Bennett's Fracture

Facts:
- Most frequent fracture at the base of the first metacarpal
- Fracture dislocation resulting from axial loading to a partially flexed thumb (i.e., in a fist fight)
- Oblique fracture involves the carpometacarpal joint, resulting in a volar fragment attached to the trapezium and the distal metacarpal fragment displacing proximally/radially/dorsally by pull of abductor pollicis longus
- First CMC joint is a saddle-shaped bone, any minor malalignment results in substantial articular incongruity. This fracture dislocation frequently requires open reduction and fixation

Imaging
- Oblique fracture line with a triangular fragment at the first metacarpal base
- Proximal displacement of the metacarpal
- Important to note the size of the triangular volar fragment and the degree of displacement of the metacarpal fragment

References:
1. Robinson P. Essential Radiology for Sports Medicine, 2010.
2. Bennett's Fracture Dislocation. Wheeless' Textbook of Orthopedics

Source: Our partner, RiT - http://radiologyinthai.blogspot.com/2010/11/bennetts-fracture-dislocation.html