Sagittal Balance Parameters after Anterior Cervical Discectomy with Spondylodesis and Arthroplasty Using Endocarbon Endoprosthesis: Results of Randomized Study.

The aim of the study was to examine the effect of cervical segment mobility on spinal sagittal balance parameters after cervical total disc arthroplasty (CTDA) and anterior cervical discectomy and fusion (ACDF) using the first domestic intervertebral disc endoprosthesis. Materials and Methods: The randomized prospective study included 98 patients (48 with CTDA, 50 with ACDF). Implants used: intervertebral disc endoprosthesis or intervertebral fusion cage (Endocarbon; NPP "MedInzh", Russia).Total cervical mobility and range of motion in the target and adjacent vertebral motion segments were studied by functional radiography before surgery, at an early postoperative period (within 3 days), and 3, 6, and 12 months after the intervention.Values of cervical lordosis (CL, °), cervical sagittal vertical alignment (cSVA, mm), and first thoracic vertebra slope (T1 slope, °) were determined by using spinal radiography. Surgimap V2.2 software (Nemaris, USA) was used for measurements. Results: When comparing changes of overall cervical mobility at different time intervals, statistically significant differences were obtained in ACDF group (p=0.001). When comparing this parameter between ACDF and CTDA, a statistically significant difference was found only at the early postoperative period (p=0.004).In CTDA group, the range of motion increased at the operated segment (p=0.001) and decreased at the caudal segment (p=0.002). In ACDF group, no motion was observed at the operated segment (p=0.001) and the range of motion increased at adjacent segments (p=0.001). A statistically significant difference between ACDF and CTDA was obtained only at the operated (p=0.001) and caudal segments (p≤0.002).Correlation analysis showed no dependence between range of motion influence and regional/global balance values (p>0.5).The intergroup comparison of cervical lordosis (CL) values revealed a statistically significant difference after 6 (p=0.001) and 12 (p=0.001) months. The best results were obtained at ACDF group towards lordosis increase (p=0.001). The relationship between cervical lordosis and arthroplasty of segments C5-C6, C6-C7 (p=0.003; ρ=0.41) was determined using correlation analysis. The correlation between CL and ACDF (p=0.001; ρ=0.72) was also established.cSVA comparison between groups showed no difference at preoperative period (p=0.215), 6 (p=0.20) and 12 (p=0.425) months after surgery. cSVAs at both groups were equally close to normal values.T1 slope changes before and 12 months after surgery were statistically significant at ACDF (p=0.008) and CTDA (p=0.001) groups. T1 slope values comparison between ACDF and CTDA shows statistically significant difference after 12 months (p=0.003). T1 slopes were equally close to normal values 1 year after surgical treatment. Conclusion: Over a 12-month observation period, the segmental range of motion was found to have no effect on changes of regional and global balance of the cervical spine. No influence was confirmed of range of motion on adjacent level syndrome development - the syndrome was diagnosed in none of the cases.This study demonstrated the effectiveness of arthroplasty using an Endocarbon endoprosthesis in improving cSVA and T1 slope values, but no significant improvement of CL values after treatment compared to ACDF group.

Biological Response to a Novel Hybrid Polyoligomer: in vitro and in vivo Models.

The aim of the study is to evaluate biocompatibility of a novel hybrid polyoligomer in in vitro and in vivo models. MATERIALS AND METHODS: Cytotoxicity of the material was investigated using the MTT assay with human dermal fibroblasts as test cultures. To study direct interaction of the hybrid polyoligomer with cells, the fibroblasts were cultured on the polymer samples for 96 h, the cultures were assessed every 24 h using fluorescence microscopy. To study the tissue reaction in the area of contact with the donor bed and the morphological features of the implanted sample restructuring, a case-control study was performed using a rabbit model. Samples of hybrid polyoligomer were implanted into the bone defect formed in the left iliac crest in 10 rabbits. In the control group, the prepared allograft samples were transplanted into similar defects in 10 animals. The rabbits were sacrificed 4 and 8 weeks after the operation. The standard morphological methods with hematoxylin and eosin staining and immunohistochemical Ki-67 proliferation marker evaluation were used to assess the state of tissues in the defect area. RESULTS: The results demonstrate that the hybrid polyoligomer is not cytotoxic (cytotoxicity score 0-1), cells adhere well to its surface, retain their viability and typical morphology throughout the entire observation period. No negative impact of material implantation on the health state and behavior of animals was detected. Morphological examination showed the absence of inflammatory changes, formation of thin-walled capillary vessels, and considerable proliferative activity of mesenchymal cells in the defect area, even though it was more intense than in the control group. CONCLUSION: No inflammation signs were detected by 8th week of the experiment. It was defined that new bone was beginning to form. The results of analysis support the conclusion that the developed hybrid materials are prospective for further research as potential bone substitute.

[Philosophy of some problems of spine neurosurgery]. / Filosofiya nekotorykh problem spinal'noi neirokhirurgii.

The development of spine neurosurgery raises some questions concerning the methodology, practical significance, treatment and diagnosis of spinal diseases. In this regard, we inevitably turn to the methods of philosophical knowledge as a basis for analysis and synthesis of scientific information. This approach allows you to avoid mistakes in practice, which can have negative ethical and socio-economic consequences for society. Some controversial issues of spine surgery are discussed in the manuscript. Advisability of syndromic approach in the treatment of spine diseases, determining the length of spine fusion for injury, prediction of postoperative segmental instability due to osteoporosis and extrapolation of the principles of spine fusion surgery to arthroplasty are considered through the prism of philosophical categories.

Augmentation of Pedicle Screws Using Bone Grafting in Patients with Spinal Osteoporosis.

The aim of the study was to develop a new method of vertebral augmentation based on autologous and allogeneic bone chips to be used in pedicle screw fixation and to compare this method with the technique based on polymethyl methacrylate (PMMA). Materials and Methods: This prospective non-randomized study included 164 patients with degenerative pathologies or traumatic injuries of the lumbar spine and transitional thoracolumbar segments; 153 of the operated patients were followed up for 18 months. In these patients, radiodensity of the cancellous bone tissue was below 110 HU by the Hounsfield scale. Patients with degenerative spinal disorders underwent pedicle screw fixation using transforaminal interbody fusion; patients with traumatic spinal injuries underwent intermediate pedicle screw fixation, and those with a loss of vertebral body height by >50% underwent anterior fusion.The patients were divided into three groups: in group 1 (n=39), bone tissue augmentation was performed using PMMA; in group 2 (n=21), augmentation was done with bone chips; in group 3 (n=93), no augmentation was performed (control group). The follow-up period was 12 months; cases with fixator breakage or loosening were recorded. Results: After augmentation with PMMA, 11 cases (28.2%) of fixator destabilization were detected. With bone chips, fixator instability developed in 2 patients (9.5%) only, whereas in patients operated without augmentation, the instability was observed in 43 cases (46.2%). With PMMA augmentation, the incidence rate of fixator destabilization did not significantly differ from that in the control group (p=0.0801), while the use of bone chips resulted in a statistically significant decrease of this index compared to the control group (p=0.0023). A logistic regression analysis confirmed the superiority of the developed method over the PMMA-based vertebral augmentation. Conclusion: The use of bone chips for vertebral augmentation provides a statistically significant decrease in the incidence of pedicle screw fixator destabilization in the post-operative period. By reducing the risk of proximal loosening and eliminating the risk of bone cement drainage into the spinal canal and vascular bed, the proposed method may become especially effective in patients with impaired bone density.

Lumbar Spinal Fusion Using Lateral Oblique (Pre-psoas) Approach (Review).

Lumbar spinal fusion is one of the most common operations in spinal surgery. For its implementation, anterolateral (pre-psoas) approach (oblique lumbar interbody fusion, OLIF) is now increasingly used due to its high efficacy and safety. However, there is still little information on the clinical and radiological results of using this technique. The aim of the study was to analyze the safety and efficacy of OLIF in the treatment of lumbar spine disorders as presented in the literature. Materials and Methods: The systematic electronic search was performed using the Ovid Medline, PubMed, and eLIBRARY.RU electronic databases. The following search key words were used: Oblique Lumbar Interbody Fusion, OLIF, Anterior to Psoas Lumbar Interbody Fusion, and ATP. Results: For the final analysis, 17 sources were selected; with a total of 2900 patients. Total complication rate was 13.9% (403 cases). The incidence of severe persistent complications was less than 1%. Based on the data obtained, we compared the clinical and radiological results of OLIF with other lumbar fusion methods. Conclusion: OLIF is an effective, versatile, and minimally traumatic option for lumbar fusion with relatively few complications, which makes it superior to other retroperitoneal approaches. However, the OLIF technique is not completely free of complications associated with the ventral approach, and it cannot provide adequate decompression of the spinal canal in all cases. In addition, anterior approach surgery is still of limited use in cases of spinal deformities; adequate correction of deformity is achievable mainly in combination with posterior surgery.