients. Newly occurring fractures, Kümmel’s disease and postoperative complications were not identified. Instrumental diagnostics revealed spontaneous fusion at the fracture level during the first year after transpedicular decompression in all cases.

Conclusion. Transpedicular decompression is an effective, safe and pathogenetically substantiated method of treating vertebrogenic pain syndrome associated with spinal fracture.

Objective. To determine the values of Hounsfield units (HU) of the lumbar vertebrae predicting unsatisfactory radiological results of circumferential interbody fusion at the lumbar level.

Material and Methods. The data of patients who underwent a single-level decompression and stabilization intervention at the L4–L5
or L5–S1 level for degenerative diseases of the spine were analyzed. The CT images of the lumbar spine were assessed before surgery with the measurement of HU values of the vertebral bodies at the intervention level, as well as CT images one year after surgery to evaluate the degree of interbody block formation and subsidence of the cage. Three groups of patients were distinguished: patients with a formed interbody bone block and without cage subsidence (control group), patients with failed fusion and patients with cage subsidence.

Results. The study presents CT data of 257 patients. The incidence of non-union was 32.3 % (83/257), and of cage subsidence – 43.6 % (112/257). The proportion of patients with reduced bone mineral density (BMD) was 26.1 % (67/257). Patients with non-union and subsidence had higher ODI scores (p = 0.045 and p = 0.050, respectively) compared to controls. The presence of fusion failure and subsidence is associated with reduced BMD (p < 0.05), HU values of vertebrae (p < 0.05), and higher ODI score (p < 0.05). According to the ROC analysis, threshold HU values were determined equal to 127 HU, 136 HU and 142 HU for the L4, L5, S1 vertebral bodies, respectively. Upon reaching these values, the risk of a combination of fusion failure and subsidence increases significantly (p = 0.022).

Conclusions. Patients with non-union and cage subsidence have less satisfactory clinical outcomes. The HU values of the vertebral bodies equal to 127 HU, 136 HU and 142 HU for the L4, L5, and S1, respectively, are advisable to use in practice to predict non-union and subsidence after a single-level decompression and stabilization intervention at the lower lumbar levels.

Objective. To analyze clinical and morphological features of neurogenic hourglass tumors in the thoracic spine and their impact on outcomes of treatment through posterior surgical approaches.

Material and Methods. The results of surgical treatment of 295 patients with tumors growing from the nerve roots of the thoracic spinal cord were studied. In 63 (21 %) of them, tumors of the spinal nerves were diagnosed. The vast majority of neoplasms were represented by Grade 1 neuromas – in 57 (90 %) patients, Grade 1 neurofibromas were found in 3 (5 %) patients, and High-grade malignant tumors – in 3 (5 %). Intracanal neoplasms were found in 42 (66.7 %) cases and intraextravertebral (hourglass) – in 21 (33.3 %).

Results. Microsurgical removal of tumor was performed using two types of low-traumatic surgical approaches: 1) posterior median approach – in 56 (89.0 %) cases, of which hemilaminectomy was performed in 36 (64.4%) cases, interlaminectomy – in 15 (26.8 %) cases, and laminectomy – in 5 (8.1 %) cases; 2) paravertebral approach – in 7 (11.0 %) out of 63 cases with partial facetotomy or facetectomy and resection of part of the head and upper or lower edge of the rib at the same level. Tumors were removed totally in 56 (88.9 %) patients and subtotally – in 7 (11.1%). Intracanal tumors were removed totally in 40 (95.2 %) patients. A similar totality was achieved in removal of 16 (76.2 %) of hourglass neurinomas. Surgical interventions performed in the early postoperative period improved the functional state of  patients: the Karnofsky Performance Scale (KPS) index increased from 70–80 to 90 %, the VAS pain score decreased from 5–6 to 2 points. Good clinical outcomes were achieved in 42 (66.7 %) patients, satisfactory – in 17 (27.0 %), and unsatisfactory – in 6 (6.3 %). Twenty nine patients had symptoms of myelopathy, complete regression of which occurred in 3 (10.3 %) cases, partial – in 9 (34.6 %), in 13 (50.0 %) cases they remained at the preoperative level, and in 4 (15.4 %) – worsened.

Conclusion. The use of modern neurointroscopy, microsurgical techniques and low-traumatic posterior surgical approaches for resection of tumors of the spinal nerve roots in the thoracic spine provides good clinical outcomes of treatment in the early postoperative period. The existing hourglass tumor in the thoracic spine reduces the likelihood of its total removal when performing a low-traumatic posterior approach.

Objective. To analyze the leading pathogens of implant-associated infection (IAI) after spinal surgery and identification of trends in the change in the pattern of microorganisms at the stages of treatment using the negative pressure method (NPWT systems).

Material and Methods. The results of microbiological cultures of 25 patients with IAI of the spine were studied. The frequency of occurrence of Gram-positive and Gram-negative pathogens was estimated. The leading pathogens in the species spectrum were identified. Changes in the structure of identified microorganisms were studied at various time intervals of treatment.

Results. A total of 136 microbiological studies were performed in 25 patients at the stages of treatment with the negative pressure method, with the identification of microorganisms in 127 (93.3 %) cases. The frequency of gram-negative microflora was 50.0 %, gram-positive – 42.6 %, Candida sp. – 0.7%, in 15.4 % microbial associations with the dominance of gram-negative microflora were identified at all periods of treatment. Not only the diversity of the isolated flora was noted (E. faecalis – 16.5 %, P. aeruginosa – 14.2 %, K. pneumoniae – 11.0 %, S. aureus and A. baumannii – 9.4 % each and S. epidermidis – 8.6 %), but also changes in the spectrum of flora at the stages of treatment: on the 1st and 2nd weeks from the first debridement intervention and the installation of the NPWT system, E. faecalis was most often detected, on the 3rd and 4th weeks – P. aeruginosa and A. baumannii, during the 2nd month – E. faecalis and P. aeruginosa, later – gram-negative bacteria against the background of an increase in the incidence of K. pneumoniae. The frequency of verification of other species of microorganisms had no statistically significant differences. Microbial associations were found from the 2nd month of treatment. The change in pathogens was noted in 72 % of cases during the treatment of IAI of the spine. On average, this treatment required 7–8 NPWT dressing changes per patient. This method of treatment made it possible to achieve both negative results of microbiological examination and stable relief of the infectious process.

Conclusion. IAI, which complicates surgical interventions on the spine, is characterized by a change in pathogens during treatment, which requires not only multiple debridement with the replacement of the NPWT dressing, but also adequate long-term rational (etiologically justified) antibacterial therapy, based on the control of data on both the spectrum and on microbial resistance.

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