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What causes a bone fracture?
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bone
A long bone of the human body, showing a magnified cross section of the interior.
A fracture occurs when bone tissue is subjected to tensile, compressive, or shear forces that exceed its structural strength. The specific causes of these fractures generally fall into two categories:1
- Mechanical Forces: In healthy bone, fractures are typically caused by high-energy trauma, such as motor vehicle accidents or falls, which overwhelm the bone's natural resistance to deformation. Conversely, stress fractures result from repetitive, low-impact loadingāsuch as running or marchingāthat causes microdamage to accumulate faster than the body can repair it.12
- Pathological Conditions: Diseases that weaken the bone structure can cause a fracture even under minor stress. Osteoporosis, which reduces bone mineral density, is a primary cause of fractures in the elderly. Other conditions, such as osteomalacia, osteogenesis imperfecta, Paget disease, or the presence of tumours, can also compromise bone integrity, leading to what are known as pathologic fractures.314
Factors such as age, nutrition, and overall health influence a bone's susceptibility to these forces and its subsequent ability to heal.13