Patent Publication Number: US-2009234386-A1

Title: Suture Cleat for Soft Tissue Injury Repair

Description:
BACKGROUND 
     Tearing or avulsion of soft tissue from bone is a relatively common type of injury, especially in sports, and can occur in many types of orthopedic injuries, such as torn or ruptured tendons and/or ligaments. In the shoulder, for example, portion of the rotator cuff tendons can tear within themselves or avulse from their insertion into the bone.  FIGS. 1A-1B  show superior views of a shoulder having a typical torn rotator cuff. Here, the tear is associated with the supraspinatus muscle as it inserts into the humerus. The subscapularis muscle and the coracoid process are also shown in  FIG. 1A  for reference. 
     The tear  10 A shown in  FIG. 1A  is a simple tear and is generally perpendicular to the line of action of the muscle. In  FIG. 1B , however, the tear  10 B is more complex because the tear branches both parallel and normal to the muscle fibers. In either case, such a torn rotator cuff can lead to pain, weakness, and loss of function. 
     In many cases, the rotator cuff is repaired by surgically reconnecting the edges of the torn muscle or tendon. Repairs may also include reconnecting the edges of any interstitial tear in the tendons, as well as approximating or reattaching the torn edge of the soft tissue to the bone where it originated. Common techniques for repairing tears to soft tissue and the avulsion of soft tissue from bone include using sutures through bone tunnels, suture anchors, friction anchors, tacks, screws with spiked washers and staples, or any combination of these techniques. 
     Any repair of a rotator cuff injury should have a secure fixation to soft tissue and should preserve the range of motion through which a muscle is expected to function after the repair. The fixation should also serve to provide a means for the soft tissue to anatomically reattach to a position in the shoulder, the humeral head in this case. In the shoulder, the soft tissues may experience wide ranges of motion, as shown by the views in  FIGS. 2A-2B  of a shoulder during internal and external rotations. In addition to these rotations, the shoulder may also be moved through adduction and abduction motions (not shown). The various motions indicate that the soft tissue may undergo dramatic variations in stresses and that a wide variation in possible stresses at a particular point can occur. A surgical repair of injured soft tissue, such as the tears shown in  FIGS. 1A-1B , preferably accounts for different requirements at various points along the injured site in order to alleviate concerns associated with the repair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1B  are superior views of a shoulder and a rotator cuff demonstrating a tear in the rotator cuff. 
         FIGS. 2A-2B  are superior views of the shoulder and rotator cuff in full internal rotation and full external rotation, respectively. 
         FIG. 3A  is a top perspective view of a suture cleat according to one embodiment of the present disclosure. 
         FIG. 3B  is a bottom perspective view of the suture cleat in  FIG. 3A . 
         FIGS. 3C-3F  illustrates techniques for attaching an end of a suture to the suture cleat of  FIG. 3A . 
         FIG. 4A  is side view showing two suture cleats of  FIG. 3A  used in soft tissue repairs. 
         FIG. 4B  shows the side view of  FIG. 4A  when force is applied to the suture cleats. 
         FIG. 5A  is a side view showing one suture cleat of  FIG. 3A  used in soft tissue repairs. 
         FIG. 5B  shows the side view of  FIG. 5A  when force is applied to the suture cleat. 
         FIG. 6A  is a perspective view of a suture cleat having a post according to yet another embodiment of the present disclosure. 
         FIG. 6B  is a side view showing the suture cleat of  FIG. 6A  used in soft tissue repairs. 
         FIG. 6C  shows the side view of  FIG. 6B  when force is applied to the suture cleat. 
         FIGS. 7A-7C  show alternative embodiments of suture cleats having posts. 
         FIG. 8A  is a superior view illustrating suture cleats to repair a rotator cuff tear. 
         FIG. 8B  is a cross-sectional view illustrating suture cleats, sutures, and bone tunnels to repair a rotator cuff tear. 
         FIG. 8C  is a cross-sectional view illustrating suture cleats, sutures, and a screw to repair a rotator cuff tear. 
         FIG. 8D  is a cross-sectional view illustrating suture cleats, sutures, and a suture anchor to repair a rotator cuff tear. 
         FIG. 9  is a superior view of an injured shoulder having a torn rotator cuff repaired using interrupted sutures and augmented with an embodiment of the suture cleats. 
         FIG. 10  is a superior view of an injured shoulder having a torn rotator cuff repaired using interrupted sutures and augmented with an embodiment of the suture cleats. 
     
    
    
     DETAILED DESCRIPTION 
     A suture cleat  100  according to one embodiment is illustrated in  FIGS. 3A-3B . The suture cleat  100  has a disk body  102  with a first (top) side  104  and a second (bottom) side  106 . The second side  106  is intended to position against soft tissue with a plurality of spikes  108  extending from the second side  106  embedding into the soft tissue. The body  102  also defines a passage  105  therethrough for suture. For the sake of illustration, the cleat&#39;s body  102  in one implementation may have a diameter of about 6-mm and may fit within a space of 8.5-mm to effectuate the desired soft tissue repairs of a torn rotator cuff. The length of the spikes  108  may vary depending on the implementation and intended use of the cleat  100 . 
     Suture can attach to the cleat  100  using several techniques. In  FIG. 3C , for example, a Mulberry knot or other large knot  55  can be made on the suture  50 &#39;s end. Alternatively as shown in  FIG. 3D , the end of the suture  50  can be tied to an independent anchor or cross member  56 . Either way, the suture  50  can be passed through the suture passage  105  until this knot  55  or cross member  56  engages the passage  105  and is prevented from passing further. Alternatively as shown in  FIG. 3E , a cross member  57  can be disposed in the cleat&#39;s suture passage  105  allowing the end of the suture  50  to tie thereto. In yet another alternative shown in  FIG. 3F , the cleat  100  can be fabricated with the suture  50 &#39;s end already embedded in the cleat&#39;s material when formed so that the suture  50  and cleat  100  are integrally connected. As further shown, the suture  50  in this situation can be attached to an anchor  58  embedded in the cleat material. 
     To repair soft tissue injuries, various arrangements of the suture cleats  100  can be used to attach suture to a location in soft tissue that is remote from any distal fixation to bone or the like. In  FIG. 4A , for example, two suture cleats  100 A-B attach suture  50  at a remote attachment in soft tissue  20  away from distal fixation to bone or other location. As shown, one suture cleat  100 A fits on an under side of soft tissue  20  with its spikes  108  embedded therein, while another cleat  100 B fits on the upper side of the soft tissue  20  with its spikes  108  also embedded therein. Preferably, the lengths of the spikes  108  are the same on each cleat  100  to provide symmetry in the soft tissue  20  and decrease the stress on the tissue. Yet, these spikes  108  are configured to extend only partially into the soft tissue  20 . 
     One end of suture  50  attaches firmly at  107  to the first cleat  100 A&#39;s suture passage  105  using one of the various techniques disclosed herein. An intermediate portion  52  of the suture  50  passes from the fixed end at  107 , through the soft tissue  20 , and through the other cleat  100 B&#39;s suture passage  105 . In this way, the intermediate suture portion  52  stabilizes the two suture cleats  100 A-B together while providing a movable connection between them. From the second cleat  100 B, the suture  50  can interconnect to another cleat (not shown) at another soft tissue location or can fix distally to bone using a screw, an anchor, a bone tunnel, or the like as disclosed herein. In this way, the suture  50  can act as a tensile member between this attachment location to soft tissue  20  and some other distal attachment. 
     Because the suture  50  interconnects the cleats  100 A-B and acts as the tensile member between them, the suture portion  52 &#39;s flexible connection prevents the two cleats  10 A-B from critically compressing the soft tissue  20 , which could produce adverse effects. Furthermore, the flexibility of the suture portion  52  does not constrain the two cleats  100 A-B together in one position and can greatly increase their resistance to cyclic loading when compared to a rigid connection. As shown in  FIG. 4B , for example, force acting on the suture  50  (due to a change in distance between the attachment locations when soft tissue muscle is flexed or moved) may cause some rotation of the cleats  100 A-B. Yet, the flexible connection of the intermediate suture portion  52  may generate less rotation in the cleats  100 A-B and more shear force between the cleats  100 A-B than would be the case if a rigid connection were instead used. 
     As shown, the lower cleat  100 A firmly attached to the suture  52  experiences less of a moment because the suture  50 &#39;s force acts closer to this cleat  100 A&#39;s center of mass. A larger moment is produced on the upper cleat  100 B because the suture  50 &#39;s force acts further from its center of mass. When suture force is applied, the flexibly connected cleats  100 A-B may allow the center of the soft tissue  20  between them to remain relatively undisturbed, preventing unnecessary stress concentrations in the area of the greatest bending moment. To prevent substantial disruption of the soft tissue  20  but also to keep the cleats  100 A-B embedded, the length of the cleat&#39;s spikes  108  can be designed for a particular implementation so that the spikes  108  will not enter the center of the soft tissue  20  and create a stress concentration. Yet, the depth, shape, and location of the spikes  108  on the cleats  100 A-B in addition to the width and profile of the cleats  100 A-B are preferably selected to prevent the cleats  100 A-B from being pulled out. In addition, when the cleats  100 A-B tilt, the spikes  108  distribute more of the load from the suture  50  than the surface area of the cleat&#39;s body  102 . For this reason, several spikes  108  (e.g., three or more) are preferably used on both of the cleats  100 A-B. In any event, the arrangement of the cleats  100 A-B with interconnecting suture  52  helps to distribute load of the suture  50 &#39;s force effectively. 
     Another suture cleat arrangement is shown in  FIG. 5A . Here, one cleat  100  fits on one side of the soft tissue  20  with suture  50  firmly attached to the cleat  100  as before, either by tying, engaging, or embedding the suture&#39;s end at  107 . Because one cleat  100  is used, its spikes  108  may be longer than if two opposing cleats  100  are used. Yet, the spikes  108  preferably do not extend beyond the other side of the soft tissue  20 . In contrast to the previous embodiment having two cleats, the suture  50  connected to the cleat  100  passes through the soft tissue  20  and out at a point  54  on the other side, pulling the spikes  108  into and the cleat  100  flush with the soft tissue  20 . The other end of the suture  50  then fixes distally as disclosed herein and serves as the tensile member for the distal fixation. 
     Again, the arrangement of the cleat  100  and suture  50  in  FIG. 5A  helps to distribute load of the suture  50 &#39;s force applied to the soft tissue  20  effectively at this attachment location away from the distal fixation to bone or the like. As shown in  FIG. 5B , for example, the tissue  20  at the top of the muscle or tendon is compressed only by the suture  50  at point  54 . Because a portion of the suture  50 &#39;s load is not distributed at  54 , the shear stress on the tissue  20  may be greater than when two cleats are used ( FIG. 4B ), but the stress may still be smaller than if no cleats are used on either side of the tissue  20  and only a suture knot were used on the underside of the tissue  20 , which could lead to suture pull through. One additional advantage is that the load on the suture  50  actually pulls the cleat  100  toward the tissue  20 , preventing the chance of the spikes  108  from pulling out. Moreover, use of the single cleat  100  decreases manufacturing time, associated material cost, and time for surgical implementation. 
     Another suture cleat  100  illustrated in  FIG. 6A  is similar to previous embodiments and has a disk body  102  and a plurality of spikes  108 . In this embodiment, however, the cleat  100  has a post  110  with a distal connection end  112  (e.g., eyelet) for attachment to suture. This post  110  can be rigid or flexible and may be tapered to facilitate positioning the post  110  into soft tissue. 
     As shown in  FIG. 6B , a single one of these cleats  100  fits against one side of the soft tissue  20  with its spikes  108  embedded in the tissue  20  and with its post  110  passing either entirely or partially through the tissue  20 . The suture  50  connects to the distal end of the post  110  at the eyelet  112  and exits the soft tissue  20 . 
     As shown in  FIG. 6C , the suture cleat  100  with the post  100  may still be subjected to a moment when force is applied by the suture  50 . Because the post  110  has a larger diameter than the suture  50 , the load of the suture  50 &#39;s force may be more effectively distributed by the post  100 &#39;s surface area acting on the adjacent tissue  20 . It may be preferable that the post  110  extend slightly through the tissue  20  to the other side enough to extend the thinner suture  50  out of the tissue  20  but not enough for the post  110 &#39;s end  112  to disturb other tissues, in order that the suture will not put a load on the soft tissue. The length and shape of the post  110  can be designed accordingly for a given implementation. Preferably, the post  110 &#39;s attachment to the body  102  is strong enough to avoid fatigue failure under cyclical loading. 
     In  FIG. 7A , an alternative embodiment of the cleat  100  is shown having an independent post  120  with an eyelet  122  and threaded end  124 . As opposed to the integral post  110  of  FIG. 6A , the threaded end  124  on this post  120  threads into a threaded opening  106  in the cleat&#39;s body  102 . In another alternative, the cleat  100  in  FIG. 7B  has a post  130  that tapers from a thick portion at its connection to the disk body  102 . As it tapers, this post  130  forms a thinner, flexible portion that defines an integral length of suture  50  with an end (not shown) that can distally fix to bone or some other device. However, near the exit of the tissue  20 , the suture  50  may still be prone to pull through the tissue  20  because the diameter of the suture  50  would return to near its original size. Therefore, it may be preferable that the post  130  extend slightly through the tissue  20  to the other side enough to extend the thinner suture  50  out of the tissue  20  but not enough for the post  110 &#39;s end  112  to disturb other tissues, in order that the suture will not put a load on the soft tissue  20 . The length and shape of the post  130  can be designed accordingly for a given implementation. 
     In yet another alternative shown in  FIG. 7C , the cleat  100  has a post  140  comprised of a hollow tube through which the suture  50  passes. The proximal end of the suture  50  can attach at the base of the post  140  on the other side of the disc body  102  at  142  by a engaging a knot on the end of the suture, by tying the end of the suture  50  to a cross-member, or by one of the other techniques disclosed herein. The suture  50  passes beyond the hollow tube  140  and can then fix distally to bone or some other device. 
     As disclosed in the above suture cleat arrangements (e.g.,  FIGS. 4A-5B ,  6 B- 6 C, and  7 C), the connection of suture  50  to soft tissue by the disclosed cleats  100  is preferably not rigid in nature. This can alleviate a concern associated with connecting suture  50  to soft tissue in a way that overly compresses the soft tissue  20  enough to cause tissue necrosis from lost blood supply, while still connecting suture  50  to soft tissue  20  in a way that is strong enough to prevent pull out of the suture  50  or premature failure. The non-rigid connection of the suture  20  to the soft tissue  20  provided by the suture cleat arrangements can also alleviate concerns associated with a rigid connection such as cyclic loading that could lead to fatigue failure of the connection and require additional surgery to remove free bodies. 
     Advantageously, the moment generated on the cleats  100  in contact with the soft tissue  20  can provide improved pullout strength. In some cases, the moment is generated on the suture cleat  100  when the muscle contracts. As shown previously in  FIGS. 4B ,  5 B, and  6 C, for example, the resulting moment typically causes the suture cleat  100  to tilt with respect to the line of action of the muscle pull, such that portions of the suture cleat  100  are compressed into the soft tissue  20 . The tilted cleat  100  has a comparatively large surface area that contacts the soft tissue  20  and advantageously enhances the fixation and pullout strength of the cleat  100  and suture  50 . 
     In the previous discussion, several types of suture cleats  100  have been discussed to which suture  50  attaches for distal fixation to some other mechanism, such as another cleat, a bone tunnel, a screw, or a bone anchor. In the discussion that follows, various arrangements having suture cleats  10  and sutures  50  are described for soft tissue repairs and distal fixation to bone. 
     As shown in  FIG. 8A , for example, an arrangement  40  of cleat attachments  200 A-B and interconnecting suture  50  is used to repair a rotator cuff tear. In this arrangement  40 , opposing portions of soft tissue  20 A-B are reconnected using cleat attachments  200 A-B on both sides of the injury  25 . The first cleat attachment  200 A connects the interconnecting suture  50  to a healthy portion of the rotator cuff tissue  20 A where the tissue  20 A is thicker and stronger on one side of the injury  25 . At this attachment  200 A, a pair of cleats (e.g.,  100 A-B as in  FIG. 4A ) can be embedded in the upper and lower surfaces of the soft tissue  20 A and interconnected by portion of the suture  50 . From the first attachment  200 A, the interconnecting suture  50  then spans the torn portion of the rotator cuff to a second attachment  200 B on the opposite side of the injury  25  in another portion of healthy soft tissue  20 B. Here, a similar pair of cleats (e.g.,  100 A-B as in  FIG. 4A ) can be used to fix this end of the suture  50  to the soft tissue  20 B. In this way, the cleat attachments  200 A-B and suture  50  can augment the soft tissue repair in addition to any standard suturing performed as shown along the injury  25 . 
     In another arrangement  41  shown in  FIG. 8B , first and second cleat attachments  200 A-B, sutures  50  and  54 , and bone tunnels  60  are used to repair soft tissue  20  to bone tissue  30 . Here, interconnecting suture  50  attaches to a healthy portion of rotator cuff tissue  20  at the first attachment  200 A using a pair of suture cleats  100 A-B interconnected by a portion of the suture  52 . A length suture  50  then spans from upper cleat  100 B and across the tissue. At the second attachment  200 B, the suture  50  then reattaches the injured tissue to the healthy bone tissue  30  using an additional pair of suture cleats  100 A-B, additional suture  54 , and bone tunnels  60 . 
     Typically, in this form of repair, one or more of the bone tunnels  60  are drilled through the bone tissue  30 . The suture  54  passes through one tunnel  60 , through a portion of the rotator cuff soft tissue  20 , through the cleats  100 A-B, and through a second tunnel  60  in the bone tissue  30 . On the outside of the bone  30 , the suture  54  is then tied over a cortical bridge between the tunnels  60 . In this way, the cleats  100 A-B and sutures  50 / 54  reattach the soft tissue  20  to the bone  30  in the repair. In an alternative arrangement, one suture cleat  100  can be used at attachment  200 B with two sutures  50 / 54  passing through it and through the bone tunnels  60 ,  62 . 
     In addition to the use of a bone tunnel, other techniques can be used in conjunction with the disclosed suture cleats  100  of  FIGS. 3A through 7C  to repair a soft tissue injury to bone tissue. In another arrangement  42  of  FIG. 8C , a shoulder soft tissue repair uses one suture cleat  100 , a suture  50 , and a bone screw  70 . In this example, the suture cleat  100  fits against the underside of the soft tissue  20  at attachment  200 A and connects one end of suture  50  to a healthy portion of rotator cuff tissue  20 . As before, the attachment  200 A is proximal to the torn edge where the tissue  20  is thicker and stronger. The suture  50  passes out of the soft tissue  20  at point  54 , and the suture  50 &#39;s other end then connects at attachment  200 B directly to the bone screw  70  that reattaches the avulsed tissue  20  to the bone tissue  30 . 
     In yet another arrangement  43  of  FIG. 8D , a shoulder soft tissue repair uses suture cleats  100 , suture  50 , and a suture anchor  80 . Here, one end of the suture  50  connects at attachment  200 A to soft tissue  20  using a suture cleat  100  having a post  110  as discussed previously. Then, the suture  50  spans the tissue  20  to another suture cleat  100  at attachment  200 B. Passing through this cleat  100 , the suture  50  passes through a portion of the soft tissue  20  and ties to the suture anchor  80  engaged in the bone tissue  30  of the proximal humerus. The anchor  80  can be a conventional anchor or can be a knotless, friction-type anchor such as the Pushlock Anchor from Arthex Inc. The cleats  100 , suture  50 , and anchor  80  support the soft tissue  20  through the healing process by facilitating reattachment of the avulsed soft tissue  20  to the bone  30 . 
     In the arrangements  41 - 43  of  FIGS. 8A-8D , attachment to the soft tissue  20  has been shown using pairs of cleats  100 A-B ( FIG. 8B ) on opposing sides of the soft tissue, a single cleat  100  ( FIG. 8C ) on one side of the soft tissue, and a post-style cleat  100  ( FIG. 8D ) on one side of the soft tissue. Likewise, attachment to the bone has been accomplished using a pair of suture cleats  100 A-B and bone tunnels  60  ( FIG. 8B ), direct connection to a screw  70  ( FIG. 8C ), and a single cleat  100  on one side of the tissue and an anchor  80  ( FIG. 8C ). With the benefit of the present disclosure, however, it will be appreciated that other arrangements and combinations of cleats and bone fixation techniques disclosed herein could also be used. 
     Additional techniques for soft tissue repairs can use a plurality of the disclosed cleats  100  interconnected by various spans of suture  50  as shown in  FIGS. 9 and 10 . In  FIG. 9 , a shoulder with a torn rotator cuff is shown repaired using an arrangement  44  of sutures  50 A-B and suture cleats  100  of the present disclosure. Here, the tear in the rotator cuff similar to the tear illustrated in  FIG. 1A  and is repaired using a pair of cleats  100  similar to those disclosed in  FIG. 4A . Sutures  50 A-B pass from the cleats  100  and attach distally to the bone tissue at points  54  using bone fixation techniques disclosed herein. 
     In  FIG. 10 , the shoulder with torn rotator cuff is shown repaired using an arrangement  45  of sutures  50 A-B augmented with a plurality of interconnected cleats  100  of the present disclosure. In this case, edges of the torn rotator cuff have been reconnected using sutures  50 A that connect from cleats  100  on one side of the injury to points  54  on the other side of the injury, where the suture  50 A can connect to another cleat (not shown) on the underside of the tissue  20 , to an anchor, etc. In addition, suture  50 B interconnects the cleats  100  to each other on the same and different sides of the injury, which may provide even more strength and stability to the repair. In this manner, the present invention may be used to emulate the structure or function of a trestle. 
     U.S. Pat. Nos. 7,001,411 and 7,303,577 and co-pending application Ser. No. 11/866,220, which are each incorporated herein by reference in their entirety, disclose related soft tissue repair techniques. These related technique use soft tissue cleats that coapt together to attach to soft tissue so that suture can then attach distally to bone. In addition, the related techniques disclosed in U.S. Pat. No. 7,303,577 and co-pending application Ser. No. 11/866,220 use bridge members between attachment locations in repairing soft tissue injuries. By contrast, the repair techniques of the present disclosure do not coapt rigidly on both sides of soft tissue at an attachment location and do not use bridge members between attachment locations. Instead, the present techniques use two suture cleats  100  on both sides of the soft tissue  20  with an interconnecting portion of suture  50  between them (e.g.,  FIG. 4A ); one suture cleat  100  on the underside of soft tissue  20  with suture  50  passing freely through the soft tissue  20  to the tissue&#39;s upper side (e.g.,  FIG. 5A ); or one suture cleat  100  on one side of the soft tissue  20  with a post to support the suture  50  on an opposing side of the tissue  20  (e.g.,  FIG. 6A ). In addition, in each of these suture cleat arrangements, suture  50  can pass from these one or more suture cleats  100  at one attachment location to another location where the suture  50  can distally fix to bone or to another cleat arrangement. In this way, the suture  50  provides a tensile interconnection between attachment locations in the present techniques. 
     As detailed throughout this disclosure, the present techniques for repairing soft tissue provide several benefits beyond what is currently available. As evidenced above, for example, the techniques disclosed herein are intended to limit stress at the attachment location where suture attaches to the soft tissue away from any distal fixation to bone or the like. At this attachment location, the suture cleat arrangements reduce stress to soft tissue at the attachment location and ensure that the attached suture does not pull out when the distance between attachment location changes (e.g., when soft tissue muscle is flexed or stretched). 
     The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. For example, the inventive concepts disclosed herein have been described for use in repair of torn rotator cuffs, and the description and discussion above focus on repairs of rotator cuffs and applications to make such repairs. It will be apparent to those of ordinary skill in the art, however, in light of the present disclosure, that the inventive concepts may apply to other surgical and orthopedic applications. In addition, it will be appreciated that the cleats of the present disclosure may be made of any suitable material for medical purposes, including, but not limited to, a plastic material (e.g., polyethylene, polyetheretherketone, or delrin), a metal material, an elastomeric material, a radiolucent material, a bioabsorbable material, a non-bioabsorbable material, or a combination of these. 
     In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.