Biomedical Engineering Reference
In-Depth Information
Fig. 2
Phases of distraction osteogenesis (Adapted from [
63
]and [
45
])
•
Latency phase
: it is the period between performance of osteotomy and start of
the tension, during which the soft callus starts to be formed. This period coincides
with the initial events in the normal process of bone healing.
•
Distraction
: it is the period in which the two ends of the osteotomized bone
are gradually moved apart resulting in the formation of new bony tissues within
the progressively increasing interfragmentary gap. Through the application of
tensional stress, a dynamic microenvironment is created [
18
]. This environment
stimulates changes at the cellular and subcellular level, including the prolon-
gation of angiogenesis with increased tissue oxygenation and the increased
fibroblast proliferation. The cells alter their phenotypic expression and become
longitudinally oriented along the axis of distraction.
•
Consolidation
. The consolidation period is the time between the cessation of
traction forces and removal of the distraction device. This period represents
the time required for complete hard callus formation and mineralization of the
regenerated tissue.
•
Remodeling
: it is the time from the removal of the distraction device (and thus
application of full functional loading) to the complete remodeling of the newly
formed bone. During this period, the initially formed bony scaffold is reinforced
by parallel-fibered lamellar bone. Both the cortical bone and marrow cavity are
restored.
