Receiving part for receiving a rod for coupling the rod to a bone anchoring element, bone anchoring device, method and tool for assembling the same

Abstract

A receiving part for receiving a rod for coupling the rod to a bone anchoring element includes a receiving part body with a first end and a second end; a rod receiving portion with a channel for receiving a rod, and a head receiving portion for accommodating a head of a bone anchoring element, the head receiving portion having an open end at the second end of the receiving part body and being flexible so as to allow introduction and clamping of the head; and a locking ring configured to be positioned around the head receiving portion, wherein the locking ring can assume a first position with respect to the receiving part body in which the locking ring is latched to the receiving part body in a position where the head receiving portion is expandable to facilitate insertion of a head of a bone anchoring element, and wherein the locking ring can assume a second position with respect to the receiving part body in which the locking ring is latched to the receiving part body in a position where the locking ring compresses the head receiving portion, such that when a bone anchoring element has a head inserted in the head receiving portion, the bone anchoring element is held adjustably at a first angular position relative to the receiving part. A method for assembling a bone anchoring device includes inserting the head of the bone anchoring element into the receiving part body; and moving the locking ring and the receiving part body relative to each other until the locking ring assumes the second position with respect to the receiving part body.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)[0001]The present application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61 / 331,518, filed May 5, 2010, the contents of which are hereby incorporated by reference in their entirety, and claims priority from European Patent Application EP 10 162 063.1, filed May 5, 2010, the contents of which are hereby incorporated by reference in their entirety.BACKGROUND[0002]1. Field of the Invention[0003]The invention relates to a receiving part for receiving a rod for coupling the rod to a bone anchoring element, a bone anchoring device with such a receiving part, a method and a tool for assembling the bone anchoring device. The receiving part includes a receiving part body and a locking ring. The locking ring can assume a first position in which it is latched with respect to the receiving part body and in which a head of the bone anchoring element can be inserted, and a second position in which it is latched with ...

AI Technical Summary

Benefits of technology

[0008]It is the object of the invention to provide an improved receiving part for receiving a rod for coupling the rod to a bone anchoring element, a bone anchoring device with such a receiving part which provides for safer handling during surgery and which allows for selection of an appropriate bone anchoring element to assemble with the receiving part. Further objectives are to provide a method for assembling the bone anchoring device which can be easily carried out, and to provide a tool for assembly of the bone anchoring device.

[0009]The receiving part according to an exemplary embodiment of the invention allows the insertion of the head of the bone anchoring element into the receiving part body when the locking ring is in a first position which is an insertion position. In this position, the locking ring is latched with respect to the receiving part body. Therefore, the locking ring cannot be inadvertently moved to compress the head receiving portion of the receiving part body, in order to facilitate the insertion of the head.

[0010]In a second position, which is a pre-locking position, the locking ring is latched with respect to the receiving part body and the head receiving portion is compressed so that the bone anchoring element is held in an adjustable angular position but is not fully locked. This prevents inadvertent removal of the anchoring element and holds the receiving part body in an adjustable angular position with respect to the head of the bone anchoring element. Therefore, safe and convenient handling of the bone anchoring device during surgery can be assured.

[0013]With the bone anchoring device according to embodiments of the invention, a modular system can be provided, which allows combinations of various anchoring elements with any suitable receiving part on demand, depending on the actual clinical requirements. This reduces costs associated with polyaxial screws, reduces inventory, and gives the surgeon a wide choice of implants.

[0015]The tool is easy to handle and enables safer assembly.

Problems solved by technology

If a head of an anchoring element is freely pivotable with respect to a receiving part, alignment of the receiving part and insertion of a rod may be difficult in more complex clinical applications, for example, when multiple bone anchors are to be connected to the rod.

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