Patent ID: 11937854
Assignee: nan
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 5:
6. A receiver assembly for securing an elongate rod to a bone anchor via a threaded plug, the receiver assembly comprising:
a receiver having a longitudinal axis, a base portion, and an upper portion comprising first and second upright arms defining a channel therebetween that is configured to receive the elongate rod, the channel extending between a front surface and a back surface of the receiver and communicating with a top surface defining a top of the receiver, the receiver having first and second interior surfaces with a helically wound thread form formed in at least a portion of the first and second interior surfaces, the first upright arm including a first outwardly-facing side surface opposite the first interior surface and having a first side planar surface, the second upright arm including a second outwardly-facing side surface opposite the second interior surface and having a second side planar surface, the first side planar surface and the second side planar surface being parallel with respect to each other, the front surface of the receiver including a first front planar surface defined on the first upright arm and a second front planar surface defined on the second upright arm, the first front planar surface being parallel to the second front planar surface; and
the threaded plug configured to be positioned within the channel to secure the elongate rod to the receiver in a locked configuration, the threaded plug comprising a cylindrical body having a central axis, an upper surface having a central drive structure, a lower surface, and an outer external surface with a mating continuous helically wound thread form formed on at least a portion of the outer external surface, the thread form of the threaded plug having a lower clearance surface and an outer crest surface forming at least a portion of an obtuse angle with respect to the lower clearance surface, the thread form of the threaded plug further including a load flank extending in at least one direction that slopes upwardly and outwardly relative to the central axis of the cylindrical body or perpendicular relative to the central axis and an inner root surface extending parallel to the central axis with a lower portion adjacent to and above a base of the thread form of the threaded plug and an upper portion adjacent to and below the base of the thread form of the threaded plug,
wherein the lower surface of the cylindrical body comprises a planar surface portion configured to engage and lock the elongate rod in the channel of the receiver, and
wherein, when the receiver assembly is in the locked configuration, the threaded plug does not extend over any part of the top surface defining the top of the receiver and the entire lower clearance surface and entire outer crest surface of the thread form of the threaded plug are spaced apart from the thread form of the receiver.