Knotless suture lock apparatus and method for securing tissue

Abstract

A suture-locking apparatus comprising a body member having a proximal end, a distal end, and an axial lumen in between the proximal and distal ends, wherein the proximal end adapted for passing a portion of a suture into the lumen; and a plug member movable from a first position to a second position in the lumen, the plug member comprising a radial protrusion adapted for compressing the suture against the body member on moving to the second position. In a further embodiment the invention is a method of anchoring soft tissue in a body cavity with a suture using the present apparatus and without tying a knot.

Description

[0001] This application is a Continuation-in-part of commonly assigned U.S. patent application Ser. No. 09 / 781,793, filed on Feb. 12, 2001, which is herein incorporated by reference in its entirety.BACKGROUND [0002] 1. Field of the Invention [0003] This invention relates generally to apparatus and methods for attaching soft tissue to bone, and more particularly to a knotless suture-locking apparatus comprising a radial protrusion on a suture plug for securing a suture and for restricting the movement of the plug in the apparatus such that the plug will not be dislodged when the suture is subjected to loading after the procedure is completed. The invention has particular application to arthroscopic surgical techniques for anchoring the rotator cuff in the humeral head in repairing the rotator cuff. [0004] 2. Prior Art[0005] It is an increasingly common problem for tendons and other soft, connective tissues to tear or to detach from associated bone. One such type of tear or detachment...

AI Technical Summary

Benefits of technology

[0027] Advantageously, with the present device, since the suture is locked between the plug and the body member, the device can be used in procedures to connect and anchor a tissue in a bone without the need to tie a knot on the suture. Further, with the present device, since the suture is compressed between the plug and the body member at the radial protrusion on the plug, a surgeon can apply compressive and frictional forces on the suture by pulling on the plug to hold the suture in place without slippage. Additionally, since the radial protrusion on the plug is adapted to stop the proximal movement of the plug, and since the applied tension on the suture is in the proximal direction, the plug will not dislodge out of the lumen due to cyclical loading tensioning the suture after the procedure is completed. Further, since the plug is in a compressed state when the suture is under tension, the plug and the body member can be made of relatively soft materials such as plastic that are will withstand the compressive forces. This is in contrast to the need to use a stronger material if the plug was being tensioned. Additionally, since the radial protrusion on the plug combines two the functions of compressing the suture and stopping the movement of the plug in the lumen, the overall dimension of the lock in one embodiment can be reduced depending on the material used.

Problems solved by technology

It is an increasingly common problem for tendons and other soft, connective tissues to tear or to detach from associated bone.

One such type of tear or detachment is a “rotator cuff” tear, wherein the supraspinatus tendon separates from the humerus, causing pain and loss of ability to elevate and externally rotate the arm.

Because of this maneuver, the deltoid requires postoperative protection, thus retarding rehabilitation and possibly resulting in residual weakness.

Although the above described surgical techniques are the current standard of care for rotator cuff repair, they are associated with a great deal of patient discomfort and a lengthy recovery time, ranging from at least four months to one year or more.

It is the above described manipulation of the deltoid muscle together with the large skin incision that causes the majority of patient discomfort and an increased recovery time.

Unfortunately, the skill level required to facilitate an entirely arthroscopic repair of the rotator cuff is inordinately high.

Intracorporeal suturing is clumsy and time consuming, and only the simplest stitch patterns can be utilized.

Extracorporeal knot tying is somewhat less difficult, but the tightness of the knots is difficult to judge, and the tension cannot later be adjusted.

So, knots tied arthroscopically are difficult to achieve, impossible to adjust, and are located in less than optimal areas of the shoulder.

Suture tension is also impossible to measure and adjust once the knot has been fixed.

Consequently, because of the technical difficulty of the procedure, presently less than 1% of all rotator cuff procedures is of the arthroscopic type, and is considered investigational in nature.

Another significant difficulty with current arthroscopic rotator cuff repair techniques is shortcomings related to currently available suture anchors.

Suture eyelets in bone anchors available today, which like the eye of a needle are threaded with the thread or suture, are small in radius, and can cause the suture to fail at the eyelet when the anchor is placed under high tensile loads.

Screws are known for creating such attachments, but suffer from a number of disadvantages, including their tendency to loosen over time, requiring a second procedure to later remove them, and their requirement for a relatively flat attachment geometry.

These anchors still suffer from the aforementioned problem of eyelet design that stresses the sutures.

Other methods of securing soft tissue to bone are known in the prior art, but are not presently considered to be feasible for shoulder repair procedures, because of physicians' reluctance to leave anything but a suture in the capsule area of the shoulder.

The reason for this is that staples, tacks, and the like could possibly fall out and cause injury during movement.

Also, the tacks or staples require a substantial hole in the soft tissue, and make it difficult for the surgeon to precisely locate the soft tissue relative to the bone.

This approach is a useful method for creating an anchor point for the suture, but does not in any way address the problem of tying knots in the suture to fix the soft tissue to the bone.

Although the Golds et al. patent approach utilizes a wedge-shaped member to lock the sutures in place, the suture legs are passing through the bore of the bead only one time, in a proximal to distal direction, and are locked by the collapsing of the wedge, which creates an interference on the longitudinal bore of the anchor member.

Also, no provision is made in this design for attachment of sutures to bone.

Although there is some merit to this approach for eliminating the need for knots in the attachment of sutures to bone, a problem with being able to properly set the tension in the sutures exists.

This action increases the tension in the sutures, and may garrot the soft tissues or increase the tension in the sutures beyond the tensile strength of the material, breaking the sutures.

In addition, the minimal surface area provided by this anchor design for pinching or locking the sutures in place will abrade or damage the suture such that the suture's ability to resist load will be greatly compromised.

Although this embodiment purports to be a self-locking anchor adapted for use in blind holes for fixing sutures into bone, the construct shown is complicated, and does not appear to be adequate to reliably fixate the suture.

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