Patent ID: 9504498
Filing Date: 2016-11-29
CPC Classification: A61B

Claim Text:
1. A polyaxial bone anchor for attaching a rod to a bone, comprising: an anchor head comprising a longitudinal bore having a top opening and a bottom opening, a generally U-shaped channel transverse to the longitudinal bore for receiving the rod, and a central axis extending through the top opening and the bottom opening; a bushing configured to be retained within the anchor head, the bushing defining a spherical exterior surface which is defined by a first sphere and a spherical inner surface which is defined by a second sphere, the first sphere having a first spherical centerpoint and the second sphere having a second spherical centerpoint, wherein one of the first and second spherical centerpoints is closer than the other of the first and second spherical centerpoints to the top opening; an anchor member having a first portion configured to be supported by the bushing relative to the anchor head, and a second portion that extends from the first portion and through the bottom opening; and a fastener removably mountable to the anchor head to lock the position of the rod in the U-shaped channel and the position of the anchor member, wherein when the first portion of the anchor member is supported relative to the anchor head, the anchor member is configured to angulate with respect to the anchor head about the first and second spherical centerpoints from a neutral position whereby the anchor member is oriented substantially along with the central axis, to an angulated position whereby the second portion of the anchor member is angularly offset from the central axis, such that the anchor member abuts the anchor head when the anchor member is in the angulated position.