INSERTION INSTRUMENT FOR ANCHOR ASSEMBLY

• US 20120004669A1
• Filed: 06/29/2011
• Published: 01/05/2012
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Overes, Tom, Talbot, James, Vennard, Daniel, Manos, Jamie, Larsen, Scott, Singhatat, Wamis, Henrichsen, Kevin
• Granted Patent: US 9,451,938 B2
• Time in Patent Office: Days
• US Class Current: 606/139
• CPC Class Codes: A61B 17/0057 Implements for plugging an opening in the wall of a hollow or tubular organ, e.g. for sealing a vessel puncture or closing a cardiac septal defect sutures A61B17/04; closing rectum or urethra near body surface A61F2/0009
• 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 17/0467 Instruments for cutting sutures surgical cutting instruments A61B17/32
• CPC Class Codes: A61B 17/0469 Suturing instruments for use in minimally invasive surgery, e.g. endoscopic surgery
• CPC Class Codes: A61B 17/0482 Needle or suture guides guides for drills, pins or wire A61B17/17; for puncturing needles A61B17/3403
• CPC Class Codes: A61B 17/0483 Hand-held instruments for holding sutures A61B17/0469 takes precedence; other holders for needles or sutures A61B17/06061; surgical forceps A61B17/28; surgical pincettes A61B17/30
• CPC Class Codes: A61B 17/0487 Suture clamps, clips or locks, e.g. for replacing suture knots; Instruments for applying or removing suture clamps, clips or locks suture anchors A61B17/0401; wound clamps or clips A61B17/08; ligaturing clamps or clips A61B17/122
• CPC Class Codes: A61B 17/842 Flexible wires, bands or straps A61B17/72, A61B17/82, A61B17/86 take precedence
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00623 Introducing or retrieving devices therefor
• CPC Class Codes: A61B 2017/00663 the implement being a suture
• CPC Class Codes: A61B 2017/0406 Pledgets
• CPC Class Codes: A61B 2017/0409 Instruments for applying suture anchors
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening
• CPC Class Codes: A61B 2017/0417 T-fasteners
• CPC Class Codes: A61B 2017/0419 H-fasteners
• CPC Class Codes: A61B 2017/0464 for soft tissue
• CPC Class Codes: A61B 2017/0475 using sutures having a slip knot
• CPC Class Codes: A61B 2017/0477 with pre-tied sutures
• CPC Class Codes: A61B 2017/0496 for tensioning sutures
• CPC Class Codes: A61B 2017/06042 : located close to needle tip
• CPC Class Codes: A61B 2017/06052 : Needle-suture combinations in which a suture is extending inside a hollow tubular needle, e.g. over the entire length of the needle
• CPC Class Codes: A61B 2017/06176 : with protrusions, e.g. barbs
• CPC Class Codes: A61B 2017/2917 : with flexible part
• CPC Class Codes: A61B 2017/292 : connection of actuating rod to handle, e.g. ball end in recess

Abstract

An insertion instrument is configured to eject a pair of anchor bodies across an anatomical gap so as to approximate the gap. The insertion instrument can include a single cannula that retains the pair of anchor bodies in a stacked relationship, or a pair of adjacent cannulas that each retain respective anchor bodies. The insertion instrument can be actuated so as to eject the anchor bodies into respective target anatomical locations.

Claims

1. An insertion instrument configured to eject at least one anchor at a target location, the anchor including an anchor body that has a substrate that extends substantially along a direction of elongation, the substrate defining a plurality of openings spaced along the direction of elongation, the anchor further including an actuation member that is woven through at least two of the openings, the insertion instrument comprising:

a cannula defining an elongate opening sized to receive the anchor body; and

a pusher member insertable into the cannula and configured to be depressed in the elongate opening so as to eject the anchor body from the cannula and into the target location, such that when a tensile force is applied to the actuation member along a direction substantially along the direction of elongation, the anchor body expands along a second direction perpendicular with respect to the direction of elongation.

2. The insertion instrument as recited in claim 1, wherein the pusher member is configured to brace against the anchor body.

3. The insertion instrument according to claim 1, wherein the cannula defines a slot that receives the actuation member, such that the actuation member extends from the knot body out the cannula.

4. The insertion instrument according to claim 1, wherein the pusher member comprises a push rod that has an outer cross-sectional dimension which is smaller than that of the elongate opening of said cannula such that the actuation member extends through said elongate opening of said cannula alongside the push rod.

5. The insertion instrument according to claim 1, wherein the pusher member comprises a central bore so that the anchor body can be inserted through the central bore and into the elongate opening of the cannula.

6. The insertion instrument according to claim 1, wherein the insertion instrument further comprises a handle, and the cannula is removably attached to the handle.

7. The insertion instrument according to claim 1, wherein said cannula has a conical inlet.

8. The insertion instrument according to claim 1, wherein depressing the pusher member causes the anchor body to translate out the opening.

9. The insertion instrument according to claim 8, wherein the cannula defines a distal end that defines a needle tip, and depressing the pusher member causes the anchor body to translate distally out the opening.

10. The insertion instrument according to claim 9, wherein the needle tip is conical.

11. The insertion instrument according to claim 8, wherein the opening terminates at a distal end, and the cannula defines a side ejection portal in communication with the distal end of the opening.

12. The insertion instrument according to claim 11, further comprising a tip that extends distally from the cannula.

13. The insertion instrument according to claim 12, wherein the tip is conical.

14. The insertion instrument according to claim 13, wherein the tip comprises a cone.

15. The insertion instrument according to claim 8, wherein the cannula defines a tapered distal end.

16. The insertion instrument according to claim 1, wherein the cannula defines a first longitudinal aperture and the pusher member defines a second longitudinal aperture so that by rotating said pusher member relative to said cannula said first and second aperture can be aligned and said insertion instrument can be released from said anchor body.

17. The insertion instrument according to claim 1, wherein the pusher member is a first pusher member, the insertion instrument further comprising a cannulated second pusher member disposed in the elongate opening of the cannula.

18. The insertion instrument according to claim 17, wherein the first pusher member is disposed in the cannulated second pusher member.

19. The insertion instrument according to claim 18, wherein the cannulated second pusher member contains a first anchor body.

20. The insertion instrument according to claim 19, wherein the cannula further contains a second anchor body disposed distal to the first anchor body.

21. The insertion instrument according to claim 20, wherein the first pusher member is initially coupled to the second pusher member such that the first pusher member and the second pusher member translate distally in tandem during a first stroke.

22. The insertion instrument according to claim 21, wherein the first stroke causes the second pusher member to eject the second anchor body out the cannula.

23. The insertion instrument according to claim 22, wherein the first pusher member is decoupled from the second pusher member after the first stroke.

24. The insertion instrument according to claim 23, wherein a second stroke of the first pusher member ejects the first anchor body from the cannula.

25. The insertion instrument according to claim 24, wherein the first and second pusher members are coupled so as to translate in tandem during a first portion of the second stroke.

26. The insertion instrument according to claim 20, further comprising a casing that is translatably fixed to the cannula.

27. The insertion instrument according to claim 26, further comprising complementary first and second guide members that are operably coupled between the casing and the second pusher member so as to guide relative movement between the casing and the second pusher member.

28. The insertion instrument according to claim 27, further comprising an attachment member that is translatably fixed to the second pusher member.

29. The insertion instrument according to claim 28, further comprising a plunger translatably fixed to the first pusher member.

30. The insertion instrument according to claim 29, wherein the first and second guide members are operably coupled between the casing and the attachment member.

31. The insertion instrument according to claim 29, wherein the first and second guide members are configured to translatably couple the first pusher member to the second pusher member.

32. The insertion instrument according to claim 29, wherein the attachment member is translatably coupled to the plunger.

33. The insertion instrument according to claim 31, wherein the attachment member comprises a collar that extends about the plunger.

34. The insertion instrument according to claim 28, wherein the first and second guide members comprise a 1) guide track that extends into at least one of the attachment member and the casing, and 2) a guide pin that is coupled to the other of the attachment member and the casing, such that the guide pin rides in the guide track.

35. The insertion instrument according to claim 34, wherein the guide track extends into the attachment member and the guide pin extends from the casing into the guide track.

36. The insertion instrument according to claim 35, wherein the guide pin is translatably fixed to the casing.

37. The insertion instrument according to claim 35, wherein the guide track defines a first track portion and a second track portion that is offset with respect to the first track portion.

38. The insertion instrument as recited in claim 37, wherein rotation of the plunger causes the guide pin to ride from the first track portion to the second track portion.

39. The insertion instrument as recited in claim 38, wherein the attachment member defines a stop member at terminal ends of the first and second track portions.

40. The insertion instrument as recited in claim 34, wherein the guide pin translates proximally in the guide track as the plunger moves distally relative to the casing so as to eject the first and second anchor bodies from the insertion instrument.

41. The insertion instrument as recited in claim 34, wherein the guide track defines a base having an edge, wherein the guide pin translates along the edge so as to provide at least one of tactile and audio feedback.

42. The insertion instrument according to claim 1, further comprising a casing that is translatably fixed to the cannula.

43. The insertion instrument according to claim 42, further comprising complementary first and second guide members that are operably coupled between the casing and the pusher member so as to guide relative movement between the casing and the first pusher member.

44. The insertion instrument according to claim 42, wherein the cannula further contains a second anchor body disposed distal to the first anchor body.

45. The insertion instrument as recited in claim 44, wherein the cannula defines a distal ejection port, and the first and second anchor bodies are ejected out the distal ejection port along a direction substantially parallel to the elongate opening.

46. The insertion instrument according to claim 44, wherein the first guide member a guide track, and the second guide member is a guide pin that rides in the guide track as the plunger moves distally relative to the casing so as to eject the first and second anchor bodies from the insertion instrument.

47. The insertion instrument according to claim 44, wherein the guide track is carried by the casing.

48. The insertion instrument according to claim 47, wherein the guide pin is translatably fixed to the first pusher member.

49. The insertion instrument according to claim 48, wherein the guide track defines a first track portion and an intermediate track portion that extends out from the first track portion

50. The insertion instrument as recited in claim 49, wherein rotation of the plunger causes the guide pin to ride from the first track portion to the intermediate track portion.

51. The insertion instrument as recited in claim 49, further comprising a guide housing that defines at least one aperture extending therethrough, and the plunger carries at least one guide post that is radially offset from the at least one aperture before the plunger is rotated, and is aligned with the at least one aperture after the plunger is rotated.

52. The insertion instrument as recited in claim 51, wherein the guide post extends through the at least one aperture as the plunger further translates along a second stroke so as to eject the first and second anchor bodies from the cannula.

53. The insertion instrument according to claim 20, further comprising a coupling assembly configured to releasably translatably fix the first and second pusher members.

54. The insertion instrument according to claim 53, wherein the coupling assembly fixes the first and second pusher members during a first stroke whereby the second anchor body is ejected from the cannula.

55. The insertion instrument according to claim 54, wherein the coupling assembly decouples the first and second pusher members from each other during a second stroke such that the first pusher member is translatable relative to the second pusher member, whereby the first pusher member ejects the first anchor body out the cannula.

56. The insertion instrument according to claim 53, further comprising an attachment member that is translatably fixed to the second pusher member.

57. The insertion instrument according to claim 56, further comprising a plunger translatably fixed to the first pusher member.

58. The insertion instrument according to claim 57, wherein the attachment member is releasably attached to the plunger with respect to translation.

59. The insertion instrument according to claim 58, wherein the coupling assembly comprises a coupling member that is carried by the attachment member, and is configured to further extend into a first recess of the plunger so as to translatably couple the attachment member to the plunger.

60. The insertion instrument according to claim 59, further comprising a casing that is translatably fixed to the cannula.

61. The insertion instrument according to claim 60, wherein the casing carries a second recess that is spaced from the first recess.

62. The insertion instrument according to claim 61, wherein the casing defines the second recess.

63. The insertion instrument according to claim 62, wherein when the coupling member moves to a location aligned with the second recess, the coupling member is driven out of the first recess and into the second recess, thereby translatably decoupling the attachment member and the plunger.

64. The insertion instrument according to claim 63, wherein the attachment member defines a channel, and the coupling member is configured to move across the channel so as to decouple from the plunger and couple to the casing

65. The insertion instrument as recited in claim 61, wherein the casing carries an inner housing that carries the second recess.

66. The insertion instrument as recited in claim 65, wherein when the coupling member moves to a location aligned with the second recess, the coupling member is driven out of the first recess and into the second recess, thereby translatably decoupling the attachment member and the plunger.

67. The insertion instrument as recited in claim 66, wherein the coupling member comprises a leaf spring that is attached to the attachment member.

68. The insertion instrument as recited in claim 66, wherein the leaf spring is integral with the attachment member.

69. The insertion instrument according to claim 61, further comprising complementary first and second guide members that are operably coupled between the casing and the second pusher member so as to guide relative movement between the casing and the second pusher member.

70. The insertion instrument according to claim 69, wherein the complimentary guide members define a first portion, a second portion that is offset from the first portion, and stop at one end of the first portion.

71. The insertion instrument according to claim 70, wherein the coupling member is a latch, and a stop of the first portion prevents distal translation of the second pusher member before the latch is aligned with the second recess.

72. The insertion instrument according to claim 71, wherein the first portion has a length sufficient such that movement of the guide member along the first portion causes the second pusher member to eject the second anchor body from the insertion instrument.

73. The insertion instrument according to claim 72, wherein movement of the guide member along the second portion causes the latch to move in alignment with the second recess.

74. The insertion instrument according to claim 73, wherein the latch moves into the second recess so as to translatably decouple the first and second pusher members, such that the first pusher member is translatable independently of the second pusher member so as to eject the first anchor body from the instrument.

75. The insertion instrument as recited in claim 74, wherein the cannula defines a distal ejection port, and the first and second anchor bodies are ejected from the instrument through the distal ejection port.

76. The insertion instrument as recited in claim 73, wherein the second pusher member comprises a plug that is disposed such that an ejection port of the cannula extends between the plug and the first pusher member when the latch is in alignment with the second recess, such that the first anchor body can be ejected from the instrument through the ejection port.

77. The insertion instrument as recited in claim 73, wherein further translation of the first pusher member is independent of the second pusher member so as to eject the first anchor body from the instrument.

78. The insertion instrument according to claim 1, further comprising a depth stop that extends out from the cannula.

79. The insertion instrument according to claim 1, further configured to retain at least one end of a tensioning member that is coupled to the actuation member.

80. The insertion instrument according to claim 79, wherein the tensioning member comprises a tensioning strand having first and second ends, and the insertion instrument is configured to retain the first and second ends.

81. The insertion instrument accordingly to claim 80, configured to selectively release one of the first and second ends.

82. The insertion instrument accordingly to claim 81, further comprising a retention assembly that is movable with the pusher member, and proximal movement of the insertion instrument after the anchor body has been ejected causes the tensile force to be applied to the actuation member.

83. The insertion instrument according to claim 81, wherein the insertion instrument is further configured to eject a second anchor at a second target location, the second anchor including a second anchor body that has a second substrate that extends substantially along a second direction of elongation, the second substrate defining a plurality of openings spaced along the second direction of elongation, the second anchor further including a second actuation member that is woven through at least two of the openings of the second anchor body, such that the tensioning strand is configured to apply a tensile force to the second anchor body so as to expand the second anchor body along a direction perpendicular with respect to the second direction of elongation.

84. The insertion instrument accordingly to claim 83, wherein the at least one anchor is a first anchor, the anchor body is a first anchor body, the substrate is a first substrate, the plurality of openings is a first plurality of openings, the direction of elongation is a first direction of elongation, the actuation member is a first actuation member, the tensile force is a first tensile force, and the retention assembly is movable with the pusher member, such that proximal movement of the pusher member after the first anchor body has been ejected causes the first tensile force to be applied to the first actuation member, and

the pusher member is configured to be depressed in the elongate opening so as to eject the anchor body from the cannula, such that when a second tensile force is applied to the second actuation member, the second anchor body expands, wherein the retention assembly is movable with the pusher member, such that proximal movement of the pusher member after the second anchor body has been ejected causes the second tensile force to be applied to the second actuation member.

85. The insertion instrument as recited in claim 81, further comprising a tapered surface that defines a tapered bore, and a first locking member having a cross-sectional dimension less than a first end of the tapered bore and greater than a second end of the tapered bore, wherein the first locking member is configured to releasably retain at least one of the first and second ends of the tensioning strand between the locking member and the tapered surface.

86. The insertion instrument according to claim 85, further comprising a second locking member that is configured to attach to a second end of the tensioning strand.

87. The insertion instrument according to claim 85, wherein the second locking member is threadedly attached at a location adjacent the tapered inner surface.

88. The insertion instrument according to claim 87, wherein the second locking member is aligned with the tapered bore, such that the second end of the tensioning strand extends through the tapered bore and is attached to the second locking member.

89. The insertion instrument according to claim 86, further comprising a plunger translatably fixed to the first pusher member, wherein the plunger is configured to depress the first pusher member in the elongate opening.

90. The insertion instrument according to claim 89, further comprising a release member in communication with the first locking member, wherein movement of the release member biases the first locking member out to release the tensioning strand.

91. The insertion instrument according to claim 90, wherein the release member pushes the first locking member toward the first end of the bore so as to create a gap between the first locking member and the tapered inner surface.

92. The insertion instrument according to claim 81, further comprising a retention assembly including a first locking body configured to releasably retain the first end of the tensioning strand, and a second locking body configured to retain the second end of the tensioning assembly.

93. The insertion instrument according to claim 92, further comprising an actuator operably coupled to the first locking body so as to release the first locking body from the first end of the tensioning strand.

94. The insertion instrument according to claim 92, further configured to eject a second anchor body out the cannula, wherein the actuator becomes operably coupled to the first locking body once the first and second anchor bodies have been ejected.

95. The insertion instrument according to claim 81, further comprising a cutting assembly having a cutting blade, the cutting assembly movable between a disengaged position whereby the cutting blade is spaced from the tensioning strand and an engaged position whereby the cutting blade severs the tensioning strand.

96. The insertion instrument according to claim 95, wherein the cutting assembly includes a longitudinally elongate shaft that is coupled to the cutting blade, and longitudinal translation of the shaft causes the blade to sever the tensioning strand.

97. The insertion instrument according to claim 96, wherein the cutting assembly further includes a switch pivotally coupled between both the elongate shaft and the cutting blade.

98. The insertion instrument according to claim 95, wherein the cutting assembly includes an actuator that is elongate along a direction angularly offset with respect to the cannula, and movement along the direction angularly offset with respect to the cannula severs the tensioning strand.

99. The insertion instrument according to claim 1, further comprising a retention assembly comprising a first locking member and a second locking member adjacent the first locking member so as to define a strand-receiving gap therebetween, wherein the second locking member is movable toward the first locking member so as to retain at least one strand in the gap.

100. The insertion instrument according to claim 99, wherein the cannula defines a slot in communication with the elongate opening, and the at least one strand extends from the at least one knot anchor out the slot and into the gap.

101. The insertion instrument as recited in claim 99, wherein the second locking member is threadedly coupled to the first locking member.

102. The insertion instrument according to claim 24, further comprising a stop member that is translatably fixed with respect to the cannula, and a clip removably couples the first and second pusher members.

103. The insertion instrument according to claim 102, further comprising a plunger that is translatably fixed to the first pusher member, the plunger configured to be depressed so as to depress the first pusher member in the elongate opening.

104. The insertion instrument according to claim 102, wherein the clip is removably attached to the plunger.

105. The insertion instrument according to claim 104, further comprising an attachment member that is translatably fixed to the second pusher member, wherein the clip abuts the attachment member.

106. The insertion instrument according to claim 105, further comprising a casing that is translatably fixed to the cannula.

107. The insertion instrument according to claim 106, wherein the plunger is depressed a first distance that causes the anchor body to be ejected from the instrument, and the clip abuts the casing once the plunger has been depressed the first distance so as to prevent the plunger from being depressed a second distance greater than the first distance.

108. The insertion instrument according to claim 107, wherein removal of the clip from the plunger translatably decouples the first and second pusher members, such that depression of the plunger the second distance causes the first pusher member to eject another anchor body from the insertion instrument.

109. The insertion instrument as recited in claim 1, wherein the anchor is a first anchor, the substrate is a first substrate, the direction of elongation is a first direction of elongation, the actuation member is a first actuation member that is woven through at least two of the openings, the cannula is a first cannula, the elongate opening is a first elongate opening, and the pusher member is a first pusher member, the insertion instrument further comprising:

a second cannula that defines a second elongate opening sized to receive a second anchor body that has a second substrate that extends substantially along a second direction of elongation, the second substrate defining a plurality of openings spaced along the second direction of elongation, the second anchor further including a second actuation member that is woven through at least two of the openings of the second anchor body; and

a second pusher member insertable into the second cannula and configured to be depressed in the second elongate opening so as to eject the second anchor body from the second cannula and into a second target location, such that when a tensile force is applied to the second actuation member along a direction substantially along the second direction of elongation, the second anchor body expands along a second direction perpendicular with respect to the direction of elongation.

110. The insertion instrument as recited in claim 109, further wherein the first and second cannulas extend substantially parallel to each other.

111. The insertion instrument as recited in claim 109, further comprising a casing that supports the first and second cannulas such that the first and second cannulas extend distally to respective first and second tips, wherein the first tip is disposed distal to the second tip when the first anchor body is ejected, and the insertion instrument further comprises a swap actuator that is configured to position second tip is disposed distal to the first tip after the first anchor body is ejected and before the second anchor body is ejected.

112. The insertion instrument as recited in claim 111, further comprising a first plunger extending out from the first push member and a second plunger extending out from the second push member, and first and second pair of lock-out tabs removably attached to the first and second plungers, respectively, at a location between the casing and proximal ends of the respective first and second plungers, wherein the lock-out tabs prevent the first and second plungers from moving the respective first and second push a distance sufficient to eject the respective first and second anchor bodies.

113. The insertion instrument as recited in claim 112, wherein removal of the first and second lock-out tabs from the first and second plungers allows the first and second plungers to translate, thereby causing the respective first and second pusher members to eject the respective first and second anchor bodies from the corresponding first and second cannulas.

114. The insertion instrument as recited in claim 111, wherein the swap actuator is configured to translate the first tip proximally with respect to the second tip after the first anchor body has been ejected from the first cannula.

115. The insertion instrument as recited in claim 114, wherein the casing comprises a body portion that supports and a handle portion that extends out from the body portion, the first and second cannulas extend out from the body portion, and the swap actuator extends out from the handle portion.

116. The insertion instrument as recited in claim 114, further comprising at least one latch assembly that couples the swap actuator to the first cannula with respect to proximal translation, such that proximal translation of the swap actuator causes the first cannula to translate proximally with respect to the second cannula.

117. The insertion instrument as recited in claim 111, further comprising a first plunger extending out from the first push member and a second plunger extending out from the second push member, the first and second plungers disposed in respective first and second slots that extend through the casing.

118. The insertion instrument as recited in claim 111, wherein the swap actuator is configured to translate the second tip distally with respect to the second tip after the first anchor body has been ejected from the first cannula.

119. The insertion instrument as recited in claim 118, wherein the swap actuator is further configured to translate the second tip distally with respect to the casing.

120. The insertion instrument as recited in claim 119, wherein the swap actuator further comprises a swap tab that rides in a slot defined by the casing.

121. The insertion instrument as recited in claim 118, further comprising at least one latch assembly that attaches the swap actuator to the second cannula with respect to distal translation, such that distal translation of the swap actuator causes the second cannula to advance distally with respect to the first cannula.

122. The insertion instrument as recited in claim 111, wherein the casing comprises a first casing portion and a second casing portion, the first cannula extends from the first casing portion, and the second cannula extends from the second casing portion.

123. The insertion instrument as recited in claim 111, wherein the first and second casing portions are configured to slide relative to each other.

124. The instrument assembly as recited in claim 123, wherein the swap actuator selectively couples and decouples the first and second casing portions with respect to relative translation.

125. The instrument assembly as recited in claim 124, wherein movement of the swap actuator from a first position to a second position allows the second casing portion to slide distally with respect to the first casing portion such that the second tip is disposed distal with respect to the first tip.

126. The instrument assembly as recited in claim 125, wherein the swap actuator comprises a button that is spring loaded in the second casing portion.

127. The insertion instrument as recited in claim 111, further comprising a reciprocal motion assembly that causes one of the first and second cannulas to translate proximally when the other of the first and second cannulas translates distally.

128. The insertion instrument as recited in claim 127, wherein the reciprocal motion assembly includes a first rack coupled the first cannula, and further includes a second rack coupled to the second cannula, a first gear mated with the first rack, and a second gear mated with the second rack, such that the first and second gears are mated with each other.

129. The insertion instrument as recited in claim 128, further comprising a handle extending from one of the racks and out the casing.

130. The insertion instrument as recited in claim 129, wherein the handle defines a safety catch configured to engage the casing so as to prevent movement of the handle along at least one direction when the handle is engaged with the casing.

131. The insertion instrument as recited in claim 128, further comprising a plunger configured to selectively engage one of the first and second pusher members.

132. The insertion instrument as recited in claim 131, wherein the plunger carries a biasing member and is movable from a first position whereby the biasing member is aligned with the first and second pusher members to a second position whereby the biasing member is out of alignment with the first and second pusher members.

133. The insertion instrument as recited in claim 132, wherein the plunger rides in a track having a first portion that extends along a direction substantially parallel to the first and second pusher members, such that the plunger is movable distally along the track so as to drive a select one of the first and second pusher members distally within a respective one of the first and second cannulas so as to eject the respective one of the first and second anchors.

134. The insertion instrument as recited in claim 133, wherein the track has a second offset portion, wherein translation of the plunger into the second offset portion causes the biasing member to become misaligned with the first and second pusher rods.

135. The insertion instrument as recited in claim 134, wherein a relative position of the first and second cannulas can be reversed when the plunger is disposed in the second offset portion of the track.