A<unk>  is a bone<unk>  caused by weakness of the bone structure that leads to decrease mechanical resistance to normal mechanical loads. This process is most commonly due to osteoporosis, but may also be due to other<unk> s such as cancer, infection (such as osteomyelitis), inherited bone disorders, or a bone cyst. Only a small number of conditions are commonly responsible for<unk> al<unk> s, including osteoporosis, osteomalacia, Paget's disease, Osteitis, osteogenesis imperfecta, benign bone tumours and cysts, secondary malignant bone tumours and primary malignant bone tumours. Fragility<unk>  is a type of<unk>  that occurs as a result of an injury that would be insufficient to cause<unk>  in a normal bone. There are three<unk>  sites said to be typical of fragility<unk> s: vertebral<unk> s,<unk> s of the neck of the femur, and Colles<unk>  of the wrist. This definition arises because a normal human being ought to be able to fall from standing height without breaking any bones, and a<unk> , therefore, suggests weakness of the skeleton.<unk> al<unk> s present as a chalkstick<unk>  in long bones, and appear as a transverse<unk> s nearly 90 degrees to the long axis of the bone. In a<unk> al compression<unk>  of a spinal vertebra<unk> s will commonly appear to collapse the entire body of vertebra.
Pathologic fracture
Occult fracture
Intraarticular fracture
Nonunion
Open fracture
Pica 
Osteolysis
Intermittent claudication