Bennett fracture: Intra-articular two-part fracture of the base of the first metacarpal with carpometacarpal joint involvement. Thumb fracture usually sustained with forced abduction of the first metacarpal.
Thumb metacarpal fractures are rare because of the thumb’s inherent mobility. However, when fractures do occur they usually involve the base — and the Bennett fracture is the most common type.
The Bennett fracture usually results from axial loading onto a partially flex thumb metacarpal. This can occur when a fist strikes a solid object.
The ulna portion of the base of the thumb remains in place, whereas the larger radial fragment is radially subluxed or dislocated by the pull of the abductor pollicus longus (APL) muscle. The ulna portion is stabilised by the deep ulnar ligament from the ulna and the anterior oblique ligament from the trapezium.
- Routine views of the thumb adequately define the nature of the fragment(s).
- CT scans may be performed as part of the definitive management work-up.
Treatment goals are to achieve articular congruity and stability of the thumb carpo-metacarpal joint.
- thumb spica splint
Definitive management options
- closed reduction alone is unlikely to be successful as CMC stability is compromised by the pull of APL
- closed reduction with percutaneous pinning (most common)
- open reduction and internal fixation (this is also the usual treatment of a Rolando fracture, although external fixation may be performed depending on the size of the fragments).
History of the Bennett fracture
1881 – Bennett presented to a meeting of the Pathological Society of Dublin Nov 12th 1881 the fracture-dislocation now eponymous with him. He published his treatise on fractures of the base of the first metacarpal in the Dublin Journal of Medical Science. Bennet observed 27 first metacarpal fractures in a series of 113 metacarpal fractures.
…of the five examples of fracture of the metacarpal bone of the thumb…the type and character of the fracture is the same – a form and type of fracture not hitherto described in these bones; and if this series be of any value as representing the ordinary injuries, the commonest fracture, certainly the most common of the thumb, possibly of all the bones taken together. The fracture passes obliquely (a, b in woodcut) through the base of the bone, detaching the greater part of the articular facette with that piece of the bone supporting it, which projects into the palm.Bennett 1882
1886 – Bennett published further ‘On Fracture of the Metacarpal Bone of the Thumb‘
1897 – Bennett presented at the surgical section of the Royal Academy of Medicine. He produced anatomic specimens, photographs, casts of hands, and roentgenograms to demonstrate. Bennett presented nine anatomic specimens related to first metacarpal fractures. Five of these specimens showed the following lesion:
The fracture passed obliquely across the base of the bone, detaching the greater part of the articular surface and the piece of bone that was resting on this surface was projected toward the palm of the hand. The separated fragment was very large, and the deformity that resulted therefrom seemed more a dorsal subluxation of the first metacarpal.
Following the presentation and discussion:
…Sir William Stokes expressed the wish that the injury might in the future be associated with the name of Professor Bennett.Br Med J 1897;1:1479
Transcript of 1897 Presentation to the Royal Academy of Medicine in Ireland
- Bennett’s fracture
- Bennett fracture luxation; Bennett fracture-dislocation
- Intra-articular two-part fracture of the base of the first metacarpal
- Bennett EH. Fractures of the metacarpal bones. Dublin J Med Sci 1882; 73: 72-75
- Bennett EH. On fracture of the metacarpal bone of the thumb. Br Med J 1886; 2: 12-13
- Bennett EH. Report of a Meeting of the Royal Academy of Medicine in Ireland 14 May 1897. Br Med J 1897; 1: 1479
- Nickson C. Gordon Bennett! Bone and Joint Bamboozler 004
- Baba Y. Bennett fracture. Radiopaedia
- Cadogan M. Bennett fracture. Eponym A Day. Instagram
the person behind the name
Associate Professor Curtin Medical School, Curtin University. Emergency physician MA (Oxon) MBChB (Edin) FACEM FFSEM Sir Charles Gairdner Hospital. Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |