Introduction to Trauma X-ray
Other fracture types

Key points

  • An avulsion injury arises when a bone fragment is pulled away by a ligament or tendon
  • A stress fracture arises in a normal bone as a result of repetitive low impact trauma
  • Periprosthetic fractures occur at the site of orthopaedic metalwork
  • Describing a fracture is usually better than labelling it with an eponymous term

Avulsion injury

Range of movement at a joint is normally limited by ligaments or tendons which may withstand injury better than the bone to which they are attached. Excessive movement at a joint, may result in a bone fragment being pulled off, or 'avulsed', by a tendon or ligament.

A fracture arising in this way is called an 'avulsion fracture'.

Avulsion fracture example - finger

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Avulsion fracture example - finger

  • A bone fragment has been avulsed from the distal phalanx due to hyperflexion at the distal interphalangeal joint (DIPJ)
  • The tendon remains intact

Stress fracture

Whereas a pathological fracture can arise from a single minor trauma to an abnormal bone, a stress fracture is the result of repeated low impact trauma to a normal bone.

The 'march' fracture is a common stress fracture of a metatarsal bone. This is not only seen in soldiers who march, but also as the result of other repetitive weight-bearing activities.

Stress fracture example - Metatarsal

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Stress fracture example - Metatarsal

  • No visible fracture line
  • Subtle calcification of the periosteum is a phenomenon known as 'periosteal reaction' (arrows) which may be the only visible abnormality

Periprosthetic fracture

A periprosthetic fracture occurs at the site of orthopaedic metalwork.

Periprosthetic fracture

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Periprosthetic fracture

  • The lucent (black) areas around the metalwork are a sign of loosening of the prosthesis
  • The weakened bone has fractured

Eponymous fractures

There is great variance in understanding of the defining features of many eponymous injuries. For example, there is no common agreement on the definition of a 'Colle's fracture'.

Eponyms may be useful in some settings, but if there is any doubt about the nature of an injury, then it is best to avoid using an eponymous term and describe the injury more specifically.

Eponymous fractures example - Colle's fracture

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Eponymous fractures example - Colle's fracture

  • Transverse and partially comminuted fracture of the distal radius
  • Distal component dorsally displaced and angulated
  • Associated transverse fracture of the ulnar styloid