RESUMO
PURPOSE: The clinical demand for bone grafting materials necessitated the development of animal models. Critical size defect model has been criticized recently, mainly for its inaccuracy. Our objective was to develop a dependable animal model that would provide compromised bone healing, and would allow the investigation of bone substitutes. METHODS: In the first group a critical size defect was created in the femur of adult male Wistar rats, and a non-critical defect in the remaining animals (Groups II, III and IV). The defect was left empty in group II, while in groups III and IV a spacer was interposed into the gap. Osteoblast activity was evaluated by NanoSPECT/CT imaging system. New bone formation and assessment of a union or non-union was observed by µCT and histology. RESULTS: The interposition model proved to be highly reproducible and provided a bone defect with compromised bone healing. Significant bone regeneration processes were observed four weeks after removal of the spacer. CONCLUSION: Our results have shown that when early bone healing is inhibited by the physical interposition of a spacer, the regeneration process is compromised for a further 4 weeks and results in a bone defect during the time-course of the study.
Assuntos
Fraturas do Fêmur/patologia , Fêmur/patologia , Consolidação da Fratura , Fraturas não Consolidadas/patologia , Osteoblastos/patologia , Animais , Regeneração Óssea , Modelos Animais de Doenças , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Fêmur/cirurgia , Fraturas não Consolidadas/fisiopatologia , Masculino , Imagem Multimodal/métodos , Nanotecnologia , Osteogênese , Tomografia por Emissão de Pósitrons , Ratos , Ratos Wistar , Fatores de Tempo , Tomografia Computadorizada por Raios X , Microtomografia por Raio-XRESUMO
Between 1993 and 2002, we treated 43 patients with malignant musculoskeletal tumours of the knee region. All patients had partial resection of the femur or tibia together with endoprosthetic replacement. We were able to follow-up 23 patients with an average follow-up of 30 (12-97) months. Complications occurred in ten cases, of which one was a case of local recurrence. Most of the patients were completely satisfied with their condition, with a decreased walking distance as the only notable restriction. There was no correlation between the functional outcome and life quality assessment and the type of the implanted prosthesis, length of resected bone and type of resection. However, patients with tumours in the distal femur had significantly better functional and life quality outcome than those with a proximal tibial tumour.
Assuntos
Artroplastia do Joelho , Neoplasias Ósseas/cirurgia , Carcinoma/cirurgia , Fêmur , Sarcoma/cirurgia , Tíbia , Adulto , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Carcinoma/secundário , Feminino , Humanos , Masculino , Qualidade de Vida , Recuperação de Função Fisiológica , Sarcoma/patologia , Resultado do TratamentoRESUMO
In cortex, habenular- or hypothalamic regions of white rats electrocoagulation was carried out. Animals were killed from 6 days to 5 months after the operation. Serial slides of the brain were investigated by the aid of a reaction of SDH, alfa-GPDH, LDH, G6PDH, TPND. Group of neurons around the lesion may show a decreased, normal and increased activity of the enzymes investigated. As for the far effect of the lesion in case of the injury of the postcomissural fornix changes could have to be revealed in the corpus mamillare. Activization of neuroglia is marked by the increase of the reaction of G6PDH, LDH and TPNDH. Enzyme activity of cells of microglial origin at the beginning seems to be significant, later on, when the activity of phagocytes comes to the end it decreases to the minimum. Regeneration of cells of the leptomeninges and their role in demarcation of the process is marked by the increase of enzyme activity.