1. The Field of the Invention
The present invention relates to systems and methods for use in repairing soft tissue (e.g., cartilage) tears, for example a meniscal tear formed in the meniscus of a patient's knee.
2. The Relevant Technology
It has been shown that fixation of meniscus traumas, like ruptures and lesions by suturing gives better results than the removal of traumatized meniscal tissue. However, existing repair techniques are often complicated and tedious and present risks for the patient. For example there is a risk that vessels and/or nerves may be damaged during the surgery. Therefore, development efforts have centered on providing meniscal lesion fixation devices and methods which may be used more safely and rapidly. Although various meniscal lesion fixation devices and methods have been developed, such devices and methods often require complicated surgical techniques or complex configurations of components, which can also lead to damage to the surrounding tissue. For example, such techniques and systems often leave tied knots, clips, or locking mechanisms on or near meniscal surfaces which are subject to rubbing against other tissues. The presence of such hard and/or sharp non-biological materials and/or components can result in further damage to surrounding tissue.
As such, there is a continuing need for meniscal repair systems and methods that may be accomplished with minimal invasion, which are rapid, easy to install, and which provide strong and safe fixation of a tissue tear.
In one embodiment, the present invention is directed to a meniscal repair system including a pair of elongate needles with a suture filament attached between respective proximal ends of the needles. Two implants are attached to the suture filament (e.g., molded thereon) between the needles so as to form a suture bridge between the implants. One implant may comprise a barbed shaft with a longitudinal axis aligned with the suture, while the other may be in the form of a T-bar that can be deployed by pivoting so as to be perpendicular to one end of the suture. Each needle is associated with one of the implants. The system is particularly configured for pulling the implants into place, rather than pushing the implants into place, which pulling provides for greater control during placement.
The system may further include one or more dilators (e.g., one or more suture knots, molded beads, and/or other means for dilating) disposed along the length of the suture filament. In one embodiment, a first plurality of spaced apart dilators is disposed along the suture filament between the first needle and the first soft tissue implant, and a second plurality of spaced apart dilators is disposed along the suture filament between the second needle and the second implant. The first plurality of dilators are advantageously arranged so as to be of progressively increasing size (i.e., a dilator of the first plurality of dilators having a smallest size is situated closest to a proximal end of the first needle). The second plurality of dilators may advantageously be configured in a similar manner so that the smallest dilator (e.g., having the smallest diameter or thickness) is situated closest to a proximal end of the second needle.
An alternative system also configured for pulling includes an implant with a fish-vertebrae type configuration in which the anchor implant may comprise separate sections, each section being molded or otherwise attached to a suture filament. An anteriorly disposed head section which includes an anterior head of a small cross-sectional area so as to be relative sharp, which allows easier penetration as the head section follows a needle into an opening. Such a system may include two implants and two needles, as the system described above, or it may only include a single needle and single implant connected by a suture filament that runs between the anteriorly located needle and the posteriorly located implant.
In a related method of use, one needle is used to pierce the meniscus from the inside of the patient's knee. The needle is initially pushed through and across the meniscal tear until the needle exits the skin out the back of the knee. The needle is then used to pull its associated implant into place on one end of the meniscal tear. Once one implant is in position, the other needle is pushed through the meniscus on the other side of the tear (so as to allow closing of the tear) and out the back of the knee. The needle is then pulled so as to pull the other implant into place. Pulling of the implants provides greater control to the practitioner as compared to trying to push the implants through the meniscal tear and into a desired position. The dilators (e.g., one or more knots within the suture filament and/or one or more beads or other shapes molded onto the suture) act to enlarge the passageway as the suture filament and dilator(s) are pulled through behind the needle in preparation for the implant. The presence of the dilators minimizes any tendency for the following implant to tear or otherwise damage adjacent tissue during pulling of the implant
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
In one embodiment, the present invention is directed to a meniscal repair system including a pair of elongate needles with a suture filament attached between respective proximal ends of the needles. Two implants are attached to the suture filament (e.g., molded thereon) between the needles so as to form a suture bridge between the implants. One implant may comprise a barbed shaft with a longitudinal axis aligned with the suture, while the other may be in the form of a T-bar that can be deployed by pivoting so as to be perpendicular to one end of the suture. The system may further include one or more dilators (e.g., one or more suture knots, molded beads, and/or other means for dilating) disposed along the length of the suture filament. Each needle is associated with one of the implants.
In one method of use, one needle is used to pierce the meniscus from the inside of the patient's knee. The needle is initially pushed through and across the meniscal tear until the needle exits the skin out the back of the knee. The needle is then used to pull its associated implant into place on one end of the meniscal tear. Once one implant is in position, the other needle is pushed through the meniscus on the other side of the tear (so as to allow closing of the tear) and out the back of the knee. The needle is then pulled so as to pull the other implant into place. Pulling of the implants provides greater control to the practitioner as compared to trying to push the implants through the meniscal tear and into a desired position. The dilators (e.g., one or more knots within the suture filament and/or one or more beads or other shapes molded onto the suture) act to enlarge the passageway as the suture filament and dilator(s) are pulled through behind the needle in preparation for the implant. The presence of the dilators minimizes any tendency for the following implant to tear or otherwise damage adjacent tissue during pulling of the implant.
The illustrated system 100 further includes a plurality of dilators affixed to suture filament 102 at spaced apart locations along suture filament 102 between each needle and its associated implant. For example, a pair of dilator beads 116a and 118a are disposed along suture filament 102 between needle 108 and implant 112. The two dilator beads are arranged so that first dilator 116a, which is smaller in size (i.e., it has a smaller maximum thickness) than dilator 118a, is disposed closer to needle 108 than second dilator 118a. Similarly, another first dilator 116b, which is smaller in size than second dilator 118b, is disposed closer to needle 110 than second dilator 118b.
Although illustrated with pairs of dilators between each needle and each implant, an alternative embodiment may include fewer (e.g., 0-3) or more dilators. As described above, in embodiments including two or more dilators between each needle and each implant, the dilators may preferably be arranged so as to be progressively larger in size with the smallest dilator nearest the associated needle and the largest dilator being situated closest to the associated implant. This allows passage of the smallest dilator behind the associated needle, which is then followed by progressively larger dilators so as to enlarge the passageway in preparation for the associated implant. Although illustrated as beads which may be molded onto suture 102, dilators having different shapes (e.g., spheres) or other structures (e.g., one or more knots tied into suture 102, or other dilating means) may be used. In one embodiment a knot may be formed into suture 102, after which a plastic dilator bead is molded over the knot. Beads having a smooth oval like shape (as illustrated) may be particularly preferred over other shapes or structures as they act to gently enlarge the passageway in preparation for passage of the implant as a result of their smooth outer surface and oval shape (i.e., an oval shape oriented as illustrated presents a more gentle slope as the dilator is pulled into the opening relative to a sphere).
As perhaps best seen in
Head section 150′ is followed by one or more posteriorly located tail sections 154′ which may be molded or otherwise attached to suture filament 102′ so as to be spaced apart. Illustrated tail sections 154′ each include a plurality of fin-like barbs 156′ to aid in securing implant 114′ within the meniscal tissue. The illustrated configuration including a head section 150′ and one or more tail sections 154′, wherein each section is spaced apart from the preceding section by a length of suture filament 102′ provides excellent flexibility to anchor implant 114′ as a result of its fish-vertebrae like configuration. Such flexibility is helpful when placing the implant, and is not detrimental during a pulling placement, while such flexibility might be impractical if attempting to position such an implant by pushing. Although illustrated as only being connected by suture filament 102′, an alternative embodiment may be configured such that each section of anchor implant 114′ is attached by a relatively thin section (e.g., molded over filament 102′), between barb fins 156′, although in such an embodiment the individual sections are still substantially spaced apart so as to provide similar flexibility along the longitudinal axis of the implant 114′ (i.e., implant 114′ can be easily flexed along its longitudinal axis).
As shown in
Second needle 110 may then be pushed through meniscal tear 124 at a second location which is spaced apart from the location through which needle 108 was pushed. Once second needle 110 exits the exterior surface 128 of the meniscus and is pulled through the skin at the back of the knee, needle 110 may be pulled so as to pull and guide dilators 116b and 118b through the passageway defined by needle 110 and suture filament 102. As needle 110 and/or suture filament end 106 continues to be pulled, second implant 114, for example illustrated as an arrow shaped anchor including retention barbs formed thereon, is pulled through the passageway previously defined by needle 110. Because implant 114 is pulled into position rather than pushed, the practitioner has a greater degree of control over movement and positioning of implant 114, as needle 110 (which is much smaller and sharper relative to implant 114) is first pressed through meniscal tear 124 at a desired location so as to exit exterior surface 128 at a desired location. Once the practitioner is satisfied with the positioning and pathway defined by needle 110, the dilators 116b, 118b and second implant 114 are pulled through the same passageway, as shown in
As second implant 114 is pulled into meniscal tear 124 the walls on either side of the tear are pressed and pulled together by the action of the retention barbs formed on implant 114 and suture 102. As shown in
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.