Mechanical properties of radial bone defects treated with autogenous graft covered with hydroxyapatite in rabbit.

PURPOSE: To determine biomechanical property of autogenous bone graft covered with hydroxyapatite in the defect of radial bone in rabbit. METHODS: Eighteen adult male New Zealand white rabbits were used which were divided into three groups (I, II, III) of six rabbits each. A segmental bone defect of 10 mm in length was created in the middle of the right radial shaft under general effective anesthesia in all rabbits and were stabilized using mini-plate with four screws. The defects In group I were left as such without filler, whereas in group II the defect were filled up with harvested 10 mm rib bone and in group III the defect were packed with rib bone covered with nano-hydroxyapatite. All rabbits in three groups were divided into two subgroups (one month and three months duration with three rabbits in each one). RESULTS: The mechanical property and the mean load for fracturing normal radial bone was recorded 388.2 ± 6 N whereas it was 72.4 ± 12.8 N for group I in 1 month duration which was recorded 182.4 ± 14.2 N for group II and 211.6 ± 10.4 N for group III at the end of 1 month. These values were 97.6 ± 10.2 N for group I and 324.6 ± 8.2 N for group II and 372.6 ± 17.4 N for group III at the end of three months after implantation. CONCLUSION: Implantation of autologous graft covered with hydroxyapatite indicated to have positive effect in integral formation of qualitative callus at the site of fracture and early re-organization of callus to regain mechanical strength too.

Value of color Doppler ultrasonography and radiography for the assessment of the cancellous bone scaffold coated with nano-hydroxyapatite in repair of radial bone in rabbit.

PURPOSE: To evaluate the osteo-regenerative capacity of proprietary bone grafting material as a bone defect filler and osteogenetic stimulation to speed up bone healing too. METHODS: Eighteen adult male New Zealand white rabbits were anesthetized and a segmental full thickness bone defect of 10 mm in length was created in the middle of the right radial shaft in all rabbits. They were divided into two groups of 9 rabbits. Group I was considered as control and the fractured site was fixed using finger bone plate with 4 screws, whereas the cancellous bone scaffold coated with Nano-Hydroxyapatite was used to fill the gap after fracture fixation in Group II. Radiography, two dimensional and color Doppler ultrasonography were done before and after creating defects and on 0, 15, 30, 60 and 90 days to evaluate local reaction as far as new blood vessels network and callus formation are observed. RESULTS: On the radiographs during the whole process, bone repair in Group I was not as perfect as those in Group II samples and trace of internal callus filled the gap incompletely in 60 days in Group I, whereas in Group II internal callus almost was formed on 30 days and in addition intercortical callus was seen supporting to cover and filled the gap completely in this group in 60 day; Sonographic findings confirmed the protrusion of newly formed blood vascular network in 30 days in Group I and from 15 days in Group II and remarkably increased till end of observation period. CONCLUSIONS: The nano-hydroxyapatite with more features and shorter in time, made possible the reconstruction of bone tissue and alternative techniques as well as previous bone graft, also radiography and ultrasonography are reliable techniques to trace local reaction at proper time.

Mechanical properties of radial bone defects treated with autogenous graft covered with hydroxyapatite in rabbit / Propriedades mecânicas de defeito de osso radial tratado com enxerto autógeno coberto com nano-hydroxyapatite em coelho

PURPOSE: To determine biomechanical property of autogenous bone graft covered with hydroxyapatite in the defect of radial bone in rabbit. METHODS: Eighteen adult male New Zealand white rabbits were used which were divided into three groups (I, II, III) of six rabbits each. A segmental bone defect of 10 mm in length was created in the middle of the right radial shaft under general effective anesthesia in all rabbits and were stabilized using mini-plate with four screws. The defects In group I were left as such without filler, whereas in group II the defect were filled up with harvested 10 mm rib bone and in group III the defect were packed with rib bone covered with nano-hydroxyapatite. All rabbits in three groups were divided into two subgroups (one month and three months duration with three rabbits in each one). RESULTS: The mechanical property and the mean load for fracturing normal radial bone was recorded 388.2±6 N whereas it was 72.4±12.8 N for group I in 1 month duration which was recorded 182.4±14.2 N for group II and 211.6±10.4 N for group III at the end of 1 month. These values were 97.6±10.2 N for group I and 324.6±8.2 N for group II and 372.6±17.4 N for group III at the end of three months after implantation. CONCLUSION: Implantation of autologous graft covered with hydroxyapatite indicated to have positive effect in integral formation of qualitative callus at the site of fracture and early re-organization of callus to regain mechanical strength too.

OBJETIVO: Determinar as propriedades biomecânicas de enxerto ósseo autógeno coberto com hidroxiapatita em defeito do osso radial em coelhos. MÉTODOS: Foram utilizados 18 coelhos adultos, machos, brancos, Nova Zelândia, distribuídos em três grupos (I, II, III) de seis coelhos cada. Um defeito segmentar de 10 mm de comprimento foi criado no meio do eixo radial direito sob anestesia geral efetiva em todos os coelhos e foram fixados usando mini-placa com quatro parafusos. Os defeitos no grupo I foram deixados sem preenchimento, enquanto no grupo II o defeito foi preenchido com 10 mm de costela recoberta com nano-hidroxiapatita. Os coelhos nos três grupos foram distribuídos em dois subgrupos (Um e três meses, com três coelhos cada um). RESULTADOS: A propriedade mecânica e a média do peso para fraturar o osso radial normal foi 388,2±6 N, enquanto para o Grupo I, com um mês foi 72,4±12,8 N, para o grupo II 182,4±14,2 N e para o Grupo III 211,6±10,4 N. Após três meses de implantação, os valores foram 97,6±10,2 N para o Grupo I, 324,6±8,2 N para o Grupo II e 372,6±17,4 N para o Grupo III. CONCLUSÃO: A implantação de enxerto autólogo recoberto com hidroxiapatita indicou ter um efeito positivo na formação integral qualitativa do calo ósseo no local da fratura e precoce reorganização do calo com recuperação da força mecânica.

Value of color Doppler ultrasonography and radiography for the assessment of the cancellous bone scaffold coated with nano-hydroxyapatite in repair of radial bone in rabbit / Valor da ultrassonografia Doppler em cores e da radiografia na avaliação da capacidade osteo-regenerativa da nano-hidroxiapatita no reparo de osso radial em coelho

PURPOSE: To evaluate the osteo-regenerative capacity of proprietary bone grafting material as a bone defect filler and osteogenetic stimulation to speed up bone healing too. METHODS: Eighteen adult male New Zealand white rabbits were anesthetized and a segmental full thickness bone defect of 10 mm in length was created in the middle of the right radial shaft in all rabbits. They were divided into two groups of 9 rabbits. Group I was considered as control and the fractured site was fixed using finger bone plate with 4 screws, whereas the cancellous bone scaffold coated with Nano-Hydroxyapatite was used to fill the gap after fracture fixation in Group II. Radiography, two dimensional and color Doppler ultrasonography were done before and after creating defects and on 0, 15, 30, 60 and 90 days to evaluate local reaction as far as new blood vessels network and callus formation are observed. RESULTS: On the radiographs during the whole process, bone repair in Group I was not as perfect as those in Group II samples and trace of internal callus filled the gap incompletely in 60 days in Group I, whereas in Group II internal callus almost was formed on 30 days and in addition intercortical callus was seen supporting to cover and filled the gap completely in this group in 60 day; Sonographic findings confirmed the protrusion of newly formed blood vascular network in 30 days in Group I and from 15 days in Group II and remarkably increased till end of observation period. CONCLUSIONS: The nano-hydroxyapatite with more features and shorter in time, made possible the reconstruction of bone tissue and alternative techniques as well as previous bone graft, also radiography and ultrasonography are reliable techniques to trace local reaction at proper time.

OBJETIVO: Avaliar a capacidade osteo-regenerativa de biomaterial no preenchimento de defeito ósseo e como estímulo osteogênico para acelerar a cicatrização óssea. ÉTODOS: Dezoito coelhos brancos, Nova Zelandia, adultos, machos foram anestesiados e um defeito ósseo segmentar de toda a espessura e 10 mm de comprimento foi criado no meio do eixo do osso radial direito de todos os coelhos. Os animais foram distribuídos em dois grupos de nove: Grupo I foi considerado como controle e o local da fratura foi fixado usando placa de dedo de osso com quatro parafusos, enquanto o molde de osso esponjoso revestido com nano-hidroxiapatita foi usado para preencher o espaço após fixação da fratura no Grupo II. Radiografia, bidimensional e ultrassonografia Doppler colorida foi feita antes e após criar os defeitos e nos dias 0, 15, 30, 60 e 90 para avaliar a reação local tais como nova rede vascular e formação do calo ósseo. RESULTADOS: Nas radiografias durante todo o processo, o reparo ósseo no Grupo I não foi perfeito como no Grupo II; amostras e traços de calo ósseo preencheram o espaço de forma incompleta em 60 dias no Grupo I, enquanto no Grupo II o calo ósseo interno foi quase formado em 30 dias e, além disso, calo intercortical foi visto apoiar para revestir e preencher o espaço completamente em 60 dias; nos achados ultrassonográficos a protrusão da rede vascular neoformada em 30 dias no Grupo I e a partir de 15 dias no Grupo II e acentuado aumento até o fim do período de observação. CONCLUSÕES: A nano-hidroxiapatita, com mais propriedade e menor período de tempo, tornou possível a reconstrução de tecido ósseo e técnicas alternativas como o enxerto ósseo prévio, assim como a radiografia e a ultrassonografia são técnicas confiáveis para traçar a reação local em tempo adequado.

Value of color Doppler ultrasonography and radiography for the assessment of the cancellous bone scaffold coated with nano-hydroxyapatite in repair of radial bone in rabbit / Valor da ultrassonografia Doppler em cores e da radiografia na avaliação da capacidade osteo-regenerativa da nano-hidroxiapatita no reparo de osso radial em coelho

PURPOSE: To evaluate the osteo-regenerative capacity of proprietary bone grafting material as a bone defect filler and osteogenetic stimulation to speed up bone healing too. METHODS: Eighteen adult male New Zealand white rabbits were anesthetized and a segmental full thickness bone defect of 10 mm in length was created in the middle of the right radial shaft in all rabbits. They were divided into two groups of 9 rabbits. Group I was considered as control and the fractured site was fixed using finger bone plate with 4 screws, whereas the cancellous bone scaffold coated with Nano-Hydroxyapatite was used to fill the gap after fracture fixation in Group II. Radiography, two dimensional and color Doppler ultrasonography were done before and after creating defects and on 0, 15, 30, 60 and 90 days to evaluate local reaction as far as new blood vessels network and callus formation are observed. RESULTS: On the radiographs during the whole process, bone repair in Group I was not as perfect as those in Group II samples and trace of internal callus filled the gap incompletely in 60 days in Group I, whereas in Group II internal callus almost was formed on 30 days and in addition intercortical callus was seen supporting to cover and filled the gap completely in this group in 60 day; Sonographic findings confirmed the protrusion of newly formed blood vascular network in 30 days in Group I and from 15 days in Group II and remarkably increased till end of observation period. CONCLUSIONS: The nano-hydroxyapatite with more features and shorter in time, made possible the reconstruction of bone tissue and alternative techniques as well as previous bone graft, also radiography and ultrasonography are reliable techniques to trace local reaction at proper time.(AU)

OBJETIVO: Avaliar a capacidade osteo-regenerativa de biomaterial no preenchimento de defeito ósseo e como estímulo osteogênico para acelerar a cicatrização óssea. ÉTODOS: Dezoito coelhos brancos, Nova Zelandia, adultos, machos foram anestesiados e um defeito ósseo segmentar de toda a espessura e 10 mm de comprimento foi criado no meio do eixo do osso radial direito de todos os coelhos. Os animais foram distribuídos em dois grupos de nove: Grupo I foi considerado como controle e o local da fratura foi fixado usando placa de dedo de osso com quatro parafusos, enquanto o molde de osso esponjoso revestido com nano-hidroxiapatita foi usado para preencher o espaço após fixação da fratura no Grupo II. Radiografia, bidimensional e ultrassonografia Doppler colorida foi feita antes e após criar os defeitos e nos dias 0, 15, 30, 60 e 90 para avaliar a reação local tais como nova rede vascular e formação do calo ósseo. RESULTADOS: Nas radiografias durante todo o processo, o reparo ósseo no Grupo I não foi perfeito como no Grupo II; amostras e traços de calo ósseo preencheram o espaço de forma incompleta em 60 dias no Grupo I, enquanto no Grupo II o calo ósseo interno foi quase formado em 30 dias e, além disso, calo intercortical foi visto apoiar para revestir e preencher o espaço completamente em 60 dias; nos achados ultrassonográficos a protrusão da rede vascular neoformada em 30 dias no Grupo I e a partir de 15 dias no Grupo II e acentuado aumento até o fim do período de observação. CONCLUSÕES: A nano-hidroxiapatita, com mais propriedade e menor período de tempo, tornou possível a reconstrução de tecido ósseo e técnicas alternativas como o enxerto ósseo prévio, assim como a radiografia e a ultrassonografia são técnicas confiáveis para traçar a reação local em tempo adequado.(AU)

Mechanical properties of radial bone defects treated with autogenous graft covered with hydroxyapatite in rabbit / Propriedades mecânicas de defeito de osso radial tratado com enxerto autógeno coberto com nano-hydroxyapatite em coelho

PURPOSE: To determine biomechanical property of autogenous bone graft covered with hydroxyapatite in the defect of radial bone in rabbit. METHODS: Eighteen adult male New Zealand white rabbits were used which were divided into three groups (I, II, III) of six rabbits each. A segmental bone defect of 10 mm in length was created in the middle of the right radial shaft under general effective anesthesia in all rabbits and were stabilized using mini-plate with four screws. The defects In group I were left as such without filler, whereas in group II the defect were filled up with harvested 10 mm rib bone and in group III the defect were packed with rib bone covered with nano-hydroxyapatite. All rabbits in three groups were divided into two subgroups (one month and three months duration with three rabbits in each one). RESULTS: The mechanical property and the mean load for fracturing normal radial bone was recorded 388.2±6 N whereas it was 72.4±12.8 N for group I in 1 month duration which was recorded 182.4±14.2 N for group II and 211.6±10.4 N for group III at the end of 1 month. These values were 97.6±10.2 N for group I and 324.6±8.2 N for group II and 372.6±17.4 N for group III at the end of three months after implantation. CONCLUSION: Implantation of autologous graft covered with hydroxyapatite indicated to have positive effect in integral formation of qualitative callus at the site of fracture and early re-organization of callus to regain mechanical strength too.(AU)

OBJETIVO: Determinar as propriedades biomecânicas de enxerto ósseo autógeno coberto com hidroxiapatita em defeito do osso radial em coelhos. MÉTODOS: Foram utilizados 18 coelhos adultos, machos, brancos, Nova Zelândia, distribuídos em três grupos (I, II, III) de seis coelhos cada. Um defeito segmentar de 10 mm de comprimento foi criado no meio do eixo radial direito sob anestesia geral efetiva em todos os coelhos e foram fixados usando mini-placa com quatro parafusos. Os defeitos no grupo I foram deixados sem preenchimento, enquanto no grupo II o defeito foi preenchido com 10 mm de costela recoberta com nano-hidroxiapatita. Os coelhos nos três grupos foram distribuídos em dois subgrupos (Um e três meses, com três coelhos cada um). RESULTADOS: A propriedade mecânica e a média do peso para fraturar o osso radial normal foi 388,2±6 N, enquanto para o Grupo I, com um mês foi 72,4±12,8 N, para o grupo II 182,4±14,2 N e para o Grupo III 211,6±10,4 N. Após três meses de implantação, os valores foram 97,6±10,2 N para o Grupo I, 324,6±8,2 N para o Grupo II e 372,6±17,4 N para o Grupo III. CONCLUSÃO: A implantação de enxerto autólogo recoberto com hidroxiapatita indicou ter um efeito positivo na formação integral qualitativa do calo ósseo no local da fratura e precoce reorganização do calo com recuperação da força mecânica.(AU)