<prompt> Bennetts fracture is fracture dislocation of base of which of the following metacarpal?3rd4th1st2nd  <response>: Bennetts fracture dislocation is paial aicular fracture of 1st metacarpal base with trapeziometacarpal dislocation subluxation. Also know Rolandos fracture dislocation: It is complete fracture of 1st metacarpal. It involves whole aicular surface with comminuted T or Y intraaicular fracture. Ref: Apleys 8e, Page 631-32; Watson Jones: fracture Joint injuries 6e, Page 760-62; Rockwood Greens Fracture in Adults 6e, Page 836-42. 