Bone microdamage

Excerpt

Frost was the first to suggest that bone remodeling targets microdamage, to maintain the skeletal integrity [1], because microcracks are associated with intracortical resorption in overuse fractures in human and dogs [2] and with resorption spaces in canine compact bone [3]. In canine bone, the microdamage induced by cyclic loading is more often spatially associated to new remodeling sites than what would be expected by chance [2, 3]. In rats—which do not have intracortical remodeling—cyclic loading can induce intracortical remodeling, and the intracortical resorption is associated with microdamage and morphologically altered osteocytes [4]. This new remodeling seems to occur after the microdamage generation, supporting the concept of targeted bone remodeling [5]. Targeted remodeling might represent 30% of all bone remodeling [6]. As bone remodeling is considered to be targeted towards the repair of fatigue microdamage, an excessive reduction of bone turnover might result in inadequate microdamage repair and cause fracture. …