RESUMO
In a previous ultrastructural study, the benefit of a single high dose of vitamin D3 on fracture healing in a healthy animal model was demonstrated. This study examined the biomechanical consequences of applying a single high dose of vitamin D3 in a healthy rabbit model subsequent to femoral fracture. The fracture load, the values of energy absorbed until fracture and the flexural rigidity values of the vitamin D group were significantly higher than the corresponding ones of the control group in the case of fracture. On the other hand, for intact bones, those values did not differ significantly between the two groups. It was concluded that single high-dose vitamin D3 application had positive effects on fracture healing in a healthy animal model, as far as the parameters related to mechanical strength are concerned.
Assuntos
Colecalciferol/farmacologia , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Consolidação da Fratura/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Colecalciferol/administração & dosagem , Fêmur/efeitos dos fármacos , Injeções Intramusculares , Masculino , CoelhosRESUMO
The benefits of vitamin D3 on fracture healing have been commonly demonstrated in vitamin-D3-depleted animal models. The aim of this study was to examine the effects of a single high dose of vitamin D3 on fracture healing in a healthy animal model, which has not been previously reported. Twenty healthy young adult guinea pigs were randomly divided into groups as 'control' and 'vitamin D', and their right tibias were fractured with digital manipulation. Guinea pigs in vitamin D group were injected intramuscularly with 50,000 i.u./kg of vitamin D3. The animals were killed at 7, 14, 21 and 28 days following fracture. Ultrastructural analysis of the harvested tibias revealed that a single high dose of vitamin D3 stimulated fracture healing. The observed effects at the fracture zone in a healthy animal model included advancement of blood supply, acceleration of synthesis and organization of collagen fibres, acceleration of the proliferation and differentiation of osteoprogenitor cells, and activation of the mineralization of the matrix.