The Bennett fracture is an intraarticular fracture of the base of the first metacarpal. The fracture must involve the first carpometacarpal joint to be called a Bennett fracture. The action of the abductor pollicis longus causes distraction of the fracture fragments. The volar base of the first metacarpal stays with the trapezium.
|  A | Oblique radiograph of the hand. There is an intraarticular fracture at the base of the first metacarpal. | 
|  B | PA radiograph of the first digit. This view better defines the Bennett fracture. | 
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