Patent ID: 7147639

Claim:
A disposable axial external fixation device for reducing bone fractures comprising: an extendible rod-like middle body and oppositely located bone screw clamps which are articulated to respective ends of the rod-like middle body by means of ball joints; a ball-and-socket joint mounted to each clamp within a main body; and locking means for locking the ball-and-socket joint in a selected angular position is provided through a permanent set of the ball-and-socket joint; wherein said ball-and-socket joint comprises a cylindrical socket formed in the main body of the clamp, and a ball head received in the cylindrical socket, wherein said locking means comprises a slider which is guided for movement in said socket toward and away from said ball head by the action of driving means, for locking said ball head in a positive manner, the driving means comprising a shaft, wherein said slider comprises a plurality of contrate teeth projecting toward a same direction, wherein said contrate teeth are adapted to bite into the surface of the ball head and form a plurality of impressions to a suitable depth therein, and wherein means for limiting the rotation of the shaft is provided, the means comprising a radial nose integrally formed with the shaft and appearing externally of the main body, the radial nose being adapted to abut against a stop formed on the main body at an appropriate angular setting of the shaft relative to the main body.