FIELD

The application relates generally to devices and methods for securing soft tissue (e.g., ligament, tendon, graft) to bone, and more particularly to suture constructs that employ particular loop configurations that are adjustable in one direction.

BACKGROUND

Ligaments are the fibrous tissue that connects bones to other bones within the body. Tissue detachment may occur in many ways, e.g., as the result of an accident such as a fall, overexertion during a work-related activity, during the course of an athletic event, or in any one of many other situations and/or activities. These types of injuries are generally the result of excess stress or extraordinary forces being placed upon the tissues. When ligaments are damaged, surgical reconstruction can be necessary, as the ligaments may not regenerate on their own. In the case of a partial detachment, commonly referred to under the general term “sprain,” the injury frequently heals without medical intervention, the patient rests, and care is taken not to expose the injury to undue strenuous activities during the healing process. If, however, the ligament or tendon is completely detached from its attachment site on an associated bone or bones, or if it is severed as the result of a traumatic injury, surgical intervention may be necessary to restore full function to the injured joint.

A number of surgical procedures exist for re-attaching ligaments, or other soft tissue, to bone. One example is the knee100shown inFIG. 1, which includes anterior and posterior cruciate ligaments102,104extending from the head of the tibia106to the intercondylar notch of the femur108. These ligaments operate to prevent forward and backward relative motion between the two bones. When ruptured (e.g., as can happen in strenuous athletic movements), surgical reconstruction can be necessary.

Tears in the cruciate ligaments of the knee can be repaired using a ligament graft taken from a cadaver (i.e., an allograft) or from a patient's own tissue (i.e., an autograft). Reconstruction procedures generally involve forming a hole in both the femur and tibia, and then securing opposite ends of the ligament graft in these holes. In one cruciate ligament repair procedure, a ligament graft is associated with a surgical implant and secured to the femur. A common femoral fixation means includes an elongate “button,” sometimes referred to as a cortical button. The cortical button is attached to a suture loop that is sized to allow an adequate length of the soft tissue graft to lie within the femoral tunnel while providing secure extra-cortical fixation.

Existing devices and methods can be limited because they do not always provide the desired strength or adjustability. In some instances, for example, one or more knots tied to help maintain a location of the suture loop with respect to a cortical button, and thus the graft associated therewith, can loosen or slip. Thus, even if a ligament graft is disposed at a desired location during a procedure, post-operatively the circumference of the loop can increase, causing the graft to move away from the desired location. Further, it can be desirable to limit the number of knots used in conjunction with such devices, because of the potential for the knots loosening and because the additional surface area of the knots can increase the risk of trauma to surrounding tissue. Still further, existing devices and methods also lack adjustability in many instances. For example, in procedures in which multiple ligament grafts are associated with the cortical button, it can be difficult to control placement of one ligament graft without also moving the other ligament graft.

Current adjustable cortical buttons used in orthopedics employing knots are dependent on button geometry and/or multiple loops to achieve security. These are limiting factors for the versatility of the devices and raise potential difficulty in usability. Splices have been used as one-way fixation elements to try and address these concerns, however, such configurations are limited at least because they are not amiable to tape, sutures with tight sheaths and/or cores, and generally require a longer length of the loop to achieve security, thereby increasing the minimum adjustable length. Moreover, in use with purely suspensory fixation devices (e.g., cortical button without locating/retention feature), location or migration of the button with respect to the bone tunnel, possibly caused by offloading of the device due to a non-isometric repair, can cause a reduced interference area on one side of the device, reducing the fixation strength.

Accordingly, there is a need for improved graft fixation devices and methods for use in repair and reconstruction procedures that include, for example, the cruciate ligaments of the knee. In particular, there is a need for devices and methods for positioning and securing ligament grafts that provide increased strength and adjustability without splicing suture or using suture that cannot be spliced.

SUMMARY

The present disclosure is directed to a suture construct that has a one-way adjustable loop. The suture construct can be formed from a single suture filament and, in at least some embodiments, can be coupled to one or more fixation bodies (e.g., cortical buttons) for use in various soft tissue repair procedures. The single suture filament includes at least two knots formed therein, and at least two loop portions. Each loop portion extends from a respective knot, and then the two loop portions are interconnected to form the one-way adjustable loop. They can be interconnected, for example, by passing one loop portion through an opening defined by the other loop portion. Sliding tails formed from the suture filament and extending from the knots can be operable to constrict or otherwise make the loop portions smaller, which in turn constricts or otherwise makes smaller the adjustable loop. Further, constricting tails formed from the suture filament and extending from the knots can be operable to constrict the knots, thereby preventing the sliding tails from sliding with respect to the knots. When the constricting tails constrict the knots, the loop portions, and thus the adjustable loop, cannot be expanded. In at least some embodiments, the constricting tails form a bridge portion that extends between the two knots with the bridge portion keeping the construct in a locked configuration such that the one-way adjustable loop can be constricted but not expanded.

The constructs disclosed herein can be used in various surgical repair procedures in which soft tissue is to be disposed at desired locations with respect to bones. Procedures in which a ligament or graft is designed to be disposed in a bone tunnel can benefit from the presently disclosed constructs and implant devices, such as ACL and MCL repairs. The present disclosure also allows for beneficial use in other types of repairs, including but not limited to AC joint repairs, bunion repairs, and ankle syndesmosis repairs.

In one exemplary embodiment, a suture construct formed from a suture filament includes a first knot formed in the suture filament, a first tail of the suture filament that extends from the first knot, a bride portion of the suture filament, a second knot formed in the suture filament, and a second tail of the suture filament that extends from the second knot. The first knot creates a first loop that extends from the first knot, with the first loop defining a first loop opening. The bridge portion extends from the first knot, connecting the first knot to the second knot. The second knot creates a second loop that extends from the second knot, with the second loop defining a second loop opening, and a portion of the second loop passing through the first loop opening to define an adjustable loop of the suture construct. The adjustable loop defines an adjustable loop opening. The first tail is configured to slide with respect to the first knot to reduce a size of the first loop opening, and thus reduce the size of the adjustable loop opening. Similarly, the second tail is configured to slide with respect to the second knot to reduce a size of the second loop opening, and thus reduce the size of the adjustable loop opening. The bridge portion is configured to prevent expansion of the adjustable loop opening when the suture is manipulated into a locked configuration.

At least one of the first knot or the second knot can be a self-locking knot. Non-limiting examples of such knots include aFIG. 8noose knot, an expandedFIG. 8noose knot, and a prusik-style knot. The suture filament can be unspliced at locations of the first and second knots. In some embodiments, a second suture filament can be configured to capture a portion of the knot and/or knots to permit a release of the knot's constriction when traction is applied to the second filament. In one exemplary embodiment of this configuration the second filament is threaded through the first knot and the second knot, with a first limb of the second suture filament extending through the first knot and a second limb of the second suture filament extending through the second knot such that tension on the limbs loosens the respective first and/or second knots.

A fixation body can be coupled to the bridge portion of the suture filament. For example, the bridge portion can be passed through a plurality of through-holes disposed in the fixation body. In some embodiments, a second fixation body can be coupled to the adjustable loop.

The suture can also include an unlocked configuration. In some such embodiments, the suture can be configured to be moved between the unlocked configuration and the unlocked configuration by adjusting relative loading of the bridge portion and/or the tail portion (i.e., the first tail and the second tail). In one exemplary embodiment of a surgical implant, the implant includes a fixation body and a suture filament coupled to the fixation body. The fixation body has a longitudinal axis extending therealong, first and second sides, and first and second through-holes. The suture filament includes a first portion having a first tail, a first knot formed on the first portion, and a first loop portion. The first tail extends through the first through-hole, the first knot is disposed on the first side of the body, and the first loop portion extends from the first knot, away from the body. The suture filament also includes a second portion having a second tail, a second knot formed on the second portion, and a second loop portion. The second tail extends through the second through-hole, the second knot is disposed on the first side of the body, and the second loop portion extends from the second knot, away from the body. The second loop portion is coupled to the first loop portion to define an adjustable loop of the surgical implant. The suture filament further includes a bridge portion that extends from the first knot to the second knot. The first and second knots are configured such that tension on the first tail constricts the adjustable loop by constricting the first loop portion and tension on the second tail constricts the adjustable loop by constricting the second loop portion. The first and second knots are further configured such that tension on the bridge portion prevents expansion of the adjustable loop.

At least one of the first knot or the second knot can be a self-locking knot. Non-limiting examples of such knots include aFIG. 8noose knot, an expandedFIG. 8noose knot, and a prusik-style knot. The suture filament can be unspliced at locations of the first and second knots.

In some embodiments, the bridge portion can extend from the first knot, through the first through-hole, across the body, and through the second through-hole to the second knot. The implant can include a second fixation body, in which case the second fixation body can be coupled to the adjustable loop. The fixation body, or bodies, can include a cortical button(s). In some embodiments, the fixation body can include a third through-hole. In some such embodiments, as well as in embodiments that include a second fixation body but do not necessarily include a third through-hole, the surgical implant can include a second suture filament that captures a portion of the first knot and the second knot, with a first limb of the second suture filament extending through the first knot, and a second limb of the second suture filament extending to the second knot. The second suture filament can be configured such that tension on at least one of the first or second limbs loosens the respective first or second knots.

One exemplary method for preparing a surgical implant includes forming a first knot in a first portion of a suture length to form a first tail extending from one side of the first knot and a second portion of the suture length extending from an opposite side of the first knot. The method further includes forming a first loop from the second portion with the first loop being closed by way of the first knot. Still further, a second knot is formed in the second portion of the suture length to form a second tail extending from one side of the second knot and a third portion of the suture length extending from an opposite side of the second knot. The method further includes forming a second loop from the third portion, the second loop being closed by way of the second knot, and the second loop being interconnected with the first loop to define an adjustable fixation loop of the suture construct.

The second portion of the suture length can include a bridge portion that extends between the first knot and the second knot. In some embodiments, at least one of the first tail or the second tail can be configured to constrict a size of an opening defined by the adjustable fixation loop when tension is applied to the tail(s) to constrict a size of first or second openings defined by the respective first or second loops.

The method can also include passing the first tail through a first through-hole of a fixation body, passing the second tail through a second through-hole of the fixation body, and passing the second portion of the suture length through at least two of: (1) the first through-hole of the fixation body; (2) the second through-hole of the fixation body; (3) another through-hole of the fixation body; or (4) still another through-hole of the fixation body. Still further, the method can include coupling the adjustable fixation loop to a second fixation body.

