Adjustable suture-button construct for ankle syndesmosis repair

An adjustable, knotless button/loop construct for fixation of ankle syndesmosis tibio-fibular diastasis and an associated method of ankle repair using the same. The knotless construct comprises a pair of buttons attached to a flexible, continuous, self-cinching, adjustable loop integrated with two splices that are interconnected. The knotless construct is passed through fibular and tibia tunnels and the buttons are secured on the cortical surfaces of tibia and fibula. One of the buttons (for example, an oblong button) is secured on the medial side of the tibia by passing the button and the flexible, adjustable loop though the fibular and tibia tunnels and then flipping and seating the button outside the tibia. The length of the flexible adjustable loop is adjusted so that the second button (for example, a round button) is appropriately secured on the lateral fibula.

FIELD OF THE INVENTION

The present invention relates to the field of ankle surgery and, more particularly, to ankle syndesmosis repair techniques and associated fixation and reconstruction devices.

BACKGROUND OF THE INVENTION

Ankle injuries are among the most common of the bone and joint injuries. The ankle joint is formed of three bones coming together: the tibia which makes up the medial, or inside, anklebone; the fibula which parallels the tibia and makes up the lateral, or outside, anklebone; and the talus. The far ends of the tibia and fibula are known as the malleoli and together they form an arch that sits on top of the talus.

A fibrous membrane (the joint capsule) encases the joint architecture and is lined with a smoother layer called the synovium. The joint capsule contains the synovial fluid produced by the synovium. The synovial fluid allows for smooth movement of the joint surfaces. The ankle joint is stabilized by three groups of ligaments, which are fibers that hold these bones in place.

Surgery to fix an ankle fracture is indicated for patients who suffer a displaced ankle fracture involving the bone on the inside to the ankle (tibia), the bone on the outside of the ankle (fibula), or both. One injury that may occur in the ankle is a disruption of the syndesmosis. A syndesmostic injury is a disruption of the strong fibrous ligaments that hold the fibula and tibia together near the ankle joint. If the syndesmosis is disrupted, then the ankle joint will be unstable and surgery is usually indicated.

A suture-button construct for ankle syndesmosis repair is the subject matter of U.S. Pat. No. 7,235,091, the disclosure of which is incorporated by reference herein in its entirety. The construct and technique disclosed in this prior patent greatly facilitates ankle syndesmosis repair as compared to the prior art, but it requires the tying of knots to secure the second (round) button against the surface of the lateral fibular cortex. An ankle syndesmosis repair construct and technique is needed which provides the same fixation as disclosed in the aforementioned patent, but without the need for tying knots.

SUMMARY OF THE INVENTION

The present invention provides methods and reconstruction systems (an adjustable, self-locking knotless button/loop construct) for ankle syndesmosis with or without associated ankle fractures repair. One embodiment system of the present invention comprises an adjustable, knotless button/loop construct formed of a pair of fixation devices (for example, two buttons) connected by an adjustable, knotless flexible loop. Another embodiment system of the present invention comprises an adjustable, knotless button/loop construct interlocked with a non-adjustable loop each attached to a fixation device (for example, two buttons. The loop includes a flexible material (preferably suture or suture tape), for fracture fixation when a plate is disposed between the fractured bone and one fixation device.

The present invention also provides a method of assembling an adjustable self-locking, knotless button/loop construct by inter alia: (i) providing two fixation devices (i.e., an oblong button and a round button); (ii) threading a flexible strand through holes of the first and second button, to form a braid loop and an intertwining or interlinking “x” of the braid on the round button; (iii) forming two adjustable eyesplices on the braid loop and through the oblong button, so that the oblong button is centered between the two spliced sections; and (iv) threading the tails through the top holes of the round button.

The present invention also provides a method of ankle syndesmosis repair by inter alia: (i) providing an ankle repair system comprising an adjustable, self-locking knotless button/loop construct including two fixation devices (for example, a round button and an oblong button), and at least one flexible, adjustable loop attached to the fixation devices (i.e., the buttons); and (ii) securing the repair system to misaligned bones of the ankle.

The present invention also provides a method of ankle syndesmosis repair by inter alia: (i) providing an ankle repair system comprising an adjustable, self-locking knotless button/loop construct including two fixation devices (for example, a round button and an oblong button), and at least one flexible, adjustable loop attached to one fixation devices (i.e., the buttons) and a non-adjustable loop connected to the second fixation device; and (ii) securing the repair system to misaligned bones of the ankle.

The present invention also provides a fracture management system by inter alia: (i) providing an ankle repair system comprising an adjustable, self-locking knotless button/loop construct including two fixation devices (for example, a round button and an oblong button), and at least one flexible, adjustable loop attached to the fixation devices (i.e., the buttons); (ii) providing a fracture plate, and (iii) securing the repair system and plate to misaligned and fractured bones of the ankle.

These and other features and advantages of the present invention will become apparent from the following description of the invention that is provided in connection with the accompanying drawings and illustrated embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides assembling steps and reconstruction systems for the stabilization of ankle bones (for ankle syndesmosis repair) using an adjustable, knotless button/loop construct in a minimally invasive approach.

The stabilization system of the present invention comprises a knotless button/loop construct including two fixation devices (for example, two buttons) and at least one flexible, adjustable loop attached to the two fixation devices (i.e., the buttons). The knotless button/loop construct has an adjustable loop length and allows adjustment in one direction while preventing or locking the construct from loosening in the opposite direction, due to applied tensile forces.

The present invention also provides a method of ankle repair by inter alia: (i) providing a button/loop construct with two buttons and at least one flexible, adjustable loop (a four-point knotless fixation device) that is capable of adjusting tension (i.e., is provided with a loop having an adjustable perimeter and length) attached to the buttons; and (ii) securing the ankle bones in the proper position by advancing the button/loop construct through tunnels formed within the ankle bones.

Referring now to the drawings, where like elements are designated by like reference numerals,FIG. 1illustrates top views of two fixation devices10,20(button10,20) used for assembling the knotless, integrated, ankle repair system100(button/loop construct100) of the present invention (shown inFIGS. 15 and 16). The knotless repair system100is an integrated system comprising two fixation devices10,20attached to at least one flexible, adjustable loop formed of a flexible material30.

The flexible material30forming the loop has an adjustable length and, as described below, is connected to two fixation devices (buttons) that are further secured on tibial cortex and fibular cortex, respectively. The flexible material is threaded through apertures/holes/eyelets of each of the first and second fixation devices10,20and splices are created to form the knotless, integrated, self-cinching ankle repair system100. In an exemplary only embodiment, and as detailed below, the flexible material30may be suture such as a suture braid with braided filaments having a hollow core (for example, strands of suture such as ultrahigh molecular weight polyethylene (UHMWPE) braided with strands of polyester, collagen, or other suture materials, such as PET, PEEK, silk nylon, and absorbable polymers, among many others).

In an alternative embodiment, the flexible material30may be suture such as FiberWire®, e.g., UHMWPE and polyester braided over a core of UHMWPE, such as #2 FiberWire®.

In an exemplary embodiment only, the first fixation device10is a round button provided with four circular holes having a round configuration, and the second fixation device20is an oblong button provided with two eyelets5and6having an oblong or elliptical configuration, or any other configuration including round, teardrop shape, or circular configuration. Although the embodiments below will be detailed with reference to particular configurations for the first and second fixation devices10,20(i.e., a round button and an oblong, elongate button), the invention is not limited to this exemplary embodiment only and has applicability to fixation devices with other shapes and geometries, as long as the fixation devices are provided with apertures/holes/passages that allow a flexible material (a flexible strand) to pass therethrough (or be threaded therethrough) to form the flexible, adjustable, self-cinching, knotless loop of the invention.

FIGS. 2-14illustrate exemplary steps of a method of assembling the reconstruction system100ofFIGS. 15 and 16(with the following starting materials which are only exemplary).

Needle with nitinol loop41

A braided strand30is inserted through holes1and2of the round button10. Fold braid30at midpoint to create two parallel equal length strands.FIG. 1shows the braided strand30through holes1and2of the round button10. In an exemplary embodiment, braided strand30is a braided UHMWPE strand.

One end of the braided strand30is inserted through both eyelets1and2of the oblong button20.FIG. 3shows the braided strand30through the eyelets5and6.

The same strand30(that passed through oblong button20) is threaded through hole3of the round button10. This creates a loop31(FIG. 5) connecting both buttons10,20.FIG. 4shows the strand30through hole3of the round button10, andFIG. 5shows the braid loop31connecting the round button10and the oblong button20.

The tail of the same strand30(that passed through hole3) is passed under the strand looped through holes1and2.FIG. 6shows the strand from hole3passing under the strand in holes5and6of the round button10. The tail of the same strand30is then passed over the strand looped through holes1and2.

The tail of same strand30is then threaded down through hole4. This forms an intertwining or interlinking “X”35of the braid30. The strand looped across holes1and2will be linked with the strand across holes3and4.FIG. 7Aand its schematic representation ofFIG. 7Bshow the intertwined strands forming an “X” structure35on the round button10.

The following is confirmed:a) The tails of each strand are pulled towards the oblong button20on each side of the round button10(as shown inFIG. 8).b) Viewing the underside of the round button10, the tail strands are exiting from holes adjacent to one another (as shown inFIGS. 9 and 10).c) Viewing the underside of the round button10, the strands forming the loop31through the oblong button20are adjacent to one another (as shown inFIGS. 9 and 10).

FIG. 8shows the tail strands of each side of the round button10pulled towards the oblong button20.FIG. 9shows the tail strands exiting from holes adjacent to one another on the round button10and strands forming loop31through the oblong button20exiting from holes adjacent to one another on the round button10.FIG. 10shows the close up view of the underside of the round button10.

One tail strand is used to start a splice towards the midpoint of the braid loop31at oblong button20. A splice44a(FIG. 12) is created by passing the blunt tip needle41through the center of the braid30with the end of the strand30being carried through in the nitinol loop of the needle41. The oblong button20may need to be moved to the side to allow splicing. The splice location should preferably be on the same side as the tail strand making the splice.FIG. 11shows a close up of splice44a. The oblong button20is moved to the side to allow splicing near center of braided loop31formed between buttons10,20.

After the strand30is carried with needle41to create the splice44a, the tail of the strand is threaded through both eyelet holes in the oblong button20(in from the bottom and out the top of the button20). The oblong button20is slid so that it rests over spliced section.FIG. 12shows the splice44aon one side with the tail passing through the oblong button20.

Steps7and8(detailed above) are repeated to create another splice44bwith the opposing strand on the other side. The second splice44bshould be created such that the exiting aperture of the splice is as close as possible to the first splice44a. The splice length may be about 17-19 mm. The tail of the strand is threaded through both eyelet holes of oblong button20.FIG. 13shows the formation of second splice44bwith the strand exiting at end of first splice44aand as part of knotless, adjustable flexible loop33.

The oblong button20is slid to center between the two spliced sections44a,44b. The oblong button20sits approximately centered between the splices. The lower round button10sits approximately centered between intertwining/crossing “X”35of the strands.

The tails of each strand are threaded through the top holes (holes1and3) in the round button10. Care should be taken to thread the tails through holes on same side of the button10. Strands should not be crossed or twisted. The result is one overall adjustable knotless loop33.FIG. 14shows the strands passing through top holes1and3of the round button10.

After the button/loop construct100is constructed, the construct is stretched. The force to stretch the loop of the construct is applied such that it acts on the overall loop created between the two splices44a,44brather than on individual splice loop.

FIGS. 15 and 16show the final construct100. As shown inFIGS. 15 and 16and as detailed above, button/loop construct100(reconstruction system100) is formed of a pair of buttons10,20connected by a flexible, knotless, adjustable loop33. Loop33includes a flexible material30with two adjustable eyesplices44a,44b.

In an exemplary and illustrative embodiment only, self-locking, knotless, adjustable button/loop construct100includes buttons10,20and flexible material30with two adjustable eyesplices44a,44bthat are interconnected to form one adjustable loop33. By pulling on the free braid strands30, the individual eyesplices constrict and, in turn, reduce the loop length of loop33. Elongation of loop33is prevented because for loop33to elongate, a force must be applied interior to one or both of the eyesplices to elongate the individual loops.

Details regarding the formation/assembly of a self-locking adjustable construct with only one fixation device and two adjustable discrete splices, each splice (and which allows a graft to be fully inserted and seated in a bone tunnel) are provided in U.S. Patent Application Publication Nos. 2010/0256677 and 2010/0268273, the disclosures of which are incorporated by reference in their entirety herewith.

As described in the above-noted applications, a self-locking, adjustable, knotless construct includes a button and a flexible material with two adjustable eyesplices that are interconnected to form an adjustable continuous loop. By pulling on the free braid strands, the individual eyesplices constrict and, in turn, reduce the loop length L of loop. In order for the loop to elongate, a force needs to be applied interior to one or both of the eyesplices to elongate the individual loops.

Exemplary steps of a method of forming/assembling a self-locking adjustable knotless construct with only one fixation device (i.e., with only one button) and two splices/eyesplices are detailed in the above-noted applications, and include as starting materials a suture strand (for example, 50 inches of braided UHMWPE strand); a needle (for example, a blunt tip needle with nitinol loop) and a button (for example, a 3.5 mm titanium button). The suture strand is folded to create two equal length parallel braid strands. At this step, the braid is folded at the midpoint, 25 inches, to create two parallel equal length braid strands (Step1). At Step2, a first eyesplice is created on the first strand of braid by passing the blunt tip needle through the center of the braid with the end of the braid being carried through in the nitinol loop of the needle. The splice should travel for a distance of about 17-19 mm through the braid towards the braid midpoint created in Step1.

Once the first eyesplice has been formed, at Step3, the button is slid over the non-spliced strand passing the strand through both button holes. The button is slid so that it rests over the first spliced section. At Step4, a second eyesplice is formed, similar to the first one, with the opposing strand. The strand should be looped through the first eyesplice loop resulting in two eyesplice loops that are interconnected. Again, the splice length should be between 17-19 mm. The splice should be created such that the exiting aperture of the splice is as close as possible to the first eyesplice.

Buttons10,20of the construct100of the present invention may be formed, for example, of metal, PEEK or PLLA. As detailed above, the buttons are provided with openings (apertures, eyelets, holes) that allow the passage of the flexible material30to pass thereto.

The flexible material30is preferably a braided high strength suture material. The flexible material30may be provided with optional colored strands to assist surgeons in distinguishing between suture lengths with the trace and suture lengths without the trace. The flexible material30may be also provided in the form of a suture tape, or a combination of suture strand and suture tape, and as desired. The flexible material30may be suture such as a suture braid with braided filaments having a hollow core (for example, strands of suture such as ultrahigh molecular weight polyethylene (UHMWPE) braided with strands of polyester, collagen, or other suture materials, such as PET, PEEK, silk nylon, and absorbable polymers, among many others). The flexible material30may also contain a bioabsorbable material, such as PLLA, one of the other polylactides, or collagen, for example, and/or may be formed of twisted fibers having strands of a contrasting color added to the braided threads, to make the suture more visible during surgical procedures. In exemplary embodiments, flexible material30may be a braided suture cover containing strands of a high strength suture material, such as FiberWire™ suture, sold by Arthrex, Inc. of Naples, Fla. The tail ends may preferably be coated (for example, tipped with Loctite or other adhesive).

The method of ankle syndesmosis repair using the suture-button construct of the present invention is similar to that disclosed in U.S. Pat. No. 7,235,091, except that, advantageously, no knot tying is required. Instead, the first (oblong) button of the construct is passed (with a suture passing instrument such as a needle) through drill holes passing through the fibula and tibia bones, flipped and secured against the medial tibial cortex, and the second (round) button is then tightened against the lateral fibular cortex simply by cinching the adjustable construct (instead of tying knots).

FIGS. 17-20illustrate ankle repair system100of the present invention employed in a method of ankle repair (fracture fixation and/or syndesmosis reduction) according to the present invention. A drill hole88is formed through tibia90and fibula80. A long straight needle85with pull-through sutures86and optionally87, are attached to the repair system100and passed through the drill hole88, to advance the first, leading oblong button20substantially horizontally through the drill hole88, as shown inFIGS. 18 and 19. Slight upward tension should be placed on the white pull-through suture, while placing downward tension on the green/white suture. The button should seat easily along the medial cortex. Once the first, oblong button20has exited the medial tibia90, the angle of traction on the pull-through suture86,87is changed and counter-traction is exerted on the loop33, in order to flip (pivot) and engage the oblong button20against the medial tibial cortex (FIG. 20).

Once the oblong button20is anchored, the pull-through suture88can be cut and removed. The trailing or second, round button10is tightened down on the lateral side by further traction on the free ends of the suture30to tightened the adjustable, flexible loop33and adjust the tension between the two buttons10,20(FIG. 20). This will further squeeze the syndesmosis but will not over-tighten it.

FIGS. 21,27and30-32illustrate fixation or buttress plates using the reconstruction system100, whereasFIGS. 22-26and28-29illustrate assembly steps for attaching reconstruction system100, after a fracture plate200,400,500,600or buttress plate300is affixed.FIGS. 22-26illustrate, drilling all four cortices, 1.5 cm above the ankle joint, in the transmalleolar plane (30° anterior to the coronal plane), using the 3.5 mm Drill Bit. The needle and pull-through sutures86,87are passed along the drill hole and out the intact medial skin. The white 2-0 FiberWire pull-through suture advances the button20, until it just exits the medial tibial cortex. A number 2.0 FiberWire suture may be added to facilitate placement of button20. The pull-through sutures are cut where they connect to the needle after passage through the medial skin. The button20should seat easily along the medial.

FIGS. 28-29illustrate attachment of construct100of the present invention may with a buttress plate300that features a four-hole plate. The contoured, titanium plate is preferably used as a “buttress” for ankle syndesmotic repairs with or without ankle fracture. The plate has two inner holes that custom fit the button10, and two outer holes that accept two 3.5 mm×14 mm non-locking screws. The 3.5 mm screws are placed in the proximal and distal holes of the plate and the construct100is then placed in either the third hole (6), or both central holes (inset), if desired.

FIGS. 33 and 34schematically illustrate alternative attachment construct embodiments where loop31of construct100interlocked with a non-adjustable loop131of flexible material. The construct embodiment ofFIG. 33is deployed in a manner similar to that illustrated inFIGS. 17-20when a plate is not needed or used, andFIGS. 22-29when a plate is used as detailed above. In the construct embodiment ofFIG. 34, a 4-hole button120is used and the suture, after passing from eyesplices44aand44bis threaded through the holes in button20and though the 3rd and 4th holes in button120.

While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, embodiments and substitution of equivalents all fall within the scope of the invention. Accordingly, the invention is not to be considered as limited by the foregoing description.