Patent ID: 6979334

Claim:
A bone fixation assembly comprising: (a) a fixation device having a through passage; (b) a fastening screw having a threaded shaft for insertion through the through passage and threadable insertion into bone, and a head having substantially frustospherical shaped side surfaces; (c) a bushing having; (i) upper and lower surfaces; (ii) a side wall with an exterior surface configured and dimensioned for axial rotation within said through passage of the fixation device and an interior surface which defines a socket bore that extends through the upper and lower surfaces and is configured and dimensioned for polyaxial rotation of said screw head therein; and (iii) at least one slot located on the sidewall for allowing inward compression of said bore against said screw head; and (iv) an access passage in said upper surface dimensioned for receiving said screw head therethrough for access to said socket bore; cam means disposed on and integral with said bushing, said cam means disposed between said through passage and said bushing and configured and dimensioned for inwardly compressing said bushing upon axial rotation thereof in said through passage whereby said bore is compressed against said screw head for locking said screw at a desired attitude relative to said fixation device.