Joint fusion implant and methods

Patent metadata

Field	Value
Publication number	US-11129649-B2
Application number	US-201916528591-A
Country	US
Kind code	B2
Filing date	Jul 31, 2019
Priority date	Apr 25, 2016
Publication date	Sep 28, 2021
Grant date	Sep 28, 2021

Abstract

An implant for fusing a joint between first and second bone portions. The implant includes a screw member, and a washer polyaxially rotatable relative to the screw member. The screw member includes a head, a lag zone, and a threaded engagement zone. The implant includes a fusion zone for joint compression, extending from the washer to the proximal end of the engagement zone. Fenestrations may be present in the fusion zone. The length of the fusion zone ranges from about 10 mm to about 37 mm. Different surface finishes including roughened and non-roughened may be applied selectively to selected portions of the implant. In an embodiment, the joint is a sacro-iliac joint, and upon implantation the implant extends from the exterior of the ilium, across the joint and into the sacral vertebral body. Instrumentation and methods for preparing the joint and implanting the implant are disclosed.

First claim

The invention claimed is:

1. A method for compressing a joint between a first bone portion and a second bone portion, wherein a cavity is located within the joint between the first bone portion and the second bone portion, the method comprising:
undercutting the cavity with a cutter;
positioning an implant proximate the joint, the implant comprising:
a screw member having a screw head and a screw body projecting distally from the screw head along a longitudinal axis to a screw distal end, the screw body comprising a threaded engagement zone and a non-threaded lag zone comprising an opening into a central longitudinal bore; and
a washer member having a proximal side and a distal side;
wherein the implant further comprises a fusion zone having a length extending from the distal side of the washer member to a proximal end of the threaded engagement zone;

inserting bone graft material into the central longitudinal bore;
inserting the threaded engagement zone through the first bone portion and into the cavity;
engaging the threaded engagement zone with the second bone portion;
positioning at least a portion of the non-threaded lag zone within the cavity such that the opening is in the cavity to allow the bone graft material to move from the central longitudinal bore into the cavity;
rotating the screw member to compress the joint; and
angling the washer member with respect to the screw member to permit maximum surface contact of the distal side of the washer member with the first bone portion.

2. The method of claim 1 , wherein the non-threaded lag zone comprises a fenestration on which the opening is formed.

3. The method of claim 1 , wherein:
the proximal side of the washer member comprises a semispherical capsule; and
the screw head is received in the semispherical capsule.

4. The method of claim 1 , wherein the washer member comprises a bore having a central bore axis; wherein angling the washer member with respect to the screw member comprises angling the washer member central bore axis with respect to the screw member longitudinal axis within the range of at least −8 degrees to at least +8 degrees.

5. The method of claim 1 , wherein the implant is a sacro-ilial fusion implant and the joint is a sacro-iliac joint, and wherein the first bone portion is an ilium, and the second bone portion is a sacrum, and the cavity is located between the ilium and the sacrum.

6. The method of claim 1 ,
wherein the cutter consists essentially of a single blade.

7. The method of claim 1 ,
wherein the length of the implant fusion zone ranges from about 10 mm to about 37 mm.

8. A method for compressing a joint between a first bone portion and a second bone portion, wherein a cavity is located within the joint between the first bone portion and the second bone portion, the method comprising:
undercutting the cavity with a cutter;
positioning an implant proximate the joint, the implant comprising:
a screw member having a screw head and a screw body projecting distally from the screw head along a longitudinal axis to a screw distal end, the screw body comprising a non-threaded lag zone and a threaded engagement zone; and
a washer member having a distal side and a proximal side with a recess, wherein the screw head is received in the recess of the washer member;
wherein the implant further comprises a fusion zone having a length extending from the distal side of the washer member to a proximal end of the threaded engagement zone;

inserting the threaded engagement zone through the first bone portion and into the cavity;
engaging the threaded engagement zone with the second bone portion;
positioning at least a portion of the non-threaded lag zone within the cavity;
rotating the screw member to compress the joint; and
angling the washer member with respect to the screw member to permit maximum surface contact of the distal side of the washer member with the first bone portion.

9. The method of claim 8 , wherein:
the non-threaded lag zone comprises an opening into a central longitudinal bore;
the method further comprises inserting bone graft material into the central longitudinal bore; and
positioning at least a portion of the non-threaded lag zone within the cavity comprises positioning the opening in the cavity to allow the bone graft material to move from the central longitudinal bore into the cavity.

10. The method of claim 8 , wherein:
the recess comprises a semispherical capsule; and
the screw head has a semispherical shape complementary to the semispherical capsule.

11. The method of claim 8 , wherein the washer member comprises a bore having a central bore axis; wherein angling the washer member with respect to the screw member comprises angling the washer member central bore axis with respect to the screw member longitudinal axis within the range of at least −8 degrees to at least +8 degrees.

12. The method of claim 8 , wherein the implant is a sacro-ilial fusion implant and the joint is a sacro-iliac joint, and wherein the first bone portion is an ilium, and the second bone portion is a sacrum, and the cavity is located between the ilium and the sacrum.

13. The method of claim 8 , wherein the cutter consists essentially of a single blade.

14. The method of claim 8 , wherein the length of the implant fusion zone ranges from about 10 mm to about 37 mm.

15. A method for compressing a joint between a first bone portion and a second bone portion, wherein a cavity is located within the joint between the first bone portion and the second bone portion, the method comprising:
undercutting the cavity with a cutter consisting essentially of a single blade;
positioning an implant proximate the joint, the implant comprising:
a screw member having a screw head and a screw body projecting distally from the screw head along a longitudinal axis to a screw distal end, the screw body comprising a non-threaded lag zone and a threaded engagement zone; and
a washer member having a proximal side and a distal side, wherein the screw head is received in the washer member;
wherein the implant further comprises a fusion zone having a length extending from the distal side of the washer member to a proximal end of the threaded engagement zone;

inserting the threaded engagement zone through the first bone portion and into the cavity;
engaging the threaded engagement zone with the second bone portion;
positioning at least a portion of the non-threaded lag zone within the cavity;
rotating the screw member to compress the joint; and
angling the washer member with respect to the screw member to permit maximum surface contact of the distal side of the washer member with the first bone portion.

16. The method of claim 15 , wherein:
the non-threaded lag zone comprises an opening into a central longitudinal bore;
the method further comprises inserting bone graft material into the central longitudinal bore; and

positioning at least a portion of the non-threaded lag zone within the cavity comprises positioning the opening in the cavity to allow the bone graft material to move from the central longitudinal bore into the cavity.

17. The method of claim 15 , wherein:
the proximal side of the washer member comprises a semispherical capsule; and
the screw head has a semispherical shape complementary to the semispherical capsule.

18. The method of claim 1 , wherein the washer member comprises a bore having a central bore axis; wherein angling the washer member with respect to the screw member comprises angling the washer member central bore a

Assignees

• Imds Llc
• Mayo Found Medical Education & Res

Inventors

• Schumacher Brian Scott
• Slater Nicholas
• Cross Iii William W

Classifications

• A61B17/8625 Primary

  Shanks, i.e. parts contacting bone tissue · CPC title

• A61B2017/0046

  with a releasable handle; with handle and operating part separable · CPC title

• A61B17/1617

  with mobile or detachable parts · CPC title

• A61B17/1671

  for the spine · CPC title

• A61B17/7055 Primary

  connected to sacrum, pelvis or skull · CPC title