Bone fixation assembly

摘要

A bone fixation assembly comprises a tulip-shaped assembly and a bone fixation device such as a surgical or pedicle screw, comprising a head and a bone fixation portion. The tulip assembly comprises an upper portion to receive a rod and a lower portion that has a cavity in which the head of the bone fixation device rests. The cavity has an aperture below. The aperture has a length through which the tulip assembly may slide with respect to the bone fixation device, for movement of the tulip assembly when the bone fixation device is in place, while also maintaining the angular movement of the tulip assembly. The bone fixation device may comprise an aperture engaging part, which locks the bone fixation device position on the aperture length. A tulip assembly translation mechanism comprises a head, a cavity, an aperture to the cavity.

主权项

1. A bone fixation assembly comprising:
(a) a bone fixation device comprising
a bone fixation portion anda head, said bone fixation portion extending away from said head; and (b) a tulip assembly comprising
an upper portion and a lower portion, said upper portion extending upward from said lower portion and structured to receive a rod,and said lower portion comprisinga cavity within said lower portion, andan aperture to the cavity, said aperture located below said cavity, and said head being inside said cavity with said bone fixation portion extending out through said aperture,said aperture comprising an aperture length,said aperture dimensioned to prevent the entire bone fixation device from passing through said aperture and to allow said tulip assembly to slide on said bone fixation device through said aperture length;whereby when said bone fixation device is fixed to a bone said tulip assembly may be moved with respect to said bone through the aperture length to reach the rod to be fitted in said tulip assembly.