nonunion fracture

nonunion fracture

Orthopedics A fracture unhealed after 9 months. See Pseudoarthrosis.

fracture

1. the breaking of a part, especially a bone.

2. a break in the continuity of bone. Fractures may be caused by trauma, by twisting due to muscle spasm, or indirect loss of leverage or by disease that results in decalcification of the bone.

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avulsion fracture

separation of a small fragment of bone cortex at the site of attachment of a ligament or tendon.

blow-out fracture

fracture of the orbital floor caused by a sudden increase of intraorbital pressure due to traumatic force; the orbital contents herniate into the maxillary sinus so that the inferior rectus or inferior oblique muscle may become incarcerated in the fracture site, producing diplopia on looking up.

capillary fracture

one that appears on a radiograph as a fine, hairlike line, the segments of bone not being separated; sometimes seen in fractures of the skull.

closed fracture

one that does not produce an open wound.

comminuted fracture

one in which the bone is splintered or crushed.

complete fracture

one involving the entire cross-section of the bone.

compound fracture

see open fracture (below).

compression fracture

one produced by compression.

contaminated fracture

see open fracture (below).

depressed fracture

fracture of the skull in which a fragment is depressed. See also depression fracture.

direct fracture

one at the site of injury.

dislocation fracture

fracture of a bone near an articulation with concomitant dislocation of that joint.

double fracture

fracture of a bone in two places.

fissure fracture

a crack extending from a surface into, but not through, a long bone.

greenstick fracture

one in which one side of a bone is broken, the other being bent.

impacted fracture

fracture in which one fragment is firmly driven into the other.

incomplete fracture

one that does not involve the complete cross-section of the bone.

indirect fracture

one at a point distant from the site of injury.

interperiosteal fracture

greenstick or incomplete fracture.

intrauterine fracture

fracture of a fetal bone incurred in utero.

lead pipe fracture

one in which the bone cortex is slightly compressed and bulged on one side with a slight crack on the other side of the bone.

malunion fracture

a large space between the displaced ends of the bone has been filled by new bone.

nonunion fracture

there is still a wide translucent space between the ends of the broken bone.

oblique fracture

a common type, usually seen in the shaft of a long bone, such as the femur, tibia or humerus.

Oblique fractures of the radius and ulna. By permission from Lamb CR, Diagnostic Imaging of the Dog and Cat, Mosby, 1993

open fracture

one in which a wound through the adjacent or overlying soft tissues communicates with the site of the break; called also compound fracture. A classification system has been used which is based on the mechanism of injury and the extent of tissue damage. In type I, a bone fragment was briefly forced through the skin leaving a communicating wound; type II fractures are caused by impact and there is damage to overlying tissues and exposure of the bone; in type III, there is extensive damage and loss of overlying tissues, including shearing and degloving wounds, with loss of vascular supply.

pathological fracture

one due to weakening of the bone structure by pathological processes, such as neoplasia, osteomalacia or osteomyelitis.

pertrochanteric fracture

fracture of the femur passing through the greater trochanter.

Salter fracture

see salter classification.

saucer fracture

creates a saucer-shaped fragment; caused usually by direct trauma at midshaft in a long bone. Likely to create a sequestrum.

simple fracture

closed fracture.

slab fracture

one in which a flat piece of underlying bone or tooth is separated or lost. Common in carpal bones of horses and in teeth.

spiral fracture

one in which the bone has been twisted apart.

spontaneous fracture

pathological fracture.

sprain fracture

the separation of a tendon from its insertion, taking with it a piece of bone. See also avulsion fracture (above).

stellate fracture

one with a central point of injury, from which radiate numerous fissures.

stress fracture

fracture produced by the stress created by the pull of muscles without the intervention of trauma or extreme weight-bearing.

trabecular fracture

there is no discontinuity of the bone as a whole but microscopic examination shows fractured trabeculae.

transverse fracture

one at right angles to the axis of the bone.

trophic fracture

one due to a nutritional (trophic) disturbance.