# US 2019/0167318 A1 · Apparatus and methods for reduction of vertebral bodies in a spine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167318 A1 - Document ID: US20190167318A1 - Status: Published application - Kind: A1 - Application number: 16/269,132 - Filed: 2019-02-06 - Published: 2019-06-06 - Earliest claimed: 2006-12-07 - Assignees: Zimmer Spine, Inc. - Applicants: Zimmer Spine, Inc. - Inventors: Matthew E. Seelig - Web page: https://patentgrep.com/patent/US20190167318A1 ## CPC - A61B 17/7086: {Rod reducers, i.e. devices providing a mechanical advantage to allow a user to force a rod into or onto an anchor head other than by means of a rod-to-bone anchor locking element; rod removers} - A61B 17/8866: {for gripping or pushing bones, e.g. approximators (joint distractors A61B17/025)} - A61B 17/7032: {Screws or hooks with U-shaped head or back through which longitudinal rods pass} - A61B 2090/037: {with a frangible part, e.g. by reduced diameter} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A system for reduction of vertebral bodies (or vertebrae) various embodiments includes a reducer, and extender, and a hollow tube. The reducer couples to the extender, which in turn couples to an elongated member, such as a rod, and to a bone fastener assembly. The reducer allows reduction of the vertebral body incrementally, and by a desired amount. The reducer may include or may be used in conjunction with a holding device or holder in order to hold or keep the amount of reduction constant or steady once the desired amount of reduction has been obtained. The reducer may use one of several embodiments, including embodiments that use threaded assemblies or members, inclining members or wedges, offset cams, scissor jacks, and/or levers. ## Claims ### Claim 1 A rod reducing apparatus, comprising: a screw assembly comprising: a threaded shaft with a controlling member at a proximal end thereof; and a threaded body engaged with the threaded shaft; a rod contacting member engaged at a distal end of the threaded body; and a grasping element having a distal end, a proximal end and a longitudinal axis extending therebetween, the distal end configured to grasp and detachably couple to a bone fastener and the proximal end connected to the threaded shaft of the screw assembly; wherein the rod contacting member defines a passage configured to slidably receive the grasping element; and wherein rotation of the threaded shaft slides the rod contacting member along the longitudinal axis. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein turning the controlling member causes the rod contacting member and the grasping element to move relative to each other in opposite directions. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the controlling member is a knob. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein: turning the knob in a first direction causes the rod contacting member to extend; and turning the knob in a second direction opposite the first direction causes the rod contacting member to retract. ### Claim 5 (canceled) ### Claim 6 (depends on 1) The apparatus of claim 1, further comprising at least a first locking member coupled to the threaded shaft of the screw assembly and configured to selectively engage the grasping element. ### Claim 7 (depends on 6) The apparatus of claim 6, further comprising a second locking member coupled to the threaded shaft of the screw assembly and configured to selectively engage the grasping element, wherein the first and second locking members are disposed on opposing sides of the screw assembly. ### Claim 8 (canceled) ### Claim 9 A spinal reduction assembly comprising: a bone fastener configured to be coupled to a vertebral body; a collar configured to be coupled to the bone fastener, the collar including a slot for seating a rod; and a reducer configured to be coupled to the collar to seat the rod in the slot, the reducer comprising: a screw assembly comprising: a threaded shaft with a controlling member at a proximal end thereof; and a threaded body engaged with the threaded shaft; a rod contacting member engaged at a distal end of the threaded body; and a grasping element having a distal end, a proximal end and a longitudinal axis extending therebetween, the distal end configured to grasp and detachably couple to the collar and the proximal end connected to the threaded shaft of the screw assembly; wherein the rod contacting member defines a passage configured to slidably receive the grasping element; and wherein rotation of the threaded shaft slides the rod contacting member along the longitudinal axis. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein turning the controlling member causes the rod contacting member and the grasping element to move relative to each other in opposite directions. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the controlling member is a knob located at a proximal end of the reducer, wherein: turning the knob in a first direction causes the rod contacting member to extend; and turning the knob in a second direction opposite the first direction causes the rod contacting member to retract. ### Claim 12 (canceled) ### Claim 13 (canceled) ### Claim 14 (depends on 9) The apparatus of claim 9, further comprising at least a first spring-biased locking member coupled to the screw assembly and configured to selectively engage the grasping element. ### Claim 15 (depends on 14) The apparatus of claim 14, further comprising a second spring-biased locking member coupled to the screw assembly and configured to selectively engage the grasping element, wherein the first and second spring-biased locking members are disposed on opposing sides of the screw assembly. ### Claim 16 (canceled) ### Claim 17 (canceled) ### Claim 18 (depends on 6) The apparatus of claim 6, wherein: the grasping element comprises an outer channel; and the first locking member comprises a tab that is resiliently biased into the outer channel. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein the first locking member can be displaced via a button to overcome the resilient bias and linearly push the tab directly out of the channel to unlock the threaded shaft from the grasping member. ### Claim 20 (depends on 18) The apparatus of claim 18, wherein the first locking member can be displaced via a lever to overcome the resilient bias and rotate the tab out of the channel to unlock the threaded shaft from the grasping member. ### Claim 21 (depends on 18) The apparatus of claim 18, wherein the threaded shaft comprises a pocket to retain the first locking member and prevent axial displacement of the first locking member. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the first locking member is rotatable within the pocket. ### Claim 23 (depends on 14) The apparatus of claim 14, wherein the locking member comprises a button having a tab resiliently biased into the grasping element, wherein pushing of the button moves the tab out of engagement with the grasping element. ### Claim 24 A rod reducer apparatus comprising: a resiliently-biased attachment mechanism configured to selectively couple to an extender positioned within the resiliently-biased attachment mechanism; a rod-contacting tube configured to be positioned coaxially with the extender; and a reducing mechanism comprising: a knob located at a proximal end of the rod reducer apparatus and coupled to the resiliently-biased attachment mechanism; and a body threadedly engaged with the knob and engaged with the rod-contacting tube. ### Claim 25 (depends on 24) The rod reducer apparatus of claim 24, further comprising: a shaft extending downward from the knob, the shaft comprising: an outer surface having external threading; and an internal surface; internal threading located on the body to engage with the external threading; a locking member adjustably extending from the resiliently-biased attachment mechanism; and a spring to bias the locking member away from the internal surface and toward the extender when the extender is positioned within the resiliently-biased attachment mechanism. ### Claim 26 (depends on 25) The rod reducer apparatus of claim 25, wherein the locking member comprises: a button slidably coupled to a housing of the resiliently-biased attachment mechanism; and a tab extending from the button and configured to engage the extender when the extender is positioned within the resiliently-biased attachment mechanism; wherein the spring biases the button such that the tab is biased into engagement with the extender when the extender is positioned within the resiliently-biased attachment mechanism. ### Claim 27 (depends on 25) The rod reducer apparatus of claim 25, wherein the locking member comprises: a first locking handle pivotably coupled to a housing of the resiliently-biased attachment mechanism; and a first tab extending from the first locking handle and configured to engage the extender when the extender is positioned within the resiliently-biased attachment mechanism; and wherein the spring biases the first locking handle such that the first tab is biased into engagement with the extender when the extender is positioned within the resiliently-biased attachment mechanism.