# US 12,594,104 B2 · Screw implants for bone fusion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,594,104 B2 - Document ID: US12594104B2 - Status: Granted - Kind: B2 - Application number: 18/774,014 - Filed: 2024-07-16 - Published: 2024-11-07 - Granted: 2026-04-07 - Earliest claimed: 2011-07-15 - Assignees: Globus Medical, Inc. - Applicants: Globus Medical, Inc. - Inventors: Liana Mari - Web page: https://patentgrep.com/patent/US12594104B2 ## CPC - A61B 17/8685: {comprising multiple separate parts} - A61B 17/7055: {connected to sacrum, pelvis or skull} - A61B 17/863: {with thread interrupted or changing its form along shank, other than constant taper} - A61B 17/864: {hollow, e.g. with socket or cannulated} - A61B 17/8695: {Washers (surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028)} - A61B 17/866: {Material or manufacture} - A61F 2002/30995: {for sacro-iliac joints} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract Systems, apparatuses and methods for bone fusion are disclosed. In particular, a fixation screw assembly is provided that comprises a bone engagement portion including a shaft and a head member. The assembly also includes a flexible washer member that can be operably attached and secured around the head member of the bone engagement portion. The washer member is polyaxial relative to the bone engagement portion, such that it can assume a variety of angles. The washer member can help prevent back out of the bone engagement portion when the bone engagement portion is implanted into a bone member. The design of the fixation screw assembly can be used in different fusion procedures, including fusion of the sacroiliac joint. ## Claims ### Claim 1 A fixation screw assembly comprising: a bone screw including a head and a shank to define a longitudinal axis of the bone screw, the head defining an equator plane, and the shank including a first window and a second window; and a washer disposed around the bone screw head, wherein the washer comprises a plurality of vertical slits that provide flexibility to the washer and is configured for polyaxial movement around the head relative to the longitudinal axis of the bone screw, wherein the bone screw is monolithically formed, the plurality of vertical slits accommodate expansion of the washer around the bone screw head, and the head of the bone screw includes a groove at a proximal-most end of the head and the washer includes a lip at a proximal-most end of the washer such that, when the washer is sufficiently angled relative to the longitudinal axis of the bone screw, the lip of the washer bottoms out on the groove of the head. ### Claim 2 The fixation screw assembly 1, wherein the washer includes a plurality of teeth configured to directly engage the bone. ### Claim 3 (depends on 2) The fixation screw assembly of claim 2, wherein the teeth are tapered inward to allow the teeth to recess into the bone. ### Claim 4 (depends on 1) The fixation screw assembly of claim 1, wherein the first and second windows are disposed circumferentially perpendicular to one another. ### Claim 5 (depends on 1) The fixation screw assembly of claim 1, wherein the shank shaft includes a third window offset 90 degrees relative to the first window. ### Claim 6 (depends on 1) The fixation screw assembly of claim 1, wherein the bone screw is cannulated and has a cannulated opening at a proximal end of the shank, and the first and second windows are each in fluid communication with the cannulated opening. ### Claim 7 (depends on 6) The fixation screw assembly of claim 6, wherein the bone screw includes a dual inner diameter including a first portion with shallow threads and a second portion with deep threads. ### Claim 8 (depends on 1) The fixation screw assembly of claim 1, wherein the bone screw is a 3D printed bone screw. ### Claim 9 (depends on 1) The fixation screw assembly of claim 1, wherein the washer is configured to be angled, rotated or swiveled in multiple directions. ### Claim 10 (depends on 1) The fixation screw assembly of claim 1, wherein the bone screw includes a dual inner diameter including a first portion with shallow threads and a second portion with deep threads. ### Claim 11 A fixation screw assembly comprising: a bone screw including a head and a shank, the head defining an equator plane, the shank including a first window and a second window, wherein the shank includes a dual inner diameter including a first portion with shallow threads and a second portion with deep threads; and a washer disposed around the head of the bone screw, wherein the washer comprises a plurality of vertical slits that provide flexibility to the washer and is configured for polyaxial movement relative to the bone screw, and at least a portion of the washer is positioned below the equator plane at any polyaxial angle of the washer, wherein the bone screw is monolithically formed, the plurality of vertical slits accommodate expansion of the washer around the bone screw head, and the head of the bone screw includes a groove at a proximal-most end of the head and the washer includes a lip at a proximal-most end of the washer such that, when the washer is sufficiently angled relative to the longitudinal axis of the bone screw, the lip of the washer bottoms out on the groove of the head. ### Claim 12 (depends on 11) The fixation screw assembly of claim 11, wherein the bone screw is cannulated with an opening extending from a proximal portion to a distal portion of the bone screw. ### Claim 13 (depends on 11) The fixation screw assembly of claim 11, wherein the shank includes a third biomaterial window circumferentially offset 90 degrees relative to the second window and overlaps the second window longitudinally. ### Claim 14 (depends on 13) The fixation screw assembly of claim 13, wherein the bone screw is cannulated and has a cannulated opening at a proximal end of the shank, and the first, second and third windows are each in fluid communication with the cannulated opening. ### Claim 15 (depends on 11) The fixation screw assembly of claim 11, wherein the bone screw is a 3D printed bone screw. ### Claim 16 (depends on 11) The fixation screw assembly of claim 11, wherein the washer is configured to be angled, rotated or swiveled in multiple directions. ### Claim 17 (depends on 11) The fixation screw assembly of claim 11, wherein the washer includes one or more engagement surfaces configured to engage the bone. ### Claim 18 (depends on 17) The fixation screw assembly of claim 17, wherein the engagement surfaces are teeth that are tapered inward to allow the teeth to recess into bone.