Patent ID: 11925391
Assignee: BIEDERMANN TECHNOLOGIES GMBH & CO. KG
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 9:
10. A bone anchoring device for coupling a rod to a bone, the bone anchoring device comprising:
a bone anchoring element comprising a shank for anchoring to the bone and a head;
a receiving part having a first end, a second end below the first end, a central axis extending through the first end and the second end, a recess for receiving the rod, and an accommodation space for accommodating the head of the bone anchoring element;
a retainer element positionable at least partially in the accommodation space, wherein the retainer element comprises an upwardly facing surface configured to contact and to exert an upwardly directed pressure on the head; and
a pressure element positionable at least partially in the accommodation space and separable from the retainer element, wherein the pressure element comprises a downwardly facing surface configured to contact and to exert a downwardly directed pressure on the head for locking the head in the receiving part;
wherein when the retainer element and the pressure element are in the receiving part and the head is in the accommodation space, a spring is configured to contact and exert an axial force on the pressure element to hold the pressure element against another portion of the bone anchoring device, wherein the spring extends circumferentially around a spring axis and has a substantially flat upwardly facing surface that extends from a first region located at a lowermost axial position relative to the receiving part to a second region located at an uppermost axial position relative to the receiving part before extending entirely around the spring axis.