1. Field of the Invention. The present invention relates generally to medical devices, systems, and methods and more particularly to methods and apparatus for tensioning and fixating soft tissue and prosthetic grafts to bone, for example in orthopedic graft reconstruction surgeries, such as anterior cruciate ligament (ACL) repair and other procedures.
ACL reconstruction is commonly performed to restore knee joint function and to decrease the risk of post-traumatic osteoarthritis (OA) in the ACL-injured knee. While the result of ACL reconstruction are generally successful, such procedures still face challenges. For example, the initial tension applied to the graft before fixation affects knee stability and joint contact forces, and an improper initial tension may cause OA.
It can be a difficult to continuously and accurately measure the tension being applied on a distal end of the graft prior to fixation of a proximal end of the graft and, even when the such tension can be accurately assessed, it can be difficult to complete fixation of the proximal end of the graft while maintaining a desired amount of tension.
For these reasons, it would be desirable to provide improved apparatus, systems, and methods for the controlled tensioning, positioning, and fixation of grafts used in ACL and other orthopedic procedures. At least some of these objectives will be met by the inventions described and claimed hereinbelow.
2. Listing of Background Art. U.S. Pat. Nos. 8,298,247 and 8,939,999 describe graft tensioning devices. The INTRAFIX® System for tibial fixation and tensioning for use in ACL repair is commercially available from DePuyMitek, Raynham, MA.
The present invention provides a graft tensioning tool for use in soft tissue fixation procedures, for example in orthopedic graft reconstruction surgeries, such as anterior cruciate ligament (ACL) repair and other joint reconstruction procedures. A distal end of a tissue graft is attached to a remote bone surface and pulled back through a tunnel formed in an adjacent bone toward a proximal opening the tunnel. A suture is typically attached to the free proximal end of the tissue graft, and two free ends of the suture are pulled through the proximal tunnel opening, and the suture ends are fixed to the tunnel opening to apply an appropriate tension to the graft.
The procedures of the present invention rely on placing a tunnel ring, such as a shoulder washer or “top hat,” at the proximal opening of the bone tunnel. A suture lock is secured to the tunnel ring to lock or fix the suture after a desired tension has been applied by a graft tensioning tool. Although the description and claims herein will after refer to fixation of suture, in some cases, at least a portion of the tissue graft itself may be pulled through the tunnel ring and locked in place by the suture lock, either with the suture or in some instances in place of the suture.
In a first aspect of the present invention, the graft tensioning tool comprises an elongate frame having a proximal end, a distal end, and an axial passage extending therethrough. The distal end of the shaft is configured to detachably engage the tunnel ring, and the frame is coupled to a first suture puller and a second suture puller. Each suture puller is configured to detachably engage a length of suture (or in some cases a length of graft), and a tensioner on the elongate frame is configured to displace the first and second suture pullers in a proximal direction relative to the elongate frame. A tension gauge is coupled to the tensioner to measure tension applied by the tensioner to the first and second suture pullers, and a locking tool is configured to engage the suture lock through the axial passage of the frame when the distal end of the frame engages the opening in the tunnel ring.
In some examples, the first suture puller is disposed on a first side of the elongate frame and the second suture puller is disposed on a second side of the tensioner frame. Usually, the first and second suture pullers will be aligned on laterally opposite sides of the frame, but in other instances the suture pullers could be axially staggered, be in tandem on the same side of the frame, or have other configurations which allow for tension to be applied in a proximal direction away from the bone tunnel. The first and second suture pullers will typically be arranged to be pulled in unison but that is not necessary as separate tensioning of the suture lengths, although not preferred, could be implemented.
In the examples herein, the tensioner is configured to displace the first and suture pullers simultaneously.
In some examples, the locking tool is configured to carry the suture lock through the axial passage of the frame and position the suture lock in the opening in the tunnel ring.
In some examples, the distal end of the elongate frame comprises an opening configured to circumscribe the tunnel ring.
In some examples, the tunnel ring has a lower surface configured to engage cortical bone and un upper surface and wherein the opening of the elongate frame is configured to circumscribe the upper surface of tunnel ring.
In some examples, the opening is configured to interlock with the upper surface the tunnel ring. For example, an interlock may include a protrusion on the opening of distal end of the elongate frame and a recess on an exterior surface of the tunnel ring, where the protrusion is configured to engage the recess when the opening circumscribes the tunnel ring.
In some examples, the first and second suture pullers each comprise a cleat.
In some examples, the first and second suture pullers may be mounted on a carriage that is slidably disposed in a distal portion of the passage in the frame, wherein the suture pullers are exposed through slots in the frame. For example, the tensioner may comprise a shuttle assembly coupled to the carriage, wherein the shuttle assembly is configured to be retracted to proximally displace the carriage. The shuttle assembly is typically configured to be manually retracted, but in other instances could be configured to be immortalized or otherwise have a powered operation.
In some examples, the shuttle assembly comprises an externally threaded cylinder and an internally threaded knob, where in knob is rotatably mounted on the frame at a fixed axial position and the threaded cylinder is slidably mounted in the passageway of the frame but prevented from rotating, wherein a proximal portion of the threaded cylinder is received in a distal portion of the knob so that manual rotation of the knob will proximally retract the threaded cylinder. It will be appreciated, of course, that a variety of other shuttle assemblies could be used, such as ratchet assemblies, levered assemblies, and the like.
In some examples, the shuttle assembly may further comprise a spring coupling the threaded cylinder to the puller carriage. In such instances, the tension gauge is typically coupled to the spring to provide a tension readout based upon elongation of the spring.
In other examples, the tension gauge comprises a load cell transducer and the readout comprises a digital display.
In some examples, the graft tensioning tool may further comprise a wireless transmitter connected to the load cell for transmission to a remote digital display. For example, the load cell is wired to a digital display on the elongate frame.
The locking tool may have a variety of structures, typically comprising a shaft with a proximal handle and a distal end configured to detachably engage the suture lock.
The tensioner may be configured to apply a continuously variable tension, such as when a threaded tensioner is used. In other instances, the tensioner may apply an incremental tensioning, such as when a ratcheting retraction mechanism is employed.
The tensioner will typically be configured to displace the first and second suture pullers simultaneously, but in other instances may be configured to displace the pullers separately.
The tensioner is typically configured to displace the first and second suture pullers in both proximal and distal directions relative to the elongate frame, but in some instances could be configured to retract only in a proximal direction, for example if a separate release mechanism is provided to release the tensioner and all tension on the sutures.
In a second aspect, the present invention provides graft tensioning systems comprising the graft tensioning tool as described above in combination with a tunnel ring and a suture lock.
In some examples of the graft tensioning systems, the tunnel ring comprises a shoulder washer. For example, the shoulder washer may have a pair of interior channels on an interior surface for receiving and guiding the suture lengths and, the interior surface may be threaded.
In some examples of the graft tensioning systems, the suture lock comprises a threaded shaft that can be rotatably advanced into the tunnel ring to compress and lock the suture and/or a graft implant.
In a third aspect, the present invention provides a cortical implant comprising a tunnel ring and a suture lock, where the suture lock is configured to be advanced into an interior of the tunnel ring to compress and lock suture and/or a graft implant.
The suture ring lock of the cortical implant typically comprises a locking element configured to compressively engage the suture lock as the suture lock is advanced into the interior of the tunnel ring.
The tunnel ring of the cortical implant typically comprises a threaded passage having a pair of axial suture channels formed therein, and the suture lock typically comprises a threaded shaft configured to be rotatably advanced into the threaded passage to compress and lock the suture.
In a fourth aspect, the present invention provides a method of tensioning a pair of suture ends extending through an opening of a tissue tunnel in bone. The method comprises fixing at least one suture strand to a tissue structure or implant to be tensioned, where the pair of suture ends extends through the opening of the tissue tunnel. A tensioning tool comprising an elongated frame, first and second suture pullers, and a locking tool is provided, a distal end of the elongated frame is engaged against a tunnel ring disposed at the opening of the tissue tunnel. Each of the suture ends is detachably secured to one of the suture pullers, and the suture pullers are drawn in a proximal direction relative to the frame to tension the at least one suture strand. A locking tool is advanced distally through a central passage of the frame to engage a suture lock proximate the tunnel ring, and the suture lock is tightened in the opening of the tunnel ring with the locking tool to lock the suture in place.
When performing such methods, the suture lock may be advanced to the tunnel ring through the central passage of the frame by the locking tool.
When performing such methods, the suture lock may be placed in the opening of the tunnel ring prior to engaging the distal end of the elongated frame against the tunnel ring.
Such methods may further comprise determining an amount of tension exerted on the suture while the drawing the suture pullers, wherein the suture lock is positioned and coupled to the tunnel ring when the amount of tension is at target value or within a target range.
Such methods may further comprise displaying the amount of tension to allow monitoring by a user while the user is manually drawing the suture pullers.
When performing such methods, fixing the at least one suture strand may comprise attaching the suture strand directly or indirectly to a prosthetic joint graft.
When performing such methods, engaging the distal end of the elongated frame against the tunnel ring may comprise circumscribing an upper opening of the tunnel ring to align the central passage of the elongated frame with said upper opening.
When performing such methods, detachably securing each of the suture ends to one of the suture pullers may comprise securing the suture ends to a pair of cleats on opposite side of the frame. For example, the cleats may be coupled to a carriage slidably mounted in the central passage of the frame, and the suture pullers may be drawn in a proximal direction by pulling the carriage proximally through the central passage. For example, drawing the carriage proximally through the central passage may comprise rotating a knob that is threadably coupled to the carriage.
In a specific instance, the tunnel ring may have a threaded interior surface with channels for receiving the suture ends and the suture lock comprises a threaded shaft, and coupling the suture lock to the tunnel ring may comprise rotatably inserting the threaded shaft into the tunnel ring to compress and lock the suture in place.
Such methods may further comprise determining and an angle of flexion of a joint during performance of the procedure. Such methods may further comprise observing an amount of tension exerted on the suture at different angles of flexion, allowing the user to lock the suture in place when a target amount or range of tension is observed.
In other aspects, the present invention provides a graft tensioning system comprising a top hat configured to be placed in an entrance into a bone bore. A frame has a proximal end and a distal end, where the distal end is configured to engage the passage in the top hat. A graft tightening assembly disposed on the frame includes a first suture puller on a first side of the tensioner frame and a second suture puller on a second side of the tensioner frame. A variable load transfer element is attached to a proximal end of the graft tightening assembly, and a tensioner on a proximal portion of the frame is configured to apply a controlled proximal tension on a proximal end of the variable load transfer element. A read out on the frame shows the magnitude of tension being applied by the tensioner to the graft tightening assembly.
In specific embodiments, the variable load transfer element comprises a spring and the readout may comprise a scale coupled to the spring. In alternative embodiments, the variable load transfer element may comprise a load cell transducer and the readout may comprise a digital display. In either embodiment, the digital display shows both tension and angle.
In other embodiments, the graft tensioning system of the present invention may further comprise a lock configured to threadably engage the top hat to secure suture to the top hat, optionally further comprising a lock driver having a distal end configured to removably carry the lock. Typically, the frame will have a central passage extending axially therethrough where the lock driver is rotatably received in the central passage with the lock positioned distally of the distal end of the frame.
In still other embodiments, the frame further may comprise a pair of guide channels at the distal end of the frame. The guide channels may taper in a distal direction to form a distal tip which engages with the top hat. The lock driver may be configured to advance the lock through the distal tip formed by the channels and into the top hat, and the tensioner may comprise a threaded knob on a proximal portion of the frame.
Referring to
A tensioner assembly 30 is coupled to the pair of suture pullers 20 and 22 to allow a user to apply a controlled on during ligament reconstruction or other surgery, as described in more detail below. The tensioner assembly 30 typically includes a partially threaded cylinder 32 having a threaded portion 34 and a distal extension 36. A ring 38 is disposed in the middle of the partially threaded cylinder 32 between the threaded portion 34 and the distal extension 36. The ring has a pair of sliders 40, generally located on diametrically opposed sides, which are received in slots 42 in sides of the frame 12. The sliders 40 allow the partially threaded cylinder 32 to axially translate in the axial passage 18 of the elongated frame 12 while preventing rotation. In this way, a knob 50, which is rotatably mounted in the proximal end 16 of the elongated frame 12, can be used to advance and retract the partially threaded cylinder 32 within the axial passage 18. As best seen in
Axial translation of the partially threaded cylinder 32 is coupled to a puller body 70 of the tensioner assembly 30 by a spring 60. The spring 60 is typically a coil spring which is fully axially collapsed in a non-tensioned state. A proximal end of the spring 60 is attached to the partially threaded cylinder 32 on the distal side of the ring 38. A distal end of the spring 60 is attached to a proximal end of the puller body 70 so that proximal translation of the partially threaded cylinder 32 will axially tension the spring 60 causing a spring force to draw the puller body 70 in a proximal direction which in turn will draw suture pullers 20 and 22 in the proximal direction. The amount of tension applied to the puller 70 will depend on both the distance that the partially threaded cylinder 32 travels as well as the spring constant of the spring 60.
While use of a spring, such as spring 60, to transmit a proximal force to the puller body 70 is generally preferred, in other instances, the tensioner assembly 30 could be directly attached to the puller body 70 or other equivalent structure so that the suture pullers are translated directly by the tensioner assembly with a 1:1 travel ration.
The puller body 70 has a viewing slot 72 with a tension scale 74 aligned along an edge thereof. A distal end 44 of the distal extension 36 of the partially threaded cylinder 32 is visible through the viewing slot 72 and provides a marker which indicates the amount of tension being applied by the spring 60 on the tensioner assembly 30. The combination of the spring 60 and puller body 70 provides a simple spring scale which allows a user to monitor the tension applied by the tensioning tool 10 to the suture at all times during a procedure.
The suture pullers 20 and 22 typically comprise cleat bodies 76 and cleat arms 78 and are typically fixedly attached to the puller body 70 by attachment screws 82. The cleat arms 78 are attached to the cleat bodies at pivots 80, and can be moved between an open configuration, as shown in broken line in
Referring now to
Referring now to
Referring now to
Other embodiments of suture ring-suture lock combinations are shown in
Referring now to
At this point in the procedure, the distal end 44 the distal extension 36 of the partially threaded cylinder 32 will be at the 0 marker on the scale 74. The knob 50 may then be rotated to draw the pullers 20 and 22 proximally, applying tension to the sutures as indicated on the scale 74. When the distal end 44 is observed to reach a desired tension level as indicated on the tension scale 74. When a target tension is achieved, rotation of the knob 50 may be stopped and tensioning of suture left at the target level, as shown in
Alternatively, the suture lock 102 may be loosely placed into the suture ring 100 prior to tensioning of the suture, and the locking tool 90 used only to heighten a suture lock after the desired suture tension has been achieved. In either case, use of the separate locking tool to advance and/or lock suture lock in place allows the target tension to be maintaining with minimal or no variation.
The graft tensioning tools 10 of the present invention may be used to check graft tension in the knee or other joint while the joint is moved through different degrees of flexion. As shown in
Such plots can be useful for determining the outcome of an implementation. As shown in
While preferred embodiments of the present invention have and the opening shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention methods and structures within the scope of these claims and their equivalents be covered thereby.
This application is a continuation of PCT Application No. PCT/US21/55073 (Attorney Docket No. 58948-704601), filed Oct. 14, 2021, which claims the benefit of U.S. Provisional No. 63/091,731 (Attorney Docket No. 58948-704.101), filed Oct. 14, 2020, the entire content of which is incorporated herein by reference.
Number | Date | Country | |
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63091731 | Oct 2020 | US |
Number | Date | Country | |
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Parent | PCT/US2021/055073 | Oct 2021 | US |
Child | 18300701 | US |