Plasticity is permanent deformation of the bone without a fracture or that which occurs prior to a definite discontinuity / fracture. With surgical correction of fractures, the bone ends may be opposed but the limb deformity may persist due to plastic deformation of the pre-pubertal bone.

There are a multitude of causes of bone deformities. A fracture that healed into malalignment or nutritional deficiencies can be a couple of causes. Deformities can also develop from birth, such as congenital bone deformities. Many of these can straighten out over time with the growth of the child.

Abstract. Acute plastic deformation of a bone refers to traumatic bending or bowing without a detectable cortical defect. We present a case that is unusual in that bowing of the ulna occurred in a skeletally mature individual and was associated with injury to the distal radioulnar joint.

Bowing fractures are incomplete fractures of tubular long bones in pediatric patients (especially the radius and ulna) that often require no intervention and heal with remodeling.

“Malunion” is a clinical term used to indicate that a fracture has healed, but that it has healed in less than an optimal position. This can happen in almost any bone after fracture and occurs for several reasons. Malunion may result in a bone being shorter than normal, twisted or rotated in a bad position, or bent.

A malunion occurs when a fractured bone heals in an abnormal position, which can lead to impaired function of the bone or limb and make it look like it is ‘bent’. Similarly, a nonunion is the result of a fractured bone failing to heal after an extended period of time – in some cases over a period of 9 to 12 months.

Butterfly fragments are large, triangular fracture fragments seen commonly in comminuted long bone fractures.

Some materials break very sharply, without plastic deformation, in what is called a brittle failure. Others, which are more ductile, including most metals, experience some plastic deformation and possibly necking before fracture.

This plastic deformation, which is not limited to polymers, is also seen in metal alloys. Materials that undergo brittle fracture, on the other hand, will fracture with negligible plastic deformation. In other words, they break without warning. Regardless of the type of fracture, during failure a material will experience:

Materials undergoing ductile fracture first experience plastic deformation, i.e., the material resists the fracture by stretching itself. Imagine pulling on two ends of a plastic bag. The bag stretches by a considerable amount before it eventually tears. This plastic deformation, which is not limited to polymers, is also seen in metal alloys.

What is a Material Fracture? Fracture is the separation of a material into two or more pieces under the action of an applied stress. A material may undergo one of two major types of fracture modes depending on its mechanical properties: ductile and brittle.