INSTRUMENT FOR USE WITH A POLYAXIAL BONE ANCHORING DEVICE AND SYSTEM INCLUDING THE INSTRUMENT AND A POLYAXIAL BONE ANCHORING DEVICE

摘要

An Instrument for use with a polyaxial bone anchoring device is provided, where the polyaxial bone anchoring device includes a receiving part for receiving a rod and for accommodating a head of a bone anchoring element. The head can be clamped by exerting a pressure force onto it via a clamping element and the pressure force can be adjusted using the instrument. The instrument includes a first member having a first engagement portion configured to engage the receiving part in a positive-fit manner. The instrument also includes a second member having a front end and a second engagement portion configured to engage the clamping element and apply torque to the clamping element. In a first configuration, the second member is axially displaceable along a longitudinal axis relative to the first member and is restricted from rotational movement. In a second configuration, the second member is rotatable with respect to the first member.

主权项

1. An instrument for use with a polyaxial bone anchoring device, wherein the polyaxial bone anchoring device includes a receiving part for receiving a rod and for accommodating a head of a bone anchoring element, wherein the head can be clamped by exerting pressure onto it via a clamping element and wherein the pressure can be adjusted using the instrument, the instrument comprising:
a first member comprising a longitudinal axis and a front end having a rigid engagement portion configured to engage the receiving part; a second member having a front end configured to engage the clamping element and apply torque to the clamping element when the second member is positioned in the first member; wherein when the second member is positioned in the first member, the second member is movable from a first configuration where the second member is axially displaceable along the longitudinal axis toward the front end of the first member and is restricted from rotational movement relative to the first member, to a second configuration where the second member is rotatable with respect to the first member.