Suture anchor and installation tool

• US 5,217,486 A
• Filed: 02/18/1992
• Issued: 06/08/1993
• Est. Priority Date: 02/18/1992
• Status: Expired due to Term

• Current Assignee: Mitek Surgical Products, Inc. (Johnson & Johnson)
• Original Assignee: Mitek Surgical Products, Inc. (Johnson & Johnson)
• Inventors: Wenstrom, Richard F. Jr., Rice, John T.
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): Jackson, Gary
• Application Number:
  US07/837,061
• Time in Patent Office: 476 Days
• Field of Search: 606/220, 606/232, 606/72, 606/139, 606/144, 606/75, 606/78, 604/59
• US Class Current: 606/232
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 2017/0409 Instruments for applying suture anchors
• CPC Class Codes: A61B 2017/0412 having anchoring barbs or pins extending outwardly from suture anchor body
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening
• CPC Class Codes: A61B 2017/0437 the barbs being resilient or spring-like
• CPC Class Codes: A61B 2017/06142 having needle- or suture- retaining members, e.g. holding tabs or needle parks
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: Y10S 606/907 Composed of particular material or coated
• CPC Class Codes: Y10S 606/916 Tool for installing or removing orthopedic fastener

Abstract

A system for attaching an object to a workpiece including an anchor and an installation tool is provided. The anchor includes a body having a transverse cross-section slightly smaller than the transverse cross-section of a hole in a surface of the workpiece in which it is to be deployed, and at least two barbs. The body has a distal portion having an inner end, a proximal portion having an inner end, and a middle portion connecting the inner ends of the distal and proximal portions respectively. The barbs extend from the first end of the distal portion axially and radially outwardly to outer ends located radially outwardly of an axial projection of the maximum transverse cross-section of the distal portion. The barbs are located in channels having bases which extend parallel to the longitudinal axis of the body in the middle section and thereafter slant outwardly relative to the longitudinal axis of the body as they extend to the outer end of the proximal portion. Each barb is curved in its normal unstressed state, but is capable of being deformed into a substantially straight configuration. The anchor assembly is deployed by an installation tool which includes an elongated shaft having a distal end and a proximal end, tubular means associated with said distal end of said shaft adapted to receive and hold said middle and proximal portions of said anchor body, and plunger means adapted for engagement with said outer end of said proximal portion of said anchor body, said plunger means being axially movable through said tubular means so as to expell said anchor from said tubular means and to drive said anchor into said hole. A method of attaching an object to a workpiece utilizing such anchors and installation tools also is provided.

Claims

1. Apparatus for attaching an object to a workpiece comprising:

an anchor comprising a body and at least two barbs;

said body having a longitudinal axis, a maximum cross-section transverse to said longitudinal axis, a distal portion having an outer end and an inner end, a proximal portion having an outer end and an inner end, and a middle portion joining said inner end of said distal portion and said inner end of said proximal portion;

said middle portion and said proximal portion together defining at least two equally-circumferentially-spaced channels extending inwardly from an axial projection of said maximum transverse cross-section of said distal portion, said channels extending longitudinally from said inner end of said distal portion to said outer end of said proximal portion, each of said channels having a base which is substantially parallel to said longitudinal axis in said middle portion and which slants outwardly relative to said longitudinal axis as it extends from said inner end of said proximal portion to said outer end of said proximal portion, said channels being separated by longitudinal walls extending radially outwardly from said longitudinal axis to an outer surface located on said axial projection of said maximum transverse cross-section;

one of said barbs extending axially and radially outwardly from said inner end of said distal portion adjacent the base of each of said channels to an outer end located radially outwardly of said axial projection of said maximum transverse cross-section, each said barb being curved in its normal, unrestrained state but capable of being deformed into a substantially straight configuration; and

attachment means associated with said proximal portion for connecting an object to said anchor.

2. The apparatus of claim 1 wherein said barbs are made of nickel titanium alloy.

3. The apparatus of claim 1 wherein said distal portion of said body defines at least two bores extending longitudinally from said inner end of said distal portion toward said outer end of said distal portion, one bore adjacent said base of each of said channels, and wherein each of said barbs comprises a piece of wire having a first end and a second end, said first end of each said wire fixedly engaging one of said bores in said inner end of said distal portion.

4. The apparatus of claim 1 wherein there are two barbs, and further wherein said attachment means comprises an opening having a second longitudinal axis, said opening extending through said proximal portion and said second longitudinal axis being located in the plane containing said first longitudinal axis.

5. The apparatus of claim 4 wherein said attachment means further includes a cord-like connecting element threaded through said opening so as to securely engage said attachment means and provide at least one free end for attachment to said object.

6. The apparatus of claim 5 wherein said opening is formed in said proximal portion so as to provide a smoothly contoured bearing surface in said proximal portion against which said cord-like element may be slid after said anchor has been deployed in said hole.

7. The apparatus of claim 1 wherein there are three barbs and three channels.

8. The apparatus of claim 1 wherein said anchor is made of a titanium alloy material.

9. The apparatus of claim 1 wherein all of said cross-sections are substantially circular.

10. The apparatus of claim 1 wherein said workpiece is bone.

11. A system for attaching an object to a workpiece using a hole formed in the workpiece, said system comprising:

a) an anchor comprising a body and at least two barbs;

said body having a longitudinal axis, a maximum cross-section transverse to said longitudinal axis slightly smaller than the transverse cross-section of said hole, a distal portion having an outer end and an inner end, a proximal portion having an outer end and an inner end, and a middle portion joining said inner end of said distal portion and said inner end of said proximal portion;

said middle portion and said proximal portion together defining at least two equally-circumferentially-spaced channels extending inwardly from an axial projection of said maximum transverse cross-section of said distal portion, said channels extending longitudinally from said inner end of said distal portion to said outer end of said proximal portion, each of said channels having a base which is substantially parallel to said longitudinal axis in said middle portion and which slants outwardly relative to said longitudinal axis as it extends from said inner end of said proximal portion to said outer end of said proximal portion, said channels being separated by longitudinal walls extending radially outwardly from said longitudinal axis to an outer surface located on said axial projection of said maximum transverse cross-section;

one of said barbs extending axially and radially outwardly from said inner end of said distal portion adjacent the base of each of said channels to an outer end located radially outwardly of said axial projection of said maximum transverse cross-section, each said barb being curved in its normal, unrestrained state but capable of being deformed into a substantially straight configuration; and

attachment means associated with said proximal portion for connecting an object to said anchor; and

b) an installation tool for deploying said anchor in said hole in said workpiece, said tool comprising;

an elongated shaft having a distal end and a proximal end;

tubular means associated with said distal end of said shaft adapted to receive and hold said middle and proximal portions of said anchor body; and

plunger means adapted for engagement with said outer end of said proximal portion of said anchor body, said plunger means being axially movable through said tubular means so as to expell said anchor from said tubular means and to drive said anchor into said hole.

12. The system of claim 11 wherein portions of said object are attached to said attachment means, and further wherein said tool comprises:

an elongated, hollow shaft having a longitudinal axis, an axial bore having a cross-section transverse to said longitudinal axis corresponding to but slightly larger than said maximum transverse cross-section of said anchor body, a proximal end and a distal end,

a plurality of circumferentially-spaced longitudinal first slots in said shaft, said slots extending proximally from said distal end along said shaft and sized to accommodate the barbs of an anchor received in said axial bore;

at least one longitudinal second slot in said shaft, said at least one slot extending proximally from said distal end along said shaft and sized to accommodate the object attached to said attachment means of an anchor received in said axial bore; and

an elongated, solid shaft longer than said hollow shaft having a second longitudinal axis and a cross-section transverse to said second longitudinal axis corresponding to but slightly smaller than the cross-section of said axial bore in said hollow shaft, said solid shaft being adapted for insertion into and through said hollow shaft.

13. The system of claim 12 wherein said tool is formed of stainless steel.

14. The system of claim 12 wherein said object comprises a suture.

15. The system of claim 14 wherein at least two lengths of suture emanate from said anchor, and further wherein said tool comprises at least two longitudinal second slots.

16. The system of claim 12 wherein each of said shafts has a proximal end, and a handle is attached to each of said proximal ends of said shafts.

17. The system of claim 16 wherein said handles matingly engage each other when said shafts are oriented with respect to each other in at least one use position.

18. The system of claim 12 wherein said solid shaft includes a distal end and wherein the portion of said solid shaft adjacent said distal end has a transverse cross-section smaller than the transverse cross-section of the remainder of said solid shaft.

19. The system of claim 11 wherein portions of said object are attached to said attachment means and wherein said tool comprises:

an elongated, rigid shaft, said shaft including a distal end, a proximal end, a first small diameter portion adjacent said distal end and a second intermediate diameter portion located between said first small diameter portion and the remainder of said shaft, said second intermediate diameter portion defining capturing means disposed about the outer surface of said intermediate portion;

a deformable, tubular sleeve having a second distal end, a second proximal end, walls having a thickness approximately equal to the difference between the radius of said intermediate portion and the radius of said remainder portion of said shaft, and a length smaller than the combined length of said small diameter portion and said intermediate diameter portion of said shaft;

a counterbore formed in said distal end of said sleeve and adapted to receive said anchor body;

a plurality of circumferentially-spaced longitudinal radial slots in said sleeve, said slots extending proximally from said second distal end along said sleeve, said slots being adapted to receive the barbs of an anchor engaging said installation tool and said object attached to said attachment means, and

a rib located substantially adjacent said proximal end of said sleeve, said rib extending inwardly from said wall of said sleeve;

said sleeve being mounted about said intermediate diameter portion of said shaft such that in a first position the rib extends inwardly from the wall of the sleeve and engages said capturing means of said intermediate portion of said shaft, and in a second position said proximal end of said sleeve abuts said remainder portion of said shaft.

20. The system of claim 19 wherein said capturing means comprises a groove formed in the outer surface of said intermediate portion of said shaft.

21. The system of claim 19 wherein said capturing means comprises a pair of spaced projections formed on the outer surface of said said intermediate portion of said shaft.

22. Apparatus for deploying an anchor of the sort comprising a body and at least two barbs, said body having a longitudinal axis, a maximum cross-section transverse to said longitudinal axis slightly smaller than the transverse cross-section of said hole, a distal portion having an inner end and an outer end, a proximal portion having an inner end and an outer end, and a middle portion joining said inner end of said distal portion and said inner end of said proximal portion, said middle portion and said proximal portion together defining at least two equally-circumferentially-spaced channels extending inwardly from an axial projection of said maximum transverse cross-section of said distal portion, said channels extending longitudinally from said inner end of said distal portion to said outer end of said proximal portion, each of said channels having a base which is substantially parallel to said longitudinal axis in said middle portion and which slants outwardly relative to said longitudinal axis as it extends from said inner end of said proximal portion to said outer end of said proximal portion, said channels being separated by longitudinal walls extending radially outwardly from said longitudinal axis to an outer surface located on said axial projection of said maximum transverse cross-section, one of said barbs extending axially and radially outwardly from said inner end of said distal portion adjacent the base of each of said channels to an outer end located radially outwardly of said axial projection of said maximum transverse cross-section, each said barb being curved in its normal unrestrained state but capable of being deformed into a substantially straight configuration, and attachment means associated with said second portion for connecting an object to said anchor, said apparatus comprising:

an installation tool comprising;

an elongated, hollow shaft having a longitudinal axis, an axial bore having a cross-section transverse to said longitudinal axis corresponding to but slightly larger than said maximum transverse cross-section of said anchor body, a proximal end and a distal end,

a plurality of circumferentially-spaced longitudinal first slots in said shaft, said slots extending proximally from said distal end along said shaft, said slots being sized to accommodate the barbs of an anchor engaged by said tool;

at least one longitudinal second slot in said shaft, said at least one slot being sized to accommodate an object attached to said attachment means; and

plunger means including an elongated, solid shaft longer than said hollow shaft having a second longitudinal axis and a cross-section transverse to said second longitudinal axis corresponding to but slightly smaller than the cross-section of said axial bore in said hollow shaft, said solid shaft being adapted for insertion into and through said hollow shaft, whereby when said middle and proximal portions of said anchor body are received and held within said axial bore at said distal end of said shaft, said plunger means may be brought into engagement with said outer end of said proximal portion of said anchor body and be utilized to expel said anchor from said hollow shaft and to drive said anchor into said hole.

23. Apparatus for deploying an anchor of the sort comprising a body and at least two barbs, said body having a longitudinal axis, a maximum cross-section transverse to said longitudinal axis slightly smaller than the transverse cross-section of said hole, a distal portion having an inner end and an outer end, a proximal portion having an inner end and an outer end, and a middle portion joining said inner end of said distal portion and said inner end of said proximal portion, said middle portion and said proximal portion together defining at least two equally-circumferentially-spaced channels extending inwardly from an axial projection of said maximum transverse cross-section of said distal portion, said channels extending longitudinally from said inner end of said distal portion to said outer end of said proximal portion, each of said channels having a base which is substantially parallel to said longitudinal axis in said middle portion and which slants outwardly relative to said longitudinal axis as it extends from said inner end of said proximal portion to said outer end of said proximal portion, said channels being separated by longitudinal walls extending radially outwardly from said longitudinal axis to an outer surface located on said axial projection of said maximum transverse cross-section, one of said barbs extending axially and radially outwardly from said inner end of said distal portion adjacent the base of each of said channels to an outer end located radially outwardly of said axial projection of said maximum transverse cross-section, each said barb being curved in its normal unrestrained state but capable of being deformed into a substantially straight configuration, and attachment means associated with said second portion for connecting an object to said anchor, said apparatus comprising:

an installation tool comprising;

an elongated, rigid shaft, said shaft including a distal end, a proximal end, a first small diameter plunger portion adjacent said distal end and a second intermediate diameter portion located between said first small diameter plunger portion and the remainder of said shaft, said second intermediate diameter portion defining capturing means disposed about the outer surface of said intermediate portion of said shaft;

tubular means associated with said distal and intermediate portions said shaft adapted to receive and hold said middle and proximal portions of said anchor body, said tubular means including;

a deformable, tubular sleeve having a second distal end, a second proximal end, walls having a thickness approximately equal to the difference between the radius of said intermediate portion and the radius of said remainder portion of said shaft, and a length smaller than the combined length of said small diameter portion and said intermediate diameter portion of said shaft;

a counterbore formed in said distal end of said sleeve and adapted to receive said anchor body;

a plurality of circumferentially-spaced longitudinal slots in said sleeve, said slots extending proximally from said second distal end along said sleeve, said slots being adapted to receive the barbs of an anchor engaging said installation tool and an object attached to said attachment means, and

a rib located substantially adjacent said proximal end of said sleeve, said rib extending inwardly from said wall of said sleeve;

said sleeve being mounted about said intermediate diameter portion of said shaft such that in a first position the rib extends inwardly from the wall of the sleeve and engages said capturing means disposed about the outer surface of said intermediate portion of said shaft, and in a second position said proximally end of said sleeve abuts said remainder portion of said shaft, whereby when said middle and proximal portions of said anchor are received and held within said tubular means adjacent said second distal end thereof, said distal end of said shaft may be brought into engagement with said outer end of said proximal portion of said anchor body and be utilized to expel said anchor from said tubular means and to drive said anchor into said hole.

24. A method for attaching an object to a workpiece comprising:

(a) providing;

1) means for forming a hole in said workpiece;

2) an anchor assembly comprising a body and at least two barbs;

said body having a longitudinal axis, a maximum cross-section transverse to said longitudinal axis slightly smaller than the transverse cross-section of said hole, a distal portion having an outer end and an inner end, a proximal portion having an inner end and an outer end, and a middle portion joining said inner end of said distal portion and said inner end of said second portion;

said middle portion and said proximal portion together defining at least two equally-circumferentially-spaced channels extending inwardly from an axial projection of said maximum transverse cross-section of said distal portion, said channels extending longitudinally from said inner end of said distal portion to said outer end of said proximal portion, each of said channels having a base which is substantially parallel to said longitudinal axis in said middle portion and which slants outwardly relative to said longitudinal axis as it extends from said inner end of said proximal portion to said outer end of said proximal portion, said channels being separated by longitudinal walls extending radially outwardly from said longitudinal axis to an outer surface located on said axial projection of said maximum transverse cross-section;

one of said barbs extending axially and radially outwardly from said inner end of said distal portion adjacent the base of each of said channels to an outer end located radially outwardly of said axial projection of said maximum transverse cross-section, each said barb being curved in its normal, unrestrained state but capable of being deformed into a substantially straight configuration; and

attachment means associated with said second portion for connecting an object to said anchor assembly; and

3) an installation tool for deploying said anchor in said hole in said workpiece, said tool comprising

an elongated shaft having a longitudinal axis, a distal end and a proximal end;

tubular means associated with said distal end of said shaft adapted to receive and hold said middle and proximal portions of said anchor body; and

plunger means adapted for engagement with said outer end of said proximal portion of said anchor body, said plunger means being axially movable through said tubular means so as to expel said anchor from said tubular means and to drive said anchor into said hole;

b) forming a hole in a surface of said workpiece with said hole forming means;

c) aligning said longitudinal axis of said anchor body with said longitudinal axis of said shaft;

d) slidably engaging said middle and proximal portions of said anchor body with said tubular means;

e) inserting said distal portion of said anchor body into said hole such that said tubular means engages said workpiece adjacent said hole;

f) moving said plunger means through said tubular means so as to expel said anchor therefrom and so as to drive said anchor into said hole;

g) withdrawing said plunger from said hole and said tubular means from its engagement with said workpiece; and

h) attaching said object to said attachment means.

25. The method of claim 24 wherein step (b) occurs at any point prior to step (e).

26. The method of claim 24 wherein said attachment means comprises an opening extending transverse relative to said longitudinal axis of said anchor body through said proximal portion of said anchor body, and further including the step of threading one cord-like member through said opening prior to step (d) such that said cord-like member is securely attached to said proximal portion and at least one end of said cord-like member extends out of said hole after step (f).

27. The method of claim 24 wherein said object includes at least one attachment means-engaging portion, step (h) occurs prior to step (d), and said installation tool further comprises:

an elongated, hollow shaft having a longitudinal axis, an axial bore having a cross-section transverse to said longitudinal axis corresponding to but slightly larger than said maximum transverse cross-section of said anchor body, a proximal end and a distal end,

a plurality of circumferentially-spaced longitudinal first slots in said shaft, said slots extending proximally from said distal end along said shaft, and adapted to receive the barbs of an anchor disposed in said tool;

at least one longitudinal second slot in said shaft, said at least one slot extending proximally from said distal end along said shaft and adapted to receive said object attached to said attachment means, and

an elongated, solid shaft longer than said hollow shaft having a second longitudinal axis and a cross-section transverse to said second longitudinal axis corresponding to but slightly smaller than the cross-section of said axial bore in said hollow shaft, said solid shaft being adapted for insertion into and through said hollow shaft.

28. The method of claim 27 wherein said attachment means comprises an opening extending transversely relative to said longitudinal axis of said anchor body through said proximal portion of said anchor body, and further including the step of threading one end of a cord-like member through said bore prior to step (d) such that said cord-like member is securely attached to said proximal portion and at least one end of said cord-like member extends out of said hole after step (f).

29. The method of claim 24 wherein said object includes at least one attachment means engaging portion, step (h) occurs prior to step (d), and said installation tool further comprises:

an elongated, rigid shaft, said shaft including a distal end, a proximal end, a first small diameter portion adjacent said distal end and a second intermediate diameter portion located between said first small diameter portion and the remainder of said shaft, said second intermediate diameter portion defining capturing means disposed about the outer surface of said intermediate portion of said shaft;

a deformable, tubular sleeve having a second distal end, a second proximal end, walls having a thickness approximately equal to the difference between the radius of said intermediate portion and the radius of said remainder portion of said shaft, and a length smaller than the combined length of said small diameter portion and said intermediate diameter portion of said shaft;

a plurality of circumferentially-spaced longitudinal radial slots in said sleeve, said slots extending proximally from said second distal end along said sleeve and adapted to receive the barbs and suture of an anchor attached to said installation tool;

a rib located substantially adjacent said proximal end of said sleeve, said rib extending inwardly from said wall of said sleeve;

said sleeve being mounted about said intermediate diameter portion of said shaft such that in a first position the rib extends inwardly from the wall of the sleeve and engages said capturing means disposed about the outer surface of said intermediate portion of said shaft, and in a second position said proximal end of said sleeve abuts said remainder portion of said shaft.

30. The method of claim 29 wherein said attachment means comprises an opening extending transversely relative to said longitudinal axis of said anchor body through said proximal portion of said anchor body, and further including the step of threading one end of a cord-like member through said opening prior to step (d) such that said cord-like member is securely attached to said proximal portion and at least one end of said cord-like member extends out of said hole after step (f).

31. The method of claim 29 wherein said capturing means comprises a groove formed in the outer surface of said intermediate portion of said shaft.

32. The method of claim 29 wherein said capturing means comprises a pair of spaced projections formed on the outer surface of said intermediate portion of said shaft.

33. Apparatus for attaching an object to a workpiece comprising:

an anchor comprising a body and at least two barbs;

said body having a longitudinal axis, a maximum cross-section transverse to said longitudinal axis, a distal portion having an outer end and an inner end, a proximal portion having an outer end and an inner end, and a middle portion joining said inner end of said distal portion and said inner end of said proximal portion;

said middle portion and said proximal portion together defining at least two equally-circumferentially-spaced channels extending inwardly from an axial projection of said maximum transverse cross-section of said distal portion, said channels extending longitudinally from said inner end of said distal portion toward said outer end of said proximal portion, each of said channels having a base which is substantially parallel to said longitudinal axis in said middle portion and which slants outwardly relative to said longitudinal axis as it extending from said inner end of said proximal portion toward said outer end of said proximal portion, said channels being separated by longitudinal walls extending radially outwardly from said longitudinal axis to an outer surface located on said axial projection of said maximum transverse cross-section;

one of said barbs extending axially and radially outwardly from said inner end of said distal portion adjacent the base of each of said channels to an outer end located radially outwardly of said axial projection of said maximum transverse cross-section, each said barb being capable of being deformed so that its outer end is positioned closer to said axial projection of said maximum transverse cross-section; and

attachment means associated with said proximal portion for connecting an object to said anchor.

34. Apparatus for deploying an anchor of the sort comprising a body and at least two barbs into a hole formed in bone, said body having a distal end, a proximal end terminating in a proximal end surface, a longitudinal axis, and a maximum cross-section transverse to said longitudinal axis slightly smaller than the transverse cross-section of said hole, said barbs extending axially and radially outwardly from said body to an outer end located radially outwardly of an axial projection of said maximum transverse cross-section, each said barb being capable of being deformed so that its outer end is positioned closer to said axial projection of said maximum transverse cross-section, and said body comprising attachment means for connecting an object to said anchor,

said apparatus comprising:

an installation tool comprising;

an elongated shaft having a longitudinal axis, a first distal end and a first proximal end;

tubular means associated with said distal end of said shaft adapted to receive and hold said proximal end of said anchor body and to allow said distal end of said anchor body to extend distally from said tubular means, said tubular means comprising a tubular element having a longitudinal axis substantially aligned with the longitudinal axis of said shaft, a second proximal end surrounding the portion of said shaft adjacent said first distal end and a maximum cross-section transverse to its longitudinal axis larger than the cross-section of said hole, whereby when the proximal end of an anchor is received and held by said tubular means, the distal end of said anchor can be positioned within said bone hole and said second distal end of said tubular means will reside outside and bear against the bone adjacent said bone hole; and

plunger means adapted for engagement with said proximal end surface of said anchor body, said plunger means being axially movable through said tubular means so as to expel said anchor from said tubular means and to drive said anchor into said hole, said plunger means being adapted to extend out of the distal end of said tubular means and into said hole when driving said anchor into said hole.

35. Apparatus according to claim 34 wherein said tubular means are mounted to said shaft, said plunger means are formed at said distal end of said shaft, and said tubular means are free to rotate circumferentially about said shaft.

36. Apparatus according to claim 34 wherein the portion of said shaft adjacent said distal end of said shaft has a maximum cross-section transverse to said longitudinal axis smaller than the transverse cross-section of said hole.