Method and apparatus for meniscal repair

Abstract

An inserter including a hollow elongated shaft extending along a central longitudinal axis and having a proximal end and a distal end with a lumen extending therethrough; a sharp point at the distal end of the hollow elongated shaft, the sharp point disposed eccentric to the longitudinal axis of the hollow elongated shaft; a handle at the proximal end of the hollow elongated shaft; and a drive shaft movably disposed within the lumen of the hollow elongated shaft.

Claims

1. An inserter, comprising: a hollow elongated shaft extending along a central longitudinal axis and having a proximal end and a distal end with a lumen extending therethrough; a sharp point at the distal end of the hollow elongated shaft, the sharp point disposed eccentric to the longitudinal axis of the hollow elongated shaft; a handle at the proximal end of the hollow elongated shaft; and a drive shaft movably disposed within the lumen of the hollow elongated shaft; wherein at least one anchor is disposed within the lumen, the at least one anchor attached to a suture, wherein the anchor comprises: an elongated cylindrical body having a distal end and a proximal end, a longitudinal axis extending between the distal end and the proximal end, and an outer surface offset from the longitudinal axis, the distal end having a distal slot opening on the outer surface of the body and extending from the distal end of the body proximally along the longitudinal axis of the body, and the proximal end having a proximal slot opening on the outer surface of the body and extending from the proximal end of the body distally along the longitudinal axis of the body; the distal slot comprising a wide section and a narrow section, wherein the wide section has a width configured to slidably accommodate the suture in the wide section and the narrow section has a width configured to bind the suture in the narrow section, and further wherein the wide section is disposed distally of the narrow section.

2. The inserter of claim 1, wherein the distal end of the hollow elongated shaft has an oblique face forming the sharp point.

3. The inserter of claim 1, further comprising a lever extending from the handle and connected to the drive shaft.

4. The inserter of claim 3, wherein actuating the lever advances the drive shaft through the lumen of the hollow elongated shaft.

5. The inserter of claim 1, wherein moving the drive shaft distally through the lumen drives the at least one anchor toward the distal end of the hollow elongated shaft.

6. The inserter of claim 1, further comprising a slot formed by a perimeter and extending along the hollow elongated shaft and into the lumen.

7. The inserter of claim 6, further comprising a projection extending from the perimeter into the slot, along a length of the perimeter less than a full length of the perimeter, and back to the perimeter.

8. The inserter of claim 6, wherein the slot extends toward, but not entirely through, the sharp point of the hollow elongated shaft.

9. The inserter of claim 8, wherein the at least one anchor comprises a fin, wherein the fin extends into the slot.

10. An inserter, comprising: a hollow elongated shaft extending along a central longitudinal axis and having a proximal end and a distal end with a lumen extending therethrough; a sharp point at the distal end of the hollow elongated shaft, the sharp point disposed eccentric to the longitudinal axis of the hollow elongated shaft; a handle at the proximal end of the hollow elongated shaft; a drive shaft movably disposed within the lumen of the hollow elongated shaft; a lever extending from the handle and connected to the drive shaft; wherein actuating the lever advances the drive shaft through the lumen of the hollow elongated shaft; and a tension wheel extending from the handle; wherein at least one anchor is disposed within the lumen, the at least one anchor attached to a suture, wherein the anchor comprises: an elongated cylindrical body having a distal end and a proximal end, a longitudinal axis extending between the distal end and the proximal end, and an outer surface offset from the longitudinal axis, the distal end having a distal slot opening on the outer surface of the body and extending from the distal end of the body proximally along the longitudinal axis of the body, and the proximal end having a proximal slot opening on the outer surface of the body and extending from the proximal end of the body distally along the longitudinal axis of the body; the distal slot comprising a wide section and a narrow section, wherein the wide section has a width configured to slidably accommodate the suture in the wide section and the narrow section has a width configured to bind the suture in the narrow section, and further wherein the wide section is disposed distally of the narrow section.

11. The inserter of claim 10, wherein the drive shaft is hollow.

12. The inserter of claim 11, wherein the suture extends through the drive shaft and engages the tension wheel.

13. The inserter of claim 12, wherein rotation of the tension wheel in a first direction increases tension on the suture and rotation of the tension wheel in a second direction decreases tension on the suture.

14. The inserter of claim 10, wherein the tension wheel and the lever extend from opposing sides of the handle.

15. The inserter of claim 10, further comprising a slot formed by a perimeter and extending along the hollow elongated shaft and into the lumen.

16. The inserter of claim 15, further comprising a projection extending from the perimeter into the slot, along a length of the perimeter less than a full length of the perimeter, and back to the perimeter.

17. The inserter of claim 15, wherein the at least one anchor comprises a fin, wherein the slot receives the fin.

18. The inserter of claim 17, wherein the projection retards movement of the at least one anchor through the lumen of the hollow elongated shaft.

19. The inserter of claim 17, wherein the slot extends toward, but not entirely through, the sharp point of the hollow elongated shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:

(2) FIGS. 1-3 are schematic views showing a meniscal repair system formed in accordance with the present invention;

(3) FIGS. 3A and 3B are schematic views showing the distal end of the meniscal repair system shown in FIGS. 1-3;

(4) FIGS. 4-10 are schematic views showing further details of an anchor of the meniscal repair system shown in FIGS. 1-3;

(5) FIG. 11 is a schematic view showing a meniscal repair effected using the system shown in FIGS. 1-3;

(6) FIGS. 12-17 are schematic views showing an anchor being deployed from an inserter;

(7) FIG. 18 is another schematic view showing a meniscal repair effected using the system shown in FIGS. 1-3;

(8) FIG. 19 is still another schematic view showing a meniscal repair effected using the system shown in FIGS. 1-3;

(9) FIGS. 20-22 are schematic views showing how the suture may be twisted so as to enhance the holding strength of the meniscal repair system; and

(10) FIGS. 23 and 24 are schematic views showing an alternative anchor formed in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(11) Looking first at FIGS. 1-3, 3A and 3B, there is shown a novel system 5 for meniscal repair. System 5 generally comprises a plurality of anchors 10, a length of suture 15 and an inserter 20.

(12) Anchors 10 are shown in greater detail in FIGS. 4-10. Each of the anchors 10 generally comprises an elongated body 25 which, in its preferred construction, is generally cylindrical so that it can make a close sliding fit within the lumen of a hollow delivery needle, as will hereinafter be discussed in further detail. Elongated body 25 is characterized by a distal end 30 and a proximal end 35.

(13) On a “top” side of elongated body 25, a distal slot 40 extends proximally along the elongated body, with distal slot 40 comprising a wide section 45 and a narrow section 50. Also on the “top” side of elongated body 25, a proximal slot 55 extends distally along the elongated body, with proximal slot 55 comprising a wide section 60 and a narrow section 65. Distal slot 40 is aligned with proximal slot 55. Preferably narrow section 50 of distal slot 40 is narrower than narrow section 65 of proximal slot 55 (FIG. 5), and preferably wide section 45 of distal slot 40 is the same width as wide section 60 of proximal slot 55. Thus it will be seen that narrow section 50 of distal slot 40 is narrower than narrow section 65, which is itself narrower than the wide section 45 of distal slot 40 and wide section 60 of proximal slot 55. Furthermore, the aforementioned narrow section 50, narrow section 65, wide section 45 and wide section 60 are sized relative to suture 15 so that: (i) suture 15 will make a tight binding fit with narrow section 50 of distal slot 40, (ii) suture 15 will make a sliding fit with narrow section 65 of proximal slot 55, and (iii) suture 15 will move easily through wide section 45 of distal slot 40 and wide section 60 of proximal slot 55. A wall 70 separates narrow section 50 of distal slot 40 from narrow section 65 of proximal slot 55.

(14) On a “bottom” side of elongated body 25 (i.e., on the side diametrically opposed to the aforementioned “top” side of elongated body 25), a recess 75 (FIGS. 6 and 7) extends into elongated body 25. Thus, recess 75 is diametrically opposed to the aforementioned distal slot 40 and proximal slot 55. Recess 75 is formed long enough, and deep enough, so that it communicates with narrow section 50 of distal slot 40 and with a portion of wide section 45 of distal slot 40, and it communicates with narrow section 65 of proximal slot 55 and with a portion of wide section 60 of proximal slot 55 (FIG. 7). Recess 75 is significantly wider than suture 15, so that suture 15 can move easily through recess 75.

(15) On account of the foregoing construction, wide section 45 of distal slot 40, narrow section 50 of distal slot 40, recess 75, wide section 60 of proximal slot 55 and narrow section 65 of proximal slot 55 provide a suture pathway about elongated body 25 of anchor 10. Furthermore, and as will hereinafter be discussed in further detail, on account of the disposition and sizing of the aforementioned wide section 45, narrow section 50, recess 75, wide section 60 and narrow section 65, anchor 10 can be slidably mounted on the suture and then selectively secured to the suture.

(16) A fin 80 extends “downwardly” out of the “bottom” side of elongated body 25. Fin 80 is aligned with recess 75 and diametrically opposed to distal slot 40 and proximal slot 55.

(17) It should be appreciated that, while elongated body 25 is preferably generally cylindrical, it is also preferably not tubular: at no point along its length does elongated body 25 have a complete outer periphery with a hollow interior.

(18) Suture 15 may comprise any suture material of the sort known in the art. By way of example but not limitation, suture 15 may comprise braided suture, so-called “monofilament” suture, etc., and may be formed so as to be either “permanent” or absorbable. In one preferred form of the invention, suture 15 comprises braided suture.

(19) As will hereinafter be discussed in further detail, suture 15 is intended to be passed through anchor 10 (or, stated another way, anchor 10 is intended to be “strung” onto suture 15) by passing the suture through distal slot 40, into and along bottom recess 75, and back through proximal slot 55 (see FIGS. 14-16, 20, etc.). In this respect it will be appreciated that wide section 45 of distal slot 40, recess 75 and wide section 60 of proximal slot 55 are all sized sufficiently wide relative to suture 15 that suture 15 can slide easily through those openings. Thus, so long as suture 15 remains disposed in those openings, suture 15 will be free to move easily through anchor 10 (and, correspondingly, anchor 10 will be free to slide easily along suture 15). However, and as will hereinafter be discussed in further detail, when suture 15 is directed into narrow section 50 of distal slot 40, a tight interference fit will be created between the anchor and the suture, thereby securing the anchor and suture to one another.

(20) As will also hereinafter be discussed in further detail, a plurality of anchors 10 may be “strung” on a single suture 15 (see FIGS. 2, 13, 15, 20, etc.). As noted above, when suture 15 passes through wide section 45 of distal slot 40, recess 75 and wide section 60 of proximal slot 55 of each anchor 10, the anchors may be advanced along the suture. However, and as will hereinafter be discussed in further detail, when suture 15 is directed into narrow section 50 of distal slot 40 of an anchor, a tight interference fit will be created between that anchor and the suture, thereby securing that anchor and the suture to one another. Significantly, and as will hereinafter be discussed in further detail, when a plurality of anchors 10 are slidably mounted on a single suture 15, each of the anchors 10 may be selectively and individually secured to the suture when and where desired by the user.

(21) Looking again at FIGS. 1-3, 3A and 3B, inserter 20 generally comprises an elongated shaft 85 having a central lumen 90 extending therethrough. Elongated shaft 85 terminates in a sharp point 95 at its distal end. Sharp point 95 is created by forming an oblique face 96 (FIGS. 3A, 3B and 12) on the distal end of the elongated shaft, such that a section 97 of elongated shaft 85 is exposed at the mouth of lumen 90. A handle 100 (FIGS. 1-3) is secured to elongated shaft 85 at its proximal end. A slot 105 (FIG. 13) is formed in elongated shaft 85 on its “bottom” side. Slot 105 extends into exposed section 97 of elongated shaft 85. A small projection 106 (FIGS. 13 and 15) extends into slot 105.

(22) As seen in FIGS. 2, 3A, 3B and 13, elongated shaft 85 is sized to receive a plurality of anchors 10 therein, with those anchors being “strung” on a single suture 15. To this end, lumen 90 of elongated shaft 85 is sized to slidably receive elongated bodies 25 of anchors 10, with fins 80 extending out through slot 105 of elongated shaft 85. Fins 80 and slot 105 cooperate to keep anchors 10 aligned within lumen 90 of elongated shaft 85. The aforementioned small projection 106 provides nominal resistance to the passage of fins 80 through slot 105. Small projection 106 is positioned such that the lead anchor 10 in lumen 90 normally does not exit the distal end of the elongated shaft: however, with the application of a distally-directed force, fin 80 can slip past small projection 106 so as to release the lead anchor from lumen 90.

(23) Preferably, handle 100 includes a lever 110 for selectively advancing a drive shaft 115 along lumen 90 of elongated shaft 85, whereby to selectively advance anchors 10 along lumen 90 and thereby eject anchors 10 one at a time from the distal end of elongated shaft 85. Handle 100 preferably also includes a tension wheel 120 for selectively tensioning the suture emerging from the proximal-most anchor 10 which is held in lumen 90 of elongated shaft 85. To this end, drive shaft 115 is preferably hollow so that suture 15 can extend from the proximal-most anchor 10, through the drive shaft and be engaged by tension wheel 120.

(24) As seen in FIG. 11, system 5 may be used to close a tear 125 in a meniscus 130 using a plurality of anchors 10 and a suture 15. More particularly, and looking now at FIGS. 11-18, sharp point 95 of inserter 20 is advanced into meniscus 130, across tear 125, and then out the far side of meniscus 130. Then the leading anchor 10 in lumen 90 (i.e., anchor 10A in FIG. 18) is ejected from elongated shaft 85. This is done by advancing drive shaft 115 (e.g., with lever 110) so that the leading anchor 10 has its fin 80 forced past small projection 106 in slot 105, whereby to release the anchor from the inserter. As the leading anchor 10 is ejected from lumen 90, suture 15 initially resides in wide section 45 of distal slot 40. However, by holding suture 15 under tension as anchor 10 is forced out of lumen 90 by drive shaft 115, anchor 10 is turned (i.e., away from exposed section 97 of elongated shaft 85) and suture 15 is forced into narrow section 50 of distal slot 40, whereby to secure suture 15 to anchor 10 in a cleating action. At the same time, another portion of suture 15 advances from wide section 60 of proximal slot 55 into narrow section 65 of proximal slot 55. Thus, at this point suture 15 will extend through narrow section 50 of distal slot 40, recess 75 and narrow section 65 of proximal slot 55, with the suture being secured to the anchor by virtue of the tight binding fit established between narrow section 50 of distal slot 40 and suture 15.

(25) Then, while keeping suture 15 under tension so that anchor 10 remains positioned against the far side of meniscus 130, inserter 20 is withdrawn back across the meniscus, moved laterally by an appropriate distance, re-inserted across tear 125, passed out the far side of meniscus 130, and another anchor 10 (i.e., anchor 10B in FIG. 18) is deployed. Again, suture 15 is held under tension as the second anchor is deployed on the far side of the meniscus so that anchor 10 is turned (i.e., away from exposed section 97 of elongated shaft 85) and suture 15 is forced into the narrow section 50 of the distal slot 40 of that second anchor, whereby to secure that second anchor in a cleating action. Again, as this occurs, another portion of suture 15 advances from wide section 60 of proximal slot 55 into narrow section 65 of proximal slot 55. Thus, at this point suture 15 will extend through narrow section 50 of distal slot 40, recess 75 and narrow section 65 of proximal slot 55, with the suture being secured to the anchor by virtue of the tight binding fit established between narrow section 50 of distal slot 40 and suture 15.

(26) Thus, the suture length extending between the first-deployed anchor (i.e., anchor 10A in FIG. 18) and the second-deployed anchor (i.e., anchor 10B in FIG. 18) is maintained under tension so as to hold tear 125 closed.

(27) This operation may thereafter be repeated as many times as is necessary in order to close the tear. See, for example, FIG. 19, where six anchors 10, all connected by a single suture 15, are used to close a tear in the meniscus using a complex running stitch. This ability to set a variable number of anchors in the repair procedure, limited only by the number of anchors held in inserter 20, is a significant advance in the art.

(28) If desired, a small knot may be formed in the suture after placement of the last anchor for added holding strength. However, it should be appreciated that this knotting step is purely optional and not required.

(29) It will be appreciated that, since anchors 10 are turned away from exposed section 97 of elongated shaft 85 during deployment, the disposition of elongated shaft 85 can largely regulate the disposition of anchors 10 relative to the meniscus. Thus, where exposed section 97 of elongated shaft 85 is oriented so that it is in the “6 o'clock” or “12 o'clock” position, the anchor will be set against the meniscus with a vertical disposition. Correspondingly, where exposed section 97 of elongated shaft 85 is oriented so that it is in the “3 o'clock” or “9 o'clock” position, the anchor will be set with a horizontal disposition (e.g., in the manner shown in FIGS. 11 and 18). Of course, in some situations it may be possible to thereafter adjust the disposition of an anchor 10 against the meniscus, e.g., by using a grasper to manually turn the anchor.

(30) In one preferred form of the invention, the first anchor 10 in inserter 20 may have suture 15 permanently secured thereto, e.g., prior to insertion of the inserter into the meniscus. By way of example but not limitation, suture 15 may be glued, welded or otherwise secured to first anchor 10. Furthermore, where suture 15 is so secured to first anchor 10, the terminated suture may terminate substantially within the anchor or it may extend out of the anchor, as desired.

(31) Significantly, since suture 15 is secured to each deployed anchor, the failure of any one suture stitch does not threaten the integrity of the remainder of the repair. Indeed, if a suture stitch were to fail (e.g., break), it would not disrupt the intact stitches in the remainder of the repair. The removed anchor could then be replaced by two or more additional anchors so as to reinforce the repair.

(32) It will be appreciated that the holding power of each anchor 10 on suture 15 is a function of the cleating action provided by that anchor on suture 15. It will also be appreciated that this cleating action is largely a function of the binding interference fit which is established between the suture and narrow section 50 of distal slot 40, since the suture makes a loose fit through recess 75 and a sliding fit with narrow section 65 of proximal slot 55. In practice, it has been found that approximately 35 Newtons of holding strength can be provided without reducing the width of narrow section 50 of distal slot 40 to the point where it becomes excessively difficult to insert the suture into narrow section 50 and/or where the act of insertion causes damage to the suture. In the great majority of cases, a holding strength of approximately 35 Newtons has been found to be more than adequate for meniscal repair.

(33) However, it has also been discovered that, to the extent that it is desired to provide even greater holding strength to the system, suture 15 can be twisted on itself during deployment so as to achieve holding strength of up to 75 Newtons without requiring any change to the diameter of narrow section 50 of distal slot 40. More particularly, and looking now at FIGS. 20-22, sharp point 95 of inserter 20 is advanced into meniscus 130, across tear 125, and then out the far side of meniscus 130. Then, with suture 15 in a relaxed condition, a first anchor 10A is ejected from lumen 90 of inserter 20 so that the first anchor 10A sits on the far side of the meniscus. As this occurs, first anchor 10A will tend to turn as it exits lumen 90, but suture 15 will tend to stay in wide section 45 of distal slot 40 and not enter narrow section 50 of distal slot 40. Thus, at this point, suture 15 is still relatively free to slide relative to first anchor 10A. With suture 15 still in a relaxed condition, inserter 20 is then withdrawn from meniscus 130, moved laterally, re-inserted across tear 125 and passed out the far side of meniscus 130. Then elongated shaft 85 of inserter 20 is rotated so as to wrap the suture around the inserter. By way of example but not limitation, inserter 20 may be rotated three revolutions. As this occurs, there can be some gathering of the slack between first anchor 10A and inserter 20 and/or there can be some pay out of the suture stored inside the inserter. At this point, a second anchor 10B is ejected from lumen 90 of inserter 20 so that second anchor 10B sits on the far side of the meniscus. Inserter 20 is then withdrawn back through the meniscus. Then the suture is tensioned (e.g., with tension wheel 120) so that (i) the suture between anchors 10A and 10B is reduced, so as to close the tear in the meniscus. (ii) the winding in the suture is pulled taut, and (iii) the suture is forced into narrow section 50 of distal slot 40 and narrow section 65 or proximal slot 55. As a result, this approach provides both the aforementioned cleating action provided by capturing the suture within narrow section 50 of distal slot 40, and also a supplemental securing action provided by the suture which has been wound on itself. In practice, it has been found that this dual effect provides approximately 75 Newtons of holding strength.

(34) Thereafter, additional anchors may be provided as needed so as to close the tear.

(35) FIGS. 23 and 24 show an alternative construction for anchor 10. More particularly, with the construction shown in FIGS. 23 and 24, the distal and proximal portion of elongated body 25 are cut back on the “top” of the anchor, and recess 75 is elongated relative to distal slot 40 and proximal slot 55.

(36) Thus, the present invention provides a meniscal repair system which comprises a plurality of anchors that ride over a single suture strand, which can be singly deployed within the body, with each single anchor acting as an independent fixation point for the suture strand. The ability to lock the suture within each anchor (such as with the cleating feature provided for each anchor) provides the ability for each anchor to act as an independent fixation point for the suture strand. Furthermore, these independent fixation points allow the suture, running from one anchor to the next anchor, to act as an independent suture stitch. Additionally, the entire contiguous repair construct consists of multiple independent suture stitches extending between multiple adjacent anchors, with the construct such that if one or more stitches are damaged or become loose or disengaged from an anchor, the other suture stitches are unaffected. Also, the ability to individually tighten each suture stitch (i.e., the suture strand extending between adjacent anchors) by drawing the suture through the deployed anchor's locking feature permits the desired suture tension to be achieved.

(37) The present invention provides the ability to position variable suture patterns across the tom meniscus in a contiguous fashion. Significantly, the repairing construct can have more than two points of fixation to the meniscus using a single strand of suture, and does not require any suture tying.

(38) Also, the present invention provides the ability to remove an anchor from a deployed suture construct without disrupting previously-deployed anchors. This would be accomplished by sliding the dislodged implant along the suture strand outside of the body and breaking or cutting the implant without damaging the suture. The user can then continue to deliver subsequent implants from the same device to complete the repair.

(39) And the present invention provides the ability to cut the suture strand after two or more implants have been deployed into the body, and then secure the deployed suture strand to the leading anchor in the inserter (e.g., by knotting) so that the user can continue to deploy subsequent unused anchors still residing within the inserter as part of the repair construct.

(40) The present invention provides a gating mechanism for singly deploying each anchor from the inserter, e.g., fin 80, slot 105 and projection 106.

(41) Furthermore, the present invention provides an approach for wrapping or twisting the suture around the inserter prior to ejection of an anchor so as to form a suture loop around the suture emanating from the anchor, so that subsequent tightening of the suture through the anchor draws the wrapped suture loop towards the anchor and further secures the suture to the anchor.

MODIFICATIONS

(42) It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.