Method and apparatus for positioning a suture anchor

METHOD AND APPARATUS FOR
POSITIONING A SUTURE ANCHOR

BACKGROUND OF THE INVENTION

The present invention provides a new and improved apparatus and method for use in positioning a suture anchor in either soft or hard body tissue.

Surgeons utilize suture anchor inserters to position suture anchors in either soft body tissue or hard body tissue. Suture anchor inserters for positioning suture anchors in soft or hard body tissue are disclosed in U.S. Pat. Nos. 5,403,348; 5,464,426; and 5,549,630. During positioning of a suture anchor relative to body tissue, it is necessary to form an opening in the body tissue to receive the anchor. In addition, during positioning of the suture anchor relative to the body tissue, it is advantageous to be able to accurately position the anchor in a desired depth in the body tissue.

SUMMARY OF THE INVENTION

An apparatus which may be used to position a suture anchor relative to body tissue includes a tubular member. The tubular member is advantageously operable between a closed condition at least partially blocking a passage in the tubular member and an open condition in which the tubular member is ineffective to block the passage. By blocking the passage in the tubular member, entry of body tissue and/or other foreign matter into the passage is prevented.

In some embodiments of the invention, when the tubular member is in the closed condition, the leading end portion of the tubular member is contracted so as to be readily inserted into body tissue. Apoint at the contracted end of the tubular member facilitates piercing of body tissue.

Upon movement of a suture anchor through the end portion of the tubular member, a leading end portion of the anchor may apply force against the tubular member to effect operation of the tubular member from the closed condition to the open condition. Alternatively, a second member may be inserted into the tubular member along with the suture anchor. The second member applies force against an inner side surface of the tubular member to effect operation of the tubular member from the closed condition to the open condition.

In one specific embodiment of the invention, the tubular member includes a sheath which encloses a plurality of wires. A leading end portion of the sheath may be expanded by applying force against the wires with the anchor. A portion of the suture may be disposed between the wires.

Indicia may be provided on the outside of the tubular member to indicate the depth to which the tubular member has been inserted into body tissue. When indicia corresponding to a desired depth of insertion of the tubular member in the body tissue has been covered by the body tissue, the step of inserting the tubular member into body tissue is interrupted.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will become more apparent upon the consideration of the following description taken in connection with the accompanying drawings, wherein:

FIG. 1 is an enlarged simplified schematic illustration of a suture anchor inserter assembly which is constructed in accordance with the present invention and includes a tubular member having a pointed leading end portion which is illustrated in a closed condition;

FIG. 2 is a fragmentary pictorial illustration of a portion of the tubular member of FIG. 1 and illustrates indicia on an outer side of the tubular member;

FIG. 3 is a sectional view, taken generally along the line 5 3—3 of FIG. 2, further illustrating the construction of the tubular member;

FIG. 4 is a simplified schematic illustration, generally similar to FIG. 1, illustrating the tubular member in an open condition;

FIG. 5 is a simplified schematic pictorial illustration of a second embodiment of the inserter assembly, a pointed leading end portion of the inserter assembly being illustrated in a closed condition;

15 FIG. 6 is an enlarged simplified schematic sectional view of a portion of the inserter assembly of FIG. 5 and illustrating the manner in which a suture anchor is moved along and expands a passage in the inserter assembly;

FIG. 7 is a sectional view, taken generally along the line

20 7—7 of FIG. 6, illustrating the manner in which the suture anchor engages wires enclosed by a sheath of the inserter assembly;

FIG. 8 is an enlarged simplified schematic illustration of the manner in which the inserter assembly of FIGS. 5-7 is 25 inserted into body tissue;

FIG. 9 is an enlarged simplified schematic sectional view, generally similar to FIGS. 6 and 8, of a third embodiment of the inserter assembly; and

FIG. 10 is an enlarged simplified schematic illustration of 30 the manner in which a fourth embodiment of the inserter assembly is inserted into body tissue.

DESCRIPTION OF SPECIFIC PREFERRED EMBODIMENTS OF THE INVENTION 35 General Description

An inserter assembly 20 (FIG. 1) is used to position a suture anchor 22 relative to body tissue 24. During positioning of the suture anchor 22 relative to the body tissue 24, a suture 26 engages the suture anchor 22. Once the suture 40 anchor 22 has been positioned in the body tissue 24, the suture anchor holds the suture 26 against pulling out of the body tissue.

The inserter assembly 20 includes a tubular outer member 30. The tubular outer member 30 has a passage 32 through

45 which the suture anchor 22 moves into the body tissue 24. The suture anchor 22 has a passage 36 through which the suture 26 extends. The suture 26 includes an outer leg or portion 38 which extends along an outer side of the suture anchor 22 and an inner leg or portion 40 which extends

50 through the passage 36 in the suture anchor 22. A connector portion 42 of the suture extends across an annular leading end portion 44 of the suture anchor 22.

In the embodiment of the suture anchor 22 illustrated in FIG. 1, the suture 26 extends through the passage 36

55 disposed in the suture anchor. However, it is contemplated that the suture 26 could be connected with the suture anchor 22 in a different manner. For example, the suture 26 could be tied off at an opening in the suture anchor 22 if desired. The illustrated suture anchor 22 has a cylindrical tubular

60 side wall 48 which extends between the leading end portion 44 and an annular trailing end portion 50 of the suture anchor 22. It should be understood that the suture anchor 22 could have a different configuration. For example, the suture anchor 22 could have a polygonal configuration which is

65 similar to the polygonal configuration of a suture anchor disclosed in U.S. Pat. No. 5,549,630 issued Aug. 27,1996 to Peter M. Bonutti. Alternatively, the suture anchor 22 could have any one of the configurations disclosed in U.S. Pat. No. 5,522,846 issued Jun. 4, 1996 to Peter M. Bonutti.

The suture anchor 22 is formed of metal. Specifically, the suture anchor 22 is formed of stainless steel. However, it is contemplated that the suture anchor 22 could be formed of other materials, for example, body tissue. Alternatively, the suture anchor 22 could be formed of a polymeric material such as cellulose, petroylglutamic acid, collagen, or polylactide. If desired, the suture anchor 22 could be formed of a material which is hydrophilic and expands when exposed to body fluids.

A tubular inner or pusher member 54 is telescopically received in the tubular outer member 30. The tubular inner member 54 has a leading end portion 56 which engages the trailing end portion 50 of the suture anchor 22. The inner leg 40 of the suture 26 extends through a passage 58 in the tubular inner member 54. The tubular inner member 54 is movable axially along the passage 32 in the tubular outer member 30 to push the suture anchor 22 into body tissue.

In accordance with one of the features of the present invention, a leading end portion 62 of the tubular outer member 30 is operable between a closed condition (FIGS. 1-3) and an open condition (FIG. 4). When the leading end portion 62 of the tubular outer member 30 is in the closed condition of FIGS. 1 and 2, the leading end portion of the tubular outer member at least partially blocks the passage 32 through the tubular outer member. When the leading end portion 62 of the tubular outer member 30 is in the closed condition, the leading end portion 62 of the tubular outer member 30 prevents movement of the suture anchor 22 out of the passage 32 in the tubular outer member. In addition, when the leading end portion 62 of the tubular outer member 30 is in the closed condition, the leading end portion of the tubular outer member prevents movement of foreign material, such as body tissue, into the passage 32.

The leading end portion 62 of the tubular outer member 30 is operable from the closed condition of FIG. 1 to the open condition of FIG. 4. When the leading end portion 62 of the tubular outer member 30 is in the open condition, the suture anchor 22 can be moved out of the passage 32 under the influence of force applied against the trailing end portion 50 of the suture anchor by the tubular inner member 54. As this occurs, the suture anchor 22 moves into the body tissue 24.

To operate the leading end portion 62 of the tubular outer member 30 from the closed condition of FIG. 1 to the open condition of FIG. 4, force is applied against the inside of the passage 32 through the tubular outer member 30. The force applied against the inside of the passage 32 operates the leading end portion 62 of the tubular outer member 30 from the closed or contracted condition of FIG. 1 to the open or expanded condition of FIG. 4. Pressure applied against the leading end portion 62 of the tubular outer member 30 effects expansion of the tubular outer member from the closed condition to the open condition.

In accordance with another feature of the invention, the leading end portion 62 of the tubular outer member 30 is pointed to facilitate piercing of body tissue 24 with the leading end portion of the tubular outer member. When the tubular outer member 30 is in the closed condition of FIG. 1, a point 66 is formed at the end of the tubular outer member 30. This point can initiate the formation of an opening in an imperforate surface 68 on the body tissue 24. In addition, as force is manually applied against a handle 70 connected with the tubular outer member 30, the point 66 continues to pierce body tissue as the tubular member 30 moves into the body tissue.

It is believed that the point 66 on the leading end of the tubular member 30 will be particularly advantageous in piercing soft body tissue. However, it should be understood that the inserter assembly 20 can be utilized with hard body tissue, such as bone. When the inserter assembly 20 is used with hard body tissue, an opening will be drilled or otherwise preformed in the hard body tissue. The leading end portion 62 of the tubular outer member 30 will be inserted into the preformed opening in the hard body tissue.

During insertion of the leading end portion 62 of the tubular outer member 30 into the preformed opening in the body tissue, the leading end portion 62 of the tubular member will be in the closed condition illustrated in FIGS. 1 and 2. After the tubular outer member 30 has been inserted into the preformed opening in the hard body tissue, the leading end portion 62 of the tubular outer member will be operated to the open condition of FIG. 4 by force transmitted from the tubular inner member 54.

In accordance with another feature of the present invention, indicia 76 is provided on the outside of the tubular outer member 30. The indicia 76 indicates the distance through which the tubular outer member 76 has been inserted into the body tissue 24. Thus, as the tubular outer member 30 of the inserter assembly 20 is inserted into the body tissue 24, the body tissue covers the indicia. When indicia corresponding to a desired depth of insertion of the tubular outer member 30 in the body tissue 24 has been covered by body tissue, movement of the tubular outer member into the body tissue is interrupted.

Although it is preferred to insert the leading end portion 62 of the tubular outer member 30 into body tissue, the leading end portion of the tubular member may merely be positioned closely adjacent to a preformed opening in the body tissue. Thus, the leading end portion of the tubular outer member 30 may merely be positioned in axial alignment with an opening drilled in bone. Inserter Assembly—Embodiment of FIGS. 1-4

The tubular outer member 30 (FIG. 1) of the inserter assembly 20 is integrally formed as one piece of polymeric material. The tubular outer member 30 has a rigid cylindrical main or body portion 80. The main or body portion 80 has a cylindrical outer side surface 82 and a cylindrical inner side surface 84 which is coaxial with the outer side surface. The inner side surface 84 at least partially defines the cylindrical passage 32 which extends through the tubular outer member 30.

The cylindrical inner side surface 84 on the main or body portion 80 has a diameter which is slightly greater than an outside diameter of the cylindrical suture anchor 22. This enables the cylindrical suture anchor 22 to move easily along the main or body portion 80 of the tubular outer member 30. The outer leg or portion 38 of the suture 26 extends between the suture anchor 22 and the inner side surface 84 of the main or body portion 80 of the tubular outer member 30.

Although the suture anchor 22 could have many different sizes and configurations, the illustrated suture anchor is cylindrical. The suture anchor 22 has a length of about two millimeters. The suture anchor 22 has an outside diameter of about one millimeter and an inside diameter of about onehalf millimeter. The foregoing specific dimension for the suture anchor 22 may vary and have been set forth herein only for purposes of clarity of description.

The leading end portion 62 of the tubular outer member 30 is formed by a plurality of segments 88, 90, 92, and 94 (FIG. 3). Each of the segments 88, 90, 92 and 94 has a pair of opposite side surfaces 96 and 98 which extend from the 5

point 66 (FIGS. 1 and 2) to the main or body portion 80 of the tubular outer member 30.

When the tubular outer member 30 is in the closed condition of FIGS. 1-3, the segments 88-94 completely block the leading end portion 62 of the tubular outer member 5 30 and form the point 66. Thus, when the tubular outer member 30 is in the closed condition, the side surfaces 96 and 98 on each of the segments 88-94 are disposed in abutting engagement with the side surfaces on adjacent segments. The segments 88-94 cooperate to provide the 10 pointed leading end portion 60 with a generally conical configuration (FIGS. 1 and 2). If desired, spaces could be provided between the segments 88-94 when the tubular outer member 30 is in the closed condition.

When the tubular outer member 30 pierces body tissue 24 15 (FIG. 1), the body tissue applies force against an outer side surface 102 (FIGS. 2 and 3) on each of the segments 88-94. Pressure applied against the outer side surfaces 102 of the segments 88-94 presses the side surfaces 96 and 98 on the adjacent segments together. Thus, force applied against the 20 segments 88-94 by the body tissue 24 as the tubular outer member 30 penetrates the body tissue urges the leading end portion 62 of the tubular outer member toward the conical closed condition of FIGS. 1-3.

The closed leading end portion 62 of the tubular outer 25 member 30 is completely blocked by the segments 88-94. Therefore, it is impossible for the body tissue to enter the passage 32 in the tubular outer member 30 as the tubular outer member is inserted into the body tissue. However, if desired, the closed leading end portion 62 of the tubular 30 outer member 30 may be only partially blocked by the segments 88-94. For example, small spaces or slots could be located between the segments 88-94 at locations axially spaced from the point 66. Alternatively, the spaces or slots could extend to the point 66. 35

The tubular inner member 54 (FIG. 1) is disposed in a coaxial relationship with the tubular outer member 30 and the cylindrical anchor 22. The tubular inner member 54 is integrally formed of one piece of rigid polymeric material. The tubular inner member 54 has a cylindrical outer side 40 surface 110 with a diameter which is smaller than the diameter of the cylindrical inner side surface 84 of the tubular outer member 30. This enables the tubular inner member to move freely along the main or body portion 80 of the tubular outer member 30. 45

The passage 58 in the tubular inner member 54 has a cylindrical inner side surface 112 which is disposed in a coaxial relationship with the cylindrical outer side surface 110. The inner leg or portion 40 of the suture 26 extends through the cylindrical passage 58 in the inner member 54. 50 A suitable handle 114 is provided on an axially outer end portion of the tubular inner member 54.

When a suture 26 is to be positioned in the body tissue 24 and held in place by the suture anchor 22, the suture is first threaded through the center of the passage 36 in the anchor 55 22. The inner leg or portion 40 of the suture 26 is then threaded through the passage 58 in the tubular outer member 54. The suture anchor 22 and tubular outer member 54 are then moved into the passage 42 in the tubular outer member 30 (FIG. 1). At this time, the leading end portion 62 of the 60 tubular outer member 30 is in the closed condition and blocks movement of the anchor 22 out of the passage 32 through the leading end portion 62 of the tubular outer member.

When the anchor 22 is to be inserted into the body tissue 65 24, the point 66 on the leading end portion of the tubular outer member 30 may be moved into engagement with the

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imperforate outer surface 68 on skin 120 of a patient. Force is then manually applied against the handle 70 on the tubular outer member 30. This force causes the point 66 on the tubular outer member 30 to initiate the formation of an opening in the outer surface of the skin 120.

Continued manual application of force against a handle 70 on the tubular outer member 30 results in the point 68 moving through the skin 120 and piercing the flesh 122 disposed beneath the skin. As the leading end portion 62 of the tubular outer member 30 pierces the flesh 122, the viscoelastic material of the flesh is pressed aside and the tubular outer member 30 penetrates the body tissue 24.

As the tubular outer member 30 moves into the body tissue 24, the indicia 76 (FIG. 2) on the tubular outer member 30 is partially covered by the body tissue. In the illustrated embodiment of the invention, the indicia 76 includes a plurality of stripes 126, 128, 130, 132 and 134 (FIG. 2) of different colors. As the tubular outer member 30 moves into the body tissue, the lowermost (as viewed in FIG. 2) stripe 126 is covered. As the tubular outer member 30 moves further into the body tissue, the remaining stripes are sequentially covered by the body tissue.

When one of the stripes 126-134 corresponding to a desired depth of insertion of the tubular outer member 30 is at least partially covered by body tissue, the surgeon is informed that the desired depth of penetration has been obtained. Movement of the tubular outer member 30 into the body tissue is then interrupted. Thus, the stripes 126-134 measure the depth to which the tubular outer member 30 has been inserted into the body tissue 24.

In the illustrated embodiment of the invention, the measurement of the depth to which the tubular outer member 30 is inserted into the body tissue 24 is provided by the multi-colored strips 126-134. Alternatively, numerical indicia indicative of the distance which the tubular outer member 30 is moved into the body tissue could be provided on the outside of the tubular outer member. Of course, other indicia could be utilized if desired.

When the indicia 76 indicates that the tubular outer member 30 has moved to the desired depth into the body tissue 24 downward (as viewed in FIG. 1) movement of the tubular outer member 30 into the body tissue is interrupted. The leading end portion 62 of the tubular outer member 30 is then operated from the closed condition of FIG. 1 to the open condition of FIG. 4. The suture anchor 22 is moved through the open leading end portion 62 of the tubular outer member 30 into the body tissue 24.

When the leading end portion 62 of the tubular outer member 30 is to be operated from the closed condition of FIG. 1 to the open condition of FIG. 4, the tubular inner member 54 is manually pressed against the annular trailing end portion 50 of the suture anchor 22. This moves the annular leading end portion 44 of the suture anchor 22 into engagement with inner side surfaces 140 on the segments 88-94. Force applied against the inner side surfaces 140 of the segments 88-94 by the suture anchor 22 resiliently cams or forces the segments 88-94 away from each other to expand the end portion 62 of the tubular outer member 30.

Thus, as the suture anchor 22 moves axially downward (as viewed in FIG. 1) in the passage 32 into the closed leading end portion 62 of the tubular outer member 30, the suture anchor applies force against the inner side surface 140 on each of the segments 88-94. This force moves the segments 88-94 apart to expand the passage 32 and the end portion 62 of the tubular outer member 30. Continued axial movement of the suture anchor 22 into the leading end portion 62 of the tubular outer member 30 increases the distance which the outer or lower end portions of the segments 88-94 move apart.

7

Still further movement of the suture anchor into the leading end portion 62 of the tubular outer member 30 cams the segments 88-94 to the fully open position of FIG. 4. The leading end portion 44 of the suture anchor 22 then moves through a circular space between axially outer tips of the 5 segments 88-94. As this occurs, the natural resilience of the segments 88-94 presses them against a cylindrical outer side surface 144 of the anchor 22. This results in the segments 88-94 of the leading end portion 62 of the tubular outer member 30 being held in the open condition of FIG. 4 by the 10 anchor 22.

Continued downward (as viewed in FIG. 4) movement of the tubular inner member 54 pushes the anchor 22 through the open leading end portion 62 of the tubular outer member 30. As the anchor 22 is pushed through the open leading end 15 portion 62 of the tubular outer member 30, the inner side surfaces 140 of the segments 88-94 slide along and press firmly against the cylindrical outer side surface 144 of the anchor. Thus, the suture anchor 22 is firmly gripped by the end portion 62 of the tubular outer member 30 as the suture 20 anchor moves into the body tissue 24. This enables the tubular outer member 30 to hold the suture anchor 22 in a desired orientation as the suture anchor is moved into the body tissue 24.

When the trailing end portion 50 of the anchor moves out 25 of the open end portion 62 of the tubular outer member 30, the leading end portion 56 of the tubular inner member 54 has moved into the open leading end portion of the tubular outer member. Continued axially downward (as viewed in FIG. 4) movement of the tubular inner member 54 moves the 30 tubular inner member through the open leading end portion 62 of the tubular outer member 30. If desired, the tubular inner member 54 can then be utilized to apply force against the trailing end portion 50 of the anchor 22 as force is applied to the outer leg 38 of the suture 26 to change the 35 orientation of the anchor 22 relative to the body tissue 24 and inserter assembly 20 in the manner disclosed in U.S. Pat. No. 5,522,846 issued Jun. 4, 1996 to Peter M. Bonutti. Of course, if desired, the suture anchor 22 could remain in the orientation shown in FIG. 4. 40

Once the suture anchor 22 has been moved into the body tissue 24, the inserter assembly 20 is withdrawn from the body tissue. Since the tubular inner member 54 has moved into the open leading end portion 62 of the tubular outer member 30, the leading end portion of the tubular outer 45 member is maintained in the open condition by the presence of the tubular outer member 54. Thus, the inner side surfaces 140 of the segments 88-94 are pressed firmly against the cylindrical outer side surface 110 of the tubular inner member by the natural resilience of the segments. This 50 results in the leading end portion 62 of the tubular outer member 30 being maintained in the open condition as the inserter assembly is withdrawn from the body tissue.

In the embodiment of the invention illustrated in FIGS. 1-4, the suture anchor 22 has a cylindrical configuration. 55 Therefore, the tubular outer member 30 and tubular inner member 54 have cylindrical configurations. However, it is contemplated that the suture anchor 22 could have a polygonal cross-sectional configuration. The tubular outer member 30 and inner member 54 may have a corresponding polygo- 60 nal cross-sectional configuration.

The foregoing description of the embodiment of the invention illustrated in FIGS. 1-4 has been in conjunction with insertion of the suture anchor 22 into the soft body tissue 24. When the suture anchor 22 is to be inserted into 65 bone, an opening is drilled through a hard outer layer of the bone into soft inner material of the bone. Once this has been

8

done, the tubular outer member 30 is inserted into the opening in the bone. The closed leading end portion 62 of the tubular outer member 30 is then operated from the closed condition of FIG. 4. The anchor 22 is moved through the open end portion 62 of the tubular outer member 30 into the bone.

It is contemplated that the inserter assembly 20 may be used to position an anchor 22 in either soft or hard tissue at many different locations in a patient's body. The point 66 on the end portion 62 of the outer tubular member 30 may be used to pierce body tissue at locations remote from a patient's skin 120. Thus, the inserter assembly 20 may be used to position a suture anchor 22 in an organ within the patient's body.

When the inserter assembly 20 is to be used to position the suture anchor 22 in hard body tissue, such as the hard outer or cortical layer of bone, the point 66 may be omitted from the leading end portion 62 of the tubular outer member 30. When the inserter assembly 20 is to be used to position the anchor 22 in the soft body tissue 24, the formation of an opening in the body tissue may be initiated without piercing imperforate body tissue with the point 66. Thus, an opening could be formed in the patient's skin 120 and/or flesh 122 with a suitable cutting instrument. However, it is believed that it may be preferred to use the point 66 to form an opening in the skin 120 and/or flesh 122. Inserter Assembly—Embodiment of FIGS. 5-8

In the embodiment of the invention illustrated in FIGS. 1-4, the tubular outer member 30 is formed of a single piece of polymeric material. In the embodiment of the invention illustrated in FIGS. 5-8, the tubular outer member is formed by a sheath which encloses a plurality of wires. Since the embodiment of the invention illustrated in FIGS. 5-8 is generally similar to the embodiment of the invention illustrated in FIGS. 1-4, similar numerals will be utilized to designate similar components, the suffix letter "a" being associated with the numerals of FIGS. 5-8 to avoid confusion.

An inserter assembly 20a is utilized to position a suture anchor 22a (FIGS. 6-8) in body tissue 24a (FIG. 8). Asuture 26a extends through the suture anchor 22a. The suture anchor 22a has a cylindrical configuration. However, the suture anchor 22a could have a polygonal configuration if desired. The suture anchor 22a has a length of about two millimeters and an outside diameter of about one millimeter. However, it is contemplated that the suture anchor 22a will have many different sizes and configurations. The invention is not to be limited to the foregoing specific sizes and configurations for the suture anchor 22a.

The inserter assembly 20a (FIG. 5) includes a cylindrical tubular outer member 30a having a cylindrical passage 32a through which the suture anchor 22a moves into body tissue 24a (FIG. 8) with the suture 26a extending through the suture anchor. The suture 26a includes inner and outer legs or portions 38a and 40a (FIGS. 5 and 6) which are interconnected by a connector portion 42a (FIG. 6). The inner leg 40a of the suture 26a extends through a cylindrical passage 36a in the anchor 22a. The connector portion 42a of the suture 26a extends across an annular leading end portion 44a of the suture anchor 22a. The outer leg or portion 48a of the suture 26a extends along a cylindrical outer side surface 144a of the suture anchor 22a.

A cylindrical tubular inner member 54a (FIGS. 5 and 6) engages an annular trailing end portion 50a (FIG. 6) of the cylindrical suture anchor 22a. The tubular inner member 54a extends into the tubular outer member 30a. The tubular inner member 54a is disposed in a coaxial relationship with the cylindrical tubular outer member 30a.