Suture collet

[0002] This application is related to Ek, U.S. Ser. No. 08/915,758, filed Aug. 21, 1997, titled SUTURING TISSUE, Ek et al., U.S. Ser. No. 08/783,126, filed Jan. 14, 1997, titled SUTURE COLLET, Ek et al., U.S. Ser. No. 08/605,767, filed Feb. 22, 1996, titled SUTURE COLLET, and Thompson et al., U.S. Ser. No. 09/052,651, filed Mar. 31, 1998, titled SURGICAL DRIVE TOOL, all hereby incorporated herein by reference.

[0003] This invention relates to suture fastening.

[0004] One traditional method of fastening suture is simply by tying a knot in the suture. Alternatively, a suture clamp may be used. In a typical suture clamp, the suture is positioned between an open pair of arms which are then pivoted closed to capture the suture between them.

[0005] A suture securing device includes an inner member defining a suture receiving passage extending between a distal end surface of the inner member and a second surface of the inner member. An outer member defines an opening for receiving the inner member such that suture extending from the second surface is secured between the inner member and the outer member.

[0006] Embodiments of this aspect of the invention may include one or more of the following features.

[0007] The second surface is a proximal end surface of the inner member. The inner member has a slot extending between an outer surface of the inner member and the suture receiving passage. A region of the inner member has an outer diameter greater than the diameter of the outer member bore. The inner member is cylindrical.

[0008] Preferably, the outer member bore extends axially from a proximal end to a distal end of the outer member. The outer member bore tapers distally from a smaller diameter to a larger diameter. The outer member is cylindrical.

[0009] According to another aspect of the invention, a suture securing cartridge includes a sleeve having an axial bore and a suture securing device disposed in the bore. The suture securing device includes an inner member defining a suture receiving passage, and an outer member disposed in the bore proximally of the inner member and configured for advancement over the inner member.

[0010] Embodiments of this aspect of the invention may include one or more of the following features.

[0011] The sleeve includes two suture threading slots extending proximally from a distal end of the sleeve. One of the slots terminates distally of the other slot. At least a portion of the slots extend along a longitudinal axis of the sleeve. The sleeve has a distal clamp for selectively preventing the inner member from exiting the sleeve bore in a distal direction. The clamp is resilient to permit the inner member to exit the bore in the distal direction.

[0012] According to another aspect of the invention, a suturing apparatus includes a suture securing cartridge and a drive tool. The drive tool includes an outer sheath which fits over the cartridge sleeve, an intermediate tube which engages the sleeve to secure the cartridge to the drive tool, and a movable element located within the intermediate tube for advancing the outer member over the inner member.

[0013] Embodiments of this aspect of the invention may include the sleeve having a circumferential groove in the bore, and the intermediate tube has a grasper which engages the groove to secure the cartridge to the drive tool.

[0014] According to another aspect of the invention, a method of securing a suture includes threading a suture through a passage in an inner member. The passage extends between a distal end surface of the inner member and a second surface of the inner member. An outer member is advanced over the inner member such that suture extending from the second surface is secured between the inner member and the outer member.

[0015] Embodiments of this aspect of the invention may include one or more of the following features.

[0016] Threading includes threading the suture in a proximal direction, and advancing the outer member over the inner member to cause the suture to double back in a distal direction. A first suture strand is passed through a first suture threading slot in a sleeve containing the inner member and the outer member, and through a slot in the inner member to the passage. An outer sheath is advanced over the sleeve to at least partially cover the first suture threading slot.

[0017] Preferably, a second suture strand is passed through a second suture threading slot in the sleeve, and through a slot in the inner member to the passage. The outer sheath is advanced over the sleeve to at least partially cover the second suture threading slot.

[0018] After advancing the outer member over the inner member, the inner and outer members are expelled from a sleeve containing the members.

[0019] According to another aspect of the invention, a method of using a suture securing device includes providing a preassembled suture securing cartridge including a sleeve having an axial bore and a suture securing device. The preassembled cartridge is inserted into a drive tool that includes an outer sheath which fits over the sleeve, an intermediate tube which engages the sleeve to secure the cartridge to the drive tool, and a movable element located within the intermediate tube. The movable element is advanced to advance the outer member over the inner member.

[0020] Embodiments of this aspect of the invention may include, after advancing the outer member over the inner member, expelling the inner member and the outer member from the sleeve.

[0021] We have found that the holding power of the suture securing device is substantially greater than that of a standard open surgical knot. The suture securing device also enables the surgeon to advance the suture securing device into the body to the site of the tissue being sutured and then position the suture within the suture securing device at the surgical site.

[0022] Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.

[0023] FIG. 1 shows a suture collet for securing suture;

[0024] FIG. 2 is a perspective view of an inner pin of the suture collet of FIG. 1;

[0025] FIG. 3 is a perspective view of an outer ring of the suture collet of FIG. 1;

[0026] FIG. 4 is a side view of the suture collet of FIG. 1;

[0027] FIG. 5 is an exploded perspective view of the suture collet of FIG. 1 shown with a cartridge and drive tool;

[0028] FIG. 6 is a cross-sectional view of the cartridge of FIG. 5 pre-loaded with the suture collet;

[0029] FIG. 7 is a side view of the cartridge of FIG. 5;

[0030] FIGS. 8-8D show the drive tool in use with the suture collet and cartridge;

[0031] FIG. 9 shows the drive tool of FIG. 5 in more detail; and

[0032] FIG. 10 is a cross-sectional view of the distal portion of the drive tool of FIG. 9.

[0033] Referring to FIG. 1, a suture collet 10 is used in place of conventional securing techniques (e.g., knot tying) to secure a suture 8 in place. Suture collet 10 can be used in a wide variety of applications—in the operation shown schematically in FIG. 1, suture collet 10 clamps a loop of suture 8 in place between a ligament 2 and a bone 4 (suture 8 is attached to bone 4 by a suture anchor 6 or other suitable device). As discussed in more detail below, suture collet 10 includes an outer locking ring 12 and an inner locking pin 14 between which suture 8 is secured when outer ring 12 is advanced over pin 14.

[0034] Referring to FIG. 2, pin 14 is generally cylindrical in shape with a section 20 of enlarged outer diameter defining a distal shelf 20aand a proximal shelf 20b. On the proximal side of section 20 is a first portion 21aof pin 14, and on the distal side of section 20 is a second portion 21bof pin 14. Pin 14 has an axially-oriented, longitudinal passage 22 for receiving, e.g., two sections 8a, 8b(FIG. 1) of suture 8, though more than two suture sections can be used. Passage 22 extends completely through pin 14, from proximal surface 26 to distal surface 24, along a longitudinal central axis 34 of pin 14. A slot 30 extends from the outer surface 32 of pin 14 to passage 22. As described further below, suture sections 8a, 8bare positioned within passage 22 when pin 14 is located within the body by passing the suture sections through slot 30.

[0035] Referring to FIG. 3, ring 12 is generally cylindrical in shape and has an axially-oriented, longitudinal bore 40. Bore 40 extends completely through ring 12, from proximal end 44 to distal end 42, along a longitudinal central axis 46 of ring 12. Bore 40 is sized to receive the first portion 21aof pin 14, but is not large enough to receive section 20. The internal wall 48 of ring 12 defining bore 40 has an outwardly tapered, distal wall section 48a. The tapered wall section aids in aligning ring 12 over pin 14 when advancing the ring over the pin.

[0036] There is a close fit between the outer surface 32 of pin 14 and the internal wall 48 of ring 12 to clamp the suture therebetween. Additionally, the overall size of suture collet 10 with ring 12 positioned over pin 14 corresponds, e.g., approximately to the size of three successive throws of a suture knot. For example, ring 12 is about 0.15 inches long, has an outer diameter of about 0.125 inches and an inner diameter of about 0.07 inches; pin 14 is about 0.225 inches long, section 20 has an outer diameter of about 0.13 inches, section 21ahas an outer diameter of about 0.07 inches, and section 21bhas an outer diameter of about 0.094 inches. Passage 22 has a diameter of about 0.025 inches. Ring 12 and pin 14 can be made from a non-absorbable material such as polyacetal available from M. Holland Co., Northbrook, Ill., or a bio-absorbable material, such as Maxon, a polyglyconate, available from Davis & Geck.

[0037] Referring to FIG. 4, suture collet 10 clamps suture as follows. After suture sections 8a, 8bhave been passed through slot 30 into passage 22 (a tool and procedure for doing so are described below) ring 12 is advanced over pin 14 so that suture sections 8a, 8bare looped back axially along the outer surface 32 of pin 14, and secured between internal wall 48 of ring 12 and outer surface 32 of pin 14. Advancement of ring 12 over pin 14 is stopped when the suture sections are compressed at looped regions 33a, 33bbetween distal end 42 of ring 12 and proximal surface 20bof enlarged pin section 20. The suture extends from suture collet 10 at the junction 35 of the ring and pin. The compression of the suture between the internal wall 48 of ring 12 and the outer surface 32 of pin 14 securely clamps the suture in place.

[0038] FIG. 5 is an exploded view of instruments which can be used to emplace suture collet 10 in the body and advance ring 12 over pin 14 to clamp suture in place in the manner discussed above. Ring 12 and pin 14 are carried within a cartridge 80 (as shown in FIG. 6), and drive tool 110 including an outer sheath 360 is used to advance ring 12 over pin 14 and expel the suture collet from cartridge 80.

[0039] Referring also to FIGS. 6 and 7, cartridge 80 includes a hollow sleeve 82 the distal end of which is provided with a clamping lip 130 having a reduced diameter, internal shoulder 132 which receives distal section 21bof pin 14. The internal diameter of shoulder 132 is smaller than the diameter of enlarged section 20 such that suture collet pin 14 is held in place within cartridge 80.

[0040] The outer diameter of lip 130 is enlarged relative to that of the remainder of sleeve 82, such that an outer shoulder 134 is defined, for purposes to be discussed. As shown in FIG. 6, an axial passage 94 extends through sleeve 82. Ring 12 is supported within passage 94 by an interference fit with the inner wall surface 82aof passage 94 to maintain ring 12 axially spaced from pin 14 until it is to be advanced over pin 14. Sleeve 82 has a circumferential groove 328 in inner wall surface 82aproximally of ring 12 for purposes to be described.

[0041] Sleeve 82 has a suture threading slot 100 through sleeve wall 102 extending proximally from distal end 104 of sleeve 82 along a longitudinal axis A of sleeve 82. Slot 100 bifurcates into two threading slots 106, 108 each having a curved section 111, 112 terminating in an axial slot 114, 116, respectively. Axial slots 114, 116 are located circumferentially 90 degrees from slot 100 on opposite sides of sleeve 82. Slot 106 extends further proximally than slot 108. Pin 14 is loaded within sleeve 82 with pin slot 30 aligned with cartridge slot 100. Sheath 360 includes slots 120, 122 (FIG. 5) which are aligned with axial slots 114, 116. Slot 100 permits lip 130 of sleeve 82 to resiliently expand radially when suture collet 10 is to be expelled from the cartridge.

[0042] Referring to FIGS. 8A-8D, suture collet 10 is emplaced with drive tool 110 as follows. For example, as a preliminary step, suture 8 can be mounted to bone 4 with anchor 6 and passed through ligament 2 (FIG. 1). Multiple sutures can be mounted to the bone using multiple anchors prior to securing the sutures. Drive tool 110 with a cartridge 80 loaded with pin 14 and ring 12 is then advanced intracorporally, for example, through a conventional trocar used in arthroscopic or laproscopic surgery, to the fixation site. A single portal can be used to secure multiple sutures.

[0043] To secure a suture, sheath 360 is withdrawn proximally in the direction of arrow 124 while cartridge 80 is held stationary, as described below, to expose slots 106, 108. The user then passes section 8aof suture 8 through slot 106 and rotates drive tool 110, which rotates cartridge 80. Rotation of cartridge 80 results in curved section 111 of slot 106 guiding suture section 8ainto axial slot 114. Since axial slot 114 is located circumferentially 90 degrees from slot 100, when suture section 8ais moved into slot 114, the suture section also passes through pin slot 30 into passage 22.

[0044] Referring to FIG. 8B, the user then advances sheath 360 distally in the direction of arrow 126 with sheath slot 120 aligned with axial slot 114 to trap strand 8awithin axial slot 114. The sheath is not advanced as far as slot 108 such that slot 108 remains exposed. The user then passes strand 8bof suture 8 through slot 108 and rotates sheath 360 to lodge suture strand 8ain axial slot 116, and thus through pin slot 30 into passage 22. Sheath 360 is then advanced fully distally in the direction of arrow 126 to trap strand 8bwithin axial slot 116, as shown in FIG. 8C. At this point, suture section 8a, 8bare disposed within pin passage 22 and extend out of proximal surface 26. Referring to FIG. 8D, the user then advances ring 12 over pin 14, as described below.

[0045] Note that the placement of suture 8 within pin 14 acts as the first throw of the suture knot to reduce the tissue and allows sliding travel of the suture much like the first throw of a conventional knot. The frictionless contact between pin 14 and the suture permits the surgeon to feel how much tension is being put into the tissue even more precisely than the first throw of a conventional knot which has some friction. This is particularly advantageous when suturing vessels with thin walls or suturing delicate tissue. In addition, the tension on the suture, instead of acting to pull the suture loose, increases the holding force on the suture applied by suture collet 10.

[0046] Referring to FIG. 9, drive tool 110 includes a handle assembly 316 and a tube assembly 318. To position suture collet 10 at a surgical site, the cartridge assembly is secured to drive tool 110; the drive tool is advanced to the surgical site and the user manipulates the drive tool to deploy the suture collet from the cartridge assembly, as described in Thompson et al., U.S. Ser. No. 09/052,651, supra.

[0047] Referring also to FIG. 10, tube assembly 318 of drive tool 110 includes outer sheath 360 which fits over sleeve 82 of the cartridge assembly. A grasper 364 located within sheath 360 has a circumferential groove 366 with a distal ridge 370 configured to fit within groove 328 of sleeve 82, and a shoulder 373 which engages proximal end 294aof sleeve 82 to secure cartridge 80 within drive tool 110.

[0048] A plunger 376 is slidable within grasper 364 and engages ring 12 pushing it over pin 14. Plunger 376 and outer sheath 360 are moved by manipulating handle assembly 316 of drive tool 110, as described in Thompson et al., U.S. Ser. No. 09/052,651, supra. Pushing ring 12 over pin 14 causes suture strands 8a, 8bto double back distally securing the strands between internal wall 48 of ring 12 and outer surface 32 of pin 14.

[0049] The suture collet with clamped suture is removed from cartridge 80 simply by retracting sheath 360 axially away from shoulder 134 and advancing plunger 376 distally. With sheath 360 retracted, lip 130 of cartridge 80 flexes outwardly as suture collet 10 is moved distally thereby permitting plunger 376 to push suture collet 10 distally from cartridge 80.

[0050] Other embodiments are within the scope of the following claims. For example, rather than the suture passage in the pin emerging from the proximal end of the pin, the suture passage can emerge from the side of the pin. t least one of the slots 120, 122 in sheath 360 can be eliminated or its length decreased, such that the suture strand is crimped between the sleeve and the sheath. With one strand of the suture crimped, only the other strand need be pulled to tighten the suture.

[0051] Slots 106, 108 of sleeve 82 can extend proximally the same distance. Slot 100 of sleeve 82 need not bifurcate into two slots such the suture strands are positioned within a single slot. Slot 100 can be straight rather than include one or more curved sections.

[0052] Suture collet 10 can be used wherever a suture knot would be tied, for example, in ligating branches of vessels, in soft-tissue repair, in reducing tissues, and in securing other types of tissue to bone.

[0053] Other materials can be used according to the suturing application. Ring 12 and pin 14 can be shaped other than cylindrical. More than two suture strands can be secured with the collet.