Fragility fractures due to osteoporosis most commonly involve which skeletal sites?

• A. Skull, pelvis, ribs
• B. Clavicle, sacrum, humerus
• C. Hip, spine, wrist
• D. Ankle, foot, tibia

Answer: (C)

Fragility fractures occur from minimal trauma in osteoporosis, so the sites most commonly affected are the hip, spine, and wrist. The spine is frequently involved because vertebral bodies contain a lot of trabecular bone, which is lost early in osteoporosis, leading to vertebral compression fractures that may cause height loss or kyphosis (and can be asymptomatic). The distal radius at the wrist is a common site after a fall onto an outstretched hand, reflecting weakness in the cancellous/cortical bone at the wrist. Hip fractures, involving the proximal femur, are a major concern due to their impact on mobility and the high morbidity and mortality associated with them. These sites together represent the pattern of fragility fractures in osteoporosis, whereas fractures of the skull, pelvis, ribs, or the ankle/foot are not typical primary fragility fracture sites.