Joanna Bonecka

Biodegradable intramedullary nails reinforced with carbon and alginate fibers: In vitro and in vivo biocompatibility

Background: Commonly, intramedullary nails are made of nondegradable materials, and hence they need to be removed once the bone fracture is healed. We propose a novel composite material consisting of poly-L-lactide matrix modified with carbon and alginate fibers to be used for biodegradable intramedullary fixation. The aim of this study was to make in vitro and in vivo biocompatibility assessments. Methods: In the in vitro conditions, biocompatibility of biomaterials was compared using normal human osteoblasts. After 3 and 7 days, cytotoxicity, viability and proliferation tests were performed, as well as cell morphology and adhesion observations. In the in vivo experiments, Californian rabbits (approx. 9 months old) were used. The composite nails and controls (Kirschner wires) were used for fixation of distal femoral osteotomy. The evaluation was made on the basis of clinical observations, radiographs taken after 2, 4, 6 and 8 weeks post implantation, and macroscopic and histological observations. Results: Cell tests indicated that both modifiers had a positive influence on cell viability. Biodegradable composite nails led to bony union when used for fixation of distal diaphysis osteotomy in rabbits. Histological analysis showed that the initial focal necrosis should be fully compensated for by the osteoblast proliferation and trabeculae formation. Conclusions: Both in vitro and in vivo tests confirmed biocompatibility and potential applicability of novel biodegradable intramedullary nails modified with long carbon and alginate fibers for osteosynthesis of bone epiphysis.

Fatal gunshot injuries in the common buzzard Buteo buteo L. 1758 – imaging and ballistic findings

The conservation of the common buzzard is assured by the European Union law. In Poland, this wild bird is under strict species protection and it is used as a bioindicator for heavy metals in the environment. A case of the fatal shooting of a buzzard with a firearm by an unidentified shooter is described here. Macroscopic evaluation, X-ray imaging, post-mortem computed tomography, ballistic examination of the isolated bullets and finally a simulation of the assumed position of the bird at the time of the shot were performed. Numerous pellets were found inside the body, together with multiple bone fractures and central nervous system trauma. The buzzard died most probably as a result of spinal cord injury from a single shot that was fired from a smoothbore hunting gun. Collected evidence was insufficient to identify the shooter, which sadly confirms that identification of the perpetrator in wildlife forensics remains low.

Comparison of usefulness of different diagnostic procedures in slipped capital femoral epiphysis in cats

Slipped capital femoral epiphysis (SCFE) has been described in human medicine as a condition of predominantly teenage males, with obesity being a contributing factor (11, 22). The disease develops mainly bilaterally and is of an atraumatic origin (14). Slipped capital femoral epiphysis has also been described in mainly young (4.5-24 months), neutered male cats (16, 18, 21). Some studies have shown that SCFE occurs predominantly in Siamese cats, but until now a breed predisposition has not been confirmed (18). Untreated, SCFE leads to hypertrophic pseudoarthrosis or degenerative joint disease in humans (1, 13, 18, 22). Clinical signs are non-specific. The main symptom is lameness, which can develop acutely or be of chronic duration, without a history of previous trauma. Muscle atrophy, crepitation and painful reaction to palpation with a limited range of hip joint motion can be detected. SCFE develops mostly bilaterally, but it may have different severity and affect one or both sides independently (2, 6, 9, 18, 27). Patients do not show any other abnormalities in addition to those mentioned above (11, 13, 18). Predisposing factors for SCFE are sex, obesity, castration, and delayed physeal closure as a secondary effect of gonadectomy (13, 25). The aim of the study was to compare the usefulness of different diagnostic procedures – radiology, computed tomography, and histopathology – in slipped capital femoral epiphysis in cats.

Disseminated hyaline ring granuloma in the omentum of a dog

BackgroundHyaline ring granuloma (HRG) is an uncommon histopathologic finding of unsolved etiopathogenesis. According to the exogenous theory, HRG develops due to implantation of foreign material, most probably indigestible plant fragments. HRG is a comparatively rare condition in humans, mostly involving the oral cavity with very rare extraoral locations.Case presentationAn 1-year-old mixed-breed dog in good condition was presented for routine ovariohysterectomy. Disseminated HGR were accidentally found in the omental adipose tissue during surgery. Histopathology revealed the presence of ring-like hyaline structures surrounded by granulomatous inflammation including foreign body-type multinucleated giant cells. The histochemical examinations indicated the exogenous plant origin of the foreign material.ConclusionsThe lesions were similar to the findings in humans with HRG. The definitive diagnosis remains largely based on histopathological examination supported by special histochemical stains. To the best of our knowledge, this is the first case of hyaline ring granuloma reported in a non-human species. Moreover, the omentum is an uncommon location for this condition.