Low Friction Rod Persuader

An instrument for reducing a spinal rod comprising:

• An elongate clamp member for receiving a coupling member of a spinal fixation system, the clamp member comprising a hollow, generally cylindrical first end and a second end comprising a plurality of clamping arms, the generally cylindrical first end having at least one elongate slit disposed therein;
• a drive member rotatably disposed in the generally cylindrical first end of the clamp member, the drive member including a helical groove about its exterior;
• at least one rolling element partially disposed in the helical groove of the drive member and partially disposed within the elongate slit of the clamp member;
• an elongate reducer sleeve disposed about the clamp member and configured to be linearly shifted with respect to the clamp member, the reducer member including at least one opening sized and configured to receive the rolling element;
• and
• a one-way locking mechanism comprising:
• an annular array of ratchet teeth coupled to the exterior of the drive member;
• a ratchet pawl disposed adjacent to the ratchet teeth;
• and
• a ratchet control member that holds the ratchet pawl against the ratchet teeth when shifted to a first position and allows the ratchet pawl to shift away from the ratchet teeth when the control member is shifted to a second position;
• wherein rotation of the drive member causes linear shifting of the reducer sleeve due to the interaction between the helical groove, the rolling element, and the reducer sleeve;
• and wherein the one-way locking mechanism allows rotation of the drive member in two directions when the control member is in the first position but allows rotation of the drive member in only one direction when the control member is in the second position.