Patent ID: 8092504
Filing Date: 2012-01-10
Classification: A61B,Y10T

Abstract:
1. A bone fixation assembly for fixation of vertebral bodies, said bone fixation assembly comprising: a pedicle screw having a head and a threaded portion; and a tulip body configured to receive said pedicle screw and a rod, said tulip body comprising a tapered wall that defines at least a portion of a central bore extending along an axis of said tulip body; said tulip body also having a rod capture channel opening through an end of said tulip body and in communication with said central bore; said rod capture channel having a rod reception portion and a rod securing portion, said rod securing portion of said rod capture channel being defined by two opposing surfaces extending at least partially about said axis of said tulip body so that said rod can pass between said two opposing surfaces and be received in said rod securing portion of said rod capture channel; an expansion member received on said head for locking said tulip body onto said head, said expansion member received on said head and compressing on said head in response to longitudinal relative movement of said expansion member along said tapered wall; wherein said tulip body is configured to be free to move polyaxially on said head of the pedicle screw after said pedicle screw is screwed into bone and prior to said compression; said rod reception portion of said rod capture channel receiving said rod and when there is rotation of said tulip body, said rod becomes captured and locked in said rod securing portion of said rod capture channel; said locking of said expansion member on said head being separate from and prior to said locking of said rod in said tulip body when said bone fixation assembly as fixed to at least one of the vertebral bodies.