Anchor Element For Knotless Fixing Of Tissue To A Bone

Abstract

An anchor element serves for knotless fixing of a tissue to a bone by means of at least one suture threaded through said anchor element. A body of that anchor element has an outer surface with projections. A transverse bore is arranged in a distal end section of said body for receiving a threading passing therethrough. A clamp element serves for clamping the suture threaded transversely through the bore. The clamping element has a portion arranged within the body and is movable within the body towards that transverse bore.

Claims

1.-10. (canceled)

11. An anchor system, comprising an anchor element comprising: a body having an outer face, projections projecting from said outer face, a distal end section of said body being rounded, a proximal end of said body defining a bearing surface, a transverse bore arranged in said distal end section of said body, said transverse bore extending through said body, and an axial bore, said axial bore opening into said transverse bore and extending from the proximal end of said body up to said transverse bore, said axial bore having an inner thread; said transverse bore and said axial bore being positioned perpendicular to one another; an axially extending pin having an outer thread meshing with said inner thread and being housed axially movable in said axial bore, an outer diameter of said pin corresponding to an inner diameter of said axial bore, said pin, when turned in, adapted to move in a direction towards the transverse bore and into the latter, said pin having a distal end configured to clamp an object inserted through said transverse bore against a distal wall of said transverse bore, and said pin having a recess provided in a proximal end thereof; and a driver device comprising: a proximal end adapted to be manipulated by a user of the anchor system and a distal end engaging said anchor element, the distal end of said driver device comprising a shoulder and a pin engagement member, the shoulder of the driver device defining a bearing surface configured to mate with the bearing surface of said anchor element such that axial force exerted on the proximal end of the driver device is transmitted to the anchor element through the shoulder of the driver device, and the pin engagement member of said driver device and the recess of said pin being configured so as to provide rotational engagement therebetween while allowing for relative axial movement therebetween such that rotation of the pin engagement member of said driver device causes rotation of said pin and consequently axial movement of said pin within the axial bore of said anchor element and such that axial force exerted on the proximal end of the driver device is not transmitted to anchor element through said pin, whereby one and the same driver device is adapted to be used for both insertion of the anchor element and also clamping of the object inserted through the transverse bore in such a manner that the outer thread on said pin and inner thread in said axial bore are protected from potential damage caused by axial force being exerted on said pin.

12. The anchor system of claim 11, wherein said distal end of said pin is rounded.

13. The anchor system of claim 12, wherein opposite to said rounded distal end of said pin, a gentle hollow is provided in said transverse bore, said gentle hollow approximately corresponds to said rounded distal end.

14. The anchor system of claim 11, wherein said pin is designed as a headless screw.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The invention is described and explained in more detail below on the basis of a number of selected illustrative embodiments and with reference to the attached drawings, in which:

[0051] FIG. 1 shows as exploded view of an anchor element according to the invention and its clamp element, and with the maneuvering tool for fitting the anchor element into the bone being depleted at the lower end,

[0052] FIG. 2 shows a longitudinal section through the anchor element from FIG. 1 with the clamp element inserted, with the maneuvering tool applied, and with a suture threaded through the anchor element but still freely movable,

[0053] FIG. 3 shows a snapshot of the operating technique for fitting the anchor element, in which view the assembly shown in FIG. 2 can be seen, with the threaded suture having already been connected to a tissue and having been threaded back through the transverse bore,

[0054] FIG. 4 shows a cross section after the anchor element has been fitted and the tendon has been fixed by means of the suture, and the suture has been fixed in the bone by means of the clamp element, and

[0055] FIG. 5 shows an exploded view of another illustrative embodiment of an anchor element according to the invention with a wedge-shaped clamp element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0056] An anchor element shown in FIGS. 1 to 4 is designated in its entirety by reference number 10.

[0057] The anchor element 10 has an elongate, roughly cylindrical body 12 from whose outer face 14 a number of projections 16 to 16 protrude. The projections 16 to 16 are designed as protruding annular flanges which, viewed in the distal direction, each merge with the next annular flange via approximately conically tapering portions. A distal end area 18 of the body 12 is provided with a rounded tip 20. A proximal end 22 is formed by the cross-sectional surface area of the last projection 16.

[0058] In the distal end area 18 of the body 12, a transverse bore 24 is arranged extending through the latter. Starting from the mouth of the transverse bore 24, two diametrically opposite longitudinal grooves 25, cut into the projections 16 to 16, extend proximally along the longitudinal axis 26 of the body 12.

[0059] The transverse bore is used for threading a suture 60 through the body 12, as shown in FIG. 2. The suture portions protruding from both ends of the transverse bore 24 can be placed into the longitudinal grooves 25, such that these suture portions can be guided proximally from the direction of the transverse bore 24 while bearing closely on the body 12.

[0060] From the proximal direction, an axial bore 28 is formed centrally within the body 12 (see FIG. 2) and opens at the distal end into the transverse bore 24.

[0061] An inner thread 30 is cut in the axial bore 28.

[0062] This axial bore 28 is used for receiving a clamp element 32.

[0063] The clamp element 32 is composed of a pin 34 on whose outer face there is an outer thread 36, which meshes with the inner thread 30 of the axial bore 28.

[0064] Formed at the proximal end of the pin 34, there is a recess 38, here in the form of a diametrical incision, whose purpose will be explained below. At the distal end 40, the clamp element 32 is provided with a rounded part 42. With that design, the pin 34 is a headless screw.

[0065] A device referred to as a driver 50, with which the anchor element 10 is maneuvered, is shown at the bottom end of FIG. 1.

[0066] The driver device 50 comprises a rod 52 from whose distal end face 54 a tool 56 projects which is designed such that it can be inserted with a form-fit into the recess 38 of the clamp element 32. The end face 54 of the driver device 50 is moreover designed such that it can be placed on the proximal end 22 of the body 12 of the anchor element 10.

[0067] At a distance axially from its end face 54, the driver device 50 is provided with two diametrically protruding stubs 58, 59 around which the two protruding suture ends can be wound. At the proximal end, the rod 52 ends in a handpiece (not shown here) via which the driver device 50 can be gripped by hand by the person operating it.

[0068] FIG. 2 now shows a situation in which the clamp element 32 is received in the inside of the body 12, with the outer thread 36 inserted into the inner thread 30, specifically such that the suture 60 guided through the transverse bore 24 is freely movable, as indicated by the doubled arrows.

[0069] The proximal end 22 of the body 12 on the end one 54 or the a driver device 50, of which the tool 56 engages in the recess 38 of the clamp element 32.

[0070] As has been mentioned above, the longitudinal grooves 25 on the outer face 14 of the body 12 allow the suture ends to be guided in the proximal direction while bearing closely on the body 12. Correspondingly, grooves 62 are cut into the rod 52 of the driver device 50 in order to guide these suture ends as far as the diametrically protruding stubs 58, 59 around which they are wound.

[0071] As will be evident in particular from the cross-sectional view in FIG. 2, turning the driver device 50 about the longitudinal axis 26 of the assembled structure causes the clamp element 32 to turn in the inside of the anchor element 10, as a result of which the clamp element 32 is moved in the direction toward the transverse bore 24 and into the latter. The portion of the suture 60 received in the transverse bore 24 is applied, by the rounded part 42, against the opposite inner wall of the transverse bore 24 and, when driven further forward, correspondingly clamped.

[0072] By means of the round and gentle profile of the rounded part 42 of the clamp element 32 and the corresponding profile of the inner wall of the transverse bore 24, the clamping force on the suture can be distributed across a relatively large surface area, as a result of which a squeezing on shearing off of the fixed suture 60 in the transverse bore 24 can be avoided.

[0073] It will be evident from the cross-sectional view in FIG. 2 that, on the distal side of the transverse bore 24, the axial bore 28 is continued in the form of a gentle hollow 29 which corresponds approximately to the contour of the rounded part 42, such that the suture 60 can be fixed particularly gently, but still securely between hollow 29 and rounded part 42.

[0074] As will be seen from FIG. 2, the anchor element 10 bearing on the end face 54 of the driver device 50 can be driven into a bone by means of the latter, for example with a hammer.

[0075] The length of the tool 56 and the depth of the recess 38 in the clamp element 32 are chosen such that the clamp element 32 is not damaged in this process, but such that there is sufficient engagement between these two structural elements to be able to subsequently turn the clamp element 32 and thus produce the clamping action.

[0076] FIG. 3 shows a snapshot of an operating technique in which an anchor element 10 according to the invention is fitted.

[0077] Part of a tissue 74, for example a tendon, has become detached from a bone 70 and is now to be fixed back onto the bone 70.

[0078] In the illustrative embodiment shown, an opening 72, for example a bore, has been formed in the bone 70 in the area of tissue detachment, the internal diameter of the opening 72 being slightly smaller than the external diameter of the projections 16 on the body 12 of the anchor element 10. The assembly made up of the anchor element 10, and clamp element 32 received therein, and of the driver device 50 is brought to the operating site, and the suture 60 is threaded once through the transverse bore 24, as shown in FIG. 2. One of the free ends is pushed, if appropriate with the aid of a needle, through a detached portion of the tissue 74, the resulting cut 76 being shown in cross section in FIG. 3. The suture portion emerging through the cut 76 is guided once again through the transverse bore 24, specifically in the opposite directions to the previous one.

[0079] As can be seen from FIG. 3, this creates a loop 61 via which the tissue 74 is connected to the clamp element 10. The two free suture ends are now guided closely along the surface of the structure composed of driver device 50 and anchor element 10 to the stubs 58, 59 and are threaded around these.

[0080] The anchor element 10 is then driven into the opening 72 of the bone 70 by means of the driver device 50. By pulling on the free ends of the suture 60, the detached tissue portion 74 can be brought into the desired position relative to the bone and to the anchor element. By turning the driver device 50, the damp element 32 is now moved into the transverse bore 24 and clamps the two suture portions received in the transverse bore. The driver device 50 is removed, and the protruding suture portions can be cut off.

[0081] It is still entirely possible here to make certain corrections to the lie of the suture, even with the anchor element 10 already fitted, by means of slightly loosening the clamp element 32 again. After the driver device 50 has been removed, the tissue 74 to be fixed lies once again on the bone 70, as shown in FIG. 4. Only the loop 61 of the suture 60 is visible, and these is therefore no bulky knot. In the inside of the body 12, the portions of the suture 60 received in the transverse bore 24 are fixed in position by the rotated clamp element 32.

[0082] FIG. 5 shows another illustrative embodiment of an anchor element which is designated in it entirety by reference number 90. This anchor element also has a body 92 on whose outer face 94 there are corresponding projections 96. Here too, a transverse bore 98 is provided for passage of the suture.

[0083] It will be apparent, from comparing with FIG. 1, that the outer contour of the body 92 has the same design as the outer contour of the body 12.

[0084] The axial bore 100 in the inside of the body 92 is designed as a conical bore into which a clamp element 102 with a corresponding cone 104 can be inserted.

[0085] Here too, the clamp element 102 once again has a rounded distal end 106.

[0086] The technique for fitting the anchor element 90 in place is comparable to the technique described above. To clamp the suture, however, the clamp element 102 is in this case driven into the axial bore 100 by means of the driver device and in this way provides clamping of the suture.

[0087] The cone angle chosen is suitably small in order to ensure that there is no self-release effect, and that instead there is a sufficient clamping or inhibiting effect when the clamp element 102 has be driven in.

[0088] The anchor element 90 can be made of bioabsorbable materials, for example, which also applies to the anchor element 10.

[0089] The anchor element 10 can also be made of metal, for example titanium.

[0090] The length of such anchor elements is usually in the range of between 3 and 6 centimeters, and the diameter is in the range from a few millimeters to approximately one centimeter. Even when non-metal materials are used, there is still sufficient mechanical stability both as regards the anchoring in the bone and also the fixing of the suture threaded through the anchor element.