The present disclosure relates to a device that assists in attaching a tendon to bone such as during anterior cruciate ligament (ACL) replacement.
Most people can go through the majority of their life without ever caring or knowing how complicated a structure the knee that helps them walk is. However, the knee remains a fragile mechanical structure that is readily susceptible to damage. While medical advances have made repairing the knee possible, repair of certain types of injuries results in other long-term effects. To assist the reader in appreciating the elegance of the present disclosure,
For the purposes of the present disclosure, and as illustrated, the knee may be composed of the quadriceps muscles 100, the femur 102, the articular cartilage 104, the lateral condyle 106, the posterior cruciate ligament 108, the anterior cruciate ligament (ACL) 110, the lateral collateral ligament 112, the fibula 114, the tibia 116, the patellar tendon 118, the meniscus 120, the medial collateral ligament 122, the patella 124 (shown slightly displaced to the side—it normally rests in the center of the knee), and the quadriceps tendon 126.
ACL tears are common in athletes and are usually season-ending injuries. The ACL 110 cannot heal—it must be surgically reconstructed. The reconstruction requires replacement tissue. The most common tissue used is a central slip of the patient's own patellar tendon 118. In practice, the patellar tendon 118 has proven to be generally effective, but the size of the graft that can be used is limited to the size of the patient's own patellar tendon 118. As a rule of thumb, only a third of the patellar tendon 118 may be harvested as a graft. Thus, a doctor will measure the width of the patellar tendon 118, divide by three, and take the middle third of the patellar tendon 118. Such harvested grafts are rarely more than ten millimeters (10 mm) wide and may be smaller. Taking this tissue from a person's patellar tendon 118 also causes significant pain and discomfort in the post-operative healing period, which may last up to a year, and up to twenty (20) percent of these patients are left with chronic anterior knee pain.
Some doctors recommend and use other graft sources, such as cadaver grafts, but cadaver grafts have a higher failure rate. Additionally, there is a non-zero chance of disease transmission or rejection by the patient's immune system. As a final drawback, cadaver grafts are usually quite expensive and may not be covered by some insurance companies.
Other doctors use hamstring tendons (e.g., the distal semitendinosus tendon) because the scar created during harvesting is relatively small and there is less pain during the rehabilitation, but again, the hamstring tendon has its own collection of disadvantages. The disadvantages include the fact that once the graft is taken, a patient's hamstring will never recover to its previous strength. Further, all hamstring reconstructions stretch and are looser than the original ACL 110. This loosening is particularly problematic in younger female athletes.
Another alternative graft source is the quadriceps tendon 126. The quadriceps tendon 126 is larger and stronger than either the patellar tendon 118 or the hamstring tendon. The quadriceps tendon 126 is likewise stiffer and less prone to stretching or plastic deformation. However, the qualities that make the quadriceps tendon 126 attractive also contribute to the difficulty in harvesting a graft from the quadriceps tendon 126. Existing surgical implements require a large incision up the longitudinal axis of the femur 102 on the front or ventral/anterior side of the thigh to cut down to the level of the quadriceps tendon 126, resulting in a large post-operative scar. Additionally, the quadriceps tendon 126 has a consistency similar to the proverbial shoe leather, making it difficult to cut. However, an ACL 110 repaired with grafts from the quadriceps tendon 126 generally results in almost no anterior knee pain postoperatively over the short or long term and patients recover quicker.
Regardless of what tendon is harvested, there remains a challenge in attaching the tendon to the bone of the graft recipient, particularly when no bone plug is taken with the graft at the time of harvesting. Accordingly, there is room for innovation in this space.
The present disclosure provides a tendon repair anchor. Exemplary aspects of the present disclosure relate to an anchor plug to which a tendon graft may be secured. The anchor plug is inserted into an anchor receptacle seated in a bone of a graft recipient. Sloped protrusions on the anchor plug interact with protrusions in the anchor receptacle to secure the anchor plug within the anchor receptacle and generally allow movement in a direction that more tightly secures the tendon graft to the bone. By allowing such unidirectional movement, slack in the sutures that secure the tendon graft to the anchor plug will not prevent the tendon graft from being properly positioned relative to the bone. Proper placement of the tendon graft allows for better healing and improves the likelihood of proper tendon replacement and tensioning. While a primary focus is on use in repairing an anterior cruciate ligament (ACL), the present disclosure has other tendon repair applications and is not limited to ACL repair.
In this regard, in one aspect, a fixation assembly is disclosed. The fixation assembly comprises an anchor plug comprising an elongated body comprising a plurality of tapering conical sections. The fixation assembly also comprises an anchor receptacle comprising an interior passage with interior teeth configured to interengage with the plurality of tapering conical sections of the anchor plug when the anchor plug is inserted into the interior passage.
Those skilled in the art will appreciate the scope of the disclosure and realize additional aspects thereof after reading the following detailed description in association with the accompanying drawings.
The accompanying drawings incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.
The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the disclosure and illustrate the best mode of practicing the disclosure. Upon reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications not particularly addressed fall within the scope of the disclosure and the only limitations are found in the accompanying claims.
The present disclosure provides a tendon repair anchor. Exemplary aspects of the present disclosure relate to an anchor plug to which a tendon graft may be secured. The anchor plug is inserted into an anchor receptacle seated in a bone of a graft recipient. Sloped protrusions on the anchor plug interact with protrusions in the anchor receptacle to secure the anchor plug within the anchor receptacle and generally allow movement in a direction that more tightly secures the tendon graft to the bone. By allowing such unidirectional movement, slack in the sutures that secure the tendon graft to the anchor plug will not prevent the tendon graft from being properly positioned relative to the bone. Proper placement of the tendon graft allows for better healing and improves the likelihood of proper tendon replacement and tensioning. While a primary focus is on use in repairing an anterior cruciate ligament (ACL), the present disclosure has other tendon repair applications and is not limited to ACL repair.
Before addressing exemplary aspects of the present disclosure, it is worth noting what is currently being done and the shortcomings associated with the conventional approach as shown in
Traditionally, a graft is harvested from a donor source (whether it be from the same person (e.g., a patella tendon, a quadriceps tendon, or the like being used to repair an ACL (or other tendon)) or from a cadaver). In many instances, the graft does not have a bone spur or bone plug that can be used to facilitate attachment at the repair site. The common approach in this case is the use of an endobutton 200 illustrated in
Accordingly, there is room for a better way to attach a graft at a repair site. Again, while the discussion focuses on ACL repair, other tendon repair may also benefit from aspects of the present disclosure. Exemplary aspects of the present disclosure provide an anchor that allows the surgeon to determine exactly how deep or how shallow they wish the graft to be positioned in the tunnel. Further, aspects of the present disclosure provide an adjustable option for shorter, non-looped grafts such as a quadriceps tendon graft.
In this regard,
The anchor plug 300 may further include a distal end 316 that has a general diameter 318 less than or equal to a diameter of the lips 308. The distal end 316 may have a lateral dimension 320 less than the general diameter 318, and which is also less than the diameter of the lips 308. The distal end 316 may further delimit a distal aperture 322 through which a suture thread may be inserted as better seen in
In an exemplary aspect, the anchor plug 300 may be a carbon fiber or polymeric material and may be between about 4 and 8 mm long. In a further exemplary aspect, the lips 308 may be slightly flexible or resilient to assist in passing into and through the anchor receptacle 400 while still maintaining enough rigidity to avoid backward motion as better explained below. Alternatively, the flexibility may be built into the anchor receptacle 400 and the anchor plug 300 may be substantially rigid.
In another exemplary aspect, the distal aperture 322 may be sized to accommodate an actual tendon graft rather than merely a suture thread. In such an instance, the tendon graft might be looped through the distal aperture 322 and secured to itself using sutures or the like. In general, a cross-sectional area of about 113 mm2 should fit any size graft. That is, the largest likely graft would have a lateral dimension of 12 mm or a radius of 6 mm, and given that area equals πr2, a cross-sectional area of 113 mm2 would allow such a 12 mm graft to be placed through the distal aperture 322. While specific values are provided by way of example, it should be appreciated that other dimensions may also be used without departing from the present disclosure.
The shaft 404 may include threads 412 proximate the head portion 408. The threads 412 may extend a partial length or possibly the entire length of the anchor receptacle 400. Additionally, the shaft 404 may include inwardly tapered clips 414(1)-414(2) positioned on opposite sides of the shaft 404. As better seen in
The head portion 408 may include cutouts 426 that may be used to twist the anchor receptacle 400 manually, such as by using fingers. Additionally, the interior passage 416 may adopt a hex-shaped configuration 428 so that a cannulated hex driver (e.g., an allen wrench) or cannulated screwdriver may be used to drive the anchor receptacle 400 into a bone as better seen in
The mating of the anchor plug 300 and the anchor receptacle 400 is seen in fixation assembly 500 in
While not illustrated, the present disclosure also contemplates angling the lips 308 and the interior teeth 418 in a complementary fashion akin to rifling or threads such that rotation of the anchor receptacle 400 (e.g., such as by a cannulated screwdriver) may draw the anchor plug 300 up into the anchor receptacle 400.
At the conical tip 312, a second suture thread 606 may pass through the aperture 314 and the loose ends threaded into the anchor receptacle 400 through the interior passage 416. The ends of the second suture thread 606 are pulled upwardly (e.g., arrow 608 drawing the anchor plug 300 into the interior passage 416 assisted by the conical nature of the conical tip 312 and the interior taper 422. The aperture 314 may be improved by adding a metallic (or other material) insert or eyelet, thus increasing the strength of the aperture 314 and providing a possibly superior surface through spreading the load more evenly and avoiding rough or sharp edges that could damage the suture.
An in-situ view of this process is shown in
As another possible alternate aspect, an anchor receptacle 900, illustrated in
As still another possible aspect, an anchor receptacle 1000, illustrated in
Note also that the anchor receptacle (of any of the types disclosed above) may come in different sizes and a commercial package may include a single anchor stud with multiple differently-sized anchor receptacles (or receptacles of different types (e.g., one receptacle 400, one receptacle 800, and one receptacle 900)).
While early prototyping and testing has proven favorable, as with many prototype devices, room for improvement was found. For example, when the anchor receptacle 400 is inserted into the femoral bone tunnel, the above description notes that a cannulated screwdriver may be used. The anchor receptacle 400 and screwdriver may go over the guidewire into the femur. The guidewire likely has a smaller diameter than the passage 700. Accordingly, it may be advantageous to keep the guidewire centered in the passage 700 so that the edges of the anchor receptacle 400 will line up with the edges of the passage 700.
One solution may be to leave the drill or reamer in the passage 700 while the second suture thread 606 is being passed through the anchor receptacle 400. Once the anchor receptacle 400 starts down the passage 700, the drill can be removed.
Another solution is to add an extension on a tip of the cannulated screwdriver, where the tip extends through the anchor receptacle 400 and out the distal end 420. This may reduce the need to juggle the drill while inserting the anchor receptacle 400.
Additionally, testing has shown that the tighter the anchor plug 300 fits in the anchor receptacle 400, the less the chance of failure. However, the anchor receptacle 400 may not have a tight hold (even with the threads 412). Accordingly, it may be appropriate to leave the cannulated screwdriver engaged with the anchor receptacle 400, pushing the anchor receptacle 400, and particularly the flange 410, against the femur, while at the same time, pulling the second suture thread 606 out a hole in the screwdriver. The force on the second suture thread 606 pulls the anchor plug 300 into the anchor receptacle 400. Too much force may pull the anchor plug 300 too far into the anchor receptacle 400. To prevent this over insertion, the screwdriver may be equipped with a crank or ratchet that would put force on the second suture thread 606, but only in small increments. Another option would be to take a needle driver or hemostat and wrap the second suture thread 606 around same. As the needle driver or hemostat is rotated, the second suture thread 606 is pulled through the anchor receptacle 400.
Exemplary aspects of the present disclosure allow the anchor plug 300 to be positioned adjustably within the anchor receptacle 400. As previously indicated, the graft tissue may be securely fixed or connected to the anchor plug 300 so that the graft tissue is readily drawn up into the passage 700. There are three commonly-used graft materials, any of which may be attached to the anchor plug 300. The three commonly-used graft materials are 1) a bone plug (e.g., a piece of patella attached to a patellar tendon), 2) a looped tendon (e.g., such as a hamstring tendon), or 3) a free end of a tendon (e.g., such as a tendon only quadriceps tendon). Different suture constructs may be utilized depending on the structure of the graft material. These are detailed below.
In a first exemplary aspect, where there is bone plug fixation, a #2 or a #5 suture 1100 (single or double stranded) is passed through a drill hole 1102 in a bone plug 1104 and the distal aperture 322 of the anchor plug 300 as shown in
In a second exemplary aspect where there is bone plug fixation, a luggage tag suture structure may be formed, as illustrated in
A “hook” could also be used to replace the distal aperture 322 to make use of the lark's head knot. Such a hook may be easier for a metal anchor plug 300. An anchor plug 300 made from a plastic such as polyetheretherketone (PEEK) may not be strong enough to support the tension on the hook.
Where there is tendon fixation without a bone plug and no looping, a suture weave may be used. This may be accomplished a number of ways, both with looped sutures or single-stranded sutures. In a first exemplary aspect, illustrated in
Alternatively, the Krakow weave may be done in such a manner that the knot 1306 is tied distally, at a portion 1400 of the graft 1300 further away from the anchor plug 300 as better illustrated in
While outlined above, a process 1500 for placing the anchor receptacle 400 is provided again with reference to
The pathway is then widened (block 1508). That is, the pathway to the bone through the skin, subcutaneous fat, and muscle may be too small for the anchor receptacle 400 after just using the guidewire/beeth pin. Accordingly, the surgeon may use a scalpel or the like to divide the subcutaneous tissue, fat, and iliotibial band from around the guide wire. A scalpel may be insufficient to get through the muscle without enlarging unnecessarily the entrance incision. Accordingly, femoral or tibial tunnel drill bits can be passed down the guidewire to the bone and spread the muscle tissue out of the way and make sure there are no fibrous bands that might be caught under the flange 410 of the anchor receptacle 400. Instead of the drill bits, a blunt instrument having a diameter approximately equal to the anchor receptacle 400 may be used. This may be a custom instrument or some repurposed instrument. In an exemplary aspect, this instrument may also have graduations or indicia to indicate depth.
A drill may then be used to drill the hole/passage 700 for the anchor receptacle (block 1510). In an exemplary aspect, the drill may be a 6 mm drill and can be passed from outside in or inside out along the beeth pin/guidewire.
With the beeth pin/guidewire still in place, the anchor receptacle 400 may be passed over the beeth pin, pushed by the cannulated screwdriver through the skin and soft tissues into the bone (block 1512).
The second suture thread 606 is then threaded or looped through the end of the beeth pin (block 1514). The anchor plug 300 is then threaded onto the second suture thread 606 (block 1516). The anchor plug 300 will already have been attached to the graft before being attached to the second suture thread 606.
During the steps of blocks 1512, 1514, 1516, the cannulated screwdriver may stay in place, providing counter pressure to keep the anchor receptacle 400 flush on the bone while the beeth pin and the second suture thread 606 are then pulled through the anchor receptacle 400 (block 1518), thereby drawing the anchor plug 300 into the anchor receptacle 400. The screwdriver may then be removed.
Again, note that while repair of an ACL and use of the femur is specifically contemplated, the present disclosure is not so limited and other tendon and ligament repair using other bones may also benefit from the present disclosure. For example, in an exemplary aspect, a hamstring graft may be used. The hamstring graft may be used with sutures attaching the graft to the anchor plug as described above, or, in a further exemplary aspect, the distal aperture 322 may be sized so that the graft may fit therethrough directly. For example, the distal aperture 322 may have a diameter of approximately 6 mm to accommodate such a hamstring graft.
Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 63/364,202 filed on May 5, 2022, and entitled, “TENDON REPAIR ANCHOR,” the contents of which is incorporated herein by reference in its entirety. The present application also claims priority to U.S. Provisional Patent Application Ser. No. 63/386,042 filed on Dec. 5, 2022, and entitled, “TENDON REPAIR ANCHOR,” the contents of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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63386042 | Dec 2022 | US | |
63364202 | May 2022 | US |