Patent attributes
A receiving part of a polyaxial bone anchoring device includes a first member with a top end and a bottom end, a central axis, a head receiving portion having an inner wall defining a passage at the bottom end for introducing a head of a bone anchoring element, and a channel at the top end for receiving a rod, a second member having a bore and being connectable to the first member at the bottom end of the first member; and at least one clamping member configured to be positioned at or near the bottom end of the first member and to protrude into the passage. The second member is movable relative to the first member from a first position wherein the clamping member is movable radially, to a second position wherein the clamping member is prevented from moving, to hold a head of a bone anchoring element therein.