Bennett fracture

Dr Derek Smith and R Bronson et al.

A Bennett fracture is a fracture of the base of the thumb resulting from forced abduction of the first metacarpal. It is defined as an intra-articular two-part fracture of the base of the first metacarpal bone.

  • two piece fracture of the base of the thumb metacarpal 
  • intra-articular extension 
  • dorsolateral displacement
  • small fragment of 1st metacarpal, attached to anterior oblique ligament, continues to articulate with trapezium, 
  • lateral retraction of the first metacarpal shaft by abductor pollicis longus

When an intra-articular fracture of the 1st metacarpal is comminuted, producing at least three parts, it is referred to as a Rolando fracture which has a worse prognosis.

Non-operative treatment in a thumb spica cast for 3-4 weeks can be considered in stable, non-displaced fractures. 

Operative treatment is recommended for unstable fracture patterns and intra-articular displacement of >1 mm. While open reduction and internal fixation with a screw or K-wire are both common practice, screws are often preferred as K-wires must be removed after union. 

The treatment algorithm is also influenced by the age and profession/hobbies of the patient.

Untreated or malreduced fractures can lead to secondary osteoarthritis. Osteoarthritis or malunion can cause significant pain and functional decline.  

It is named after Edward Hallaran Bennett (1837-1907), a surgeon from Dublin, Ireland.

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Article information

rID: 984
Synonyms or Alternate Spellings:
  • Bennett's fracture dislocation
  • Bennett fracture dislocation

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