Apparatus for deploying sheet-like materials

FIELD OF THE INVENTION

0001The present invention relates generally to orthopedic medicine and surgery. More particularly, the present invention relates an implant delivery system for delivering a sheet-like implant.

BACKGROUND OF THE INVENTION

0002<patcit id="pcit0001" dnum="EP0557963A1"><text>EP 0 557 963 A1</text></patcit> describes an apparatus for positioning surgical implants adjacent to body tissue. The apparatus includes a delivery device having a plurality of delivery arms positioned at the distal end of an elongate rod, and a surgical implant releasably secured to the delivery arms by a securing device. <patcit id="pcit0002" dnum="WO2005016389A2"><text>WO 2005/016389 A2</text></patcit> discloses a medical instrument used to position a surgical mesh sheet to a surface of the human body. The instrument contains a mechanism for holding the mesh sheet against the tissue surface in more than two locations during the attaching process.

0003A device according to the preamble of claim 1 is known from the document <patcit id="pcit0003" dnum="GB2397240A"><text>GB-A-2.397.240</text></patcit>.

0004The glenohumeral joint of the shoulder is found where the head of the humerus mates with a shallow depression in the scapula. This shallow depression is known as the the glenoid fossa. Six muscles extend between the humerus and scapula and actuate the glenohumeral joint. These six muscles include the deltoid, the teres major, and the four rotator cuff muscles. As disclosed by Ball et al. in U.S. Patent Publication No. <patcit id="pcit0004" dnum="US20080188936A1"><text>U.S. 2008/0188936 A1</text></patcit> and as illustrated in <figref idref="f0001">Figure 1</figref> the rotator cuff muscles are a complex of four muscles. These four muscles are the supraspinatus, the infraspinatus, the subscapularis, and the teres minor. The centering and stabilizing roles played by the rotator cuff muscles are critical to the proper function of the shoulder. The rotator cuff muscles provide a wide variety of moments to rotate the humerus and to oppose unwanted components of the deltoid and pectoralis muscle forces.

0005The four muscles of the rotator cuff arise from the scapula 12. The distal tendons of the rotator cuff muscles splay out and interdigitate to form a common continuous insertion on the humerus 14. The subscapularis 16 arises from the anterior aspect of the scapula 12 and attaches over much of the lesser tuberosity of the humerous. The supraspinatus muscle 18 arises from the supraspinatus fossa of the posterior scapula, passes beneath the acromion and the acromioclavicular joint, and attaches to the superior aspect of the greater tuberosity 11. The infraspinatus muscle 13 arises from the infraspinous fossa of the posterior scapula and attaches to the posterolateral aspect of the greater tuberosity 11. The teres minor 15 arises from the lower lateral aspect of the scapula 12 and attaches to the lower aspect of the greater tuberosity 11.

0006The mechanics of the rotator cuff muscles 10 are complex. The rotator cuff muscles 10 rotate the humerus 14 with respect to the scapula 12, compress the humeral head 17 into the glenoid fossa providing a critical stabilizing mechanism to the shoulder (known as concavity compression), and provide muscular balance. The supraspinatus and infraspinatus provide 45 percent of abduction and 90 percent of external rotation strength. The supraspinatus and deltoid muscles are equally responsible for producing torque about the shoulder joint in the functional planes of motion.

0007The rotator cuff muscles 10 are critical elements of this shoulder muscle balance equation. The human shoulder has no fixed axis. In a specified position, activation of a muscle creates a unique set of rotational moments. For example, the anterior deltoid can exert moments in forward elevation, internal rotation, and cross-body movement. If forward elevation is to occur without rotation, the cross-body and internal rotation moments of this muscle must be neutralized by other muscles, such as the posterior deltoid and infraspinatus. The timing and magnitude of these balancing muscle effects must be precisely coordinated to avoid unwanted directions of humeral motion. Thus the simplified view of muscles as isolated motors, or as members of force couples must give way to an understanding that all shoulder muscles function together in a precisely coordinated way--opposing muscles canceling out undesired elements leaving only the net torque necessary to produce the desired action. Injury to any of these soft tissues can greatly inhibit ranges and types of motion of the arm.

0008With its complexity, range of motion and extensive use, a fairly common soft tissue injury is damage to the rotator cuff or rotator cuff tendons. Damage to the rotator cuff is a potentially serious medical condition that may occur during hyperextension, from an acute traumatic tear or from overuse of the joint. With its critical role in abduction, rotational strength and torque production, the most common injury associated with the rotator cuff region is a strain or tear involving the supraspinatus tendon. A tear in the supraspinitus tendon 19 is schematically depicted in <figref idref="f0001">Figure 2</figref>. A tear at the insertion site of the tendon with the humerus, may result in the detachment of the tendon from the bone. This detachment may be partial or full, depending upon the severity of the injury. Additionally, the strain or tear can occur within the tendon itself. Injuries to the supraspinatus tendon 19 and recognized modalities for treatment are defined by the type and degree of tear. The first type of tear is a full thickness tear as also depicted in <figref idref="f0001">Figure 2</figref>, which as the term indicates is a tear that extends through the thickness of the supraspinatus tendon regardless of whether it is completely torn laterally. The second type of tear is a partial thickness tear which is further classified based on how much of the thickness is torn, whether it is greater or less than 50% of the thickness.

0009The accepted treatment for a full thickness tear or a partial thickness tear greater than 50% includes reconnecting the torn tendon via sutures. For the partial thickness tears greater than 50%, the tear is completed to a full thickness tear by cutting the tendon prior to reconnection. In contrast to the treatment of a full thickness tear or a partial thickness tear of greater than 50%, the treatment for a partial thickness tear less than 50% usually involves physical cessation from use of the tendon, i.e., rest. Specific exercises can also be prescribed to strengthen and loosen the shoulder area. In many instances, the shoulder does not heal and the partial thickness tear can be the source of chronic pain and stiffness. Further, the pain and stiffness may cause restricted use of the limb which tends to result in further degeneration or atrophy in the shoulder. Surgical intervention may be required for a partial thickness tear of less than 50%, however, current treatment interventions do not include repair of the tendon, rather the surgical procedure is directed to arthroscopic removal of bone to relieve points of impingement or create a larger tunnel between the tendon and bone that is believed to be causing tendon damage. As part of the treatment, degenerated tendon may also be removed using a debridement procedure in which tendon material is ablated. Again, the tendon partial tear is not repaired. Several authors have reported satisfactory early post operative results from these procedures, but over time recurrent symptoms have been noted. In the event of recurrent symptoms, many times a patient will "live with the pain". This may result in less use of the arm and shoulder which further causes degeneration of the tendon and may lead to more extensive damage. A tendon repair would then need to be done in a later procedure if the prescribed treatment for partial tear was unsuccessful in relieving pain and stiffness or over time the tear propagated through injury or degeneration to a full thickness tear or a partial thickness tear greater than 50% with attendant pain and debilitation. A subsequent later procedure would include the more drastic procedure of completing the tear to full thickness and suturing the ends of the tendon back together. This procedure requires extensive rehabilitation, has relatively high failure rates and subjects the patient who first presented and was treated with a partial thickness tear less than 50% to a second surgical procedure.

0010As described above, adequate treatments do not currently exist for repairing a partial thickness tear of less than 50% in the supraspinatus tendon. Current procedures attempt to alleviate impingement or make room for movement of the tendon to prevent further damage and relieve discomfort but do not repair or strengthen the tendon. Use of the still damaged tendon can lead to further damage or injury. Prior damage may result in degeneration that requires a second more drastic procedure to repair the tendon. Further, if the prior procedure was only partially successful in relieving pain and discomfort, a response may be to use the shoulder less which leads to degeneration and increased likelihood of further injury along with the need for more drastic surgery. There is a large need for surgical techniques and systems to treat partial thickness tears of less than 50% and prevent future tendon damage by strengthening or repairing the native tendon having the partial thickness tear.

SUMMARY OF THE INVENTION

0011The present invention relates to an implant delivers system according to claim 1 and to a method of preparing a delivery system according to claim 15. Accordingly, the invention relates to an implant delivery systems for delivering sheet-like implants. The implant delivery system includes a delivery shaft, an implant expander, a sheath, and a sheet-like implant. The delivery shaft has a proximal end and a distal end. The implant expander is mounted to the distal end of the delivery shaft. The implant expander includes a central portion and a plurality of leg portions radiating from the central portion. The implant expander is evertable between an unstressed configuration in which a distal surface of the implant expander defines a concave surface, and a first compact configuration in which the distal surface of the implant expander defines a convex surface. The implant expander has a first lateral extent when the implant expander is free to assume the unstressed configuration. The sheath defines a lumen having a lumen diameter. At least a portion of the delivery shaft is slidably disposed in the lumen. The lumen diameter is smaller than the first lateral extent of the implant expander so that the sheath holds the implant expander in the first compact configuration when slidably disposed therein. The sheet-like implant overlays at least a portion of the distal surface of the implant expander with portions of the sheet-like implant extending between the leg portions of the implant expander and the sheath.

0012A free end of each leg portion of the implant expander is disposed distally of the central portion when the implant expander is assuming the unstressed configuration. The free end of each leg portion is disposed proximally of the central portion when the implant expander is assuming the first compact configuration. The implant expander has a second compact configuration. The free end of each leg portion is disposed distally of the central portion when the implant expander is assuming the second compact configuration. The delivery shaft distal end may be fixed to the central portion of the implant expander to urge relative movement between the implant expander and the sheath such that the implant expander and the sheet-like implant can be advanced through a distal opening defined by the sheath so the implant expander is free to assume a deployed configuration.

0013In some embodiments, a projection extends distally from the distal surface of the central portion of the implant expander to hold the position of delivery system when the projection is held against a target tissue. The implant expander may generally conform to the surface of a target tissue when the implant expander assumes the deployed configuration. In some embodiments, the distal surface of the implant expander defines a concave surface when the implant expander is assuming the deployed configuration and the target tissue has a generally convex shape. A free end of each leg portion may be disposed distally of the central portion when the implant expander is assuming the deployed configuration and the target tissue has a generally convex shape. In some embodiments, the implant expander causes the sheet-like implant to conform to the surface of a target tissue when the implant expander assumes the deployed configuration.

0014The implant expander assumes a second compact configuration when the implant expander is retracted proximally into the lumen of the sheath after having assumed the deployed configuration. The distal surface of the implant expander defines a concave surface when the implant expander is assuming the second compact configuration. The free end of each leg portion is disposed distally of the central portion when the implant expander is assuming the second compact configuration.

0015In some embodiments, the implant expander is integrally formed of a single material. The sheet-like implant may define a plurality of pockets. Each pocket may be dimensioned to receive a distal portion of a leg portion of the implant expander. In some of these embodiments, the sheet-like implant can be selectively separated from the implant expander by withdrawing the distal portions of the legs from the pockets. In some embodiments, the implant expander further includes a plurality of retainers to engage the sheet-like implant such that the sheet-like implant moves when the implant expander is moved. In some of these embodiments, the sheet-like implant can be selectively separated from the implant expander by withdrawing the retainers from the sheet-like implant.

0016Methods of treating a rotator cuff of a shoulder are also disclosed. The method includes the steps of providing an implant delivery system, inflating the shoulder to create a cavity therein, placing the sheet-like implant and the implant expander inside the cavity, allowing the implant expander to assume a deployed configuration, attaching the sheet-like implant to the tendon, urging the implant expander to assume a second compact configuration, and removing the implant expander from the cavity. The implant delivery system that is provided includes an implant expander. The implant expander has a central portion and a plurality of leg portions radiating from the central portion. The implant expander is evertable between an unstressed configuration in which a distal surface of the implant expander defines a concave surface, and a first compact configuration in which the distal surface of the implant expander defines a convex surface. A sheet-like implant overlays at least a portion of the distal surface of the implant expander. A sheath is disposed about the sheet-like implant and the implant expander. The sheath holds the implant expander in the first compact configuration. When the sheet-like implant and the implant expander are placed inside the cavity, a tendon is contacted with at least a portion of the implant while the implant expander is assuming the first compact configuration. When allowing the implant expander to assume a deployed configuration, the implant expander urges the sheet-like implant against a surface of the tendon. When urging the implant expander to assume a second compact configuration, the distal surface of the implant expander defines a concave surface.

0017The implant expander may include a projection extending distally from its central portion. The projection holds the position of the delivery system relative to the tendon when the sheet-like implant and implant expander are placed in the cavity against the tendon.

0018The step of allowing the implant expander to assume the deployed configuration may include urging relative movement between the implant expander and the sheath such that the implant expander and the sheet-like implant are advanced through a distal opening defined by the sheath. With this arrangement, the implant expander is free to assume the deployed configuration. Urging relative movement between the implant expander and the sheath may include withdrawing the sheath in a proximal direction relative to the implant expander. Urging relative movement between the implant expander and the sheath may include advancing the implant expander in a distal direction along the lumen of the sheath. Urging the implant expander to assume the second compact configuration may include advancing the sheath over the implant expander so that the implant expander is disposed inside the lumen defined by the sheath. Urging the implant expander to assume the second compact configuration may include drawing the implant expander proximally into the lumen defined by the sheath. Urging the implant expander to assume the second compact configuration may include drawing the implant expander and the projection that extends distally from the central portion of the implant expander proximally into the lumen defined by the sheath.

0019The present invention further relates to a method of preparing a delivery system. The method includes the steps of providing a delivery sheath and an implant expander, covering at least a portion of the distal surface with a sheet-like implant, and deflecting the implant expander. The sheath defines a lumen having a lumen diameter. The implant expander includes a central portion and a plurality of leg portions radiating from the central portion. The implant expander is evertable between an unstressed configuration in which a distal surface of the implant expander defines a concave surface and in which a free end of each leg portion of the implant expander is disposed distally of the central portion, a first compact configuration in which the distal surface of the implant expander defines a convex surface and in which the free end of each leg portion is disposed proximally of the central portion, and a second compact configuration in which the distal surface of the implant expander defines a concave surface and in which the free end of each leg portion is disposed distally of the central portion. The implant expander has a first lateral extent when the implant expander is free to assume the unstressed configuration. The first lateral extent is greater than the lumen diameter of the sheath. When the implant expander is deflected, the implant expander assumes the first compact configuration and the implant expander and the sheet-like implant are placed in the lumen defined by the sheath. The sheath holds the implant expander in the first compact configuration with portions of the sheet-like implant being interposed between the leg portions of the implant expander and an inner surface of the sheath.

0020Further aspects of the present invention will become apparent upon review of the Detailed Description with reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

0021<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a simplified perspective view of the human rotator cuff and associated anatomical structure.</li><li><figref idref="f0001">Figure 2</figref> is a schematic depiction of a full thickness tear in the supraspinatus tendon of the rotator cuff of <figref idref="f0001">Figure 1</figref>.</li><li><figref idref="f0002">Figure 3</figref> is a stylized anterior view of a patient with a shoulder being shown in cross-section for purposes of illustration.</li><li><figref idref="f0003">Figure 4</figref> is a stylized anterior view of a shoulder including a humerus and a scapula. The head of the humerus is shown mating with the glenoid fossa of the scapula at a glenohumeral joint.</li><li><figref idref="f0004">Figure 5</figref> is a stylized perspective view illustrating an exemplary procedure for treating a shoulder of a patient.</li><li><figref idref="f0005">Figure 6</figref> is an enlarged perspective view further illustrating the procedure shown in the previous Figure.</li><li><figref idref="f0006">Figure 7</figref> is an enlarged perspective view showing the delivery system shown in the previous Figure.</li><li><figref idref="f0007">Figure 8</figref> is a stylized perspective view of a shoulder including a supraspinatus muscle having a distal tendon.</li><li><figref idref="f0008">Figure 9</figref> is an additional perspective view further illustrating a delivery system in accordance with this disclosure.</li><li><figref idref="f0009 f0010 f0011">Figure 10A through Figure 10E</figref> are a series of stylized plan views illustrating an exemplary method in accordance with the present detailed description.</li><li><figref idref="f0012">Figure 11</figref> is a stylized diagram illustrating four configurations of an exemplary implant expander.</li><li><figref idref="f0013">Figure 12</figref> is a perspective view illustrating an exemplary delivery system in accordance with this disclosure.</li><li><figref idref="f0014">Figure 13</figref> is a plan view illustrating an exemplary assembly in accordance with the present detailed description.</li><li><figref idref="f0015">Figure 14</figref> is a plan view illustrating an exemplary assembly in accordance with the present detailed description.</li><li><figref idref="f0016 f0017">Figure 15A through Figure 15F</figref> are a series of stylized plan views illustrating exemplary methods and apparatus in accordance with the present detailed description.</li><li><figref idref="f0018">Figure 16</figref> is a stylized depiction of a kit that may be used, for example, for delivering a sheet-like implant to a target location within the body of a patient.</li><li><figref idref="f0019">Figure 17A</figref> is an enlarged plan view illustrating a delivery aid included in the kit of <figref idref="f0018">Figure 16</figref>. <figref idref="f0019">Figure 17B</figref> is a partial cross-sectional perspective view further illustrating the delivery aid shown in <figref idref="f0019">Figure 17A</figref>.</li><li><figref idref="f0020 f0021 f0022">Figure 18A through Figure 18I</figref> are a series of stylized plan views illustrating exemplary methods and apparatus in accordance with the present detailed description.</li><li><figref idref="f0023">Figure 19</figref> is a plan view showing a locating guide included in the kit of <figref idref="f0018">Figure 16</figref>.</li><li><figref idref="f0024">Figure 20</figref> is a plan view showing a locating guide removal tool included in the kit of <figref idref="f0018">Figure 16</figref>.</li></ul>

DETAILED DESCRIPTION OF THE INVENTION

0022The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

0023<figref idref="f0002">Figure 3</figref> is a stylized anterior view of a patient 20. For purposes of illustration, a shoulder 22 of patient 20 is shown in cross-section in <figref idref="f0002">Figure 3</figref>. Shoulder 22 includes a humerus 14 and a scapula 12. In <figref idref="f0002">Figure 3</figref>, a head 24 of humerus 14 can be seen mating with a glenoid fossa of scapula 12 at a glenohumeral joint. With reference to <figref idref="f0002">Figure 3</figref>, it will be appreciated that the glenoid fossa comprises a shallow depression in scapula 12. The movement of humerus 14 relative to scapula 12 is controlled by a number of muscles including: the deltoid, the supraspinatus, the infraspinatus, the subscapularis, and the teres minor. For purposes of illustration, only the supraspinatus 26 is shown in <figref idref="f0002">Figure 3</figref>.

0024With reference to <figref idref="f0002">Figure 3</figref>, it will be appreciated that a distal tendon 28 of the supraspinatus 26 meets humerus 14 at an insertion point. Scapula 12 of shoulder 22 includes an acromium 32. In <figref idref="f0002">Figure 3</figref>, a subacromial bursa 34 is shown extending between acromium 32 of scapula 12 and head 24 of humerus 14. In <figref idref="f0002">Figure 3</figref>, subacromial bursa 34 is shown overlaying supraspinatus 26. Subacromial bursa 34 is one of the hundreds of bursae found the human body. Each bursa comprises a fluid filled sac. The presence of these bursae in the body reduces friction between bodily tissues. Injury and/or infection of the bursa can cause it to become inflamed. This condition is sometimes referred to as bursitis.

0025The exemplary methods and apparatus described herein may be used to fix tendon repair implants to various target tissues. For example, a tendon repair implant may be fixed to one or more tendons associated with an articulating joint, such as the glenohumeral joint. The tendons to be treated may be torn, partially torn, have internal micro-tears, be untorn, and/or be thinned due to age, injury or overuse. Applicants believe that the methods and apparatus of the present application and related devices may provide very beneficial therapeutic effect on a patient experiencing joint pain believed to be caused by partial thickness tears and/or internal microtears. By applying a tendon repair implant early before a full tear or other injury develops, the implant may cause the tendon to thicken and/or at least partially repair itself, thereby avoiding more extensive joint damage, pain, and the need for more extensive joint repair surgery.

0026<figref idref="f0003">Figure 4</figref> is a stylized anterior view of a shoulder 22 including a humerus 14 and a scapula 12. In <figref idref="f0003">Figure 4</figref>, a head 24 of humerus 14 is shown mating with a glenoid fossa of scapula 12 at a glenohumeral joint. A supraspinatus 26 is also shown in <figref idref="f0003">Figure 4</figref>. This muscle, along with others, control the movement of humerus 14 relative to scapula 12. A distal tendon 28 of supraspinatus 26 meets humerus 14 at an insertion point 30.

0027In <figref idref="f0003">Figure 4</figref>, distal tendon 28 includes a first damaged portion 36. A number of loose tendon fibers 40 in first damaged portion 36 are visible in <figref idref="f0003">Figure 4</figref>. First damaged portion 36 includes a first tear 42 extending partially through distal tendon 28. First tear 42 may therefore be referred to as a partial thickness tear. With reference to <figref idref="f0003">Figure 4</figref>, it will be appreciated that first tear 42 begins on the side of distal tendon 28 facing the subacromial bursa (shown in the previous Figure) and ends midway through distal tendon 28. Accordingly, first tear 42 may be referred to as a bursal side tear.

0028With reference to <figref idref="f0003">Figure 4</figref>, it will be appreciated that distal tendon 28 includes a second damaged portion 38 located near insertion point 30. In <figref idref="f0003">Figure 4</figref>, second damaged portion 38 of distal tendon 28 has become frayed and a number of loose tendon fibers 40 are visible in <figref idref="f0003">Figure 4</figref>. Second damaged portion 38 of distal tendon 28 includes second tear 44. With reference to <figref idref="f0003">Figure 4</figref>, it will be appreciated that second tear 44 begins on the side of distal tendon 28 facing the humerus 14. Accordingly, second damaged portion 38 may be referred to as an articular side tear.

0029In <figref idref="f0003">Figure 4</figref>, a sheet-like implant 50 has been placed over the bursal side of distal tendon 28. With reference to <figref idref="f0003">Figure 4</figref>, it will be appreciated that sheet-like implant 50 extends over insertion point 30, first tear 42 and second tear 44. Some useful methods in accordance with this detailed description may include placing a tendon repair implant on the bursal side of a tendon regardless of whether the tears being treated are on the bursal side, articular side or within the tendon. In some cases the exact location and nature of the tears being treated may be unknown. A tendon repair implant may be applied to the bursal side of a tendon to treat shoulder pain that is most likely caused by one or more partial thickness tears in the tendon. In <figref idref="f0003">Figure 4</figref>, sheet-like implant 50 is fixed to distal tendon 28 by a plurality of staples.

0030<figref idref="f0004">Figure 5</figref> is a stylized perspective view illustrating an exemplary procedure for treating a shoulder 22 of a patient 20. The procedure illustrated in <figref idref="f0004">Figure 5</figref> may include, for example, fixing tendon repair implants to one or more tendons of shoulder 22. The tendons treated may be torn, partially torn, have internal micro-tears, be untorn, and/or be thinned due to age, injury or overuse.

0031Shoulder 22 of <figref idref="f0004">Figure 5</figref> has been inflated to create a cavity therein. In the exemplary embodiment of <figref idref="f0004">Figure 5</figref>, a fluid supply 52 is pumping a continuous flow of saline into the cavity. This flow of saline exits the cavity via a fluid drain 54. A camera 56 provides images from inside the cavity. The images provided by camera 56 may be viewed on a display 58.

0032Camera 56 may be used to visually inspect the tendons of shoulder 22 for damage. A tendon repair implant in accordance with this disclosure may be fixed to a bursal surface of the tendon regardless of whether there are visible signs of tendon damage. Applicants believe that the methods and apparatus of the present application and related devices may provide very beneficial therapeutic effect on a patient experiencing joint pain believed to be caused by internal microtears, but having no clear signs of tendon tears. By applying a tendon repair implant early before a full tear or other injury develops, the implant may cause the tendon to thicken and/or at least partially repair itself, thereby avoiding more extensive joint damage, pain, and the need for more extensive joint repair surgery.

0033A delivery system 60 can be seen extending from shoulder 22 in <figref idref="f0004">Figure 5</figref>. Delivery system 60 comprises a sheath that is fixed to a handle. The sheath defines a lumen and a distal opening fluidly communicating with the lumen. In the embodiment of <figref idref="f0004">Figure 5</figref>, the distal opening of the sheath has been placed in fluid communication with the cavity created in shoulder 22.

0034A tendon repair implant is at least partially disposed in the lumen defined by the sheath of delivery system 60. Delivery system 60 can be used to place the tendon repair implant inside shoulder 22. Delivery system 60 can also be used to hold the tendon repair implant against the tendon. In some embodiments, the tendon repair implant is folded into a compact configuration when inside the lumen of the sheath. When this is the case, delivery system 60 may be used to unfold the tendon repair implant into an expanded shape.

0035The tendon repair implant may be fixed to the tendon while it is held against the tendon by delivery system 60. Various attachment elements may be used to fix the tendon repair implant to the tendon. Examples of attachment elements that may be suitable in some applications include sutures, tissue anchors, bone anchors, and staples. In the exemplary embodiment of <figref idref="f0004">Figure 5</figref>, the shaft of a fixation tool 70 is shown extending into shoulder 22. In one exemplary embodiment, fixation tool 70 is capable of fixing the tendon repair implant to the tendon with one or more staples while the tendon repair implant is held against the tendon by delivery system 60.

0036<figref idref="f0005">Figure 6</figref> is an enlarged perspective view further illustrating the procedure shown in the previous Figure. <figref idref="f0005">Figure 6</figref> also illustrates the interior structure of shoulder 22 shown in the previous Figure. With reference to <figref idref="f0005">Figure 6</figref>, it will be appreciated that shoulder 22 includes a humerus 14 and a scapula 12. In <figref idref="f0005">Figure 6</figref>, a head 24 of humerus 14 is shown mating with a glenoid fossa of scapula 12 at a glenohumeral joint. A supraspinatus 26 is also shown in <figref idref="f0005">Figure 6</figref>. A distal tendon 28 of supraspinatus 26 can be seen meeting a tuberosity of humerus 14 in <figref idref="f0005">Figure 6</figref>.

0037Delivery system 60 is also shown in <figref idref="f0005">Figure 6</figref>. In <figref idref="f0005">Figure 6</figref>, a distal end of delivery system 60 has been positioned near distal tendon 28 of supraspinatus 26. Delivery system 60 comprises a sheath 102 that is fixed to a handle 104. Sheath 102 defines a lumen 108 and a distal opening fluidly communicating with the lumen. In the embodiment of <figref idref="f0005">Figure 6</figref>, a central portion of a sheet-like implant 50 can be seen extending through the distal opening defined by sheath 102. In <figref idref="f0005">Figure 6</figref>, sheet-like implant 50 is overlaying an implant expander. The implant expander and sheet-like implant 50 are both assuming a compact configuration. The majority of sheet-like implant 50 is disposed inside sheath 102. A central portion of sheet-like implant 50 is extending out of sheath 102. This central portion of sheet-like implant 50 is contacting an outer surface of distal tendon 28 in the embodiment of <figref idref="f0005">Figure 6</figref>.

0038<figref idref="f0006">Figure 7</figref> is an enlarged perspective view showing delivery system 60 shown in the previous Figure. In <figref idref="f0006">Figure 7</figref>, sheath 102 of delivery system 60 has been moved in a proximal direction P relative to handle 104. By comparing <figref idref="f0006">Figure 7</figref> to the previous Figure, it will be appreciated that sheet-like implant 50 and implant expander 120 are now disposed outside of lumen 108 defined by sheath 102. Implant expander 120 comprises a central portion 122 and a plurality of leg portions 124 radiating from central portion 122. In <figref idref="f0006">Figure 7</figref>, leg portions 124 of implant expander 120 are shown overlaying sheet-like implant 50. Hub 126 is shown overlaying central portion 122 of implant expander 120 in <figref idref="f0006">Figure 7</figref>. Implant expander 120 can be used to expand sheet-like implant 50 and hold sheet-like implant 50 against the surface of a target tissue. Sheet-like implant 50 may be fixed to the target tissue while the implant is held against the target tissue by implant expander 120.

0039<figref idref="f0007">Figure 8</figref> is a stylized perspective view of a shoulder 22 including a supraspinatus 26 having a distal tendon 28. With reference to <figref idref="f0007">Figure 8</figref>, it will be appreciated that a tendon repair implant 50 has been fixed to a surface of distal tendon 28. Tendon repair implant 50 may comprise, for example, various sheet-like structures without deviating from the spirit and scope of the present detailed description. In some useful embodiments, the sheet-like structure may comprise a plurality of fibers. The fibers may be interlinked with one another. When this is the case, the sheet-like structure may comprise a plurality of apertures comprising the interstitial spaces between fibers. Various processes may be used to interlink the fibers with one another. Examples of processes that may be suitable in some applications including weaving, knitting, and braiding. In some embodiment, the sheet-like structure may comprise a laminate including multiple layers of film with each layer of film defining a plurality of micro-machined or formed holes. The sheet-like structure of the tendon repair implant may also comprise a plurality of electro-spun nanofiber filaments forming a composite sheet. Additionally, the sheet-like structure may comprise a synthetic sponge material that defines a plurality of pores. The sheet-like structure may also comprise a reticulated foam material. Reticulated foam materials that may be suitable in some applications are available from Biomerix Corporation of Fremont, California which identifies these materials using the trademark BIOMATERIALTM. The sheet-like structure may be circular, oval, oblong, square, rectangular, or other shape conFigured to suit the target anatomy.

0040Various attachment elements may be used to fix tendon repair implant 50 to distal tendon 28 without deviating from the spirit and scope of this detailed description. Examples of attachment elements that may be suitable in some applications include sutures, tissue anchors, bone anchors, and staples. In the exemplary embodiment of <figref idref="f0007">Figure 8</figref>, a plurality of staples are fixing tendon repair implant 50 to distal tendon 28. In some exemplary methods, a plurality of staples may be applied using a fixation tool. The fixation tool may then be withdrawn from the body of the patient. Distal tendon 28 meets humerus 14 at an insertion point 30. With reference to <figref idref="f0007">Figure 8</figref>, it will be appreciated that sheet-like implant 50 extends over insertion point 30. Tendon repair implant may be applied to distal tendon 28, for example, using the procedure illustrated in the previous Figure. In various embodiments, staples may straddle the perimeter edge of the sheet-like implant (as shown in <figref idref="f0007">Figure 8</figref>), may be applied adjacent to the perimeter, and/or be applied to a central region of the implant. In some embodiments, the staples may be used to attach the implant to soft tissue and/or to bone.

0041<figref idref="f0008">Figure 9</figref> is an additional perspective view further illustrating delivery system 60. Delivery system 60 comprises a sheath 102 that is fixed to a handle 104. Sheath 102 defines a lumen 108 and a distal opening 128 fluidly communicating with lumen 108. In the embodiment of <figref idref="f0008">Figure 9</figref>, a delivery aid 130 can be seen extending through distal opening 128 defined by sheath 102.

0042In <figref idref="f0008">Figure 9</figref>, delivery aid 130 comprises a hub 126 that is disposed at the distal end of a control rod 132. An implant expander 120 is attached to hub 126. Implant expander 120 comprises a central portion 122 and a plurality of leg portions 124 radiating from central portion 122. In <figref idref="f0008">Figure 9</figref>, a sheet-like implant 50 is shown overlaying a distal surface of implant expander 120. In the exemplary embodiment of <figref idref="f0008">Figure 9</figref>, implant expander 120 is urging sheet-like implant 50 against a generally spherical surface (not shown in <figref idref="f0008">Figure 9</figref>).

0043Sheath 102 of delivery system 60 is coupled to a button 134. It will be appreciated that various other operative mechanisms may be used in addition to button 134. Relative motion between button 134 and handle 104 will cause similar relative motion between sheath 102 and handle 104. In <figref idref="f0008">Figure 9</figref>, sheath 102 will be moved distally (relative to handle 104) when button 134 is moved distally (relative to handle 104). Additionally, sheath 102 will be moved proximally (relative to handle 104) when button 134 is moved proximally (relative to handle 104).

0044In <figref idref="f0008">Figure 9</figref>, implant expander 120 is shown residing outside of lumen 108 defined by sheath 102. In <figref idref="f0008">Figure 9</figref>, implant expander 120 is shown assuming a deployed configuration. Implant expander 120 can be selectively urged to assume a compact configuration, for example, by placing implant expander inside lumen 108 defined by sheath 102. Implant expander can be placed inside lumen 108, for example, by advancing sheath 102 over implant expander 120.

0045<figref idref="f0009 f0010 f0011">Figure 10A through Figure 10E</figref> are a series of stylized plan views illustrating an exemplary method in accordance with the present detailed description. <figref idref="f0009 f0010 f0011">Figure 10A through Figure 10E</figref> may be referred to collectively as <figref idref="f0009 f0010 f0011">Figure 10</figref>. A proximal direction is illustrated with an arrow P in <figref idref="f0009 f0010 f0011">Figure 10</figref>. A distal direction is illustrated with another arrow D in <figref idref="f0009 f0010 f0011">Figure 10</figref>. The exemplary method of <figref idref="f0009 f0010 f0011">Figure 10</figref> may be used, for example, to fix a sheet-like implant 50 to a surface 136 of a target tissue 138.

0046<figref idref="f0009">Figure 10A</figref> is a partial cross-sectional view illustrating a distal portion of a delivery system 60 in accordance with this detailed description. In the embodiment of <figref idref="f0009 f0010 f0011">Figure 10</figref>, the distal portion of delivery system 60 has been positioned near a target tissue 138. Delivery system 60 comprises a sheath 102 that is fixed to a handle. Sheath 102 defines a lumen 108 and a distal opening fluidly communicating with the lumen. In the embodiment of <figref idref="f0009">Figure 10A</figref>, a central portion of a sheet-like implant 50 can be seen extending through the distal opening defined by sheath 102. In the embodiment of <figref idref="f0009 f0010 f0011">Figure 10</figref>, sheet-like implant 50 is overlaying an implant expander. The implant expander and sheet-like implant 50 are both assuming a compact configuration. With reference to <figref idref="f0009 f0010 f0011">Figure 10</figref>, it will be appreciated that the majority of sheet-like implant 50 is disposed inside sheath 102. A central portion of a sheet-like implant 50 is extending out of sheath 102.

0047Implant expander 120 of <figref idref="f0009 f0010 f0011">Figure 10</figref> comprises a central portion 122 and a plurality of leg portions 124 radiating from central portion 122. In the embodiment of <figref idref="f0009">Figure 10A</figref>, implant expander 120 is assuming a first compact configuration. With reference to <figref idref="f0009">Figure 10A</figref>, it will be appreciated that the free end of each leg portion 124 is disposed proximally of central portion 122 when implant expander 120 is assuming the first compact configuration. With continuing reference to <figref idref="f0009 f0010 f0011">Figure 10</figref>, it will be appreciated that a distal surface 140 of implant expander 120 defines a convex surface when implant expander 120 is assuming the first compact configuration 142. Portions of sheet-like implant 50 can be seen extending between leg portions 124 of implant expander 120 and the wall of sheath 102. In <figref idref="f0009 f0010 f0011">Figure 10</figref>, a fold 146 comprising a portion of sheet-like implant 50 can also be seen extending between an adjacent pair of leg portions 124.

0048In the embodiment of <figref idref="f0009">Figure 10B</figref>, a central portion of sheet-like implant 50 is trapped between implant expander 120 and surface 136 of target tissue 138. By comparing <figref idref="f0009">Figure 10A and Figure 10B</figref>, it will be appreciated that sheet-like implant 50 has been advanced distally so that central portion of sheet-like implant 50 is contacting surface 136 of target tissue 138.

0049In the embodiment of <figref idref="f0009">Figure 10B</figref>, delivery system 60 includes a projection 148 extending distally from distal surface 140 of central portion 122 of implant expander 120. In some applications, projection 148 may be used to temporarily hold the position of delivery system 60 while sheet-like implant 50 is held against surface 136 of target tissue 138. In the exemplary embodiment of <figref idref="f0009">Figure 10B</figref>, projection 148 comprises a spike 150 having a generally cone-like shape. In the embodiment of <figref idref="f0009">Figure 10B</figref>, spike 150 has been advanced so that a distal portion of spike 150 has pierced target tissue 138. Spike 150 can be seen extending through sheet-like implant 50 in <figref idref="f0009">Figure 10B</figref>. Spike 150 may be used to temporarily center implant expander 120 and sheet-like implant 50 on a target location. Once sheet-like implant 50 has been fixed to target tissue 138, spike 150 can be withdrawn from target tissue 138 and sheet-like implant 50.

0050In <figref idref="f0010">Figure 10C</figref>, implant expander 120 of delivery system 60 is shown assuming a deployed configuration. By comparing <figref idref="f0010">Figure 10C</figref> and <figref idref="f0009">Figure 10B</figref>, it will be appreciated that sheath 102 has been retracted in proximal direction P. In the embodiment of <figref idref="f0010">Figure 10C</figref>, leg portions 124 of implant expander 120 are conforming to the shape of surface 136. In the exemplary embodiment of <figref idref="f0009 f0010 f0011">Figure 10</figref>, surface 136 has a generally planar shape. Sheet-like implant 50 is resting between implant expander 120 and surface 136 of target tissue 138, with sheet-like implant 50 overlaying surface 136. With reference to <figref idref="f0010">Figure 10C</figref>, it will be appreciated that implant expander 120 is causing sheet-like implant 50 to generally conform to the shape of surface 136.

0051In <figref idref="f0010">Figure 10D</figref>, implant expander 120 of delivery system 60 is shown assuming an unstressed configuration. By comparing <figref idref="f0010">Figure 10C and Figure 10D</figref>, it will be appreciated that implant expander 120 has been lifted in proximal direction P. In the embodiment of <figref idref="f0010">Figure 10D</figref>, no external forces are acting on leg portions 124 and implant expander 120 is free to assume the unstressed configuration shown in <figref idref="f0010">Figure 10D</figref>. With reference to <figref idref="f0010">Figure 10D</figref>, it will be appreciated that the free end of each leg portion 124 is disposed distally of central portion 122 when implant expander 120 is assuming the unstressed configuration. With continuing reference to <figref idref="f0009 f0010 f0011">Figure 10</figref>, it will be appreciated that the distal surface 140 of implant expander 120 defines a concave surface when implant expander 120 is assuming the unstressed configuration.

0052In <figref idref="f0011">Figure 10E</figref>, implant expander 120 of delivery system 60 is shown assuming a second compact configuration. By comparing <figref idref="f0011">Figure 10E</figref> and <figref idref="f0010">Figure 10D</figref>, it will be appreciated that implant expander 120 and sheath 102 have been moved relative to each other. With reference to <figref idref="f0011">Figure 10E</figref>, it will be appreciated that implant expander 120 may be urged to assume the second compact configuration moving implant expander 120 and sheath 102 relative to one another so that implant expander 120 is disposed in lumen 108 defined by sheath 102. With reference to <figref idref="f0009 f0010 f0011">Figure 10</figref>, it will be appreciated that the free end of each leg portion 124 is disposed distally of central portion 122 when implant expander 120 is assuming the second compact configuration 144. With continuing reference to <figref idref="f0009 f0010 f0011">Figure 10</figref>, it will be appreciated that the distal surface 140 of implant expander 120 defines a concave surface when implant expander 120 is assuming the second compact configuration 144.

0053<figref idref="f0012">Figure 11</figref> is a stylized diagram illustrating four configurations of an exemplary implant expander 120. The step of transitioning between one configuration and another configuration is represented by three arrows in <figref idref="f0012">Figure 11</figref>. A proximal direction is illustrated with another arrow P in <figref idref="f0012">Figure 11</figref>. A distal direction is illustrated with an additional arrow D in <figref idref="f0012">Figure 11</figref>.

0054Implant expander 120 of <figref idref="f0012">Figure 11</figref> comprises a central portion 122 and a plurality of leg portions 124 radiating from central portion 122. A first arrow 1 represents a transition between a first compact configuration 142 and a deployed configuration 154. With reference to <figref idref="f0012">Figure 11</figref>, it will be appreciated that the free end of each leg portion 124 is disposed proximally of central portion 122 when implant expander 120 is assuming the first compact configuration 142. With continuing reference to <figref idref="f0012">Figure 11</figref>, it will be appreciated that a distal surface 140 of implant expander 120 defines a convex surface when implant expander 120 is assuming the first compact configuration 142. In some exemplary methods, implant expander 120 is held in the first compact configuration 142 while implant expander 120 is disposed in a lumen of a sheath. In these exemplary methods, implant expander 120 may be allowed to assume deployed configuration 154 when the sheath is retracted from around implant expander 120. Implant expander 120 may also be allowed to assume deployed configuration 154 when implant expander 120 is moved in a distal direction so that implant expander 120 exits the lumen via a distal opening of the sheath or when the sheath moves proximally to reveal the implant expander from within the distal opening of the sheath and relieve stress within leg portions 124.

0055In the exemplary embodiment of <figref idref="f0012">Figure 11</figref>, leg portions 124 of implant expander 120 conform to the shape of a target tissue when implant expander 120 is in the deployed configuration. In <figref idref="f0012">Figure 11</figref>, implant expander 120 is shown conforming to the shape of a generally planar surface (not shown in <figref idref="f0012">Figure 11</figref>) while implant expander is assuming the deployed configuration. A second arrow 2 represents a transition between the deployed configuration 154 and an unstressed configuration 152. In some exemplary methods, implant expander 120 is free to assume unstressed configuration 152 when implant expander 120 is lifted off of a target surface so that no external forces are acting on leg portions 124 of implant expander 120. With reference to <figref idref="f0012">Figure 11</figref>, it will be appreciated that the free end of each leg portion 124 is disposed distally of central portion 122 when implant expander 120 is assuming unstressed configuration 152. With continuing reference to <figref idref="f0012">Figure 11</figref>, it will be appreciated that the distal surface 140 of implant expander 120 defines a concave surface when implant expander 120 is assuming the unstressed configuration 152.

0056A third arrow 3 represents a transition between the unstressed configuration 152 and a second compact configuration 144. In some exemplary methods, implant expander 120 is urged to assume second compact configuration 144 by drawing implant expander 120 proximally into a lumen of a sheath. With reference to <figref idref="f0012">Figure 11</figref>, it will be appreciated that the free end of each leg portion 124 is disposed distally of central portion 122 when implant expander 120 is assuming the second compact configuration 144. With continuing reference to <figref idref="f0012">Figure 11</figref>, it will be appreciated that the distal surface 140 of implant expander 120 defines a concave surface when implant expander 120 is assuming the second compact configuration 144.

0057<figref idref="f0013">Figure 12</figref> is a perspective view illustrating an exemplary delivery system 360. Delivery system 360 comprises a sheath 302 that is fixed to a handle 304. Sheath 302 defines a lumen 308 and a distal opening 328 fluidly communicating with lumen 308. In the embodiment of <figref idref="f0013">Figure 12</figref>, a delivery aid 330 can be seen extending through distal opening 328 defined by sheath 302. In the embodiment of <figref idref="f0013">Figure 12</figref>, delivery aid 330 comprises a hub 326 that is disposed at the distal end of a control rod 332. An implant expander 320 is attached to hub 326. Implant expander 320 comprises a central portion 322 and a plurality of leg portions 324 radiating from central portion 322.

0058Sheath 302 of delivery system 360 is coupled to an actuator 356. Relative motion between actuator 356 and handle 304 will cause similar relative motion between sheath 302 and handle 304. In the exemplary embodiment of <figref idref="f0013">Figure 12</figref>, sheath 302 will be moved distally (relative to handle 304) when actuator 356 is moved distally (relative to handle 304). Additionally, sheath 302 will be moved proximally (relative to handle 304) when actuator 356 is moved proximally (relative to handle 304).

0059In <figref idref="f0013">Figure 12</figref>, implant expander 320 is shown residing outside of lumen 308 defined by sheath 302. In <figref idref="f0013">Figure 12</figref>, implant expander 320 is shown assuming an unstressed configuration. Implant expander 320 can be selectively urged to assume a compact configuration, for example, by placing implant expander inside lumen 308 defined by sheath 302. Implant expander can be placed inside lumen 308, for example, by advancing sheath 302 over implant expander 320.

0060<figref idref="f0014">Figure 13</figref> is a plan view illustrating an exemplary assembly in accordance with the present detailed description. The assembly of <figref idref="f0014">Figure 13</figref> includes a sheet-like implant 50 and an implant expander 520. Implant expander 520 of <figref idref="f0014">Figure 13</figref> comprises a central portion 522 and a plurality of leg portions 524 radiating from central portion 522. In the embodiment of <figref idref="f0014">Figure 13</figref>, a sheet-like implant 50 is trapped between implant expander 520 and a target tissue 538. With reference to <figref idref="f0014">Figure 13</figref>, it will be appreciated that implant expander 520 includes a plurality of retainers 558. In the embodiment of <figref idref="f0014">Figure 13</figref>, retainers 558 engage sheet-like implant 50 so that sheet-like implant 50 moves when implant expander 520 is moved and may aid in imparting lateral stress of the legs into lateral stress within the implant.

0061<figref idref="f0015">Figure 14</figref> is a plan view illustrating an exemplary assembly in accordance with the present detailed description. The assembly of <figref idref="f0015">Figure 14</figref> includes a sheet-like implant 50 and an implant expander 720. Implant expander 720 of <figref idref="f0015">Figure 14</figref> comprises a central portion 722 and a plurality of leg portions 724 radiating from central portion 722. In the embodiment of <figref idref="f0015">Figure 14</figref>, a sheet-like implant 50 is trapped between implant expander 720 and a target tissue 738. With reference to <figref idref="f0015">Figure 14</figref>, it will be appreciated that sheet-like implant 50 includes a plurality of pockets 762. In the embodiment of <figref idref="f0015">Figure 14</figref>, each pocket 762 is dimensioned to receive the end of a leg portion 724 of implant expander 720. When this is the case, implant expander 720 engages pockets 762 so that sheet-like implant 50 moves when implant expander 720 is moved.

0062<figref idref="f0016 f0017">Figure 15A through Figure 15F</figref> are a series of stylized plan views illustrating an exemplary method in accordance with the present detailed description. <figref idref="f0016 f0017">Figure 15A through Figure 15F</figref> may be referred to collectively as <figref idref="f0016 f0017">Figure 15</figref>. A proximal direction is illustrated with an arrow P in <figref idref="f0016 f0017">Figure 15</figref>. A distal direction is illustrated with another arrow D in <figref idref="f0016 f0017">Figure 15</figref>. The exemplary method of <figref idref="f0016 f0017">Figure 15</figref> may be used, for example, to fix a sheet-like implant 50 to a surface of a target tissue 138.

0063<figref idref="f0016">Figure 15A</figref> is a stylized plan view of illustrating a shoulder 22 of a patient. Shoulder 22 of <figref idref="f0016">Figure 15A</figref> has been inflated to create a cavity 62 therein. In the exemplary embodiment of <figref idref="f0016">Figure 15A</figref>, a fluid supply 64 is pumping a continuous flow of saline into cavity 62. This flow of saline exits cavity 62 via a fluid drain 66.

0064In <figref idref="f0016">Figure 15A</figref>, a sheath 102 of a delivery system 60 is shown positioned near a shoulder 22. Delivery system 60 also comprises a delivery aid 130 including an implant expander that is fixed to the distal end of a control rod 132. In 15A, a sheet-like implant 50 is overlaying the implant expander of delivery aid 130. In the embodiment of <figref idref="f0016">Figure 15A</figref>, delivery aid 130 includes a projection 148 extending distally from the implant expander. In <figref idref="f0016">Figure 15A</figref>, projection 148 comprises a spike 150 having a generally cone-like shape. Spike 150 can be seen extending through sheet-like implant 50 in <figref idref="f0016">Figure 15A</figref>. Spike 150 may be used to temporarily center sheet-like implant 50 on a target location. Once sheet-like implant 50 has been fixed to target tissue 138, spike 150 can be withdrawn from target tissue 138 and sheet-like implant 50.

0065Delivery aid 130 can be used to insert sheet-like implant 50 into cavity 62 formed in shoulder 22. Delivery aid 130 can also be used to hold the sheet-like implant against a target tissue 138. In some embodiments, the sheet-like implant is folded into a compact configuration when inside the lumen of the sheath. When this is the case, delivery aid 130 may be used to unfold the sheet-like implant into an expanded shape.

0066In <figref idref="f0016">Figure 15B</figref>, sheath 102 is shown extending into shoulder 22. A distal opening of sheath 102 has been placed in fluid communication with cavity 62 in <figref idref="f0016">Figure 15B</figref>. By comparing <figref idref="f0016">Figure 15A and Figure 15B</figref>, it will be appreciated that sheet like implant 50 has been advanced distally so that a central portion of sheet like implant 50 is contacting a surface of target tissue 138. The central portion of sheet like implant 50 is trapped between implant expander 120 and the surface of target tissue 138 in the embodiment of <figref idref="f0016">Figure 15B</figref>.

0067In <figref idref="f0016">Figure 15C</figref>, implant expander 120 of delivery aid 130 is shown assuming a deployed configuration. By comparing <figref idref="f0016">Figure 15C and Figure 15B</figref>, it will be appreciated that sheath 102 has been retracted in a proximal direction P. Implant expander 120 of <figref idref="f0016 f0017">Figure 15</figref> comprises a central portion 122 and a plurality of leg portions 124 radiating from central portion 122. In <figref idref="f0016">Figure 15B</figref>, implant expander 120 is assuming a deployed configuration. Implant expander 120 is fixed to the distal end of control rod 132 in the embodiment of <figref idref="f0016 f0017">Figure 15</figref>.

0068Sheet like implant 50 is shown overlaying an outer surface of target tissue 138 in <figref idref="f0016">Figure 15C</figref>. In <figref idref="f0016">Figure 15C</figref>, sheet like implant 50 is generally conforming to the shape of target tissue 138. Implant expander 120 is holding sheet-like implant 50 against target tissue 138 in <figref idref="f0016">Figure 15C</figref>.

0069Some exemplary methods in accordance with this detailed description include the steps of inflating a shoulder to create a cavity therein and placing a distal opening of a sheath in fluid communication with the cavity while the sheath is surrounding a delivery device disposed inside a lumen thereof and the sheath is maintaining the delivery device in a first compact configuration. A central portion of the sheet-like material may be placed in contact with a surface of a target tissue. The sheath may be withdrawn from around the delivery device so that the delivery device is free to assume a deployed configuration inside the cavity. The delivery device may be used to hold the sheet-like material against a surface of the target tissue while the delivery device is assuming the deployed configuration. The sheet-like implant 50 may be fixed to the target tissue while sheet-like implant 50 is held against the surface of the target tissue. The delivery device may be urged to assume a second compact configuration as the delivery device is removed from the cavity.

0070In <figref idref="f0017">Figure 15D</figref>, a fixation tool shaft 72 of a fixation tool 70 is shown extending into shoulder 22. In <figref idref="f0017">Figure 15D</figref>, a distal end of fixation tool shaft 72 is disposed proximate an edge of sheet like implant 50. One or more staples may be disposed inside fixation tool shaft 72. Fixation tool 70 may apply staples to fix sheet like implant 50 to target tissue 138 while sheet like implant 50 is held in place by implant expander 120.

0071Various attachment elements may be used to fix sheet like implant 50 to target tissue 138 without deviating from the spirit and scope of this detailed description. Examples of attachment elements that may be suitable in some applications include sutures, tissue anchors, bone anchors, and staples. In <figref idref="f0017">Figure 15E</figref>, sheet like implant 50 is fixed to target tissue 138 by a plurality of staples 74. In some exemplary methods, a plurality of staples may be applied using a fixation tool. The fixation tool may then be withdrawn from the body of the patient. In the exemplary embodiment of <figref idref="f0017">Figure 15E</figref>, delivery aid 130 may be used to hold sheet like implant 50 against target tissue 138 while staples 74 are applied using fixation tool 70.

0072With reference to <figref idref="f0017">Figure 15F</figref>, it will be appreciated that delivery aid 130 has been withdrawn from shoulder 22 and retracted into lumen 108 defined by sheath 102. Implant expander 120 of delivery aid 130 has been urged to assume a second compact configuration in <figref idref="f0017">Figure 15F</figref>. Implant expander 120 comprises a central portion 122 and a plurality of leg portions 124 radiating from central portion 122. With reference to <figref idref="f0017">Figure 15F</figref>, it will be appreciated that the free end of each leg portion is disposed distally of central portion 122 when implant expander 120 is assuming the second compact configuration.

0073<figref idref="f0018">Figure 16</figref> is a stylized depiction of a kit 123. In <figref idref="f0018">Figure 16</figref>, kit 123 comprises a sheet-like implant 50 and a number of tools that may be used in conjunction with sheet-like implant 50. The tools of kit 123 may be used, for example, for delivering sheet-like implant 50 to a target location within the body of a patient. These tools may also be used, for example, for fixing sheet-like implant 50 to a target tissue.

0074In <figref idref="f0018">Figure 16</figref>, kit 123 comprises a locating guide 125, a locating guide removal tool 127, a fixation tool 70, and a delivery aid 129. In some useful embodiments, locating guide 125 includes a temporary fixation mechanism proximate its distal end. A method in accordance with the present detailed description may include temporarily fixing the distal end of locating guide 125 to a target tissue and advancing sheet-like implant 50 over locating guide 125 for delivering the sheet-like implant to the target location. In some applications, delivery aid 129 may be used for advancing sheet-like implant 50 over locating guide 125 and urging sheet-like implant 50 against a target tissue. Fixation tool 70 of kit 123 may be used, for example, for fixing sheet-like implant 50 to the target tissue. Locating guide removal tool 127 may be used to remove locating guide 125 after sheet-like implant 50 has been fixed to the target tissue. In the embodiment of <figref idref="f0018">Figure 16</figref>, fixation tool 70 includes a fixation tool shaft 72.

0075<figref idref="f0019">Figure 17A</figref> is an enlarged plan view illustrating delivery aid 129 shown in the previous Figure. <figref idref="f0019">Figure 17B</figref> is a partial cross-sectional perspective view further illustrating delivery aid 129. <figref idref="f0019">Figure 17A and Figure 17B</figref> may be collectively referred to as <figref idref="f0019">Figure 17</figref>. A distal direction is illustrated with an arrow D in <figref idref="f0019">Figure 17</figref>.

0076In <figref idref="f0019">Figure 17</figref>, delivery aid 129 includes an implant expander 133 fixed to a distal end of a control rod 135. Implant expander 133 of <figref idref="f0019">Figure 17</figref> has a central portion 137 and an outer portion 139 extending radially from central portion 137. In the embodiment of <figref idref="f0019">Figure 17</figref>, no external forces are acting on implant expander 133 and implant expander 133 is free to assume an unstressed configuration. With reference to <figref idref="f0019">Figure 17B</figref>, it will be appreciated that a distal surface 143 of implant expander 133 comprises a generally concave surface 145 when the implant expander is assuming an unstressed configuration. With continuing reference to <figref idref="f0019">Figure 17</figref>, it will be appreciated that an outermost edge 147 of outer portion 139 is disposed distally of central portion 137 when implant expander 133 is assuming the unstressed configuration.

0077<figref idref="f0020 f0021 f0022">Figure 18A through Figure 18I</figref> are a series of stylized plan views illustrating an exemplary method in accordance with the present detailed description. <figref idref="f0020 f0021 f0022">Figure 18A through Figure 18I</figref> may be referred to collectively as <figref idref="f0020 f0021 f0022">Figure 18</figref>. A proximal direction is illustrated with an arrow P in <figref idref="f0020 f0021 f0022">Figure 18</figref>. A distal direction is illustrated with another arrow D in <figref idref="f0020 f0021 f0022">Figure 18</figref>. The exemplary method of <figref idref="f0020 f0021 f0022">Figure 18</figref> may be used, for example, to fix a sheet-like implant 50 to a surface of a target tissue 138.

0078In <figref idref="f0020">Figure 18A</figref>, a cannula 149 is shown extending into a shoulder 22. Cannula 149 defines a lumen 153. A distal end of cannula 149 is located proximate a target tissue 138. The distal end of cannula 149 defines a distal opening that fluidly communicates with lumen 153.

0079In <figref idref="f0020">Figure 18B</figref>, a locating guide 125 is shown extending through lumen 153 defined by cannula 149. Some methods in accordance with the present disclosure may include the step of advancing the distal end of a locating guide through a cannula. In the embodiment of <figref idref="f0020">Figure 18B</figref>, a distal portion of locating guide 125 is disposed in target tissue 138. In some useful embodiments, the distal portion of locating guide 125 includes a barb. When this is the case, the barb may help maintain the position of the distal end of locating guide 125 in the target tissue.

0080In <figref idref="f0020">Figure 18C</figref>, a sheet-like implant 50 is shown disposed about locating guide 125. Some methods in accordance with the present disclosure may include the step of inserting a locating guide through a sheet-like implant. Some of these methods may also include the step of advancing the sheet-like implant over the locating guide toward a target tissue.

0081In <figref idref="f0021">Figure 18D</figref>, a delivery aid 129 is shown disposed about locating guide 125. Some methods in accordance with the present disclosure may include the step of inserting the proximal end of a locating guide 125 into a distal aperture of a delivery aid 129. When this is the case, the delivery aid 129 may be advanced over locating guide 125 for urging a sheet-like implant 50 toward a target tissue (e.g., target tissue 138). In this way, delivery aid 129 may be used to urge sheet-like implant 50 in a longitudinal direction along locating guide 125. In some applications, delivery aid 129 may also be used to hold sheet-like implant 50 against a target tissue.

0082In <figref idref="f0021">Figure 18E</figref>, sheet-like implant 50 is disposed in a lumen 153 defined by cannula 149. By comparing <figref idref="f0021">Figure 18E and Figure 18D</figref>, it will be appreciated that sheet-like implant 50 has been pushed distally into lumen 153. In <figref idref="f0021">Figure 18E</figref>, sheet-like implant 50 has been folded into a compact configuration. Sheet-like implant 50 is shown overlaying the implant expander of delivery aid 129 in <figref idref="f0021">Figure 18E</figref>. In the exemplary embodiment of <figref idref="f0021">Figure 18E</figref>, the implant expander is urged to assume a first compact configuration as the implant expander and sheet-like implant 50 are advanced into lumen 153.

0083In <figref idref="f0021">Figure 18F</figref>, sheet-like implant 50 is shown overlaying target tissue 138. Some methods in accordance with the present detailed description include the step of passing a sheet-like implant through a cannula. In the exemplary embodiment of <figref idref="f0021">Figure 18F</figref>, for example, sheet-like implant 50 may be pushed through cannula 149 using delivery aid 129. Delivery aid 129 may also be used to hold sheet-like implant 50 against target tissue 138 while a surgeon attaches sheet-like implant 50 to target tissue 138.

0084In <figref idref="f0022">Figure 18G</figref>, a fixation tool shaft 72 of a fixation tool 70 is shown extending through cannula 149. In <figref idref="f0022">Figure 18G</figref>, a distal end of fixation tool shaft 72 is disposed proximate sheet-like implant 50. One or more staples may be disposed inside fixation tool shaft 72. Some methods in accordance with the present detailed description include the step of passing a staple through a cannula. In <figref idref="f0022">Figure 18G</figref>, for example, a staple may be passed through cannula 149 while the staple resides in fixation tool shaft 72.

0085In <figref idref="f0022">Figure 18H</figref>, sheet-like implant 50 is fixed to target tissue 138 by a plurality of staples 74. In some exemplary methods, a plurality of staples may be applied to a sheet-like implant and a target tissue using a fixation tool. The fixation tool may then be withdrawn from the body of the patient. With reference to <figref idref="f0022">Figure 18H</figref>, it will be appreciated that delivery aid 129 has been withdrawn from shoulder 22 and locating guide 125 remains in the position shown in <figref idref="f0022">Figure 18H</figref>.

0086In <figref idref="f0022">Figure 18I</figref>, locating guide 125 has been withdrawn from shoulder 22. Some useful methods in accordance with the present detailed description, include the use of a locating guide including a temporary fixation mechanism located proximate its distal end. These exemplary methods may also include the use of a locating guide removal tool to aid in withdrawing the locating guide from the body of the patient. In <figref idref="f0022">Figure 18I</figref>, a plurality of staples 74 can be seen fixing sheet-like implant 50 to target tissue 138.

0087<figref idref="f0023">Figure 19</figref> is a plan view showing a locating guide 125. With reference to <figref idref="f0023">Figure 19</figref>, it will be appreciated that locating guide 125 has a point 155 at its distal end. In the embodiment of <figref idref="f0023">Figure 19</figref>, locating guide 125 includes a barb 157 near its distal end. In <figref idref="f0023">Figure 19</figref>, point 155 is shown pointing in a distal direction D and barb 157 is shown pointing in a proximal direction

0088<figref idref="f0024">Figure 20</figref> is a plan view showing a locating guide removal tool 127. Locating guide removal tool 127 may be used, for example, to remove a locating guide 125 from a target tissue. In the embodiment of <figref idref="f0024">Figure 20</figref>, locating guide removal tool 127 includes a tubular body 159 that is fixed to a grip 163. In operation, tubular body 159 is advanced over the proximal end of a locating guide so that a portion of the locating guide extends into a lumen defined by tubular body 159. Locating guide removal tool 127 may then be used to grasp a proximal portion of the locating guide and produce relative motion between the locating guide and tubular body 159.

0089In <figref idref="f0024">Figure 20</figref>, a lever 165 is pivotably coupled to grip 163. Relative motion between locating guide 125 and tubular body 159 can be produced by rotating lever 165 relative to grip 163 when locating guide removal tool 127 is grasping the proximal portion of locating guide 125. This relative motion can be used to advance tubular body 159 over the barb 157 of locating guide 125. Locating guide 125 may be withdrawn from the body of the patient while tubular body 159 is covering barb 157.