Objective. To perform comparative analysis of osseointegration of bioceramic alumina-based granules, hydroxyapatitebased granules, and granules of deproteinized bone tissue. Material and Methods. The experiment was conducted on 52 adult male Kyoto-Wistar laboratory rats weighing 350 to 520 g. Animals were divided into five matched groups, which differed only in the type of implanted material. Granules were implanted in lumbar vertebral bodies and in distal right femur of each laboratory animal. Two months after surgery animals were euthanized with subsequent tissue sampling for morphological studies. Results. Examination of specimens from groups with implantation of alumina granules revealed the formed trabecular bone with evidence for remodeling. Bone tissue filled the space between granules fitting closely to their surfaces. There was no connective tissue capsule on the border between the bone tissue and alumina granules. Conclusion. Bioceramic alumina-based granules in the form of cylinders with a through inner channel have high strength surpassing that of analogs and ability for osseointegration close to that of hydroxyapatite and deproteinized bone granules.

To perform histological verification of osseointegration of porous bioceramic granules using scanning electron microscopy and energy-dispersive spectroscopy. Material and Methods. The experiment was conducted in six mongrel dogs weighing 15 to 18 kg which underwent implantation of hydroxyapatite bioceramic granules in the lumbar vertebral bodies. After 6-month follow-up period specimens were examined histologically using light microscopy, scanning electron microscopy, and energy-dispersive spectrometry.Results. Histological examination of the implantation zones revealed trabecular bone tissue in spaces between the granules fitting closely to their surfaces. There was no connective tissue capsule on the border between the bone tissue and hydroxyapatite granules. Conclusion. Morphological studies using light microscopy and scanning electron microscopy, as well as energy-dispersive spectrometry are basic methods for verification of osseointegration.

Objective. To analyze results of surgical treatment and correction of deformities associated with flexion-distraction injuries of the subaxial cervical spine. Material and Methods. A retrospective analysis of treatment results in 78 patients who underwent anterior and combined stabilization of subaxial dislocations in 2010-2016 was carried out. The data of clinical examination and of MRI and MSCT studies were subjected to statistical processing. Results. Significant (p < 0.05) loss of the achieved intraoperative correction of shearing and kyphotic types of deformities was noted after 3 months in the group of patients with unilateral and bilateral articular process fractures treated by anterior spinal fusion. Conclusion. Unilateral or bilateral articular process fractures accompanied by bilateral dislocations at the level of damaged spinal segment are risk factors for the loss of post-traumatic deformity correction achieved after isolated anterior stabilization.

Экспериментальные исследования ХИРУРГИЯ ПОЗВОНОЧНИКА © В.В. Рерих и др., 2014 restoration of shape and strength of the thoracolumbar vertebral bodies with alumina bioceramic granules Objective. To analyze the efficacy of the restoration of shape and strength of fractured vertebral bodies of the thoracolumbar junction by bone defect substitution with alumina bioceramic granules. Material and Methods. The study was conducted on 19 vertebrae obtained from thoracolumbar spines of four individuals died from extra-vertebral pathology. All specimens were subjected to axial compression resulting in vertebral body deformation. Thereafter, reconstruction of the vertebrae was performed with alumina granules and deproteinized bone granules inserted under pressure into their bodies. Results. Vertebral reconstruction resulted in increase in the height of anterior, middle and posterior portions of the vertebral bodies. Mean vertebral body strength was 3.223 MPa in specimens with bioceramic granules and 3.018 MPa in specimens with deproteinized bone granules. The compressive strength of the vertebrae after reconstruction with alumina bioceramic granules exceeded the original value by 8.00 %, while that after insertion of deproteinized bone granules decreased by 23.01 %. Conclusion. Reconstruction of compressed vertebral bodies with alumina bioceramic granules allows to restore both the shape and compressive strength of the vertebral body in experiment.