[The morphological study of the Perfoost demineralized bone alloimplant applied for the plastic reconstruction of the posterior wall of the external auditory canal].

The objective of the present study was to enhance the effectiveness of the surgical treatment of chronic suppurative otitis media (CSOM) by means of the application of the Perfoost demineralized bone alloimplant for the plastic reconstruction of the posterior wall of the external auditory canal. This aim was attained by the elucidation of morphological features the Perfoost alloimpalnt at the site of surgical intervention one year after the operation. The study included 12 patients presenting with CSOM (epi- and epimesotympanitis) who had underwent "closed-type" sanation surgery of the middle ear. A Perfoost demineralized bone implant (DBI) plate was used for plastic reconstruction of the posterior wall of the external auditory canal. The secondary intervention within one year after the implantation was used to obtain 5×5 mm biopsy specimens containing a fragment of Perfoost DBI together with the adjacent cicatrical tissue bordering the "living" bone. The biopsies were subjected to standard histological treatment. It was shown that the fragment of the transplanted bone tissue underwent resorption accompanied by neo-osteogenesis. The source of formation of the new bone was fibroblastic elements of connective tissue of the recipient undergoing transformation into osteoblasts under the influence of resorbable components of the alloimplant. The presence of pre-existing bone canals and perforation holes in the implant provides the favourable conditions for its invasion by connective tissue that ensures its strong immobilization and gradual replacement by the newly formed bone tissue which corresponds by "carcass" regeneration. The results of the present study give evidence of the high clinical effectiveness of reconstructive surgery for the treatment of CSOM with the application of the Perfoost demineralized bone alloimplant used for the plastic correction of the posterior wall of the external auditory canal.

[Surgical correction of nasal septum with the use of Perfoost allografts].

New partially demineralized Perfoost allografts were used for the treatment of nasal septum defects in 16 patients admitted to the Research and Clinical Otorhinolarygological Centre, Federal Healthcare and Social Development Agency, between January 2007 and November 2008. The length of the follow-up period varied from 6 months to 1 year 10 months. The plastic material manufactured in the form of plates of different size was obtained from the bank of autografts based at the Central Institute of Traumatology and Orthopedics. Long-term monitoring of major physiological functions of the nose and rhinopneumetric studies showed that that Perfoost allografts were well tolerated by the patients; their application ensured excellent functional and aesthetic outcome of surgical correction of the injured nasal septum in all cases under observation.

[Experimental study of the efficacy and clinical use of Perfoost in cases of defect substitution and correction of face supporting tissues].

Positive properties and perspectivity of demineralized osseous allogenic implants were pointed to. Experimental model of primary osseous plasty of mandible defects was described. The comparison of character and pace of reparative osteogenesis in experimental bone defects with Perfoost use and without transplantation was done. Perfoost had expressed osteoinductive and osteoconductive properties providing quicker reparative osteogenesis. In clinic osseous plasty operations of upper, middle and lower parts of face were done with the use of Perfoost. All in all 14 operations in 13 patients were conducted: in 3 patients - contour plasty of frontal region of head, in 5 patients- deformation correction of zygomatic region, lower edge and bottom of eye-socket; in 5 patients - defect substitution of mandible body and branch of the 8-10 cm length (in combination with titanium plates). In 2-3 months after operation the first signs of transplant rebuilding were detected during X-ray control. The expressed rebuilding of Perfoost with its substitution by newly formed bone was seen in 1-1.5 year. No complications followed, terms of observation - up to 8 years.

[New bioplastic materials for reconstructive surgery].

Results of creation and clinical application of bioplastic materials using specimens from the tissue bank of the Institute of Traumatology and Orthopedics are presented. The use of materials of the new generation, such as perfoost, alomatrix-implant, and osteomatrix, is illustrated by examples of the treatment of various bone diseases. High biocompatibility and efficiency, osteoconductive and osteoinductive properties of these materials are reported. Technical developments in modern bioimplantology are analysed with reference to their status in the Institute's tissue bank.

[Surgical treatment of traumatic lesions of the orbit in children].

The paper presents an analysis of traumas of the orbit combined with craniocerebral trauma in children made according to data obtained at the eye microsurgery department, Morozov's Pediatric City Clinical Hospital. Fractures of the lower orbit wall account for around 70% of all orbit fractures; clinical signs of fractures of the lower orbit wall are defined; computer tomography is shown to be the most informative diagnostic tool. The paper contains indications for plasty of the lower orbit wall. Materials used in orbitoplasty are comparatively analyzed. The use of demineralized osseous implants is preferential.

Experimental and clinical study of the demineralized bone allografts manufactured in the tissue bank of CITO.

The technology for producing demineralized bone allografts (DBA) with definable degree of demineralization and sterilization by high energy electron bean was developed in the tissue bank of Central Institute of Traumatology and Orthopaedics (CITO). The authors consider the technology to be one of the ways of producing demineralized bones. The results of the experiments show that time of demineralization process as well as the absorption dose of radioactive high energy electron beam change substantially mechanical toughness and osteoinductive properties of DBA. Mechanical properties of DBA were tested by the universal testing machine 'Zwick 1464'. Quantitative assessment of DBA osteoinductive properties resulted from the investigation of DBA samples in the culture of stromal precursor bone marrow cells and in the culture of human skin fibroblasts. Cloning efficiency of fibroblasts was considered as indecies of proliferative potential of stromal bone marrow cells, i.e. osteogenic precursor cells. The growth of the cell mass after definite time as well as the index of 3H-timidin marked cells within biological inductor were considered as indecies of proliferative potential of skin fibroblasts. The obtained results showed, that inductive properties of allografts improve when the degree of their demineralization increases whereas the dose of high energy electron radiation decreases. Mechanical toughness of DBA deteriorates when both degree of their demineralization and radiation doses increase. This emphasizes the importance of optimizing technological stages in DBA producing. Since 1998 DBA have been used in Russian clinics for bone plasty in traumatology and orthopaedics, maxilla-facial surgery, ophthalmology, and neurosurgery. The resulting analysis is based on case histories of 257 patients operated from March 1998 to July 2002. The majority of patients were children and teenagers of 3-18 years old with prime tumors, tumor-like and systemic inherited diseases of skeleton, post-traumatic complications. Observation periods were from 1.5 to 5 years and 10 months. Good and satisfactory results were obtained in 93.4% cases.