The role of microvasculature in normal and perturbed bone healing as revealed by intravital microscopy.

Bone chamber intravital microscopy brings to the study of bone circulation a combination of the control volume of in vitro models and the chemical complexity of in vivo models. As an optical tool it provides a window to circulatory events at the tissue level of magnification. In particular, it allows measures of microvascular physiology 1) in space by magnifying local perfused vasculature and microcirculation at any instant and 2) in time by providing the same volume of tissue for weekly viewing of an evolving process such as bone healing. This hollow screw's windows have revealed: 1) a consistent order for vascular and bone progression during healing, 2) vascular changes in response to implanted polymers and 3) preliminary data about effects of hyperbaric oxygenation and pulsed electromagnetic fields on vascular aspects of healing. The parameters measured are osteogenesis, angiogenesis, blood supply and permeability.