Lu Z. Possibilities of carbon based materials for filling bone cavities (experimental research with clinical approbation)

Object: restructuring and regeneration of bone under conditions of implantation of carbon material of felt-like and dense structure. Purpose: to evaluate the effectiveness of new carbon biomaterials to substantiate the possibility of their use in orthopedics and traumatology to fill the bone cavities. Methods: clinical and radiological- to evaluate the results of patients treatment; histological, morphometric, electron microscopic, polarization-optical - to study bone regeneration and reconstruction under conditions of implantation of carbon material "Carbopon-22"; cell culture and cytology - to assess the effect of carbon material on cell viability, phenotype and proliferation; biochemical - to analyze the biomaterial possible toxic effects; biomechanical - to study bone strength after implantation of biomaterial; statistical - to objectify the results. For the first time the possibility of use a new carbon biomaterial which has dense and felt-like structure ("Carbopon-22" based on viscose) as a bone substitute was substantiated theoretically. New scientific knowledge about the features of regeneration, ultrastructural organization of cells and macromolecular organization of the organic matrix of bone tissue after implantation in the created bone defects of the carbon biomaterial "Carbopon-22" were obtained. For the first time it was revealed that the new felt-like carbon biomaterial ("Carbopon-22") does not violate reparative osteogenesis, promotes the formation of suitable bone tissue with type I collagen, does not cause an inflammatory reaction, does not have a toxic effect at the level of the organism' tissues. For the first time it has been proved that the restructuration of felt-like biomaterial after its implantation into a bone defect is associated with the formation of an adhesive matrix that promotes chemotaxis and attachment of cells to fragments of the biomaterial. This provides early regeneration (3 and 7 days) formation of granulation and osteogenic tissues. At later terms (14 and 45 days) bone tissue was formed between the carbon fibers, a dense block formed. The scientific evidences were added that macrophages also carry out the resorption of carbon biomaterial. For the first time, it was found that along perimeter of specimens of a dense carbon material "Carbopon-22" a reparative osteogenesis actively takes place, which is associated with the replacement of a destroyed host bone with a newly formed bone tissue with type I collagen without the formation of a connective tissue capsule. The results of the study of structural and metabolic changes in bone tissue after implantation into bone defects of the carbon biomaterial "Carbopon-22", strength properties of the "bone-implant" system are justification for its use in traumatology and orthopedics as a bone substitute, as well as for developing a differentiated approach to selection of the species (dense or felt-like) biomaterial "Carbopon-22" in a specific clinical situation. Felted carbon can be recommended for filling "critical" bone defects of various configurations. A dense carbon biomaterial can be used in both loaded and low loaded areas of the skeleton. The positive results of an experimental study on the use of carbon biomaterials for the replacement of bone defects became the basis for conducting clinical approbation on the use of carbon to fill bone cavities in patients after the removal of cysts. The results of the research are introduced in clinical practice and lecture courses of the department of traumatology and orthopedics of SI "Zaporizhia Medical Academy of Post-graduate Education Ministry of Health of Ukraine", Transcarpathian regional clinical hospital named A. Nowak, department of general surgery with courses of traumatology, operative surgery and forensic medicine in Uzhhorod National University, OOO "Clinic MOTOR SICH", SI "Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukrane". Traumatology and Orthopaedics.