aka Bone and Joint Bamboozler 004
A 27 year-old man attempted to smash his fist through a plank of wood as part of an amateur martial arts demonstration. His success was bitter-sweet.
Following a brief period of frozen pea therapy he attended the ED for evaluation. These are the radiographs taken of his right hand:
Describe the injury?
There is a fracture involving the articular surface of the base of the right thumb metacarpal.
It is slightly displaced and the carpo-metacarpal joint is slightly subluxed as a result.
What is the eponymous name for this fracture?
Named for the Irish surgeon who introduced antisepsis to Dublin: Edward Hallaran Bennett (1837-1907).
The Bennett fracture is distinct from the Rolando fracture, which is a comminuted three part, intra-articular fracture with a T or Y-shaped appearance. Named after the Italian surgeon Silvio Rolando who first described in 1910.
What the typical mechanism of injury?
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.
What imaging and views are best for this assessing this injury?
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.
What specific complications should be considered?
- joint stiffness and 1st CMCJ arthritis
What is the management of this injury?
Treatment goals are to achieve articular congruity and stability of the thumb carpo-metacarpal joint.
- thumb spica splint
- early referral to a hand specialist
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).
Bonus Question: What is the origin of the term Gordon Bennett?
Alludes to the outrageous behavior of the American sportsman, publisher and all-round hell-raiser James Gordon Bennett Jr.
James Gordon Bennett Jr. inherited his father’s talents for journalism, controversy, and a multi-million dollar estate.
He took over control of the New York Herald in 1866, by which time he was well into an enthusiastic and hedonist playboy lifestyle, indulging in spending the family fortune on air and road racing in the USA, England and France.
- Cadogan M. Edward Hallaran Bennett (1837–1907)
- Cadogan M. Bennett fracture – a potted history. LITFL
- Gordon Bennett: Origin of the term.
- Sherman, S. Simon’s Emergency Orthopedics 7e
- Purcell, D. Minor Injuries A Clinical Guide 3e
- Rosen’s Emergency Medicine 8th edition
Bone and Joint Bamboozler