Patent Publication Number: US-2023147972-A1

Title: Knotless tensionable fixation systems and surgical methods for repairing tissue defects

Description:
BACKGROUND 
     This disclosure relates to the field of surgery, and more particularly to knotless tensionable fixation systems and associated surgical methods for repairing tissue defects. 
     Repetitive trauma to a joint, such as a knee, ankle, hip, or shoulder joint, for example, may result in the development of tissue defects (e.g., cartilage defects, soft tissue tears, etc.). If not treated, tissue defects could further deteriorate, thereby causing joint instability and discomfort. 
     SUMMARY 
     This disclosure relates to knotless tensionable fixation systems and surgical methods for repairing tissue defects within a vessel or canal of a joint. 
     An exemplary surgical method for repairing a tissue defect may include, inter alia, inserting a first knotless suture anchor into a bone, creating a first loop in the first knotless suture anchor, inserting a second knotless suture anchor into the bone, creating a second loop in the second knotless suture anchor, passing the first loop and the second loop through a graft, passing a reinforcement construct through the first loop or looping the reinforcement construct about the first loop, passing the reinforcement construct through the second loop or looping the reinforcement construct about the second loop, tightening the first loop down to the graft to approximate the graft to the tissue defect, tightening the second loop down to the graft to further approximate the graft to the tissue defect, securing a first tail portion of the reinforcement construct to the bone with a third knotless suture anchor, and securing a second tail portion of the reinforcement construct to the bone with a fourth knotless suture anchor. The reinforcement construct extends over top of the graft to compresses the graft to the tissue defect after securing the first and second tail portions. 
     Another exemplary surgical method may include, inter alia, fixating a graft over top of a tissue defect with a knotless tensionable knotless fixation system. The knotless tensionable fixation system includes a plurality of knotless suture anchors, the graft, and a reinforcement construct. The reinforcement construct establishes a fixed segment of material over the graft and is secured in place by the plurality of knotless suture anchors. 
     An exemplary knotless tensionable fixation system for repairing a tissue defect may include, inter alia, a plurality of knotless suture anchors, an osteochondral allograft, and a reinforcement construct that is connectable to the plurality of knotless suture anchors and configured for fixating the osteochondral allograft over top of the tissue defect. 
     The embodiments, examples, and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
     The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    schematically illustrates a step of surgical method for repairing a tissue defect using a knotless tensionable fixation system. 
         FIG.  2    illustrates another step of a surgical method for repairing a tissue defect. 
         FIG.  3    illustrates an exemplary graft of a knotless tensionable fixation system. 
         FIG.  4    illustrates another exemplary graft of a knotless tensionable fixation system. 
         FIG.  5    illustrates another step of a surgical method for repairing a tissue defect. 
         FIG.  6    illustrates an alternative routing configuration of a reinforcement construct of a knotless tensionable fixation system. 
         FIG.  7    illustrates another step of a surgical method for repairing a tissue defect. 
         FIG.  8    illustrates another step of a surgical method for repairing a tissue defect. 
         FIG.  9    illustrates a final repair construct of a surgical method for repairing the tissue defect. 
         FIG.  10    illustrate an alternative final repair construct of a surgical method for repairing a tissue defect. 
         FIGS.  11  and  12    illustrate an exemplary knotless suture anchor. 
         FIGS.  13  and  14    illustrate another exemplary knotless suture anchor. 
         FIGS.  15  and  16    illustrate yet another exemplary knotless suture anchor. 
         FIG.  17    schematically illustrates an exemplary knotless tensionable fixation system. 
         FIG.  18    illustrates the use of fixed suture loops as part of a surgical method for repairing a tissue defect. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure is directed to knotless tensionable fixation systems and surgical methods for repairing tissue defects within a joint. The system and methods described herein may be utilized to secure a graft over the tissue defect for providing a tissue network that can potentially signal autologous cellular interactions. These and other features of this disclosure are described in further detail below. 
     An exemplary surgical method for repairing a tissue defect may include, inter alia, inserting a first knotless suture anchor into a bone, creating a first loop in the first knotless suture anchor, inserting a second knotless suture anchor into the bone, creating a second loop in the second knotless suture anchor, passing the first loop and the second loop through a graft, passing a reinforcement construct through the first loop or looping the reinforcement construct about the first loop, passing the reinforcement construct through the second loop or looping the reinforcement construct about the second loop, tightening the first loop down to the graft to approximate the graft to the tissue defect, tightening the second loop down to the graft to further approximate the graft to the tissue defect, securing a first tail portion of the reinforcement construct to the bone with a third knotless suture anchor, and securing a second tail portion of the reinforcement construct to the bone with a fourth knotless suture anchor. The reinforcement construct extends over top of the graft to compresses the graft to the tissue defect after securing the first and second tail portions. 
     In a further embodiment, a graft configured for repairing a tissue defect is an osteochondral allograft. 
     In a further embodiment, a graft configured for repairing a tissue defect is a dermal allograft. 
     In a further embodiment, a reinforcement construct of a knotless tensionable fixation system is an absorbable suture. 
     In a further embodiment, a reinforcement construct of a knotless tensionable fixation system is a nonabsorbable suture. 
     Another exemplary surgical method may include, inter alia, fixating a graft over top of a tissue defect with a knotless tensionable knotless fixation system. The knotless tensionable fixation system includes a plurality of knotless suture anchors, the graft, and a reinforcement construct. The reinforcement construct establishes a fixed segment of material over the graft and is secured in place by the plurality of knotless suture anchors. 
     In a further embodiment, fixating a graft over top of a tissue defect with a knotless tensionable knotless fixation system includes inserting a first knotless suture anchor into a bone, creating a first loop in the first knotless suture anchor, inserting a second knotless suture anchor into the bone, and creating a second loop in the second knotless suture anchor. 
     In a further embodiment, fixating a graft over top of a tissue defect with a knotless tensionable knotless fixation system includes passing a first loop and a second loop through a graft. 
     In a further embodiment, fixating a graft over top of a tissue defect with a knotless tensionable fixation system includes connecting a reinforcement construct to a first loop and a second loop. 
     In a further embodiment, connecting a reinforcement construct to a first loop and a second loop includes looping the reinforcement construct about the first loop and passing the reinforcement construct through the second loop. 
     In a further embodiment, connecting a reinforcement construct to a first loop and a second loop includes passing the reinforcement construct through the first and second loops. 
     In a further embodiment, fixating a graft over top of a tissue defect with a knotless tensionable knotless fixation system includes tightening a first loop down to the graft to approximate the graft to the tissue defect, and tightening a second loop down to the graft to further approximate the graft to the tissue defect. 
     In a further embodiment, fixating a graft over top of a tissue defect with a knotless tensionable knotless fixation system includes securing a first tail portion of a reinforcement construct to a bone with a third knotless suture anchor, and securing a second tail portion of the reinforcement construct to the bone with a fourth knotless suture anchor. 
     In a further embodiment, a reinforcement construct of a knotless tensionable fixation system includes a double “V” pattern. 
     In a further embodiment, a reinforcement construct of a knotless tensionable fixation system includes a Z-shaped pattern. 
     In a further embodiment, a graft of a knotless tensionable fixation system is an osteochondral allograft and a tissue defect repaired by the graft is a cartilage defect. 
     In a further embodiment, a reinforcement construct of a knotless tensionable fixation system includes an absorbable suture. 
     In a further embodiment, a reinforcement construct of a knotless tensionable fixation system includes a nonabsorbable suture. 
     In a further embodiment, at least one knotless suture anchor of a knotless tensionable fixation system is a soft anchor assembly made exclusively of soft, suture-based materials. 
     An exemplary knotless tensionable fixation system for repairing a tissue defect may include, inter alia, a plurality of knotless suture anchors, an osteochondral allograft, and a reinforcement construct that is connectable to the plurality of knotless suture anchors and configured for fixating the osteochondral allograft over top of the tissue defect. 
       FIGS.  1 - 10    schematically illustrate various aspects associated with a surgical method for repairing a tissue defect  10  located within a joint  12 . The joint  12  may include one or more bones  14 . In an embodiment, the tissue defect  10  is a cartilage defect that includes localized areas of damaged articular cartridge and/or damaged subchondral portions of the bone  14  of the joint  12 . In another embodiment, the tissue defect  10  is a soft tissue tear that requires reapproximation to the bone  14  in order to stabilize the joint  12 . However, the surgical methods described in this disclosure could be utilized to repair any type of tissue defect. 
     The joint  12  may be any joint of the musculoskeletal system of the human body. For example, the surgical method described herein could be utilized to repair tissue defects associated with the knee, shoulder, hip, ankle, etc. 
     In an embodiment, the surgical method is performed as an arthroscopic procedure by working through various arthroscopic portals. However, the exemplary surgical method could alternatively be performed as an open procedure within the scope of this disclosure. As detailed below, the exemplary surgical method may be employed to deliver and fixate a graft  30  (see  FIGS.  2 - 4   ) within the joint  12  for repairing the tissue defect  10  in a manner that enhances footprint compression to maximize graft-to-tissue contact. 
     Referring first to  FIG.  1   , after appropriately preparing the joint  12  (e.g., by debriding, creating a bleeding bone bed, preparing bone sockets, etc.), a first knotless suture anchor  16 A and a second knotless suture anchor  16 B may be implanted into the bone  14  at or near the tissue defect  10 . Although two knotless suture anchors  16 A,  16 B are illustrated, a greater number of knotless suture anchors could be utilized as part of the surgical method. In an embodiment, the first knotless suture anchor  16 A is placed at a superior pole  18  of the tissue defect  10 , and the second knotless suture anchor  16 B is placed at an inferior pole  20  of the tissue defect. However, other implantation locations could be selected based on the performing surgeon&#39;s own preferences. 
     A first suture loop  22  may be formed in the first knotless suture anchor  16 A by splicing a suture  24  of the first knotless suture anchor  16 A through itself. A second suture loop  26  may be similarly formed in the second knotless suture anchor  16 B by splicing a suture  28  of the second knotless suture anchor  16 B through itself. In an embodiment, the first suture loop  22  and the second suture loop  26  are each formed at a location that is outside of or external to the tissue defect  10 . 
     The first and second knotless suture anchors  16 A,  16 B, including the first and second suture loops  22 ,  26 , may be utilized to knotlessly fixate the graft  30  over the tissue defect  10 . The surgical methods described herein are considered “knotless” because there is no need to tie any knots in the various structures for securing the graft  30  to the bone  14 . 
     Referring now to  FIG.  2   , the first and second suture loops  22 ,  26  may be passed through the graft  30 , and the graft  30  may then be slid down over top of the tissue defect  10  in order to position the graft  30  at a desired fixation location within the joint  12 . In an embodiment, the graft  30  may be positioned directly over top of the tissue defect  10 . The graft  30  may serve as a scaffold over the tissue defect  10 , thereby providing a tissue network that can potentially signal autologous cellular interactions for repairing the tissue defect  10 . 
     An exemplary graft  30  is illustrated in  FIG.  3   . In an embodiment, the graft  30  includes a porous body  32  that includes a plurality of pores  34 . The pores  34  may be configured to accommodate the first and second suture loops  22 ,  26 , for example. Although shown as being porous, the graft  30  is not limited to such an embodiment. Moreover, the size and shape of the graft  30  are intended to be non-limiting. 
     In an embodiment, the porous body  32  is disk shaped (see  FIG.  3   ). In another embodiment, the porous body  32  is rectangular shaped (see  FIG.  4   ). However, the actual size and shape of the graft  30  utilized during the surgical method may vary and could be achieved by trimming the graft  30  down to a desired size and shape that matches that of the tissue defect  10 . 
     In an embodiment, the graft  30  is an osteochondral allograft composed of viable chondrocytes, chondrogenic growth factors, and extracellular matrix proteins. In another embodiment, the graft  30  is a dermal allograft composed of an acellular dermal extracellular matrix. In another embodiment, the graft  30  is made of non-human tissue, such as synthetic materials, xeno materials, etc. In yet another embodiment, the graft  30  is an autograft. The exact material makeup of the graft  30  is not intended to limit this disclosure. 
     Referring now to  FIG.  5   , the surgical method depicted in  FIGS.  1  and  2    may continue by connecting a reinforcement construct  36  to the first and second suture loops  22 ,  26 . Although one reinforcement construct  36  is shown, two or more reinforcement constructs  36  may be provided within the scope of this disclosure where greater footprint compression of the graft  30  is desired. 
     In an embodiment, the reinforcement construct  36  is connected to the first and second suture loops  22 ,  26  by looping the reinforcement construct  36  over a portion of the first suture loop  22  and passing first and second tail portions  38 A,  38 B of the reinforcement construct  36  through an opening  40 B of the second suture loop  26  (see  FIG.  5   ). In another embodiment, the reinforcement construct  36  is connected to the first and second loops  22 ,  26  by passing the first tail portion  38 A through an opening  40 A of the first suture loop  22  and passing the second tail portion  38 B through the opening  40 B of the second suture loop  26  (see  FIG.  6   ). Other looping/passing configurations may be utilized for connecting the reinforcement construct  36  to the first and second suture loops  22 ,  26 . 
     The reinforcement construct  36  may include a suture, multiple sutures, suture tape, or any other suture-like product. In an embodiment, the reinforcement construct  36  is an absorbable suture. In another embodiment, the reinforcement construct  36  is a nonabsorbable suture. In other embodiments, the first and second suture loops  22 ,  26  may also be absorbable. 
     As illustrated in  FIG.  7   , with the graft  30  pushed against the tissue defect  10 /bone  14 , the first and second suture loops  22 ,  26  may be tightened/constricted (e.g., reduced in size) while tensioning the first and second tail portions  38 A,  38 B. The first suture loop  22  may be constricted by pulling a suture tail  42  of the suture  24 , and the second suture loop  26  may be constricted by pulling a suture tail  44  of the suture  28 . The suture tail  42  and the suture tail  44  may then be removed (e.g., cut) from their respective suture loops  22 ,  26  (see  FIG.  8   ). 
     The first and second suture loops  22 ,  26  of the system may therefore be adjustable loops. In other embodiments, first and second suture loops  22 A,  26 A of the system for performing the surgical method may be fixed, non-adjustable loops (see, e.g.,  FIG.  18   ). When the reinforcement construct  36  is tensioned, the first and second loops  22 A,  26 A may lay the loops  22 A,  26 A down against the graft  30 . 
     Next, as shown in  FIGS.  9  and  10   , the first and second tail portions  38 A,  38 B may be knotlessly fixated to the bone  14  to complete the repair. For example, the first tail portion  38 A may be fixated to the bone  14  via a third knotless suture anchor  16 C, and the second tail portion  38 B may be fixated to the bone  14  via a fourth knotless suture anchor  16 D. The first and second tail portions  38 A,  38 B may be fixated at locations of the bone  14  that are adjacent to the tissue defect  10 . In an embodiment, the fixation location of the first tail portion  38 A is located on an opposite side of the fixation location of the second tail portion  38 B. Once the tail portions  38 A,  38 B are fixated, the reinforcement construct  36  may provide a fixed segment of material over the issue defect  10 , thereby providing footprint compression that maximizes contact between the graft  30  and the underlying tissue. 
     When the reinforcement construct  36  is connected to the first and second suture loops  22 ,  26  in the manner depicted in  FIG.  5    (e.g., by looping the reinforcement construct  36  over a portion of the first suture loop  22  and passing first and second tail portions  38 A,  38 B of the reinforcement construct  36  through the opening  40 B of the second suture loop  26 ), the reinforcement construct  36  may exhibit a first fixation pattern P 1  (see  FIG.  9   ). In an embodiment, the first fixation pattern P 1  is a double “V” pattern. The first fixation pattern P 1  provides a multi-point fixation configuration for securing the graft  30 . 
     When the reinforcement construct  36  is connected to the first and second loops  22 ,  26  in the manner depicted in  FIG.  6    (e.g., by passing the first tail portion  38 A through the opening  40 A of the first suture loop  22  and passing the second tail portion  38 B through the opening  40 B of the second suture loop  26 ), the reinforcement construct  36  may exhibit a second fixation pattern P 2  (see  FIG.  10   ). In an embodiment, the second fixation pattern P 2  is a Z-shaped pattern. The second fixation pattern P 2  provides a multi-point fixation configuration for securing the graft  30 . Other fixation patterns may be achieved by modifying the fixation locations of the first and second tail portions  38 A,  38 B and/or by using additional knotless suture anchors and/or reinforcement constructs  36  as part of the surgical method. 
       FIGS.  11 - 16    illustrate exemplary knotless suture anchors that can be utilized as part of a knotless tensionable fixation system for performing the surgical method steps described above. Knotless suture anchors similar to those shown in  FIGS.  11 - 16    may be utilized either alone or in combination with one another to fixate the graft  30  to the bone  14  during the surgical method. 
     An exemplary knotless suture anchor  16 - 1  is illustrated in  FIGS.  11  and  12   . In this embodiment, the knotless suture anchor  16 - 1  is a “soft” anchor assembly made exclusively of soft, suture-based materials. The suture-based materials may include soft materials such as yarns, fibers, filaments, strings, fibrils, strands, sutures, etc., or any combination of such materials. The soft materials may be synthetic or natural materials, or combinations of synthetic and natural materials, and may be bio-degradable or non-degradable within the scope of this disclosure. The soft, suture-based materials confer the knotless suture anchor  16 - 1  with the ability to be inserted into bone sockets/holes and bunch together, collapse, expand and/or change shape to fixate within the socket/hole. 
     The knotless suture anchor  16 - 1  may include an anchor body  46  and a flexible suture strand  48  received through the anchor body  46 . A shuttle device  50  may be spliced through portions of the flexible suture strand  48 . The shuttle device  50  may be a passing wire or another suture, for example. 
     The anchor body  46  of the knotless suture anchor  16 - 1  may be inserted into a socket  54  formed in the bone  14  (see  FIG.  12   ). The socket  54  may be a preformed opening formed in the bone  14  that is configured for receiving the anchor body  46 . 
     The shuttle device  50  may be pre-assembled to the flexible suture strand  48  as shown in  FIG.  11   , and the flexible suture strand  48  may form a suture loop  52  (e.g., the equivalent of the suture loops  22 ,  26  of  FIG.  1   ) after the flexible suture strand  48  is shuttled through itself as shown in  FIG.  12   . For example, a suture tail  56  of the flexible suture strand  48  may be passed through an eyelet  58  of the shuttle device  50  (in the direction of arrow A of  FIG.  11   ), and then a free end  60  of the shuttle device  50  may be pulled (in the direction of arrow B of  FIG.  11   ) to allow flexible suture strand  48  to pass through itself and form the suture loop  52 . The perimeter of suture loop  52  is adjustable to allow the construct to be self-cinching and to adjust the tension on the graft to be fixated. 
     In an exemplary embodiment, the knotless suture anchors  16 A,  16 B of the knotless tensionable fixation system may include the design of the knotless suture anchor  16 - 1  for performing the surgical method steps discussed above. 
     Another exemplary knotless suture anchor  16 - 2  is illustrated in  FIGS.  13  and  14   . The knotless suture anchor  16 - 2  may include an anchor body  62  and a flexible suture strand  64  received through the anchor body  62 . In this embodiment, the anchor body  62  is a relatively rigid plastic body and thus the knotless suture anchor  16 - 2  is not considered to be a “soft” anchor assembly. 
     A shuttle device  66  may be spliced through portions of the flexible suture strand  64 . The shuttle device  66  may be a passing wire or another suture, for example. 
     The anchor body  62  of the knotless suture anchor  16 - 2  may be inserted into a socket  68  formed in the bone  14  (see  FIG.  14   ). The socket  68  may be a preformed opening formed in the bone  14  that is configured for receiving the anchor body  62 . 
     The shuttle device  66  may be pre-assembled to the flexible suture strand  64  as shown in  FIG.  13    and may be utilized to may form a suture loop  70  (e.g., the equivalent of the suture loops  22 ,  26  of  FIG.  1   ) after the flexible suture strand  64  is shuttled through itself as shown in  FIG.  14   . For example, a suture tail  72  of the flexible suture strand  64  may be passed through an eyelet  74  of the shuttle device  66  (in the direction of arrow A of  FIG.  13   ), and then a free end  76  of the shuttle device  66  may be pulled (in the direction of arrow B of  FIG.  13   ) to allow the flexible suture strand  64  to pass through itself and form the suture loop  70 . The perimeter of suture loop  70  is adjustable to allow the construct to be self-cinching and to adjust the tension on the graft to be fixated. 
     In an exemplary embodiment, the knotless suture anchors  16 A,  16 B of the knotless tensionable fixation system may include the design of the knotless suture anchor  16 - 2  (rather than that of the knotless suture anchor  16 - 1 , for example) for performing the surgical method steps discussed above. 
     Yet another exemplary knotless suture anchor  16 - 3  is illustrated in  FIGS.  15  and  16   . The knotless suture anchor  16 - 3  may include an anchor body  78  and an eyelet  80 . In this embodiment, the anchor body  78  and the eyelet  80  are relatively rigid plastic structures and thus the knotless suture anchor  16 - 3  is not considered to be a “soft” anchor assembly. 
     The anchor body  78  may be pre-loaded onto a driver  82 . The anchor body  78  may be configured as a screw or an interference plug that is appropriately cannulated for receiving a shaft  84  of the driver  82 . The eyelet  80  may be provided at a distal end  86  of the driver  82 . The eyelet  80  may be releasably attached to the distal end  86 . The eyelet  80  may include an aperture  88  for receiving one or more flexible strands (e.g., one or more tail portions  38  of the reinforcement construct  36 ). 
     The anchor body  78  and the eyelet  80  of the knotless suture anchor  16 - 3  may be inserted into a socket  90  formed in the bone  14  (see  FIG.  16   ). The socket  90  may be a preformed opening formed in the bone  14  that is configured for receiving the anchor body  78  and the eyelet  80 . One of the tail portions  38  of the reinforcement construct  36  may be loaded through the eyelet  80 , and then the eyelet  80  may be inserted into the socket  90 . The tail portion  38  may then be tensioned prior to moving the anchor body  78  down toward the eyelet  80  within the socket  90 . Once implanted within the socket  90 , the anchor body  78  may trap the reinforcement construct  36  between the bone  14  and the anchor body  78  in order to fixate the reinforcement construct  36  in place. 
     In an exemplary embodiment, the knotless suture anchors  16 C,  16 D of the knotless tensionable fixation system may include the design of the knotless suture anchor  16 - 3  for performing the surgical method discussed above. However, any combination of knotless suture anchors may be utilized to knotlessly fixate the graft  30  during the surgical method. 
       FIG.  17    schematically illustrates an exemplary knotless tensionable fixation system  99  that may be provided for performing the surgical method steps discussed above. The knotless tensionable fixation system  99  may be provided in the form of a surgical kit that includes all the necessary tools and components for performing surgical methods for repairing tissue defects. In an embodiment, the knotless tensionable fixation system  99  may include at least the following components:
         1. At least (4) knotless suture anchors  16 A,  16 B,  16 C,  16 D;   2. One or more grafts  30 ;   3. One or more reinforcement constructs  36 ; and   4. Tools  92  (e.g., disposable drills, drill guides, punches, taps, etc.) for inserting the knotless suture anchors.       

     Other components or different combinations of components could be provided as part of the knotless tensionable fixation system  99  within the scope of this disclosure. For example, the knotless tensionable fixation system  99  could include various templates, scorers, curettes, and/or measuring devices that may be utilized to help prepare the tissue defect for perform the surgical method discussed herein. 
     The knotless tensionable fixation systems described herein may be utilized to perform surgical methods for repairing tissue defects. The proposed systems provide a multi-point fixation configuration for fixating a graft over the tissue defect. A reinforcement construct of the system provides a fixed segment of material over top of the graft, thereby maximizing graft-to-tissue contact. 
     Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
     It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should further be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
     The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.