Patent ID: 11925392
Assignee: nan
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A pivotable bone anchor assembly configured for securing an elongate rod to a bone of a patient, the pivotable bone anchor assembly comprising:
a locking mechanism including a bottom surface and a helically wound first mating structure;
an anchor member comprising a longitudinal axis, a proximal end portion having an integral partial spherical or spheroid shape with a first diameter and an internal drive socket formed therein, an anchor portion opposite the proximal end portion configured for fixation to the bone, a neck between the proximal end portion and the anchor portion defined by a circumferentially-extending curvate surface of reduced radius, and a planar top surface perpendicular to the longitudinal axis and entirely surrounding the internal drive socket;
a receiver comprising a base portion defining an internal cavity in communication with a bottom surface of the base portion through a bottom opening, and an upper portion defining a channel communicating with the internal cavity and configured to receive the elongate rod, the upper portion having a helically wound second mating structure formed therein configured to mate with the first mating structure of the locking mechanism, the bottom surface of the locking mechanism engageable with the elongate rod when the elongate rod is received in the channel and the first mating structure of the locking mechanism mates with the second mating structure, the internal cavity having an inner seating surface adjacent the bottom opening and the bottom opening having a second diameter larger than the first diameter to allow the proximal end portion to pass through the bottom opening into the internal cavity; and
an insert at least partially positionable within the channel of the receiver and having an upper surface configured to receive the elongate rod, the insert configured to transfer a downwardly-directed force from the locking mechanism to the proximal end portion of the anchor member to result in a locked position of the anchor member relative to the receiver when the proximal end portion is pivotally supported by the inner seating surface in the internal cavity of the base portion,
wherein the planar top surface on the proximal end portion of the anchor member is configured to remain spaced apart from the insert so as to not directly receive the downwardly-directed force in the locked position.