Symptoms of Fractures and Their Associated Injuries

Many diseases decrease the strength of the bone tissue, and some expose the body to increased mechanical forces. Osteoporosis, which is prevalent in postmenopausal women, is the major cause of fractures in old age. Less-common causes of decreased bone strength are osteogenesis imperfecta, long-term treatment with corticosteroid medications, and osteomalacia. Common causes of locally decreased bone strength are injury of peripheral nerves and tumours.

The existence of a fracture is often deduced from a history of injury and observation of swelling, tenderness, faulty alignment, the sound that the broken ends make, loss of function, and associated injuries. Precise diagnosis is made by X-ray examination.

Fractures occur because the bone tissue is exposed to forces that overwhelm its capacity for structural adaptation. Examples include fractured thighbone and fractured bones of the foot (march fracture) in soldiers during their initial months of physical training. Stress injury usually produces pain even before bone abnormality can be seen by X-ray. Injuries in bones that occur because of preexisting disease are called pathologic fractures. Bone diseases associated with this type of injury are osteomalacia, Paget disease, and radiation injury to bone.

Except when forces act with explosive suddenness, vessels and nerves usually escape injury because of their elasticity and resilience. For anatomic reasons, nerve injury may occur in fracture-dislocation of the hip and in fracture of the long bone of the upper arm (humerus) through the diaphysis in adults and just above the elbow in children; the latter fracture is associated with compression of the accompanying artery. Fractured bones and dislocation of the vertebrae caused by severe forces may be associated with spinal cord injury. Certain fractured bones injure the nutrient blood vessels of the bone tissue, with osteonecrosis as a result.