fracture

Fracture is the separation of a material into two or more pieces. In medicine, it refers to a break in a bone caused by injury, disease, or overuse.

Bone fractures are classified by skin involvement (closed versus open), alignment (displaced versus non-displaced), and pattern (transverse, oblique, spiral, comminuted, or greenstick). Pathological fractures occur with underlying disease such as osteoporosis or cancer. Diagnosis combines physical examination and imaging, with X-rays as the first step and computed tomography or MRI when needed. Treatments aim to restore alignment and stability: immobilization with a cast or splint for stable fractures; reduction to reposition displaced fragments; and surgery with internal or external fixation when necessary. Healing proceeds in stages and varies by age and health.

Fracture also denotes fracture mechanics, the study of how and why materials crack and fail under stress. Brittle fractures show little plastic deformation, while ductile fractures involve substantial thinning or necking. Fatigue fractures arise from cyclic loading and crack growth. Key concepts include fracture toughness (K_IC) and the Griffith criterion for crack initiation, as well as crack modes I, II, and III describing opening, sliding, and tearing. Prevention emphasizes sound material selection, avoiding sharp geometries, protective coatings, and quality control, including nondestructive testing to detect flaws before they propagate.

Bones: adequate nutrition, weight-bearing exercise, and fall prevention reduce fracture risk; for engineered components, quality assurance and regular inspection help prevent fracture-related failures.