[SSBT (severely suppressed bone turnover) ].

Atypical fractures of femoral shaft and pelvis occurred on the long-term bisphosphonate treatment patients have been first reported in 2005. Since then many cases have been reported, while the number of atypical fractures is small compared with that of bisphosphonate treatment patients. It is speculated that accumulation of microdamage induced by severely suppressed bone turnover causes clinical fatigue fracture.