Patent Publication Number: US-2020281581-A1

Title: Devices and methods for anchoring tissue

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/357,197 filed on Nov. 21, 2016, which claims the benefit of U.S. Provisional Application No. 62/263,250, filed Dec. 4, 2015, which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     Examples of the present invention relate generally to devices and methods for anchoring soft tissue, tissue grafts, and the like to a bone. 
     BACKGROUND 
     Various conditions may affect skeletal joints such as the deterioration, elongation, shortening, or rupture of soft tissues, cartilage, and/or bone associated with the joint and consequent laxity, pain, and/or deformity. It may be desirable to change the angular alignment of a bone or a portion of a bone to restore function and/or reduce pain. In such a medical procedure it may be necessary to affix soft tissue or a tissue graft to a bone. For example, in a medical procedure to correct an angular deformity of a first ray of a human foot, e.g. hallux valgus, it is often desirable to surgically remove a protruding bone portion or bunion in a procedure known as a bunionectomy adjacent the metatarsophalangeal (MTP) joint. To gain exposure to the surgical site, soft tissues surrounding the joint and the bunion are cut and dissected away. Often these tissues are not reattached for lack of workable devices and methods. Devices and methods to reattach such tissues to provide an anatomic repair are needed. 
     SUMMARY 
     The present invention provides devices and methods for anchoring soft tissue, tissue grafts, and the like to a bone. In one example an assembly includes a suture anchor, suture, and inserter. In another example, a method provides for reattaching soft tissue to a bone. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various examples of the present invention will be discussed with reference to the appended drawings. These drawings depict only illustrative examples of the invention and are not to be considered limiting of its scope. 
         FIG. 1  is a perspective view of an illustrative example of an assembly according to an example of the present invention; 
         FIG. 2  is a perspective view of the assembly of  FIG. 1  showing a different operative state of the assembly; 
         FIG. 3  is a side elevation view of the assembly of  FIG. 1 ; 
         FIG. 4  is a section view of the assembly of  FIG. 1  taken along line  4 - 4  of  FIG. 3  with the suture omitted for clarity; 
         FIG. 5  is an exploded view of the assembly of  FIG. 1  with the suture omitted for clarity; 
         FIG. 6  is a side elevation view of an illustrative example of a hole forming device according to an example of the present invention; 
         FIG. 7  is a perspective view of the suture anchor of the assembly of  FIG. 1 ; 
         FIG. 8  is a top plan view of the suture anchor of the assembly of  FIG. 1 ; 
         FIG. 9  is a side elevation view of the suture anchor of the assembly of  FIG. 1 ; 
         FIG. 10  is a front elevation view of the suture anchor of the assembly of  FIG. 1 ; 
         FIG. 11  is a bottom plan view of the suture anchor of the assembly of  FIG. 1 ; 
         FIG. 12  is a perspective view of the suture anchor of the assembly of  FIG. 1 ; 
         FIG. 13  is a sectional view of the suture anchor of the assembly of  FIG. 1  taken along line  13 - 13  of  FIG. 8  and showing a suture routed through the suture anchor; 
         FIG. 14  is a medial view of the cuneiform, metatarsal, and proximal phalanx bones of the first ray of a human foot; 
         FIG. 15  is a dorsal view of the cuneiform, metatarsal, and proximal phalanx bones of the first ray of a human foot; 
         FIG. 16  is a dorsal view similar to  FIG. 15  illustrating a bunionectomy according to an example of the invention; and 
         FIGS. 17-24  illustrate a method of using the assembly of  FIG. 1  to anchor soft tissue according to an example of the invention. 
     
    
    
     DESCRIPTION OF THE ILLUSTRATIVE EXAMPLES 
     The following illustrative examples describe methods, implants, and instruments for connecting soft tissue to bone. The use of the illustrative devices and methods is illustrated to attach soft tissue detached in conjunction with a bunionectomy during a corrective procedure performed on a first ray of a human foot. In particular the illustrative devices and methods are illustrated to reattach capsular tissue adjacent to an MTP joint. The inventive devices and methods may be used to attach tissue at other locations in the body. 
     The terms “suture” and “suture strand” are used herein to mean any flexible member, natural or synthetic, useful in a surgical procedure and that are easily flexed. Examples include polymer sutures, wires, surgical tapes, tissue derived strands, and other suitable flexible strands or members. Sutures may be monofilament or multi-filament structures. The term “transverse” is used herein to mean crossing as in non-parallel. The term “tissue” is used herein to mean a patient&#39;s body tissue as well as a tissue graft which may be allograft, xenograft, or synthetic. 
       FIGS. 1-5  illustrate an example of a suture anchor assembly  100  according to the present invention. The suture anchor assembly  100  includes a base member  102  having a proximal end  104  and a distal end  106  ( FIG. 5 ). A bore  108  extends through the base member  102  from the distal end  106  to the proximal end  104  and defines a longitudinal axis  110  ( FIG. 4 ). A cavity  112  is formed in a proximal portion of the base member  102  and is enlarged radially relative to the bore  108 . An actuator in the form of a push button  114  is mounted in the cavity for axial translation between a first position in which it extends proximally from the cavity and abuts a shoulder adjacent the distal end of the cavity  112  and a second position distal to the first position. A spring  118  biases the button  114  into the first position. The base member  102  includes a radial projection in the form of a flange  120 . With one or more fingers positioned distal to the flange  120  and a thumb positioned proximal to the button  114 , a user can easily press the button by moving the thumb and fingers together. The base member further includes a trunnion  122  about which suture may be wound. The trunnion  122  includes a distal flange  124  to prevent wound suture from slipping distally off of the trunnion  122 . A notch  126  is formed radially in the flange to allow a suture to pass from the trunnion distally. Suture may be wound around the trunnion  122  and then passed through the notch to secure the suture to the base member. A safety device is used to block operation of the pushbutton  114 . In the illustrative example of  FIGS. 1-5 , the safety device is a cap  130  that may be moved by a user from a safe position ( FIG. 1 ) in which it prevents the user from pressing the button  114  to a delivery position ( FIG. 2 ) in which it allows the user to press the button  114 . With the cap  130  in the safe position a user can grip the assembly with a thumb on the cap  130  and manipulate the assembly without risk of prematurely pressing the button  114 . With the cap  130  in the delivery position a user can easily access the button  114  and press it. In the illustrative example of  FIGS. 1-5 , the cap  130  is hinged to the base member so that it may be moved without becoming detached from the base member. By remaining attached to the base member, the cap does not need to be separately accounted for by the surgical staff. 
     A delivery tube  220  is fixed within the bore  108  and extends from the distal end  106  of the base member  102 . The delivery tube  220  has a proximal end  222 , a distal end  224 , and a longitudinal passage  226 . The delivery tube  220  includes a slot  228  in the sidewall of the delivery tube adjacent the distal end  224  of the delivery tube. The slot  228  communicates through the sidewall to the longitudinal passage  226  and is open at the distal end  224 . The outer surface of the delivery tube  220  includes a plurality of reference marks  230  indicating a plurality of length increments. In the illustrative example of  FIGS. 1-5 , the reference marks are spaced 5 mm apart with the first reference mark being 5 mm from the proximal end of the slot  228 . Every other mark is wider than the prior mark to indicate increments of 10 mm. In the illustrative example of  FIGS. 1-5 , the delivery tube  220  is sized for delivering a suture anchor to a bone of a human foot and preferably has a diameter of 2-3 mm and a length of 30-60 mm. More preferably the delivery tube  220  has a diameter of 2.4 mm. 
     An ejector in the form of a push rod  250  has a proximal end  252  and a distal end  254 . The push rod  250  is positioned within the delivery tube  220  for axial translation between a first position in which the distal end  254  of the ejector is proximal to the distal end  224  of the delivery tube and a second position in which the distal end  254  of the ejector is distal to the first position. The proximal end  252  of the ejector is fixed to the pushbutton  114  and moves with the pushbutton  114  between the first and second positions. 
     A suture anchor  300  is positioned in the delivery tube  220  distal to the pushrod  250 . The suture anchor is best illustrated in  FIGS. 7-13 . The suture anchor  300  includes a generally rectangular body  302  having one or more holes through the body for receiving one or more suture strands. In the illustrative example of  FIGS. 7-13 , the suture anchor includes a pair of parallel holes  304  extending through the body  302  from a first side  306  to a second opposite side  308 . The second side  308  includes a groove  310  extending between the holes  304  to receive a suture  350  ( FIG. 13 ) extending through the holes  304 . With the suture  350  extending into one hole  304 , along the groove  310 , and out the other hole  304 , the suture is contained in the groove  310  to reduce the overall thickness of the suture anchor and suture assembly. Referring back to  FIGS. 1-3 , the suture anchor  300  is placed in the distal end of the delivery tube, the suture is passed through the slot  228 , through the notch  126 , and is then wound around the trunnion  122 . In the illustrative example of  FIGS. 7-13 , the suture anchor is sized for use in bones of a human foot and preferably has a width of 1.5-4 mm and a length of 4-8 mm. More preferably the suture anchor has a width of 2 mm and a length of 6.5 mm. The illustrative suture anchor has a pair of holes sized to receive a single strand of 2-0 high strength suture. Additional holes and holes of different sizes may be provided to receive more strands of suture and/or larger or smaller sutures. For example, 4 holes may be provided to receive 2 strands of suture. The suture ends may have needles attached. The suture anchor may be formed of any suitable material such as for example PEEK, stainless steel, titanium alloys, and resorbable materials. 
     A suture reservoir may be provided to hold an additional portion of the suture. For example, the suture reservoir may include a body having a circumference greater than that of the trunnion  122  so that an additional length of the suture may be wound around the reservoir body with fewer wraps than would be required for the trunnion. In the illustrative example of  FIGS. 1-5 , the suture reservoir is in the form of a flat card-like member  360  having a tab  362  extending from one end and positionable under the cap  130 . When the cap is in the safe position it traps the tab to retain the member  360  on the base member  102 . When the cap is in the delivery position the tab may be removed from under the cap and the member  360  separated from the base member. In the illustrative example of  FIGS. 1-5  the tab inserts through a gap between opposed pivots of a cap hinge assembly  364 . 
     Referring to  FIG. 6 , a hole forming instrument may be provided in a diameter suitable for forming a hole for insertion of the delivery tube  220  and anchor  300  into a bone. The hole forming instrument may be a punch, drill, wire or other suitable member. In the illustrative example of  FIG. 6 , the hole forming instrument is a k-wire  400  having an elongate shaft extending between a proximal end  402  and a distal end  404 . A diamond tip is formed at the distal end  404 . The k-wire  400  is sized to form a hole slightly larger than the delivery tube  220  diameter. For example, for a 2.4 mm diameter delivery tube, the k-wire is sized to form a 2.5 mm diameter hole. The k-wire  400  includes indicia in the form of reference marks  406  indicating a plurality of length increments and corresponding to the reference marks  230  on the delivery tube  220 . In the illustrative example of  FIG. 6 , the reference marks are spaced 5 mm apart with the first reference mark being 5 mm from the distal end of the k-wire  400 . Every other mark is wider than the prior mark to indicate increments of 10 mm. The k-wire  400  may be driven by a wire driver, drill, or other suitable device to form a hole in a bone. 
     In use, the k-wire  400  is used to form a hole into a bone from a proximal bone surface to a distal bone surface. The depth of the hole may be determined by reading the reference marks  406  on the k-wire shaft relative to the proximal bone surface. The k-wire may then be removed and the suture anchor assembly  100  may be used to position the anchor  300 . With the cap  130  in the safe position a user can grip the assembly with a thumb on the cap  130  and manipulate the assembly without risk of prematurely pressing the button  114  and ejecting the anchor  300 . The anchor  300  and delivery tube  220  may be inserted into the hole formed by the k-wire  400 . Preferably the delivery tube  220  is inserted to an indicated depth corresponding to the indicated depth of the hole formed by the k-wire  400 . Due to the reference marks  230  of the delivery tube  220  being offset from the distal end  224  of the delivery tube  220  by the length of the slot  228 , the delivery tube  220  will extend through the bone hole further than the k-wire by a distance equal to the slot length. This ensures that the anchor  300  will have room beyond the distal bone surface to rotate out of the end of the delivery tube  220  without the tube extending unnecessarily far. Once the delivery tube  220  is positioned, the safety cap  130  is flipped open and the button  114  is depressed ( FIG. 2 ). As the push rod  250  presses the anchor  300  out of the distal end of the delivery tube  220 , tension in the suture portion extending between the trunnion  122  and the anchor  300  causes the anchor  300  to pivot into a deployed position. 
       FIG. 14  illustrates a medial view of cuneiform  500 , metatarsal  502 , and proximal phalangeal  504  bones of a human foot while  FIG. 15  illustrates a dorsal view of the same bones. In the illustrative example of  FIGS. 14-15 , the bones are in the first ray of a human foot on which a bunion corrective procedure is to be performed. 
       FIGS. 16-24  illustrate a surgical procedure utilizing the illustrative examples of  FIGS. 1-13 . In  FIG. 16 , soft tissue  506  adjacent the metatarsophalangeal (MTP) joint  508 , e.g. capsular tissue extending between the metatarsal and phalangeal bones, has been dissected away from the metatarsal bone  502 . A bunionectomy has been performed to remove a protruding bone portion, e.g. a bunion, on the medial side of the metatarsal bone  502  leaving a decorticated region  510 . The decorticated region  510 , with its lack of a cortical outer layer, has little strength to support a traditional bone anchor. 
     In  FIG. 17 , the k-wire  400  of  FIG. 6  has been driven into the decorticated region  510 , across the metatarsal bone  502 , and out through the cortical bone  512  opposite the decorticated region  510 . The insertion depth of the k-wire is noted by reading the reference marks  406  on the k-wire shaft relative to the proximal bone surface. In the illustrative example of  FIG. 17 , the k-wire has been driven to the fourth reference mark from the proximal end of the k-wire. 
     In  FIG. 18 , the k-wire has been removed and the suture anchor  300  and delivery tube  220  are inserted into the hole formed by the k-wire  400 . The user&#39;s thumb  550  and at least one finger  552  grip the cap  130  and flange  120  and are used to manipulate the assembly  100  as needed. The delivery tube is inserted until the fourth reference mark  230  as measured from the proximal end of the delivery tube is aligned with the proximal bone surface of the decorticated region  510  corresponding to the k-wire indicated depth. 
     In  FIG. 19 , the safety cap  130  has been flipped open to arm the assembly  100  for deploying the anchor  300 . 
     In  FIG. 20 , the suture reservoir  360  has been dislodged from the cap  130  and allowed to hang below the rest of the assembly  100 . The button  114  has been pressed and the suture anchor  300  has been ejected from the end of the delivery tube causing it to begin to rotate. 
     In  FIG. 21 , the suture  350  has been unwound from the trunnion and tensioned to further rotate the anchor  300  and position it against the cortical bone  512  opposite the decorticated region  510 . In the illustrative example of  FIG. 21 , the suture  350  is optionally tensioned with the delivery tube still extending through the metatarsal bone  502 . The delivery tube blocks the hole through the bone and thus ensures that the anchor will rotate and be positioned against the cortical bone in the deployed position rather than be pulled back through the hole. 
     In  FIG. 22 , the delivery tube has been removed. Any number of anchors may be positioned by repeating the steps illustrated in  FIGS. 17-22 . The suture may be unwound from the suture reservoir  360  and used to repair the soft tissue  506 . 
       FIGS. 23 and 24  illustrate dorsal and medial views of the medial capsular soft tissue  506  reattached over the decorticated region by passing the ends of the suture  350  through the soft tissue and tying them in a knot. The suture  350  may be passed through the soft tissue with a suture passer, manually with a needle attached to the ends of the suture  350 , or by other suitable means known in the art. 
     Various examples have been illustrated and described. The various examples may be substituted and combined and other alterations made within the scope of the invention. For example, among other substitutions, male and female features may be reversed. The suture anchors may include features, such as additional holes, for coupling any number of sutures to the suture anchor. Needles may be supplied pre-attached to the suture ends and such needles may be attached to the suture reservoir  360 . The following are additional illustrative examples according to the invention. 
     1. A suture anchor assembly comprising:
         a base member having a proximal end and a distal end;   a delivery tube extending from the distal end of the base member, the delivery tube having a proximal end, a distal end, a longitudinal axis extending between the proximal end and the distal end, and a longitudinal passage;   an ejector having a proximal end and a distal end, the ejector being positioned within the delivery tube for axial translation between a first position in which the distal end of the ejector is proximal to the distal end of the delivery tube and a second position in which the distal end of the ejector is distal to the first position, the ejector being moveable by a user to the second position;   a safety device operable to prevent or allow movement of the ejector by a user to the second position; and   a flip-type suture anchor positioned in the delivery tube distal to the distal end of the ejector.
 
2. The assembly of example 1 wherein the safety device is manually moveable by a user from a safe position in which it prevents the user from moving the ejector to a delivery position in which it allows the user to move the ejector to the second position.
 
3. The assembly of example 2 further comprising an actuator coupled to the proximal end of the ejector, the actuator extending from the proximal end of the base member, the safety device comprising a cap covering the actuator in the safe position.
 
4. The assembly of example 3 wherein the cap is hinged to the base member.
 
5. The assembly of example 3 wherein the ejector is resiliently biased by a first force to the first position, the actuator being responsive to a user applied force greater than the first force to move the ejector from the first position to the second position.
 
6. The assembly of example 3 wherein the base member includes a radial projection engageable by one or more of a user&#39;s fingers positioned distal to the radial projection and the actuator comprises a button engageable by a user&#39;s thumb positioned proximal to the button.
 
7. The assembly of example 1 further including a slot in a sidewall of the delivery tube adjacent the distal end of the delivery tube, the slot communicating through the sidewall to the longitudinal passage and being open at the distal end, the assembly further comprising a suture extending from the base member distally outside of the delivery tube, through the slot, and into engagement with the suture anchor.
 
8. The assembly of example 7 being responsive to movement of the ejector into the second position to press the suture anchor distally, wherein tension from the suture causes the suture anchor to rotate.
 
9. The assembly of example 7 wherein the base member further comprises a trunnion about which a portion of the suture is wound.
 
10. The assembly of example 9 further comprising a suture reservoir removably attached to the assembly, the reservoir containing a portion of the suture.
 
11. The assembly of example 10 wherein the reservoir comprises a body with a portion of the suture wound around the member.
 
12. The assembly of example 11 wherein the body comprises a flat card-like member having a tab and the safety device comprise a cap, the tab being removably retained by the cap.
 
13. The assembly of example 1 further comprising a hole forming instrument having an elongate shaft extending between a proximal end and a distal end, the elongate shaft having one or more reference marks indicating a plurality of length increments, the delivery tube having corresponding reference marks indicating the plurality of length increments.
 
14. The assembly of example 13 wherein the reference marks of the delivery tube are offset proximally from the distal end of the delivery tube.
 
15. A method of anchoring tissue to a bone, the method comprising:
   forming a hole in a bone from a first outer bone surface through the bone to a second outer bone surface with a hole forming instrument having an elongate shaft with a plurality of reference marks indicating a plurality of length increments;   noting the position of the reference marks adjacent the first outer surface while a distal end of the elongate shaft is extending to or past the second outer surface;   removing the hole forming instrument;   inserting a delivery tube into the hole, the delivery tube having a plurality of reference marks corresponding to the reference marks on the hole forming instrument;   indexing the delivery tube within the hole so that the tube is inserted relative to the first outer surface with the tube reference marks in the same position as noted relative to the hole forming instrument;   ejecting a suture anchor from the delivery tube;   tensioning a suture extending from the suture anchor to set the suture anchor against the second outer surface; and   using the suture to secure the soft tissue adjacent the first outer surface.
 
16. The method of example 15 wherein the delivery tube reference marks are offset proximally from the distal end of the delivery tube.
 
17. A method of anchoring tissue to a bone, the method comprising:
   forming a hole in a bone from a first outer surface;   removing the hole forming instrument;   inserting a delivery tube into the hole;   deactivating a safety device to enable ejection of a suture anchor from the delivery tube;   ejecting a suture anchor from the delivery tube; and   using a suture extending from the suture anchor to secure the soft tissue adjacent the first outer surface.
 
18. The method of example 17 wherein deactivating the safety device comprises moving a cap to expose an actuator.
 
19. The method of example 18 wherein moving the cap comprises rotating the cap about a hinge and further wherein the actuator comprises a spring biased pushbutton connected to an ejector.
 
20. The method of example 17 wherein the delivery tube is mounted to a base member, the base member including a radial projection engageable by one or more of a user&#39;s fingers positioned distal to the radial projection and an actuator comprising a button engageable by a user&#39;s thumb positioned proximal to the button, wherein ejecting a suture anchor comprises pressing the button.
 
21. The method of example 18 wherein moving the cap frees a suture reservoir mounted relative to the delivery tube, the method further comprising removing the suture reservoir and dispensing suture from the suture reservoir.
 
22. A method of anchoring tissue to a bone adjacent a metatarsophalangeal joint of a human foot, the method comprising:
   forming a hole in a portion of a bone adjacent a metatarsophalangeal joint from a first outer surface of the bone to a second outer surface of the bone;   inserting a suture anchor through the hole;   rotating the suture anchor to engage the second outer surface of the bone to prevent the suture anchor from passing back through the hole; and   using a suture extending from the suture anchor to secure soft tissue adjacent the first outer surface.
 
23. The method of example 22 wherein the portion is a distal portion of a first metatarsal bone of a first ray of a human foot.
 
24. The method of example 23 further comprising performing a bunionectomy to remove a portion of the metatarsal bone creating a decorticated region on a medial side of the metatarsal bone.
 
25. The method of example 24 wherein forming a hole comprises forming a hole from the decorticated region through an opposite cortical surface.
 
26. The method of example 25 wherein using a suture extending from the suture anchor to secure soft tissue comprises securing capsular tissue of the metatarsophalangeal joint to the metatarsal bone.
 
27. The method of example 25 wherein inserting a suture anchor comprises:
   inserting a delivery tube into the hole;   deactivating a safety device to enable ejection of the suture anchor from the delivery tube; and   ejecting a suture anchor from the delivery tube.
 
28. The method of example 27 wherein the delivery tube is mounted to a base member, the base member including a radial projection engageable by one or more of a user&#39;s fingers positioned distal to the radial projection and an actuator comprising a button engageable by a user&#39;s thumb positioned proximal to the button, wherein ejecting a suture anchor comprises pressing the button.
 
29. The method of example 27 wherein deactivating the safety device comprises moving a cap to expose an actuator.
 
30. The method of example 29 wherein moving the cap comprises rotating the cap about a hinge and further wherein the actuator comprises a spring biased pushbutton connected to an ejector.
 
31. The method of example 29 wherein moving the cap frees a suture reservoir mounted relative to the delivery tube, the method further comprising removing the suture reservoir and dispensing suture from the suture reservoir.