Open-architecture interference screw

Patent metadata

Field	Value
Publication number	US-9808298-B2
Application number	US-201414249020-A
Country	US
Kind code	B2
Filing date	Apr 9, 2014
Priority date	Apr 9, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

The present disclosure relates to an interference screw for creating an interference fit between a bone tunnel and tissue. The screw includes a threaded body having a proximal end, distal end, and thread extending around the threaded body between the proximal and distal ends. A supporting spline extends along a cannulation through the threaded body. The supporting spline is engagable with a delivery device. The screw further includes at least one opening defined by a surface between threads of the threaded body. A ratio of open surface area to closed surface area defines the opening and is selected such that, when torsionally loaded, the screw does not exhibit plastic deformation when inserted into an undersized bone tunnel. The screw further includes a tapered tip extending from the distal end of the threaded body. The tapered tip has a thread extending at least partway around the tapered tip.

First claim

What is claimed is:

1. An open-architecture interference screw for creating an interference fit between a bone tunnel and tissue, the screw comprising:
a threaded body having a proximal end and a distal end, and a thread extending around the threaded body between the proximal end and distal end;
at least one supporting spline extending along a cannulation through the threaded body between the proximal end and distal end, the at least one supporting spline engagable with a delivery device;
at least one opening defined by an open surface between the thread, the at least one opening having a ratio of open surface area to closed surface area, the ratio being selected such that, when torsionally loaded, the screw does not exhibit plastic deformation when inserted into an undersized bone tunnel; and
a tapered tip extending from the distal end of the threaded body, the tapered tip having a thread extending at least partway around the tapered tip;
wherein a surface of the cannulation is tapered toward the distal end of the threaded body so as to form a positive seat with a corresponding tapered surface of the delivery device when the delivery device is engaged with the at least one supporting spline.

2. The open-architecture interference screw of claim 1 wherein the thread of the tapered tip extends at least one full turn around the tapered tip.

3. The open-architecture interference screw of claim 2 wherein the thread of the tapered tip is a continuation of the thread of the threaded body.

4. The open-architecture interference screw of claim 1 wherein the thread of the tapered tip is a partial thread extending less than one full turn around the tapered tip.

5. The open-architecture interference screw of claim 4 wherein the partial thread includes a first partial thread and a second partial thread, each extending a half turn around the tapered tip.

6. The open-architecture interference screw of claim 4 wherein the threaded body and tapered tip each have a different thread pitch.

7. The open-architecture interference screw of claim 6 wherein the thread pitch of the tapered tip is between 1.5 and 3 times greater than the thread pitch of the threaded body.

8. The open-architecture interference screw of claim 1 wherein the threaded body has a constant diameter.

9. The open-architecture interference screw of claim 1 wherein the threaded body has a wall thickness of 0.5-3.25 mm.

10. The open-architecture interference screw of claim 1 wherein the threaded body has a wall thickness that is a function of the diameter and length of the screw.

11. The open-architecture interference screw of claim 1 wherein the at least one supporting spline has a width of 1-2.5 mm.

12. The open-architecture interference screw of claim 1 wherein the thread has a base width of 0.76-2.54 mm.

13. The open-architecture interference screw of claim 1 wherein the ratio of open surface area to closed surface area is a function of the diameter and length of the screw.

14. The open-architecture interference screw of claim 1 wherein the screw has a diameter of 11-12 mm and a length of 30-35 mm; and wherein the ratio is about one unit of open surface area to about three units of closed surface area.

15. The open-architecture interference screw of claim 1 wherein the screw has a diameter of 7-10 mm and a length of 20-35 mm; and wherein the ratio is about one unit of open surface area to about four units of closed surface area.

16. The open-architecture interference screw of claim 1 wherein the screw has a diameter of 5-6 mm and a length of 20-25 mm; and wherein the ratio is about one unit of open surface area to about five units of closed surface area.

17. The open-architecture interference screw of claim 1 wherein the at least one opening is defined by the open surface between adjacent proximal threads.

18. The open-architecture interference screw of claim 1 wherein the at least one opening includes at least one continuous opening between adjacent proximal threads; and at least one discontinuous opening between adjacent distal threads, the at least one discontinuous opening having alternating segments of open surface area and closed surface area.

19. The open-architecture interference screw of claim 1 wherein the at least one opening is defined by the open surface between alternating pairs of adjacent threads.

20. The open-architecture interface screw of claim 1 wherein the threaded body further includes a screw head comprising a surface extending from the threaded body into a hemispherical-like end portion.

21. The open-architecture interface screw of claim 1 wherein the screw is made from a combination of poly(lactic-co-glycolic) acid, β-Tricalcium phosphate, and calcium sulfate.

22. A delivery device and open-architecture interference screw combination for creating an interference fit between a bone tunnel and tissue, the combination comprising:
a delivery device comprising a handle and a shaft connected to the handle, the shaft including a distal portion having a driving member, a surface of the distal portion being tapered;
an interference screw comprising:
a threaded body having a proximal end and a distal end, and a thread extending around the threaded body between the proximal end and distal end;
at least one supporting spline extending along a cannulation through the threaded body between the proximal end and distal end, the supporting spline engagable with a delivery device;
at least one opening defined by an open surface between the thread, the at least one opening having a ratio of open surface area to closed surface area, the ratio being selected such that, when torsionally loaded, the screw does not exhibit plastic deformation when inserted into an undersized bone tunnel; and
a tapered tip extending from the distal end of the threaded body, the tapered tip having a thread extending at least partway around the tapered tip;

wherein the interference screw is located on the distal portion of the delivery device such that the driving member engages the at least one supporting spline of the interference screw; and
wherein a surface of the cannulation is tapered toward the distal end of the threaded body so as to form a positive seat with the tapered surface of the distal portion of the delivery device when the delivery device is engaged with the at least one supporting spline.

Assignees

• Smith & Nephew Inc

Inventors

• Stroncek John
• Berube Jr Alfred R
• Aarsvold Kirsten H

Classifications

• A61F2002/0841

  Longitudinal channel for insertion tool running through the whole tendon anchor, e.g. for accommodating bone drill, guidewire · CPC title

• A61F2002/0817

  Structure of the anchor · CPC title

• A61F2/0811

  Fixation devices for tendons or ligaments · CPC title

• A61B17/888

  the driver bit acting on the central region of the screw head · CPC title

• A61B17/869

  characterised by an open form, e.g. wire helix · CPC title