Patent ID: 9198695
Filing Date: 2015-12-01
Classification: A61B

Abstract:
1. A polyaxial bone anchor comprising: a housing having an upper end, a lower end and a bore extending through the housing from the upper end to the lower end, the bore opening out at the lower end at a lower opening, the housing including a channel configured for receiving an elongate stabilization member therethrough which extends from a first side surface of the housing to a second side surface of the housing opposite the first side surface transverse to the bore; a retainer configured to be positioned into the bore of the housing and having an outermost diameter greater than a diameter of the lower opening, the retainer including a plurality of alternating tabs and first slots circumferentially arranged to define a cavity therein; a bone screw including a head portion and a shank extending from the head portion, the head portion of the bone screw positionable in the cavity of the retainer with the shank extending from the lower end of the housing by deflecting the tabs radially outward to enlarge a lower opening of the retainer into the cavity from a diameter less than a diameter of the head portion to a diameter greater than or equal to the diameter of the head portion; and wherein a portion of the retainer includes one or more circumferential or helical second slots formed therein configured for applying a force to move and bias the retainer toward the lower end of the housing while the retainer is positioned in the bore, wherein the one or more circumferential or helical second slots extend transverse to the bore.