Polyaxial bone anchor with pop-on shank, shank, friction fit retainer, winged insert and low profile edge lock

Patent metadata

Field	Value
Publication number	US-9480517-B2
Application number	US-201213573874-A
Country	US
Kind code	B2
Filing date	Oct 10, 2012
Priority date	Jun 15, 2009
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in an integral receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. A down-loadable compression insert, a down-loadable friction fit split retaining ring having inner and outer tangs and an up-loadable shank upper portion cooperate to provide for pop- or snap-on assembly of the shank with the receiver either prior to or after implantation of the shank into a vertebra. The shank and receiver once assembled cannot be disassembled.

First claim

What is claimed and desired to be secured by Letters Patent is as follows:

1. In a polyaxial pedicle screw including a shank having a body for fixation to a bone and an integral upper portion, an U-shaped receiver having a top portion and an integral base, the receiver top portion defining an open rod-receiving channel, the base defining a cavity communicating with a bottom opening, the upper portion of the shank positionable within the cavity, and the channel communicating with the cavity, the improvement comprising:
a) a retainer positioned within the cavity prior to the shank being loaded and capturing the shank upper portion once loaded, the retainer being in a non-pivotal relationship with respect to the receiver; and wherein
b) the retainer further includes a cut-out surface being sized and shaped to provide for increased polyaxial motion in at least one direction for the shank with respect to the receiver.

Assignees

• Jackson Roger P

Inventors

• Jackson Roger P
• Surber James L

Classifications

• A61B17/7038

  to a different extent in different directions, e.g. within one plane only · CPC title

• A61B17/7082

  for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws · CPC title

• A61B2090/0808

  for indicating correct assembly of components, e.g. of the surgical apparatus · CPC title

• A61B17/7008

  with parts of, or attached to, the longitudinal elements, bearing against an outside of the screw or hook heads, e.g. nuts on threaded rods (A61B17/7007 takes precedence) · CPC title

• A61B2017/681

  Alignment, compression, or distraction mechanisms · CPC title