BACKGROUND OF THE INVENTION
Current techniques for biceps tenodesis involve externalizing the tendon out of the body (eg., 2009/12011455 patent application; Arthrex technique guide for tenodesis screw). The newly described implant herein allows for in-situ fixation without externalizing the tendon, and therefore potentially significantly simplifies the procedure. Other systems have been described that do not necessarily externalize the soft tissue of interest, but technically require more steps, and in this context are more demanding to use. The described implant also addresses fixation in the setting of bone which provides only primarily cortical purchase (eg., proximal humerus). Notably, standard interference screw or interference fixation is not precluded from being used as supplemental fixation with this newly described implant and method of application—screw placement would potentially be much easier with the tendon already within the bony tunnel or void.
SUMMARY
The following description is not intended to limit or define the claims.
The “Implant” or “Device” described herein provides 1) soft tissue purchase and 2) bony purchase, both essential and fundamental to the application of this invention. The implant or device provides intra-tendinous fixation which is unique in this setting; currently, interference screws are typically used for fixation into bone as the screw presses the soft tissue against adjacent bone within a bony tunnel (note therefore, this type of interference fixation does not directly or primarily secure the soft tissue). Therefore, the design element claims for this newly described implant are unique for the purpose of fixation into soft tissue. Importantly, it also necessarily relies on aperture-mismatch fixation (eg., toggle) that is intra-osseous. It does not require fixation around, or adjacent to (eg., interference fixation) the soft tissue of interest, which is a common method currently used.
Potential areas of application include: proximal biceps, coracoclavicular (CC) ligament reconstruction, collateral ligament reconstruction in large and small joints. Interference screw fixation can be problematic, particularly in the proximal humerus where the cancellous bone cannot be relied upon as readily (eg., in the setting of proximal biceps tenodesis with interference type fixation). For the proximal biceps, the newly described implant allows for arthroscopic in-situ fixation, without externalizing the tendon, which obviates the need for whip-stitching and suture management—this also allows for facilitating the maintenance of anatomic tendon length and tension.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts one embodiment of the implant with essential features.
FIG. 2 shows another embodiment.
FIG. 3 shows an alternate embodiment.
FIG. 4 shows one embodiment of the distal insertor with fixed and mobile components in a cross-sectional view, disengaged from the implant.
FIG. 5 shows one insertor embodiment with: a handle, a primary shaft, and a movable component (the proximal aspect).
FIG. 6 shows a schematic of the implant, engaged to soft tissue, securely fixated to the deep side of cortical bone.
FIG. 7 shows pictures of a prototype embodiment, engaged to an insertor with fixed and movable aspects.
FIG. 8 shows a picture schematically depicting the insertor prior to advancement, creating an eccentric or rotational moment about the implant.
FIG. 9 shows an embodiment highlighting two of many different configurations with respect to “backstop” placement at the proximal middle region of the implant.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
The following description of the described embodiments is exemplary in nature, and in no way does it limit the disclosure, its application, or uses.
In FIG. 1, the implant has a proximal region or portion 1, a middle portion 2, and a distal portion 3. The distal end tip 4 pierces or otherwise engages the soft tissue and passes into said soft tissue—the distal tip 4 could have projections, prongs, barbs, or other similar projection that serve to help capture the soft tissue (not depicted in FIG. 1, but depicted in FIG. 2, 21). In one embodiment, a certain distance proximal to this distal-most end, is a “ridge” or lip 5, with none, one, or multiple prongs, barbs, or other appendages 7, emanating from said ridge 5 that capture the soft tissue with the emanations if present. The said ridge may be concentric (as drawn) or slanted. When more than one, the emanations may be symmetrically or asymmetrically placed, with uniform or variable lengths and or configurations. A certain distance distal to the proximal-most end is another ridge 6, with one or multiple prongs, barbs, backstops, or other appendages 8 that also help to capture the soft tissue—also, symmetrically or asymmetrically placed, with uniform or variable lengths and or configurations. The said ridge itself may be concentric (as drawn) or slanted. Therefore the soft tissue is wholly or in-part (with respect to the width or diameter of soft tissue) captured between the distal “ridge” 5 and proximal “ridge” 6 (eg. within the middle portion 2 of the implant). That portion between the said distal and proximal ridges constitute the middle portion of the implant. The proximal portion 1 contains a slot, hole, or other void 9 that is meant to mate, engage, or otherwise connect to an insertor instrument.
In FIG. 2, another embodiment is depicted that has no distal ridge present 20—the middle and distal portions are flush and continuous without an abrupt change in diameter or width between said portions. The distal end tip could have one 21 or multiple barbs, hooks, prongs, or other configuration that help(s) to capture or engage the soft tissue—these may be symmetrically or asymmetrically placed, with uniform or variable lengths and or configurations. From the proximal ridge, projections 22 that capture or otherwise engage the soft tissue can be present (single or multiple)—as shown, there are only 2 such projections. Notably, these projections may be placed in any geometrical configuration in relation to the ridge; they also may be flush to 23, or contained within, any outer circumference of the implant, or may protrude outward to a certain degree in relation to the circumference of the proximal portion (FIG. 1, 10). There is a slot, or other configuration that is meant to engage an insertor instrument.
In FIG. 3, another embodiment is depicted that has no distal ridge 30. The middle and distal portions are placed off-center 31 in relation to the proximal region. The proximal ridge has multiple projections 33 meant to help capture soft tissue. There is a slot, or other void 32 meant to engage an insertor instrument. The proximal portion is depicted with a bevel or other configuration, meant to enhance how the implant engages the deep side of the bone. This bevel or other configuration may be placed anywhere along the proximal portion of the implant, including involving the said slot 32.
In FIG. 4, cross-sectional views of the proximal implant 40 and distal insertor 42, 46 are depicted. The implant has a notch 48, configured to mate or otherwise engage the distal insertor 49. The implant has a region 43 within a slot 47 meant to engage the distal shaft insertor 46. The implant has a region 44 within a slot 47 meant to engage the distal insertor 46 after the mobile or movable mate component 42 of the distal insertor is translated, rotated, or otherwise moved thus disengaging aspect 49 from aspect 48, the translation being more proximal to the shaft insertor 46. With the movable component 42 disengaged, the distal insertor 46 is freely movable to engage area 44 of said slot 47. With forcible advancement of distal insertor 46, when abutting, or otherwise engaging aspect 44 (which has an engageable off-center edge, lip, ridge, or the like) a rotational moment is created, thus rotating the implant. With movable component 42 in its primary position, a mate configuration 45 of the movable component, engages area 44 of said slot 47 to help maintain a certain rigidity between the insertor and implant. Aspects 41 are meant to circumferentially engage the proximal portion of the implant to connect, or maintain a certain rigidity and security between, the insertor and implant—cleat, spike, or snap aspect 49 also enhances this security when engaging mate-notch aspect 48 of implant 40. Aspects 41 may be of any variable length so far as to cover the entire implant, and may be of any configuration including tapered—this is in consideration for enhancing the ability to percutaneously advance the implant apparatus without the use of an additional cannula. With aspects 41 being long and tapered, the soft tissues will be relatively protected from the implant with its potential ridges and projections as it is advanced percutaneously. Once the implant apparatus is advanced to the soft tissue of interest percutaneously, the mobile component 42 may be translated proximally to allow the completion of the procedure. This consideration does not preclude the ability to use a standard cannula of appropriate length and diameter.
In FIG. 5, one embodiment of the insertor is depicted. The proximal aspect has a handle 51, with a groove 52; the groove, recess, or other configuration is meant to enhance grip for a particular functionality of the insertor, for example, push-in or screw-in functionalities. The insertor has a shaft 56 which corresponds to the distal shaft depicted in FIG. 4, 46. The movable component 53 corresponds to FIG. 4, 42 with its various configurations—movable component 53 can translate or rotate in relation to the shaft 56. The movable component has a projection or lip 54 that facilitates moving the movable component 53—this may be configured to accept one or multiple fingers of the operator. The implant 57 depicted at the distal end of the insertor is engaged to movable component 53; one embodiment relationship between implant 57 and movable component 53 is depicted in a sectional view at FIG. 5, 4-4 (which is seen in FIG. 4).
After the soft tissue is secured by the implant, a pilot hole (circular, ovoid, or slotted) is made at the desired location in bone for soft tissue fixation into bone with the implant.
Once the proximal-most end is completely beneath the bone, a movable mate component 42, 53 of the insertor is pulled or rotated in the proximal direction via 54 (proximal to the tip of the shaft 46), leaving the fixed portion 46, 56 of the insertor in contact with the implant aspect 43 of slot 47; the movable portion of the insertor 42, 53 is now disengaged from the implant, including potential aspect 49 from aspect 48. With the movable portion of the insertor disengaged, the fixed portion (in relation to the handle) 46, 56 is forcibly advanced to rotate the implant over an “off-center” or eccentric center of rotation at aspect 44 of slot 47. This rotation of the implant creates a mismatch in the diameter of the implant 61 compared to the diameter of the pilot hole aperture, the diameter of the implant being larger. The implant is now secured to the deep surface of the cortical bone 63, along with the soft tissue 62 (FIG. 6).
For the proximal biceps, the biceps force vector will cause implant engagement on the deep side of the cortex, and the tendon diameter to compress and expand to a certain degree, further limiting pull-out. Cortical fixation is critical in this setting, and can be relatively difficult to purchase with interference screws alone.
FIG. 7 depicts an implant embodiment with insertor shaft 71 and movable component or mobile mate-component 72 both engaged to implant 73 within a space configured to mate both 71 and 72. The movable component 72 can be translated away from the implant using projection, lever, or handle 74 and is another embodiment of many compared to FIG. 4.
FIG. 8 depicts the insertor shaft 81 (dashed lines) moved to a secondary position 82 after movable component FIG. 7, 72 has been disengaged from implant 83. With the insertor at a secondary position off-center in relation to the implant 83, forcible advancement of the shaft 82 will create rotation of the implant deep to bone creating a mismatch in size between the implant and aperture of the bony hole into which soft tissue has been advanced and fixed by the implant.
FIG. 9 depicts the possible placement for projections or “backstops” 91, 92, and 93 at the proximal region of the middle portion of the implant emanating outward from the implant. The configuration 96 may allow for easier advancement of the implant as the backstop emanations, projections, or protusions may be advanced sequentially distal to proximal, versus all at once (configuration 95), through the bony aperture.
In other embodiments the implant can be applied using an arthroscopic approach, or an open approach. The implant could have sliding, or non-sliding, sutures incorporated into its body, pre-existing or placed by the operator. The implant may be cannulated for other purposes (eg., sutures, venting, passing over guide-wire). Venting would allow healing factors and tissue to incorporate through and around the implant, thus enhancing fixation to soft tissue and bone.
Although the embodiments have been described in some detail by illustration and example for purposes of clarity of understanding, certain changes and modifications may be made without departing from the spirit or scope of the claims.
Patent Application
20120245686
