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

Claim 17:
18. A method of assembling a pivotable bone anchor assembly configured for securing an elongate rod to a bone of a patient via a locking mechanism, the method comprising:
introducing a proximal end portion of an anchor member having a first diameter into a bottom opening of a base portion of a receiver having a second diameter such that the first and second diameters cooperate to allow the proximal end portion to pass through the bottom opening, the first diameter being larger than the second diameter, the receiver including an upper portion having a pair of upright arms extending upward from the base portion with opposed interior surfaces forming an open channel for receiving the elongate rod and having a locking mechanism mating structure formed therein, the base portion defining an internal cavity in communication with the open channel and with a bottom surface of the-base portion through the bottom opening, the internal cavity having an inner seating surface adjacent the bottom opening;
passing the proximal end portion entirely through the bottom opening into the internal cavity, the proximal end portion including an integral partial spherical or spheroid shape with the first diameter, the anchor member including a longitudinal axis and an anchor portion opposite the proximal end portion configured for fixation to the bone with a neck between the proximal end portion and the anchor portion defined by a circumferentially-extending curvate surface of reduced radius, the proximal end portion including an internal drive socket formed therein, a top-most planar upper surface, an adjacent curved surface, and a lower outer curved contact surface below the first diameter, the first diameter being below the planar upper surface;
positioning an insert at least partially within the open channel of the receiver, the insert including an upper surface configured to receive the elongate rod and a lower surface configured to engage the proximal end portion of the anchor member without engaging the top-most planar upper surface on the proximal end portion, the top-most planar upper surface being configured to remain spaced apart from the insert when the insert engages the proximal end portion of the anchor member; and
establishing a pivotable arrangement between the anchor member and the receiver with the proximal end portion of the anchor member positioned within the internal cavity of the base portion with the planar upper surface under the lower surface of the insert and the proximal end portion supported by the inner seating surface.