Specificity of Multispiral Computed Tomography in the Diagnosis of Avascular Necrosis of the Femoral Head

In the span of 6 years 350 patients that were clinically and radiologically diagnosed with avascular necrosis of the femoral head, at different stages, were examined. Patients were examined using comprehensive radiation examination including radiography and multispiral computed tomography (MSCT) of the hip joints, with the aim to diagnosis avascular necrosis of the femoral head at an earlier stage. According to the results of the examination, 121 patients were diagnosed with an earlier stage of avascular necrosis of the femoral head, on 99 patients was performed core decompression via drilling, 22 patients underwent a joint preservation procedure with the removal of the necrosis tissue following with a bone-graft using bonesubstituting bioresorbable material.

Decellularized matrix of the small intestine. Technology for obtaining, evaluating and using directions

Matrix (scaffold, matrix, framework, template) is a bioresorbable or non-bioresorbable material that can be filled with stem or somatic cells in/ex vivo in order to obtain a tissue-engineering structure for restoration of a lost organ, part of an organ, tissue. Scaffold must be to the extent necessary strong, non-immunogenic, bioactive. The porosity of the matrix must be open, the surface is rough and, most importantly, the matrix must contain factors of chemotaxis of endo- or exogenous origin, cell adhesion of their proliferation, differentiation. In this context, on the example of creating a decellularized small intestine matrix, a number of fundamental issues are highlighted regarding the choice of matrix material, its production technology, matrix evaluation in accordance with the criteria that correspond to the matrix for tissue engineering, and possible directions for its use. As a result, a non-immunogenic extracellular matrix of the small intestine was obtained by the method of detergent-enzymatic perfusion decellularization, which was sufficient in characteristics for use in various areas of tissue engineering, including plasty of defects of the skin, mucous membranes, small intestine, etc.

Biocidal and bioresorbable chitosan/triclosan/collagen matrixes

Biomedical application of biomaterials has increased in recent years. Some preferred characteristics of these materials are biocompatibility, biodegradability and antimicrobial effect. We are facing a constant search for antimicrobial materials to be used instead of antibiotics therapy to reduce the possibility of dental surgery contamination. In this study, biocidal, bioresorbable and non-toxic matrixes were synthesized from chitosan, triclosan and collagen. Three experimental groups received different chitosan/collagen combinations, (0.5:1, 0.75:1 and 1:1), all with the same dose of triclosan (0.1%). Antimicrobial effect was measured by the inhibition of S. aureus growth. Moreover, matrixes were placed in a PBS-collagenase solution to measure degradation over time; matrix residues were evaluated at 1, 4, and 7 days. Finally, cell toxicity of each matrix was analyzed on NIH-3T3 fibroblast cells. As a result, inhibition of S. aureus growth was similar in the three established experimental groups of matrixes vs vancomycin antibiotic as control. These data suggest potent antimicrobial effect of chitosan/triclosan/collagen matrixes. Degradation over time showed that 80% of the matrix was degraded after 4 days, thus suggesting that chitosan/triclosan/collagen matrixes are bioresorbable material. On the other hand, viability of NIH-3T3 cells was between 60% to 74% after 24 h and prior to matrix exposition to culture cells. These data indicate light toxicity in the 0.5:1 and 0.75:1 matrix groups and non-toxic effect in the 1:1 matrix group. By taking together these data, we propose the application of chitosan/triclosan/collagen matrixes to prevent bacterial contamination after dental surgery.

Bioresorbable Material in Secondary Orbital Reconstruction Surgery

Purpose. To validate the potential of bioresorbable implantation in secondary revisional reconstruction after inadequate primary orbital fracture repair, with assessment of pre- and postoperative clinical characteristics and computed tomography image findings. Methods. A retrospective chart review was conducted on 16 consecutive patients treated for orbital fractures at Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, with inadequate prior surgeries between July 2010 and June 2017; patients who had suffered orbital blowout fractures had undergone primary surgeries elsewhere. Secondary repair of orbital fractures used bioresorbable material following unsatisfactory primary orbital repair. Patients’ demographics, degree of enophthalmos, ocular motility, diplopia test results, primary implants, and surgical complications were reviewed. Results. All 16 patients had primary orbital implants consisting of Medpor, titanium mesh, hydroxyapatite, or poly-L-lactide. Of the 16 cases, 14 had malpositioned implants posteriorly and two had implant infections. Findings following primary surgery included enophthalmos (12/16), diplopia (9/16), intraorbital abscess (2/16), and ocular movement pain (1/16). Mean preoperative enophthalmos was 3.8 ± 0.8 mm. Secondary reconstruction resulted in a mean reduction of enophthalmos by 3.1 ± 0.9 mm (P<0.01). Nine in ten patients experienced improvements in postoperative ocular motility and diplopia following secondary surgery. Intraorbital abscesses and eyeball movement-associated pain were cured. Conclusions. This study demonstrates that secondary orbital reconstruction of previously repaired orbital fractures using bioresorbable material can achieve excellent functional and aesthetic results with minimal complications. Bioresorbable material should be considered in secondary orbital reconstruction when clinically indicated.

The influence of different geometries of matrix/scaffold on the remodeling process of a bone and bioresorbable material mixture with voids

Since internal architecture greatly influences crucial factors for tissue regeneration, such as nutrient diffusion, cell adhesion and matrix deposition, scaffolds have to be carefully designed, keeping in mind case-specific mechanical, mass transport and biological requirements. However, customizing scaffold architecture to better suit conflicting requirements, such as biological and mechanical ones, remains a challenging issue. Recent advances in printing technologies, together with the synthesis of novel composite biomaterials, have enabled the fabrication of various scaffolds with defined shape and controlled in vitro behavior. Thus, the influence of different geometries of the assemblage of the matrix and scaffold on the remodeling processes of living bone and artificial material should be investigated. To this end, two implant shapes are considered in this paper, namely a circular inclusion and a rectangular groove of different aspect ratios. A model of a mixture of bone tissue and bioresorbable material with voids was used to numerically analyze the physiological balance between the processes of bone growth and resorption and artificial material resorption in a plate-like sample. The adopted model was derived from a theory for the behavior of porous solids in which the matrix material is elastic and the interstices are void of material.

Biodegradation of Porous Alpha-Tricalcium Phosphate Coated with Silk Sericin

Porous a-tricalcium phosphate (a-TCP) ceramics are attractive as a novel bioresorbable material for bone repair, since they can be easily fabricated through conventional sintering of b-TCP at high temperature. However, the solubility of a-TCP is too high to keep its body until the bone defect is repaired completely. Coating of the a-TCP porous body with organic polymer is a way to reduce the degradation rate. In the present study, biodegradation of a-TCP porous body coated with silk sericin was evaluated in vivo. Bone repair at the defect made in rabbit tibia was nearly completed after 4 weeks. Higher density of cortical bone was estimated for a-TCP coated with sericin than for mere a-TCP. The a-TCP porous body coated with sericin is expected as a material that show less degradation than mere a-TCP, and may result in suitable bone repair.