METHOD AND APPARATUS FOR DELIVERING A SHAPE MEMORY ARTICLE TO A SURGICAL SITE

Abstract

The invention pertains to a method and apparatus for delivering an article formed of a shape memory alloy to a surgical implantation site. The apparatus may include a body having a passage for receiving the proximal portion of the shape memory article, the passage being shaped to substantially prevent the shape memory article from deforming in accordance with its shape memory properties when the proximal portion of the shape memory article is positioned in the passage. An exemplary involves placing the distal portions of legs of a staple in at least one passage in a constraining device that substantially constrains the legs from deforming; and placing the proximal portions of the legs of the staple in at least one passage in an apparatus that, independently of the constraining device, substantially prevents the legs from deforming.

Claims

1-45. (canceled)

46. A shape memory surgical staple system comprising: a shape memory surgical staple that transitions from a first shape to a second shape; and a shape memory surgical staple holding device, which holds the shape memory surgical staple in the first shape and delivers the shape memory surgical staple to an implantation site, the shape memory surgical staple holding device comprising: a handle shaped to be held by a user, and an open-faced groove shaped to hold the shape memory surgical staple embedded therein, wherein the open-faced groove is open in a transverse direction with respect to the insertion direction of the shape memory surgical staple into the implantation site, and wherein the shape memory surgical staple system is packaged with the shape memory surgical staple embedded within the groove.

47. The system of claim 46 wherein the shape memory surgical staple system is packaged at a factory.

48. The system of claim 46 wherein the groove holds the shape memory surgical staple in the first shape.

49. The system of claim 46 wherein the groove comprises at least one detent that prevents the shape memory surgical staple from inadvertently falling out of the groove.

50. The system of claim 46 wherein distal ends of legs of the shape memory surgical staple are free.

50. The system of claim 46 wherein distal ends of legs of the shape memory surgical staple are not embedded within the groove.

52. The system of claim 46 wherein the shape memory surgical staple is released from the groove after distal ends of legs of the shape memory surgical staple have been inserted into pre-bored holes at the implantation site.

53. The system of claim 52 wherein after the shape memory surgical staple is released from the groove, the shape memory surgical staple is pushed into the pre-bored holes at the implantation site.

54. The system of claim 46 wherein the open-faced groove may be covered by a movable cover that transitions between a covering position and an uncovering position.

55. The system of claim 46 wherein the shape memory surgical staple transitions from the first shape to the second shape upon the shape memory surgical staple reaching a temperature above its transformation temperature.

56. A method of packaging a shape memory surgical staple system comprising: providing a shape memory surgical staple that transitions from a first shape to a second shape; providing a shape memory surgical staple holding device that comprises an open-faced groove, wherein the open-faced groove is open in a transverse direction with respect to the insertion direction of the shape memory surgical staple into the implantation site; and embedding the shape memory surgical staple within the groove of the shape memory surgical staple holding device.

57. The method of packaging the shape memory surgical staple system of claim 56 wherein the packaging is performed at a factory.

58. The method of packaging the shape memory surgical staple system of claim 56 wherein the groove holds the shape memory surgical staple in the first shape.

59. The method of packaging the shape memory surgical staple system of claim 56 wherein the groove comprises one or more detents that prevent the shape memory surgical staple from inadvertently fall out of the groove.

60. The method of packaging the shape memory surgical staple system of claim 56 wherein distal ends of legs of the shape memory surgical staple are free.

61. The method of packaging the shape memory surgical staple system of claim 58 wherein distal ends of legs of the shape memory surgical staple are not embedded within the groove.

62. The method of claim 56 wherein the open-faced groove may be covered by a movable cover that transitions between a covering position and an uncovering position.

63. The method of claim 56 wherein the shape memory surgical staple transitions from the first shape to the second shape upon the shape memory surgical staple reaching a temperature above its transformation temperature.

64. A method of packaging a shape memory surgical staple system comprising: providing a shape memory surgical staple that transitions from a first shape to a second shape; providing a shape memory surgical staple holding device that comprises an open-faced groove, wherein the open-faced groove is open in a transverse direction with respect to the insertion direction of the shape memory surgical staple into the implantation site; and embedding the shape memory surgical staple within the open-faced groove of the shape memory surgical staple holding device, wherein the opened-face groove holds the shape memory surgical staple in the first shape, and wherein the packaging is performed at a factory.

65. The method of claim 64 wherein the open-faced groove may be covered by a movable cover that transitions between a covering position and an uncovering position.

66. The method of claim 64 wherein the shape memory surgical staple transitions from the first shape to the second shape upon the shape memory surgical staple reaching a temperature above its transformation temperature.

67. A factory packaged package comprising: a shape memory surgical staple that transitions from a first shape to a second shape; and a shape memory surgical staple holding device, which holds the shape memory surgical staple in the first shape and delivers the shape memory surgical staple to an implantation site, the shape memory surgical staple holding device comprising: a handle shaped to be held by a user, and an open-faced groove shaped to hold the shape memory surgical staple embedded therein, wherein the open-faced groove is open in a transverse direction with respect to the insertion direction of the shape memory surgical staple into the implantation site.

68. The factory packaged package of claim 67 wherein the open-faced groove may be covered by a movable cover that transitions between a covering position and an uncovering position.

69. The factory packaged package of claim 67 wherein the shape memory surgical staple transitions from the first shape to the second shape upon the shape memory surgical staple reaching a temperature above its transformation temperature.

70. The factory packaged package of claim 67 wherein the groove holds the shape memory surgical staple in the first shape.

71. The factory packaged package of claim 67 wherein the groove comprises at least one detent that prevents the shape memory surgical staple from inadvertently falling out of the groove.

72. The factory packaged package of claim 67 wherein distal ends of legs of the shape memory surgical staple are free.

73. The factory packaged package of claim 67 wherein distal ends of legs of the shape memory surgical staple are not embedded within the groove.

74. A method of implanting a shape memory surgical staple, the method comprising: receiving a factory packaged package comprising: a shape memory surgical staple that transitions from a first shape to a second shape, and a shape memory surgical staple holding device having an open-faced groove shaped to hold the shape memory surgical staple embedded therein, wherein the open-faced groove is open in a transverse direction with respect to the insertion direction of the shape memory surgical staple into the implantation site, and wherein the open-faced groove holds the shape memory surgical staple in the first shape; inserting distal ends of legs of the shape memory surgical staple into pre-bored holes at an implantation site; after the distal ends of the legs of the shape memory surgical staple have been inserted into the pre-bored holes, releasing the shape memory surgical staple from the open-faced groove; and after the shape memory surgical staple is released from the open-faced groove, pushing the shape memory surgical staple into the pre-bored holes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a graphical representation of a dynamic scanning calorimetry for one particular NiTinol composition

[0021] FIG. 2 is a perspective view of a shape memory surgical staple disposed in a constraining device pre-surgically.

[0022] FIG. 3 is a perspective view of a transfer apparatus in accordance with the principles of the present invention.

[0023] FIGS. 4A-4F illustrate the transfer apparatus of FIG. 3 in various stages of use.

[0024] FIG. 5 is a perspective view of a transfer apparatus in accordance with another embodiment with a staple partially released therefrom.

[0025] FIG. 6 is a perspective view of a shape memory surgical staple packaged pre-surgically in accordance with another embodiment of the present invention.

[0026] FIG. 7A is a top perspective view of an alternative embodiment of a transfer apparatus in accordance with the principles of the present invention in a closed condition.

[0027] FIG. 7B is a top perspective view of the transfer apparatus of FIG. 7A in an open condition.

[0028] FIG. 7C is a bottom perspective view of the transfer apparatus of FIGS. 7A and 7B.

DETAILED DESCRIPTION OF THE INVENTION

[0029] As noted above, shape memory staples and other shape memory articles often are packaged in a constraining device so that they do not deform should they be exposed to temperatures higher than the phase transition starting temperature. Nevertheless, shape memory articles must spend some period of time between being removed from their constraining packaging and being fully implanted into bone, tissue, or any other anatomical feature, during which time the article may deform prematurely, which may make it difficult or impossible to implant correctly.

[0030] FIG. 2 shows a shape memory staple 500 comprising a backspan 504 with legs 505a, 505b extending substantially orthogonally from the opposite ends of the backspan. The staple is disposed with its legs 505a, 505b extending into passages such as holes 501 and 502 in a constraining device 503 and with its backspan without (i.e., outside of) the constraining device 503. As long as the staple is disposed with its legs in the holes 501, 502 of the constraining device 503, it essentially cannot deform to any significant extent.

[0031] In order to further prevent or minimize the possibility of the shape memory staple 500 (or other shape memory article) from deforming prematurely after it is removed from the constraining device 503, but before it is fully implanted, a transfer device is provided such as the exemplary transfer device 506 shown in FIG. 3. In accordance with this embodiment, the transfer device 506 includes a wedge formation 510 that provides a ramp running from a minimal height at its front end 510a and terminating at a maximum height, H, at its rear end 510b, as shown in FIG. 3. The transfer device 506 further comprises a passage such as groove 521 in a major surface 506a of the transfer device 506 having a first portion 521a that conforms to the size and shape of the backspan 504 of the staple 500 (at least in terms of the length, L, and the diameter, D, of the backspan 504) and second and third portions 521b, 521c that each conforms to a proximal portion of the legs of the staple. The ends of the second and third portions 521b, 521c of the groove are open to a second surface of the transfer device so that the distal portions of the legs of the staple may extend from the transfer device from those ends.

[0032] As will be described in detail below, the staple will be secured in the groove 521 from a time prior to removing the staple 500 from the constraining device 503 up until the staple 500 is implanted. Particularly, with reference to FIG. 4A, when a surgeon is ready to deliver the shape memory staple 500 to the implantation site, the ramp 510 of the transfer apparatus is used to partially pull the legs of the staple out of the holes in the constraining device. Particularly, as shown in FIG. 4A, the surgeon pushes the ramp 510 of the transfer apparatus 506 in the direction of arrow A between the backspan 504 of the staple 500 and the surface 503a of the constraining device 503 against which the staple backspan is abutted so as to force the backspan 504 away from the surface 503a up to the height H of the ramp. This terminal height H of the ramp may be equal to or slightly greater than the length of the leg portions of the groove 521 in the transfer apparatus.

[0033] The transfer apparatus is then pulled back out in the direction opposite of arrow A to disengage it from the staple 500 and the constraining device 503. At this point, after the ramp has been removed, the shape memory staple still essentially cannot deform from its constrained state since the ends of the legs 505a, 505b are still constrained within the holes 501, 502 of the constraining device 503. Next, the surgeon grasps the transfer apparatus 506 by the ramp portion 510 and forces the groove 521 over the backspan 504 and proximal portions of the legs 505a, 505b of the staple 500 as shown in FIG. 4B to lodge the staple 500 in the groove 521.

[0034] With reference to FIG. 3, in one embodiment of the invention, the groove 521 may have one or more detents 522 to assure that the staple 500 does not inadvertently fall out of the groove after it has been pushed into it. The detents may, for instance, be narrowed portions of the groove formed by one or more protrusions in the groove that make that portion of the groove narrower than the diameter D of the wire from which the staple is formed, which protrusions the staple must be snapped past to become seated within the groove 521.

[0035] Next, with reference to FIGS. 48 and 4C, the surgeon can pull the transfer device 506 away from the constraining device 503 in the direction of arrow C (see FIG. 4B) to pull the distal ends of the staple legs 505a, 505b out and completely free of the constraining device 503 (FIG. 4C). At this point, even though the distal ends of the legs 505a, 505b of the shape memory staple 500 are free, the transfer apparatus 506 is constraining the proximal ends of the legs (as well as the backspan 504) of the staples, thus still substantially preventing the staple 500 from deforming.

[0036] The transfer apparatus 506 can then be used to hold the staple and deliver the staple to the implantation site. Only after the distal ends of the legs 505a, 505b have been inserted into the pre-bored holes at the implantation site is the staple 500 released from the transfer apparatus 506.

[0037] For instance, once the distal ends of the legs are reasonably firmly implanted in the holes, the staples should be relatively stable such that the transfer apparatus can release the staple without inadvertently removing the staple from the holes. If the staple is not sufficiently stable in the implantation holes, the part of the exposed portion of one of the legs of the staple 500 that is extending from the hole but not within the groove 521 of the transfer apparatus 506 can be grasped with a clamp to help stabilize it while the transfer apparatus 506 is snapped off of the staple 500. The staple can be removed from the transfer apparatus 506 by twisting it about an axis substantially parallel to the axes of the legs of the staple. For instance, the transfer apparatus 506 may first be twisted about the axis of one of the legs, e.g., leg 505a, of the staple (to snap the other leg 505b past the detent 522 and out of the transfer apparatus) as illustrated in FIG. 40 (with arrow 1201 showing the direction of twisting and axis 1200 showing the axis of twisting. Then, referring to FIG. 4E, the transfer apparatus 506 may be twisted in the opposite direction (see arrow 1205 showing the direction of twisting) about another axis 1203 substantially parallel to, but not collinear with, the axis 1202 of the first leg 505a to snap the first leg 505a past the detent 522 and out of the transfer apparatus to completely remove the staple from the transfer apparatus. At this point, the staple 500 can then be pushed fully into the holes, as needed.

[0038] Alternately, with reference to FIG. 4F, the transfer apparatus may be twisted about an axis 1207 generally defined by the backspan 504 of the staple as illustrated by arrow 1206 to snap both legs 505a, 505b out of the transfer apparatus simultaneously. Then, the backspan (assuming no detent adjacent the backspan) will simply fall out of the transfer apparatus. It should be noted however, that because the backspan of surgical shape memory staples typically have a zigzag in them as seen in the Figures (to allow the backspan to also achieve some compression during the transition from martensitic state to austentitic state), if the portion 521a of the channel in the transfer apparatus that accommodates the backspan is formed as a straight groove and with a width reasonably close to the diameter of the staple, there may not be enough clearance in that channel portion to permit releasing of the staple from the transfer apparatus by twisting about the backspan. Specifically, the zigzag in the backspan 504 may hit the wall of the channel portion 521a and prevent further twisting before the staple can be twisted enough to cause the legs 505a, 505b to clear the detents 522. Since a reasonably tight fit of the backspan 504 in the channel portion 521a of the transfer apparatus 500 is desirable in order to keep the staple 500 from sliding in the transfer apparatus in the direction parallel to the legs 505a, 505b of the staple 500 when seated in the transfer apparatus 506, channel portion 521a may be shaped eccentrically to accommodate the zigzag and to permit twisting of the staple about its backspan. FIG. 5 illustrates such an embodiment. As can be seen, the portion of the channel 521a′ in the transfer apparatus 506′ that accepts the backspan 504 of the staple has two portions 1301 and 1302 that cause that channel portion 521a′ to correspond generally to the zigzag shape of the backspan of the staple. As shown, the channel portion 521a′ can accommodate the backspan 504 of the staple even when the staple is twisted a full 90° out of the transfer apparatus, as shown.

[0039] FIG. 5 also illustrates another alternative feature of the transfer apparatus. Particularly, in order to enhance the ability of the transfer apparatus 500′ to deform to allow the legs 505a, 505b of the staple 500 to snap past the detents 522 as previously described, grooves 1306, 1307 are cut into the material of the transfer apparatus 506′ parallel to the channel portions 521b, 521c bearing the detents, This will allow more flex in the material portions 1308, 1309 adjacent these channel portions 521b, 521c. This feature may be particularly desirable in connection with transfer apparatus for larger size staples, which transfer apparatus may be larger in size, and therefore inherently more rigid.

[0040] The transfer apparatus also may be used to remove the staple from the surgical site in cases where that is necessary. Again, the wedge formation 510 may be inserted between the backspan of the staple (or other proximal portion of a shape memory article) and the bone (or other anatomical feature) to which the backspan is adjacent in order to force the backspan away from the bone essentially as described above in connection with the use of the wedge portion to pull the backspan away from the constraining device 503. Once the wedge is inserted so as to push the backspan sufficiently away from the surface, the surgeon can simply pull the transfer apparatus 506 perpendicularly away from the surface of the bone. If more force is necessary than can reasonably be applied via the transfer apparatus, then the surgeon may instead remove the transfer apparatus and grasp the staple with a grasping tool to pull it out.

[0041] The transfer apparatus comes in contact with the anatomy at the surgical site. Accordingly, it should be made of a biocompatible material, preferably a plastic biocompatible material. The transfer apparatus can be designed as a re-usable device or as a single use device. If it is to be reused, it should be fabricated from a material that can withstand repeated autoclaving processes. Many such materials are well known in the medical arts.

[0042] FIG. 6 illustrates an alternative embodiment of the invention. In this embodiment, the shape memory article 500 is packaged at the factory embedded within both a constraining device 555 and a transfer apparatus 560 as shown in FIG. 6. In this embodiment, there is no ramp on the transfer apparatus insofar as the staple backspan and the proximal portion of the legs are already embedded in the groove of the transfer apparatus.

[0043] In another embodiment, the constraining device may be completely eliminated. For instance, depending primarily on the size, shape, and shape memory properties of the shape memory device as well as the size and shape of the passage in the transfer apparatus relative to the shape memory device, the transfer apparatus may sufficiently restrain the shape memory article so as to completely eliminate the need for a separate constraining device to hold the distal end of the shape memory article pre-surgically. Accordingly, the shape memory article may simply be packaged without a constraining device essentially as shown in FIG. 4C, i.e., with the proximal end embedded in the transfer apparatus and the distal end free.

[0044] FIGS. 7A-7C illustrate another embodiment of the invention, This embodiment is substantially similar to the embodiment described above in connection with FIGS. 2-3 insofar as the transfer apparatus includes a wedge formation 910 and a groove 921 that conforms to the size and shape of the backspan of the shape memory staple and the proximal portions of the legs of the staple. However, rather than having one or more detents in the groove to assure that the staple does not inadvertently fall out of the groove, this transfer apparatus includes a cover portion 950 that is slidable between an open position, in which it does not cover the opening of the groove 921 in the major surface 951 of the transfer apparatus (the position shown in FIG. 7A) and a closed position, in which it does at least partially cover the groove 921 (the position shown in FIG. 7B). The cover 950 may be shaped, as shown, to provide a convenient thumb rest for the surgeon when holding the transfer device with a staple in it.

[0045] In this embodiment, the transfer apparatus is delivered to the surgeon with the cover 950 in the closed position, as shown in FIG. 7A. The cover would remain in this closed position throughout the entire surgical procedure until the time when the transfer apparatus is to be detached from the staple (e.g., after the distal portions of the legs of the staple have been inserted into the holes in the anatomical feature in which it will be implanted). Then, the surgeon can slide the cover 950 back with his thumb and simply translate the transfer apparatus in the direction represented by arrow B in FIG. 7B, i.e., parallel to the major surface 951, to disengage the transfer apparatus from the staple. An advantage of this embodiment is that the detents may be eliminated so that the entire groove 921 is sized slightly larger than the diameter of the staple so that no force need be applied to the staple when removing the transfer apparatus from the staple after partial implantation.

[0046] The slidable cover 950 may be attached to the main body of the transfer apparatus by any reasonable mechanism that would allow it to slide. For instance, in one embodiment illustrated in FIG. 7C, a slot 955 is provided in the aforementioned major surface 951 and completely through to the opposing major surface 922 of the transfer apparatus 906 and a corresponding pin 957 is provided on the underside of the cover 950 to mate with the slot 955 and slide in the slot. The distal-most portion of the pin 957 may be enlarged to form a button, ball, T shaped extension or other form of flange 958 with a diameter larger than the width of the slot so that the flange 957 is trapped in the slot 955 to hold the cover 950 to the main portion of the transfer apparatus, but allow it to slide in the slot 955.

[0047] In the embodiment illustrated in FIGS. 7A-7C, the cover 950 covers only the backspan portion of the groove 921. However, in other embodiments, it can cover the entire groove, including the portions that hold the proximal portions of the legs of the shape memory staple. This might provide more support for the staple and, particularly, prevent it from rocking about an axis parallel to the legs of the staple during implantation.

[0048] In another embodiment, the features of the embodiment of FIG. 5 allowing easier removal of the staple by providing grooves 1306, 1307 parallel and adjacent the channel portions 521b, 521c that allow the material portions 1308, 1309 that bear the detents 522 to flex more easily (see FIG. 5) may be combined with the cover feature of the embodiment of FIGS. 7A-7C, In fact, in yet another embodiment, the grooves 1306, 1307 may be reduced to nominal size such that there is a very small gap or no actual gap between material portions 1308, 1309 and middle material portion 1311. Instead, material portion 1311 (or at least a substantial portion of it extending up to the front surface) may be integral with or attached to the cover so that it slides back with the cover. Thus, when the cover is in the closed position covering backspan channel portion 521a, the staple is held securely in the channel by detents 522 because material portions 1308, 1209 bearing the detents cannot move because they are blocked by material portion 1311. However, when the cover is slid open to reveal the backspan channel 521a, the material portion 1311 also slides back so that it no longer blocks material portions 1308, 1309. Material portions 1308, 1309 may be slidable medially once material portion 1311 is moved away. Alternately, they may be flexible as described in connection with the embodiment of FIG. 5. Of course, in such an embodiment, material portion 1311 would need to be specially shaped and attached to the cover to provide clearance to slide back without being blocked by the backspan of the staple held in the channel portion 521a. For instance, material portion 1311 could be attached to the cover via the flange 958 adjacent the back surface 922 (as illustrated in the embodiment of FIG. 7C) and material portion could be shallower in depth so as not to extend all the way to front surface 951 so as not to interfere with the staple. Furthermore, another channel would need to be provided in the transfer apparatus into which material portion 1311 would slide when the cover is opened.

[0049] Having thus described a few particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements as are made obvious by this disclosure are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto.