Arthroscopic devices and methods

Patent metadata

Field	Value
Publication number	US-10028767-B2
Application number	US-201615271187-A
Country	US
Kind code	B2
Filing date	Sep 20, 2016
Priority date	Sep 20, 2016
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

An arthroscopic or other surgical cutter has features which facilitate fabrication by ceramic molding. The arthroscopic cutter includes a cutter body having a longitudinal axis and a window, an interior channel, and a plurality of cutting edges extending radially outwardly from an outer surface thereof. The features include non-helical, longitudinally aligned cutting edges, controlled thicknesses of the cutting edges, controlled heights of the cutting edges, controlled areas of the windows, controlled diameters of the internal channels, controlled rake angles of the cutting edges, and other parameters.

First claim

What is claimed is:

1. An arthroscopic cutter, comprising:
a ceramic cutter body having a longitudinal axis and a plurality of cutting edges separated by flutes on an outer surface thereof;
wherein each cutting edge has a cutting face with a radial cutting face height measured from an innermost peripheral location on a flute to an outermost peripheral location on an adjacent cutting face and a cutting edge thickness measured along a tangent to a midpoint of the cutting face to the adjacent flute;
wherein each cutting edge has an outer edge diameter measured from the longitudinal axis of the ceramic cutter body to an outer periphery of the cutting edge and a land with a constant diameter equal to the outer cutting edge diameter, wherein said constant diameter of the land extends over a radial angle of 15° behind the cutting edge; and
wherein the ratio of the cutting edge thickness to the cutting face height is at least 1.5:1.

2. The arthroscopic cutter of claim 1 wherein the ratio of the cutting edge thickness to the cutting face height is at least 2:1.

3. The arthroscopic cutter of claim 1 wherein each cutting edge is non-helical and aligned with the longitudinal axis.

4. The arthroscopic cutter of claim 1 wherein least some of the cutting edges have a linear cutting edge.

5. The arthroscopic cutter of claim 1 wherein at least some of the cutting edges have a substantially flat cutting face.

6. The arthroscopic cutter of claim 1 wherein the cutter body has an outer diameter through the longitudinal axis at the outermost periphery of the cutting edges wherein a ratio of the cutting face height to the outer diameter of the cutter body is 0.2:1 or less.

7. The arthroscopic cutter of claim 6 wherein a ratio of the cutting face height to the outer diameter of the cutter body is 0.1:1 or less.

8. The arthroscopic cutter of claim 1 wherein each cutting face has a radial rake angle ranging between −5° and +10°.

9. The arthroscopic cutter of claim 1 wherein the cutter body has an interior channel and a window with a width and length, the window being open to the interior channel therein and configured to communicate with a passageway in a shaft that carries the cutter body, wherein the ratio of window width to the cutting face height is at least 5:1.

10. The arthroscopic cutter of claim 9 wherein each cutting face has a surface area and the window has an area that is open to the interior channel; and
wherein the ratio of window area to the cutting face surface area is at least 8:1.

11. The arthroscopic cutter of claim 9 wherein the interior channel has a diameter and is configured to communicate with the passageway in the shaft; and
wherein the ratio of the interior channel diameter to the cutting face height is at least 2:1.

12. The arthroscopic cutter of claim 11 wherein the ratio of the interior channel diameter to the cutting face height is at least 4:1.

13. The arthroscopic cutter of claim 11 wherein the ratio of the interior channel diameter to the cutting face height is at least 6:1.

14. The arthroscopic cutter of claim 9 wherein the cutter body has a distal portion comprising the cutting edges and a proximal shaft portion having the window; and
wherein the window has lateral edges with a non-zero positive radial rake angle.

15. The arthroscopic cutter of claim 14 wherein said lateral edges have a radial rake angle ranging from 15° to 45°.

16. The arthroscopic cutter of claim 14 wherein a distal end of the window is axially spaced apart from a proximal end of the cutting edges by less than 0.10 inch.

17. The arthroscopic cutter of claim 14 wherein a distal end of the window is axially spaced apart from a proximal end of the cutting edges by less than 0.05 inch.

18. An arthroscopic cutter configured to be fabricated by ceramic molding, said arthroscopic cutter comprising:
a cutter body having a longitudinal axis and a plurality of cutting edges separated by flutes, the cutting edges extending radially outwardly from an outer surface thereof;
wherein the cutter body is formed from a wear-resistant ceramic material;
wherein each cutting edge has an outer edge diameter measured from the longitudinal axis of the ceramic cutter body to an outer periphery of the cutting edge and a land with a constant diameter equal to of the outer cutting edge diameter, wherein said constant diameter of said land extends over a radial angle of 15° behind the cutting edge; and
wherein each cutting edge is non-helical and aligned with the longitudinal axis to facilitate ceramic injection molding of the cutter body.

19. The arthroscopic cutter of claim 18 wherein each cutting edge has a cutting face with a radial cutting face height measured from an innermost peripheral location on a flute to an outermost peripheral location on an adjacent cutting face and a cutting edge thickness measured along a tangent to a midpoint of the cutting face to the adjacent flute; and
wherein the ratio of the cutting edge thickness to the cutting face height is at least 1.5:1.

20. The arthroscopic cutter of claim 19 wherein the ratio of the cutting edge thickness to the cutting face height is at least 2:1.

21. The arthroscopic cutter of claim 19 wherein the cutter body has a distal portion comprising the cutting edges and a proximal shaft portion having a window open to the interior channel therein; and
wherein the window has lateral edges with a non-zero positive radial rake angle.

22. The arthroscopic cutter of claim 21 wherein said lateral edges have a radial rake angle ranging from 15° to 45°.

23. The arthroscopic cutter of claim 21 wherein the window and interior channel are configured to communicate with a passageway in a shaft that carries the cutter body, wherein the ratio of the window width to the cutting face height is at least 5:1.

24. The arthroscopic cutter of claim 21 wherein each cutting face has a surface area and the window has an area that is open to the interior channel; and
wherein the ratio of window area to the cutting face surface area is at least 8:1.

25. The arthroscopic cutter of claim 21 wherein the interior channel has a diameter and is configured to communicate with the passageway in the shaft; and
wherein the ratio of the interior channel diameter to the cutting face height is at least 2:1.

26. The arthroscopic cutter of claim 21 wherein the ratio of the interior channel diameter to the cutting face height is at least 4:1.

Assignees

• Relign Corp

Inventors

• Germain Aaron
• Klein Kyle
• Echeverry Jan

Classifications

• A61B17/32002 Primary

  with continuously rotating, oscillating or reciprocating cutting instruments · CPC title

• A61B2017/00526

  Methods of manufacturing · CPC title

• A61B2217/005

  with suction drainage system · CPC title

• A61B17/320758 Primary

  with a rotating cutting instrument, e.g. motor driven (A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002) · CPC title

• A61B2017/00836

  corrosion-resistant (A61B2017/00853 takes precedence; preventing galvanic or electrolytic corrosion in prostheses A61F2210/0009) · CPC title