Instrument for delivery of implant

A surgical instrument has a main shaft underlying a slide member. The slide member is movable in a proximal-distal direction. The distal end of the slide member has an open position and a closed position. The closed position is spaced from the open position in the proximal-distal direction. There is a gap between the distal end of the slide member and the distal end of the main shaft when the instrument is in the open position. The gap is smaller when the instrument is in the closed position. An implant can be received in the gap and delivered to a damaged tissue site using the instrument. An implant protector can be used when delivering the implant with the instrument. A pivotable implant cover can be used to protect the implant instead of the slide member.

FIELD OF THE INVENTION

The present invention relates generally to a surgical instrument for delivering an implant to a damaged tissue site in the human body.

BACKGROUND OF THE INVENTION

Several different types of soft tissue are found in human joints. For example, a joint can include articular hyaline cartilage, intra-articular fibrocartilage, tendons and ligaments. Articular hyaline cartilage is found on the surfaces of the bones of the joint. Intra-articular cartilage is found between the joint surfaces. Tendons connect muscle to the bones of the joint, and ligaments connect articular extremities of the bones of the joint.

When the soft tissue of a joint is no longer healthy, there can be debilitating pain in the joint. Soft tissue health can be adversely affected by disease, aging, or trauma. The adverse effects of disease, aging and trauma can be, for example, in the form of a tear in the soft tissue, or in the form of a breakdown, thinning or delamination of the tissue.

One form of intra-articular cartilage that is frequently damaged or degenerated is the meniscus of the knee. The meniscus is frequently damaged in twisting injuries. It is also damaged with repetitive impact over time. Meniscus degeneration can also occur by aging; as a person ages, the meniscus can become soft in places, so that even common motions like squatting can cause meniscal tears.

Common surgical procedures for treating meniscal damage include tear repairs and menisectomies. A tear repair is most commonly performed when the tear is a clean longitudinal vertical lesion in the vascular red zone of the meniscus. The basic strategy is to stabilize the tear by limiting or eliminating radial separation of the faces of the tear when the meniscus is load bearing. Many devices and surgical procedures exist for repairing meniscal tears by approximating the faces of the meniscus at the tear. Examples of such devices and procedures are disclosed in the following U.S. Pat. Nos.: 6,319,271; 6,306,159; 6,306,156; 6,293,961; 6,156,044; 6,152,935; 6,056,778; 5,993,475; 5,980,524; 5,702,462; 5,569,252; 5,374,268; 5,320,633; and 4,873,976.

Menisectomies involve the surgical removal of part of the meniscus. Such procedures have generally been performed in cases of radial tears, horizontal tears, vertical longitudinal tears outside the vascular zone, complex tears, or defibrillation. Although menisectomies provide immediate relief to the patient, in the long term the absence of part of the meniscus can cause cartilage wear on the condylar surface, eventually leading to arthritic conditions in the joint.

Such surgical procedures are commonly performed arthroscopically. In arthroscopy, small incisions are made at the affected joint to form portals for the insertion of instruments, including a small lens and lighting system (an arthroscope). The arthroscope is connected to a viewing device, such as a television monitor to allow the surgeon to see the interior of the joint. Other instruments are inserted through other portals to perform a variety of tasks. For example, the surgical instrument may include an implement for manipulating native tissue (for example, tissue grasping, tissue cutting, bone abrading).

Typical surgical instruments used in arthroscopic procedures include rongeurs, such as the Kerrison rongeur, punch forceps, basket forceps, suction punches and cup curet, for example. Examples of arthroscopic instruments are described and illustrated in O'Connor's Textbook of Arthroscopic Surgery, 2nded., 1992, Chapter 19.

Other common surgical techniques in orthopaedic surgery include open surgery and mini-arthrotomy. For example, for knee surgery, the surgery may be performed by an open knee arthrotomy, where the incision may typically be 20-30 cm in length, and wherein the patella is everted during surgery. Knee surgery may also be performed by a mini-knee arthrotomy, where the incision is typically 10-13 cm in length and patella tension is avoided.

Intra-articular fibrocartilage is also present, for example, in the temporomandibular joint and between vertebrae. Injury and degeneration can also occur to the intra-articular fibrocartilage in these other joints.

Another common site of soft tissue injury and degeneration is the rotator cuff in the shoulder. The rotator cuff comprises the tendons that attach muscles to a bone in the shoulder. Where one of the tendons is thin, delaminated or frayed to the point that surgical repair or reconstruction is necessary, the damaged tendon can be reinforced with graft tissue or with an orthopaedic implant.

A variety of orthopaedic implants are available for treating damaged soft tissue at a joint site. One commercially available orthopaedic implant is the RESTORE orthobiologic implant. The RESTORE orthobiologic implant comprises layers of small intestine submucosa. The commercial RESTORE product is typically sold in the form of a thin circular sheet with a diameter of about 2.5 inches in diameter. Other shapes and sizes of RESTORE orthobiologic implants can be used. In addition, the surgeon can cut the commercial RESTORE product intra-operatively to the desired shape and size. The RESTORE implant is used in treating rotator cuff injuries.

Orthopaedic implants for treatment of damaged menisci are disclosed in the following U.S. Pat. Nos.: 6,042,610; 5,735,903; 5,681,353; 5,306,311; 5,108,438; 5,007,934; and 4,880,429.

SUMMARY OF THE INVENTION

Orthopaedic implants useful in approximating, repair or regeneration of fibrocartilage are disclosed in the following applications for U.S. patent application Ser. No. 10/195,794 entitled “Meniscus Regeneration Device and Method”; Ser. No. 10/195,719 entitled “Devices from Naturally Occurring Biologically Derived Materials”; Ser. No. 10/195,347 entitled “Cartilage Repair Apparatus and Method”; Ser. No. 10/195,344 entitled “Unitary Surgical Device and Method”; Ser. No. 10/195,341 entitled “Hybrid Biologic/Synthetic Porous Extracellular Matrix Scaffolds”; Ser. No. 10/195,606 entitled “Cartilage Repair and Regeneration Device and Method”; Ser. No. 10/195,354 entitled “Porous Extracellular Matrix Scaffold and Method”; Ser. No. 10/195,334 entitled “Cartilage Repair and Regeneration Scaffolds and Method”; Ser. No. 10/195,633 entitled “Porous Delivery Scaffold and Method”, each of which is assigned to the same assignee as the present application, each of which was filed on Jul. 15, 2002, and each of which is hereby incorporated by reference herein. Cross reference is also made to U.S. patent application Ser. No. 10/172,347 entitled “Hybrid Biologic-Synthetic Bioabsorbable Scaffolds” which was filed on Jun. 14, 2002, which is assigned to the same assignee as the present application, and which is incorporated by reference herein. Additional orthopaedic implants are disclosed in U.S. Pat. No. 6,176,880, entitled “Tissue Grant Construct for Replacement of Cartilaginous Structures” and U.S. patent application Ser. Nos. 09/767,345 and 09/767,346 of the same title, both filed on Jan. 23, 2001 and claiming priority to U.S. Pat. No. 6,176,880, which are incorporated by reference herein.

As used herein “implant” is intended to mean any device that is intended to be implanted at a damaged tissue site for the approximation, repair or regeneration of tissue at the damaged tissue site. “Orthopaedic implant” is intended to mean any device that is intended to be implanted at a joint site for the approximation, repair or regeneration of soft tissue at the joint site. While “implant” and “orthopaedic implant” are intended to include all of the devices identified in the preceding paragraph and commercial devices such as the RESTORE™ orthobiologic implant, “implant” and “orthopaedic implant” should not be limited to these particular devices or to any particular material unless expressly set forth in the claims. For example, “implant” and “orthopaedic implant” as used herein are intended to include devices made from synthetic sources, from purified natural fibers as well as devices made from naturally occurring tissue. An implant may comprise a tissue scaffold, patch or graft (including autografts, allografts and hetergrafts), for example. In addition, “implant” and “orthopaedic implant” are intended to include such devices either alone or in combination with bioactive agents, biologically-derived agents, cells, a biological lubricant, a biocompatible synthetic or a biocompatible inorganic material, for example.

Materials forming orthopaedic implants can find use in other parts of the body as well. Accordingly, the term “implant” is intended to mean such materials regardless of their intended end use.

The present invention provides a surgical instrument that allow for delivery of implants to a damaged tissue site. The damaged tissue site can be a damaged joint site, such as in the area of the meniscus in the human knee joint or in the area of the rotator cuff of the shoulder joint, and the implant can be an orthopaedic implant used to approximate, repair or regenerate damaged or diseased soft tissue at the damaged joint site.

In one aspect, the present invention provides a surgical instrument for delivering an implant to a damaged tissue site. The surgical instrument comprises a main shaft and a slide member. The main shaft has a proximal end and a distal end. The side member is juxtaposed with the main shaft and also has a proximal end and a distal end. The surgical instrument has open and closed positions. The slide member is movable in a proximal-distal direction with respect to the main shaft to move the surgical instrument between the open and closed positions. The distal end of the slide member has an open position when the surgical instrument is in the open position and a closed position when the surgical instrument is in the closed position. The closed position of the distal end of the slide member is spaced from the open position of the distal end of the slide member in the proximal-distal direction. There is a gap between the distal end of the slide member and the distal end of the main shaft when the instrument is in the open position. There is a smaller gap between the distal end of the slide member and the distal end of the main shaft when the instrument is in the closed position.

In another aspect, the present invention provides a surgical instrument for delivering an implant to a damaged tissue site. The surgical instrument comprises a main shaft and a cover. The main shaft has a distal end shaped to define a well for receiving a substantial portion of the implant. The cover is movable between a position substantially overlying the well to protect the implant to another position wherein a substantial part of the well is exposed.

In another aspect, the present invention provides a combination comprising a surgical instrument for delivering an implant to a damaged tissue site and an implant. The implant includes an edge. The surgical instrument includes a main shaft having a distal end and a slide member juxtaposed with the main shaft. The slide member has a distal end. The edge of the implant is received between the distal end of the main shaft and the distal end of the slide member. The shape of the distal end of the main shaft and the shape of the distal end of the slide member follow the shape of the edge of the implant.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The instrument of the present invention is useful in delivering an orthopaedic implant, as defined above, to a damaged joint site in the body. The damaged joint site may for example be an intra-articular site such as the knee, where the instrument can be used to deliver an orthopaedic implant for use in approximating, repairing or regenerating a diseased or damaged meniscus. The damaged intra-articular site may be in other locations in the body, such as the temporomandibular joint, between vertebrae, or any site where there is fibrocartilage in need of approximation, repair or regeneration. The instrument of the present invention can also be used to deliver an orthopaedic implant to location outside of the intra-articular space of a joint site. For example, the instrument of the present invention can be used to deliver an orthopaedic implant to a damaged joint site such as the area of the rotator cuff of the shoulder joint site. Unless expressly limited in the claims, “joint site” as used herein is intended to include the intra-articular space and other areas near the bones comprising a joint. “Damaged joint site”, unless expressly limited in the claims, is intended to mean such a joint site that requires surgical repair, whether due to injury, degeneration or disease.

The instrument of the present invention may also find utility in delivering an implant to damaged tissue sites other than the joints. “Damaged tissue site”, unless expressly limited in the claims, is intended to mean a tissue site that requires surgical repair, whether due to injury, degeneration or disease.

Several embodiments of the instrument of the present invention are illustrated in the accompanying drawings. The first embodiment of the instrument is illustrated inFIGS. 1-18and21-22. The first illustrated instrument10includes a handle12at the proximal end14, a main shaft16and a slide rod18. The main shaft16and slide rod18extend from the handle12to the distal end19of the instrument10. The first illustrated instrument10may also optionally include a delivery guide20, shown inFIGS. 1,3,21and22but not inFIGS. 2,4and5-20.

The handle12of the first illustrated instrument10includes two arms22,24connected together at a pivot26. Each arm22,24includes a grip portion28,30through which the surgeon may insert a thumb and a finger and squeeze to pivot the arms about pivot26. As the grip portions28,30are brought closer together, the slide arm18is moved from the open or unclamped position shown inFIGS. 1-2,5and7to the closed or clamped position shown inFIGS. 3-4,6and8.FIGS. 1 and 3also illustrate a possible locking mechanism32that cooperates with the arms22,24for locking the slide arm18in either the open or closed positions.

One arm22has a body portion23that is connected to a proximal end34of the main shaft16of the instrument10through standard means, such as a set screw or the like. The body portion23of the arm22is opposite the grip portion28and has an opening and channel (not shown) extending in a proximal-distal direction to receive the proximal end portion34of the main shaft16. As shown inFIG. 12, the proximal end portion34of the main shaft16may have indentations or cavities36,38that align with holes (not shown) in the body portion23of the arm22so that screws or the like can be used to secure the main shaft16to the body23of the arm22. It will be appreciated that other means of connecting the main shaft16to the arm22may be used, and that the main shaft16and arm22could be made integral if desired.

The other arm24has a top end40opposite its grip portion30. The pivot26that connects the two arms22,24is positioned between the top end40and grip portion30. When the grip portions28,30are squeezed together, the top portion40of the arm24is pivoted in a generally proximal direction. When the grip portions28,30are released, the top end40of the arm24is pivoted in a generally distal direction.

The top end40of the arm24has a hole or slot42(seeFIGS. 5-6) that receives the proximal end44of the slide rod18. A pin45or other suitable mechanical connector is used to connect the slide rod18to the top end40of the arm; this pin may provide a pivotable connection. As shown inFIG. 10, the proximal end44of the slide rod18has a hole46to receive the pin45. A portion of the slide rod18at its proximal end44has a reduced height or thickness; this portion, designated47inFIG. 10, extends through the channel (not shown) in the body23of arm22. Thus, when the top end40of the arm24is moved in a distal direction, the slide rod18is also moved in a distal direction; when the top end40of the arm24is moved in a proximal direction, the side rod18is also moved in a proximal direction.

As shown in the top plan view ofFIG. 9, the slide rod18has a thin elongate portion48extending from its proximal end44to a thicker curved portion50at its distal end52. As shown in the side elevation view ofFIG. 10, the slide rod also has a pair of spaced, integral downward-extending extensions54,56. Each extension54,56has a distal edge or surface58,60defining an obtuse angle with the bottom edge or surface62of the adjacent segments of the thin elongate portion48. The distal edges58,60are parallel to each other. Each extension54,56also has a through slot64,66(seeFIGS. 7-8and10). The through slots64,66of both extensions54,56are parallel to each other and extend upward in a distal direction. As shown inFIGS. 7-8, the through slots64,66each receive a pin68,70.

A substantial part of the thin elongate portion48of the slide rod18is received in an elongate channel72of the main shaft16. The channel72is defined by two spaced parallel side walls74,76and a bottom wall78. The channel72extends from the junction of the main shaft16with the body23of the arm22to a thick curved portion80at the distal end82of the main shaft16. As shown inFIG. 12, the curved portion80of the main shaft16is displaced downward from the bottom edge or surface84of the bottom wall78.

As shown inFIGS. 11-12, the side walls74,76of the main shaft16have spaced, aligned through holes86,87,88,89. These through holes86,87,88,89receive pins68,70to mount the slide rod18to the main shaft16. As shown inFIG. 11, the bottom wall78has a pair of slots90,91positioned near the through holes86,87,88,89. As shown inFIGS. 7-8, the extensions54,56of the slide rod18are received in these slots90,91.

As can be seen inFIGS. 5-8, the curved portions50,80of the main shaft16and slide rod18are similarly shaped. Each has a radius of about 1.1 inches. In the illustrated embodiment, the curved portion50of the slide rod has a length of 0.773 inches and the curved portion80of the main shaft16has a length of 0.783 inches. It should be understood that these dimensions are provided as examples only; the present invention is not limited to any particular dimension unless expressly set forth in the claims.

To use the first illustrated instrument10, the grips28,30are moved apart to place the instrument in the open or unclamped position shown inFIGS. 1-2,5and7. In this position, the distal end52of the slide rod18extends distally beyond the distal end82of the main shaft16. As shown inFIGS. 2 and 7, the curved portions50,80of the slide rod18and main shaft16are spaced apart by a gap92of about 1-2 mm. The total height of the distal end of the instrument, including the heights of the gap92(at the fully open or unclamped position) and the heights of the curved portions50,80is about 5 mm.

With the instrument in the open or unclamped position, the surgeon can then place a portion of the implant in the gap between the spaced curved portions50,80of the slide rod18and main shaft16. As shown inFIG. 13, a meniscal implant, shown at94may comprise a flat periphery96and an inner wedge-shaped portion98with curved inner and outer edges100,102. Such a meniscal implant94may be used to replace a part of a damaged meniscus removed in a menisectomy. In the illustrated embodiment, the curvature of the spaced curved portions50,80of the slide rod18and main shaft16follows the curvature of the inner edge100of the wedge-shaped portion98of the implant. Thus, the curvature of the spaced portions50,80of the slide rod and main shaft protect the inner edge100of the wedge-shaped portion98of the implant as it is introduced to the damaged tissue site.

The flat periphery96of the implant94is inserted in the gap92between the curved portions50,80of the main shaft16and slide rod18. The curved inner edge100of the inner wedge-shaped portion98of the implant is placed along side the curved edges of the portions50,80of the main shaft and slide rod.

When the instrument is in this fully open or unclamped position, the pins68,70are at the lowest ends of the slots64,66in the slide rod18, and the slide rod is slightly raised with respect to the channel72of the main shaft16. As shown inFIG. 7, in this position, substantial portions of the slide rod extensions54,56are above the slots90,91and the distal end52of the slide rod18extends slightly beyond the distal end82of the main shaft16.

Once the implant94is in position in the gap92, the surgeon may close the instrument to clamp the implant between the curved portions50,80of the main shaft16and slide rod18. The surgeon moves the grip portions28,30of the arms22,24closer together, causing the top end40of the arm24to pivot away from the body23of the arm22. As the top end40of the arm24moves away from the body23of arm22, the slide rod18is pulled in a proximal direction. As the slide rod18moves proximally, it also moves deeper into the channel72as the slots64,66of the extensions54,56move downward along the pins68,70until the pins68,70are at or near the top ends of the slots64,66. As the slide rod18is moved proximally and deeper into the channel72, the extensions54,56move deeper into the slots90,91of the main shaft16, and the curved portion50of the slide rod18moves closer to the curved portion of the main shaft80. As the two curved portions50,80moves closer together, the gap92is closed, clamping the periphery96of the implant94between the two curved portions50,80. Thus, the total height of the distal end of the instrument decreases.

The surgeon may then deliver the implant94to the damaged tissue site. If the surgery is an arthroscopic procedure, or a mini-arthrotomy, access to the damaged tissue site may be confined. To prevent the implant94from being damaged by the close confines of the damaged tissue site, the surgeon may use the first illustrated instrument in combination with an implant protector.

One form of implant protector that may be used is an elongate tube as illustrated inFIGS. 18-19. As there shown, the implant protector104comprises a hollow, open-ended tube that is oval-shaped in cross-section. The implant protector104has a slot106extending along its length. In the illustrated embodiment, the slot106is along the top of the tube. To use the instrument10with the implant protector104, the surgeon may place the distal end108of the implant protector at the damaged tissue site, such as in the intra-articular space of the knee near the area where a portion of the meniscus has been removed. The implant protector104is long enough so that its proximal end110is exposed outside of the patient's body.

The surgeon may insert the distal end19of the instrument10, with the implant94captured by the curved portions50,80, into the implant protector104and move the distal end19of the instrument10in a distal direction along the length of the implant protector104until the distal end19of the instrument10and the implant94are at the damaged tissue site beyond the distal end108of the implant protector104. The surgeon may then release the implant94from the instrument10.

To release the implant94from the instrument10, the grip portions28,30of the arms22,24are moved apart. As the grip portions28,30are moved apart, the slide rod18is moved in a distal direction. As the slide rod18moves distally, the extensions54,56move upwardly and distally along the pins68,70and the entire slide rod18moves upward in the channel72. As the slide rod18moves in an upward and distal direction, the curved portion50of the slide rod separates from the curved portion80of the main shaft16, releasing the implant94. The released implant may then be moved into its final position and secured to native tissue.

The surgeon may also use the device disclosed in U.S. patent application Ser. No. 10/609,768 entitled “Implant Stabilizing Instrument, Kit and Method,” filed concurrently herewith by Andrew M. Jacobs, Carolyn K. Day, Rhonda B. Clarke, Herbert E. Schwartz, John W. Kemppainen, Prasanna Malaviya and Anthony D. Zannis, which is incorporated by reference herein in its entirety. The instrument, kit and method disclosed in that patent application may be used to move and stabilize the implant while securing the implant to the native tissue.

It will be appreciated that the instrument10requires little space when in the open or unclamped position. This feature of the invention is particularly advantageous when delivering an implant to a damaged tissue site that is closely confined, such as in the intra-articular space of a joint.

To remove the instrument10from the implant protector104, the instrument may be pulled in a proximal direction until its distal end19is free from the implant protector104outside of the patient's body. Alternatively, the surgeon may raise the instrument so that the main shaft16and slide rod18are raised through the slot106of the implant protector104. Once the main shaft16and slide rod18are clear of the implant protector104, the instrument may be moved out of the patient's body.

Alternative implant protectors can be used with the instrument10. For example, as shown inFIG. 20, an implant protector112can comprise an elongate hollow, open-ended tube of circular cross-section. If desired, the implant protector112can have a slot as in the first illustrated implant protector104.

Another implant protector114is illustrated inFIGS. 21-23. This implant protector114is used in conjunction with the delivery guide20illustrated mounted on the instrument10inFIGS. 1,3,21and22. This implant protector114comprises an elongate guide shaft116and an integral protector118at its distal end120. A portion of the guide shaft116is received in a complementary channel on the top of the delivery guide20to mount the implant protector114to the instrument10. The integral protector118is sized and shaped to substantially surround the curved portions50,80of the instrument and an implant fixed between these curved portions50,80.

All of the implant protectors may be sized to fit through a standard arthroscopic portal. Typical arthroscopic portals have a length of about 8-12 mm. However, the surgical instrument10and implant protectors may also be used in a minimally invasive procedure, such as a mini-arthrotomy, as well as in an open arthrotomy or other orthopaedic surgical procedure. The instruments and protectors could have larger sizes for use in these other procedures. In addition, it should be understood that the present invention is not limited to any particular dimension unless expressly called for in the claims.

It will be appreciated that the structure of the first illustrated instrument10can be modified if desired. For example, parts shown as assembled may be made integral and parts shown as a single element may be constructed as assemblies. In addition, instead of providing curved end portions50,80, the end portions of the main shaft16and the slide rod18can be shaped to correspond with the shape of the implant if the implant is different from that shown in the drawings; for example, the distal ends52,82of the main shaft16and slide rod18could be straight. By following the shape of the inner edge of the implant, the end portions of the main shaft and slide rod protect the inner edge of the implant from potential damage as the implant is introduced to the damaged tissue site.

Another embodiment of a surgical instrument illustrating the principles of the present invention is illustrated inFIGS. 24-32. The second illustrated instrument210includes a handle212at the proximal end214, a main shaft216and a slide arm218. The main shaft216and slide arm218extend from the handle212to the distal end219of the instrument210.

The handle212of the second illustrated instrument210includes two arms222,224connected together at a pivot226. Each arm222,224includes a grip portion228,230that the surgeon squeeze to pivot the arms about pivot226. As the grip portions228,230are brought closer together, the slide arm218is moved from an open or unclamped position, shown inFIGS. 24-25,29and31, to a closed or clamped position, shown inFIGS. 26-27,30and32.

One arm224is integral with the main shaft216of the instrument210. The other arm222is integral with the slide arm218of the instrument210. When the grip portions228,230of the arms222,224are squeezed together, the top portion of the arm222and the integral slide arm218are moved in a generally distal direction. When the grip portions228,230are released, a spring mechanism232urges the arms222,224and the integral main shaft216and slide arm218to the open or unclamped position shown inFIGS. 24 and 25.

The slide arm218of the second illustrated instrument210has a distal end252illustrated in side elevation inFIG. 28. As there shown, the distal end252is tapered in side elevation. The height of the distal end252of the slide arm218gradually increases in the proximal direction. The top surface235of the distal end252of the slide arm218defines an angle α with the bottom surface237of the distal end252of the slide arm218.

The main shaft216of the second illustrated instrument210has a distal end282that is smoothly curved, or bull-nosed in shape. The distal end282is shaped to define an enlarged well283that may receive part of an implant. The well283is open at its top facing the bottom surface237of the slide arm218. The well283may be sized and shaped so that a substantial part of the implant is received within the well283.

The minimum vertical distance between the bottom surface237of the slide arm218and the top surface285of the main shaft216surrounding the well283is shown inFIG. 29at d1. Generally, distance d1is greater than the thickness of the implant. Also as shown inFIGS. 24-25and29, a substantial part of the well283is exposed or uncovered when the instrument210is in the open or unclamped position.

In contrast, when the instrument210is placed in the closed or clamped position, the minimum vertical distance between the bottom surface237of the slide arm218and the top surface285of the main shaft216surrounding the well283decreases substantially to the distance shown at d2inFIG. 30. Generally, distance d2is equal to or slightly less than the thickness of the implant. Also as shown inFIGS. 26-27and30, when a substantial part of the well283is covered by the distal end252of the slide arm218when the instrument210is in the closed or clamped position.

Thus, as shown inFIG. 31, when the instrument210is in the open or unclamped position, the implant294rests loosely on and in the well283at the distal end282of the main shaft216and the implant is substantially uncovered. When the instrument210is in the closed or clamped position a shown inFIG. 32, part of the implant294is secured or squeezed between the bottom surface237of the slide arm218and the top surface285of the main shaft216and the implant is substantially covered by the distal end of the slide arm218. Only a small part of the periphery of the implant294is exposed. With the instrument210and implant294in the position shown inFIG. 32, the implant294will be substantially protected from damage as it is introduced to the damaged tissue site. The surgeon can use standard surgical procedures to introduce the implant using the second illustrated instrument210, and may use the technique described above using implant protectors like those shown inFIGS. 19 and 20. However, with the second illustrated instrument210, it may not be necessary to use separate implant protectors like those shown inFIGS. 19 and 20since the distal end of the instrument210substantially encloses the implant to protect the implant from damage. In addition, if no implant protector is used, the bull-nose distal end of the second instrument210may be smooth and rounded to prevent cutting or abrasion of native tissue as the bull-nose distal end is moved through native tissue to deliver the implant.

An alternative distal end for the instrument ofFIGS. 24-32is shown inFIGS. 35-38. As there shown, the distal end of the main shaft could be open instead of bull-nosed as in the embodiment illustrated inFIGS. 24-32. The distal surfaces of the distal end of the main shaft may be finished to be smooth with no sharp edges to damage tissue as the instrument is introduced to the damaged tissue site. InFIGS. 35-38, the same reference numbers have been used as inFIGS. 24-32, followed by the letter “a” to indicate thatFIGS. 35-38is an alternative embodiment. The remaining features of the instrument ofFIGS. 35-38may be like those described above for the instrument ofFIGS. 24-32.

With both the first and second illustrated instruments10,210, the distal end52,252of the slide rod or arm18,218is displaced in the proximal-distal direction as the instrument is moved between the open and closed position. In both of these instruments, the gap between the distal end52,252of the slide rod or arm18,218and the distal end82,282of the main shaft16,216decreases as the instrument is closed or clamped. In both of these instruments, the distal end of the slide rod or arm moves between the open and closed positions without pivoting. And in both of these instruments10,210, the maximum distance between the top surface of the distal end of the slide rod or arm and the bottom surface of the distal end of the main shaft can be made to be less than 12 mm so that the instrument can be used in arthroscopic surgery and so that the instrument can be opened to release the implant in a confined space, such as that present in a typical intra-articular site.

If the maximum dimension of the instrument is of less concern, the distal ends of the slide arm and main shaft may be modified from the structures described above. For example, as shown inFIGS. 33-34, a main shaft316could be provided with a distal end382shaped like that of the second instrument210, with a bull-nosed end and an enlarged well383. Instead of comprising a slide member, the top member could comprise a pivotable cover318at the distal end352, connected to one of the arms (not shown) through an actuator cable353and to the main shaft316through a hinge pin317. The design shown inFIGS. 33-34should be suitable to protect the implant from damage as the implant is delivered to the damaged tissue site, since a substantial part of the implant can be received in the well383and since the implant will be substantially covered by the pivotable cover318. In this embodiment, the distal surfaces of the main shaft316and pivotable cover318can be curved and smooth to prevent damage to native tissue as the implant is delivered.

All of the above illustrated instruments10,210can be made of standard materials for surgical instruments. The implant protectors104,112can also be made of standard materials, including surgical grade plastic such as ABS plastic.

Alternative designs for the delivery of implants to damaged tissue sites are disclosed in the following U.S. Patent Applications, filed concurrently herewith and incorporated by reference herein in their entireties: U.S. patent application Ser. No. 10/610,287 entitled “Slide and Kit for Delivering Implants,” filed concurrently herewith by Thomas S. Camino, Anthony D. Zannis, John W. Kemppainen and Herbert E. Schwartz, and U.S. patent application Ser. No. 10/610,288 entitled “Implant Delivery Instrument,” filed concurrently herewith by Anthony D. Zannis, Thomas S. Camino, John W. Kemppainen, Herbert E. Schwartz and Danny E. McAdams.

The present invention is expected to have particular utility in delivering orthopaedic implants to damaged joint sites, although it will be appreciated that the invention has broader applications. For example, the instrument of the present invention can also be used to deliver other types of implants to other damaged tissue sites in the body. The present invention could be used to deliver any type of tissue scaffold, patch, or graft (allograft, autograft or heterograft) to any type of tissue, and the illustrated embodiments may be modified if desired to allow for such use. Unless otherwise expressly limited, the claims should not be construed as being limited to the delivery of orthopaedic implants to damaged joint sites.

While only specific embodiments of the invention have been described and shown, it is apparent that various alternatives and modifications can be made thereto. Those skilled in the art will also recognize that certain additions can be made to the illustrative embodiments. It is, therefore, the intention in the appended claims to cover all such alternatives, modifications and additions as may fall within the true scope of the invention.