Bone is a dynamic tissue. It remodels, thereby maintaining serum calcium, repairing micro damage and maintaining strength. A reduction in the strength of bone leads to osteoporosis that may manifest clinically as low energy vertebral and non-vertebral fractures. The bone strength, in turn, is determined by its material, structural properties and on its remodeling potential. Commonly, osteoporosis is objectively evaluated by 'T' and 'Z' scores and these are the indicators of bone density as determined by Dexa scan; these scores correlate inversely with the fracture risk. Quite often, we forget that Dexa scan results are not the only factors determining bone strength and the association between bone density and bone strength is not fixed, and is exemplified by the example of "osteopetrosis". The same issue is happening with the prolonged use of bisphosphonates (BP's).
Keywords: Bisphosphonates; Osteoporosis.