# US 12,178,486 B2 · Transdiscal screw > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,178,486 B2 - Document ID: US12178486B2 - Status: Granted - Kind: B2 - Application number: 17/712,781 - Filed: 2022-04-04 - Published: 2022-11-24 - Granted: 2024-12-31 - Earliest claimed: 2013-12-17 - Assignees: H. Lee Moffitt Cancer Center and Research Institute, Inc. - Applicants: H. Lee Moffitt Cancer Center and Research Institute, Inc. - Inventors: Sabrina A. Gonzalez Blohm; James J. Doulgeris; Kamran Aghayev; Frank D. Vrionis - Web page: https://patentgrep.com/patent/US12178486B2 ## CPC - A61B 17/8685: {comprising multiple separate parts} - A61B 17/70: Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant - A61B 17/864: {hollow, e.g. with socket or cannulated} - A61B 17/7037: {wherein pivoting is blocked when the rod is clamped} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract This invention relates to a transdiscal screw capable of following a non-linear trajectory. The screw assembly includes a first screw and second screw coupled at a poly-axial joint. The first screw and the second screw capable of rotating independently of each other. The screw can also include a third screw coupled to the second screw at a poly-axial joint such that the first screw, second screw and third screw can rotate independently of each other. ## Claims ### Claim 1 A screw assembly for transdiscal fixation of vertebral bodies including: a first screw; a second screw defining a central passage; and a poly-axial joint at least partially coupling the second screw to the first screw, the poly-axial joint at least partially disposed within the central passage of the second screw; wherein the first screw and the second screw rotate independently of each other; wherein the second screw is configured to advance axially over at least a portion of the poly-axial joint to fix an orientation of the first screw with respect to the second screw in at least one direction. ### Claim 2 (depends on 1) The screw assembly of claim 1, wherein the poly-axial joint comprises a base and an articulated coupling, and wherein the portion of the poly-axial joint is the base. ### Claim 3 (depends on 2) The screw assembly of claim 2, wherein the base defines a connector sized and configured to receive a corresponding driver. ### Claim 4 (depends on 1) The screw assembly of claim 1, wherein the second screw comprises a connector sized and configured to receive a corresponding driver, the connector disposed at a proximal end of the second screw. ### Claim 5 (depends on 1) The screw assembly of claim 1, wherein the first screw defines a first outer diameter and the second screw defines a second outer diameter. ### Claim 6 (depends on 5) The screw assembly of claim 5, wherein the first outer diameter is equal to the second outer diameter. ### Claim 7 (depends on 5) The screw assembly of claim 5, wherein the first outer diameter is less than the second outer diameter. ### Claim 8 (depends on 2) The screw assembly of claim 2, wherein the articulated coupling is a universal joint. ### Claim 9 (depends on 1) The screw assembly of claim 1, wherein an external thread of the first screw has a pitch less than a pitch of an external thread of the second screw. ### Claim 10 (depends on 1) The screw assembly of claim 1, wherein the first screw includes a central passage sized and configured to receive a guide wire. ### Claim 11 (depends on 2) The screw assembly of claim 2, further comprising a casing disposed within the central passage of the second screw, the casing defining a set of external threads that engage with a corresponding set of internal threads in the central passage of the second screw such that rotational movement of the casing with respect to the central passage of the second screw translates into axial movement of the casing within the central passage and a corresponding axial movement of the first screw with relative to the second screw. ### Claim 12 (depends on 11) The screw assembly of claim 11, wherein the casing defines a cavity sized and configured for receiving the base of the poly-axial joint. ### Claim 13 (depends on 11) The screw assembly of claim 11, wherein, as the casing is moved axially in a proximal direction, a proximal end of the first screw is translated towards a proximal end of the second screw. ### Claim 14 (depends on 12) The screw assembly of claim 12, wherein a distal end of the cavity comprises a protrusion extending radially towards a longitudinal axis of the casing, where interference between the protrusion and an outer surface of the base limits distal axial motion of the base. ### Claim 15 (depends on 14) The screw assembly of claim 14, wherein the casing is moveable axially between a first condition wherein the base of the poly-axial joint is free to rotate and move axially within the cavity and a second condition wherein at least one degree of axial motion or rotation of the base of the poly-axial joint is constrained. ### Claim 16 (depends on 12) The screw assembly of claim 12, wherein a proximal end of the cavity comprises an opening, the opening having a diameter less than a diameter of the cavity, wherein the opening defines a central passage extending through a proximal end of the casing. ### Claim 17 (depends on 16) The screw assembly of claim 16, further comprising a lock sized and configured to be received within the central passage of the casing, wherein the lock is movable axially in the central passage in a distal direction such that, when a distal end of the lock engages the base of the poly-axial joint, axial movement of the base of the poly-axial joint in a proximal direction is restricted. ### Claim 18 (depends on 17) The screw assembly of claim 17, wherein a proximal portion of the lock comprises external threads that engage with the internal threads in the central passage of the second screw.