AU2008200827B2 - Concave resurfacing prosthesis - Google Patents

Description

Regulalion 3.2 AuSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Concave resurfacing prosthesis The following statement Is a full description of this Invention, including the best method of performing It known to us: 005089168v4 2 CONCAVE RESURFACING PROSTHESIS TECHNICAL FIELD OF THE INVENTION The present invention relates generally to the field of 5 orthopaedics, and more particularly, to a tamp for use in arthroplasty. BACKGROUND OF THE INVENTION There are known to exist many designs for and methods 10 for manufacturing implantable articles, such as bone prostheses. Such bone prostheses include components of artificial joints, such as elbows, hips, knees, and shoulders. An important consideration in the design and manufacture of virtually any implantable bone prosthesis is 15 that the prosthesis has adequate fixation when implanted within the body. Earlier designs of implantable articles relied upon the use of cements such as polymethylmethacrylate (PMMA) to anchor the implant. The use of such cements can have some 20 advantages, such as providing a fixation that does not develop free play or does not lead to erosion of the joining bone faces postoperatively. However, the current trend is to use the cements to a lesser extent because of their tendency to lose adhesive properties over time and the 25 possibility that the cement contributes to wear debris within a joint. Recently, implantable bone prostheses have been designed such that they encourage the growth of hard bone tissue around the implant. Such implants are often 30 implanted without cement and the bone grows around surface 005089168v4 3 irregularities for example, porous structures on the implant. One such implantable prothesis is a shoulder prothesis. During the lifetime of a patient, it may be necessary to 5 perform a total shoulder replacement procedure on a patient as a result of, for example disease or trauma, for example, disease from osteoarthritis or rheumatoid arthritis. In a total shoulder replacement procedure, a humeral component having a head portion is utilized to replace the 10 natural head portion of the arm bone or humerus. The humeral component typically has an elongated intermedullary stem which is utilized to secure the humeral component to the patient's humerus. In such a total shoulder replacement procedure, the natural glenoid surface of the scapula is 15 resurfaced or otherwise replaced with a glenoid component that provides a bearing surface for the head portion of the humeral component. Glenoid components have been designed which include a number of plastic inserts coupled to metal backings. The 20 metal backings are provided to secure the plastic inserts to the glenoid surface of the scapula. Unfortunately, for a variety of reasons, an implant, for example, a shoulder prosthesis, may occasionally need to be revised or have the old implant surgically removed and a 25 new implant positioned where the prior implant had been removed. Such a procedure is called a revision surgery. In total shoulder arthroplasty, failure of the glenoid component is the primary cause for revision surgery. Primary failure modes are premature wear of the articulating 30 surface and loss of fixation.

005089168v4 4 When a failed glenoid component is removed, often the subcondylar plate is damaged or missing along with a large defect in the cancellous bone of the glenoid vault of the scapula. 5 Fixation of a revision glenoid component can be difficult to achieve with a resulting limited bone stock remaining on the glenoid vault of the scapula after the revision surgery has been performed. Often the surgeon has to graft the glenoid defects and convert to a hemi 10 arthroplasty with a prosthetic humeral head articulating on the remaining natural glenoid articulating surface. Attempts to provide for a adequate revision glenoid component for revision surgery have met with less than optimal results. For example, current glenoid prothesis is designs include pegged, finned, interference peg and metal back screw type of glenoid prosthesis. Referring now to FIG. 1, a healthy glenoid fossa 1 which is a portion of the scapula is shown. The healthy glenoid fossa 1 includes a glenoid articulating surface 2 20 positioned on the subcondylar plate 3. The humeral head (not shown) of a healthy humerus rides against the glenoid articulating surface. Referring now to FIG. 2, a glenoid 4 is shown with posterior erosion 5 on the glenoid articulating surface 6. 25 Prior art glenoid components have a generally concave shape with a cylindrical member or peg extending outwardly in a direction opposed to the concave articulating surface. When utilizing a standard glenoid prosthesis to repair a failed glenoid component, the posterior erosion requires 30 that the subcondylar plate be resected or reduced. The 005089168v4 5 subcondylar plate needs to be reamed or resected away to correct the version. As shown in FIG. 3, the standard glenoid prosthesis 7 rests on only cortical bone 8 along the periphery of the 5 glenoid articulating surface. Not only is the support at the cortical bone areas 8 very limited, the support between the cortical bone maybe full of voids 9 which further reduce the ability of the standard glenoid prosthesis to be properly supported. 10 Referring now to FIG. 4, a glenoid 10 is shown after removal of a failed glenoid component. The failed glenoid component resulted in a void in the subcondylar plate and the underlying cancellous bone bed. Referring now to FIG. 5, the failed glenoid of FIG. 4 15 is shown with a standard glenoid prosthesis 11 positioned over the remaining portions 12 of the subcondylar plate. Again with the configuration of FIG. 5, the standard glenoid prosthesis is only supported at the remaining portions 12 of the subcondylar plate. 20 Referring now to FIGS. 6, 7, 8, and 9 various prior art attempts at providing a satisfactory glenoid prosthesis are shown. Referring first to FIGS. 6 and 7, prosthesis 13 and 17 are shown, respectively, for use with PMMA cement. 25 Referring first to FIG. 6, standard glenoid prosthesis 13 is shown positioned over subcondylar plate 14. A series of pegs 15 are positioned through the subcondylar plate 14 into the cement 16 and cancellous bone bed. As can be seen, the prosthesis 13 requires an intact subcondylar plate 14 to 30 properly support the prosthesis 13.

005089168v4 6 Referring now to FIGs. 7 and 7A, a finned glenoid prosthesis 17 is shown. The finned prosthesis 17 includes grooves 19 located on fin 18 of the prosthesis 17. The prosthesis 17 is also used with cement 20. As can be seen, 5 the finned prosthesis 17 also requires a subcondylar plate to properly support the prosthesis 17. Referring now to FIG. 8, a anchor peg prior art glenoid prosthesis 21 is shown. The anchor peg prosthesis 21 includes cement pegs 22 as well as anchor peg 24. The 10 anchor peg 24 may be press fitted for bone ingrowth while the cement pegs 22 are secured to the glenoid articulating surface with cement 23. The anchor peg glenoid 21 also depends on the quality of the subcondylar plate. Referring now to FIG. 9, yet another prior art glenoid 15 prosthesis is shown as a metal backed glenoid with a screw 25. The glenoid prosthesis 25 includes a metal backing 26 that supports a screw 27 that is fitted into scapula 28. The metal backed with screw glenoid prosthesis 25, as shown in FIG. 9, also requires a well preserved subcondylar plate 20 to properly support the prosthesis 25. As can be shown in FIGS. 1 through 9, in many cases the subcondylar plate defects and the underlying cancellous bone defects increase the difficulty in achieving appropriate prosthesis fixation and support. A need, 25 therefore, exists for a glenoid prosthesis for use in a patient with a damaged or missing subcondylar plate. Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment, or any form of suggestion, that this prior art forms part of the common 30 general knowledge in Australia or any other jurisdiction or 2836177_1.DOC 7 that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. 5 SUMMARY OF THE INVENTION In the present invention there is provided a tamp for use in forming grafting material into a cavity in the glenoid vault to prepare the vault for a glenoid component for performing shoulder arthroplasty. The tamp includes a 10 body and a forming portion extending in a first direction from the body. A stop is positioned between the body and the forming portion. There may further comprise a handle extending from the body in a second direction. In one aspect of the present invention the forming 15 portion has a surface shaped to assist in preparing the vault to receive the glenoid component. In a second aspect of the present invention, the forming portion includes a surface thereof shaped to assist in tamping the graft material into a shape to matingly 20 receive the glenoid component. In a third aspect of the present invention, the forming portion includes a surface thereof having a shape matching the glenoid component. The present invention may provide for a glenoid 25 component and system that has fixation to the inside walls of the glenoid vault and provides compressive load support from the remaining glenoid cortical rim. The present invention may provide for a glenoid resurfacing prosthesis with particular application for treatment of posterior 30 erosion and revision applications. For the resurfacing 2836177_1.DOC 8 prosthesis of the present invention, the fixation and stabilization of the prosthetic component may occur inside the glenoid vault. As described herein, a glenoid component system may be 5 provided with multiple variable size variations to accommodate variations in the human anatomy. Glenoid components consist of both concave lateral surfaces for articulation with a prosthetic humeral head and medial body configured for fixation against the inner wall of the to glenoid vault. The rim of the concave articulating surface may be configured to rest against the remaining glenoid cortical rim. The medial body configuration can be of a all polyethylene design for fixation against the inner wall of 15 the glenoid vault with bone cement. It can also be designed with a metal porous coating backing and holes to accept bone screws. The bone screws are used to provide initial fixation until bone ingrowth occurs on the porous surfaces of the metal backing member. Also the prosthesis can be 20 configured to replace lost bone when posterior erosion of the glenoid surface has occurred. The glenoid component may be fitted at least partially into a cavity formed in the glenoid vault. The glenoid component includes a body having a stem portion for 25 inserting at least partially into the cavity formed in the glenoid vault. The stem portion cooperates with the interior wall of the cavity formed in the glenoid vault. The body has a bearing portion for articulating cooperation with the prosthetic humeral component.

2836177_1.DOC 9 As also described herein, a method for providing shoulder arthroplasty. The method includes the steps of resecting a glenoid vault, providing a tool for forming a cavity in the glenoid vault, forming a cavity in the glenoid 5 vault with the tool, providing a glenoid prosthetic component for at least partially fitting into the cavity in the glenoid vault, and implanting the glenoid prosthetic component in the cavity. The technical advantages of the present invention may to include the ability to provide a glenoid prosthesis that does not depend upon the condition of the patient's subcondylar plate. For example, a glenoid prosthesis may be provided which substantially fills the glenoid vault and provides complete support under the articulating surface of 15 the glenoid prosthesis. Thus, the present invention may provide for improved support of the glenoid prosthesis independent of the condition of the subcondylar plate. Another technical advantage of the present invention may be the ability to provide for an effective glenoid 20 prosthesis when the cortical walls of the glenoid vault are severely damaged. For example, the prosthesis may include metal walls that substitute for a portion of the cortical walls of the glenoid vault. Yet another technical advantage of the present 25 invention may be the ability to provide for a glenoid prosthesis when the cancellous bone in the glenoid vault has voids. For example, the glenoid vault is cleaned and removed of cancellous bone. The glenoid vault then is filled with a combination of bone graft and/or cement, and a 2836177_.DOC 9a prosthesis, as described herein that fills a substantial portion of the glenoid vault is implanted. Thus, the present invention may provide for a glenoid prosthesis to be used where the glenoid vault includes voids of cancellous 5 bone.

005089168v4 10 Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, descriptions and claims. 5 BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in connection with the accompanying drawings, in which: 10 FIG. 1 is a top view partially in cross section of a healthy human glenoid; FIG. 2 is a top view partially in cross section of a human glenoid with posterior erosion; FIG. 3 is a top view partially in cross section of a 15 failed human glenoid; FIG. 4 is a top view partially in cross section of a prior art glenoid component in position on an eroded human glenoid for use with a prosthetic humeral component for use in performing shoulder joint arthroplasty; 20 FIG. 5 is a top view partially in cross section of a prior art glenoid component in position on a failed human glenoid for use with a prosthetic humeral component for use in performing shoulder joint arthroplasty; FIG. 6 is a top view partially in cross section of a 25 prior art cemented pegged glenoid component in position on a human glenoid for use with a prosthetic humeral component for use in performing shoulder joint arthroplasty; FIG. 7 is a top view partially in cross section of a prior art cemented finned glenoid component in position on a 005089168v4 11 human glenoid for use with a prosthetic humeral component for use in performing shoulder joint arthroplasty; FIG. 7A is a medial/lateral view partially in cross section of the FIG 7 finned glenoid component in position on 5 a human glenoid; FIG. 8 is a top view partially in cross section of a prior art non-cemented anchor peg glenoid component in position on a human glenoid for use with a prosthetic humeral component for use in performing shoulder joint 10 arthroplasty; FIG. 9 is a top view partially in cross section of a prior art non-cemented metal backed glenoid component with screw in position on a human glenoid for use with a prosthetic humeral component for use in performing shoulder 15 joint arthroplasty; FIG. 10 is a top view partially in cross section of a one-piece vault fixed glenoid component for use with a prosthetic humeral component for use in performing shoulder joint arthroplasty, the glenoid component closely conforming 20 to the glenoid vault, in accordance with an embodiment of the present invention; FIG. 11 is an end view of the glenoid component of FIG. 10; FIG. 12 is a top view of another embodiment of the 25 present invention in the form of a shoulder prosthesis assembly using the a one-piece vault fixed glenoid similar to that of FIG. 10; FIG. 13 is a top view partially in cross section of a vault fixed (biological and/or cemented) glenoid component 30 with optional screw for use with a prosthetic humeral 005089168v4 12 component for use in performing shoulder joint arthroplasty, in accordance with another embodiment of the present invention; FIG. 13A is a partial top view partially in cross 5 section of the vault fixed glenoid component of FIGURE 13; FIG. 14 is a medial/lateral view of the shoulder prosthesis assembly using the metal backed glenoid of FIG. 13; FIG. 15 is a medial/lateral view of a glenoid vault 10 showing mineralized bone having been positioned in the glenoid cavity with the TAMP of FIGS. 16 and 17; FIG. 16 is a plan view of a tamp for use with the vault fixed (biological and/or cemented) glenoid component of FIGS. 13 and 14; 15 FIG. 17 is an end view of the tamp of FIG. 16; FIG. 18 a top view partially in cross section of a metal backed vault fixed (biological and/or cemented) glenoid component with screw for use with a prosthetic humeral component for use in performing shoulder joint 20 arthroplasty where there is posterior erosion, in accordance with a further embodiment of the present invention; FIG. 19 is an exploded perspective view of a shoulder prosthesis assembly in position in a humerus and a glenoid cavity using the FIG. 18 metal backed vault fixed glenoid 25 component with screw for use in performing shoulder joint arthroplasty where there is posterior erosion; FIG. 20 is a medial/lateral view of a shoulder prosthesis assembly using a resilient one-piece glenoid for cementless application in accordance with yet another 30 embodiment of the present invention; 005089168v4 13 FIG. 21 is a partial perspective view of the glenoid component of FIG. 20; FIG. 22 is an exploded perspective view of the shoulder prosthesis assembly of FIG. 19; 5 FIG. 23 is a partial perspective view of the glenoid component with resilient glenoid vault contacting fingers in accordance with yet another embodiment of the present invention; FIG. 24 is a plan view partially in cross section of a 10 umbrella type mechanically expandable vault fixed (cementless) glenoid component for use with a prosthetic humeral component for use in performing shoulder joint arthroplasty in accordance with yet another embodiment of the present invention; 15 FIG. 24A is a partial plan view of the expander of FIG. 24; FIG. 25 is a plan view partially in cross section of a wedge type mechanically expandable vault fixed (cementless) glenoid component for use with a prosthetic humeral 20 component for use in performing shoulder joint arthroplasty in accordance with a further embodiment of the present invention; FIG. 26 is a partial top view of the expander of FIG. 25; and 25 FIG. 27 is a process flow chart for a method of performing shoulder joint arthroplasty according to an embodiment of the present invention; FIG. 28 is a top view of a template for preparing a resected surface for the implantation of a metal backed 30 glenoid; 005089168v4 14 FIG. 29 is a plan view partially in cross section of the template of Figure 28; and FIG. 30 is a tool for use with the template of FIG 28. 5 DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention and the advantages thereof are best understood by referring to the following descriptions and drawings, wherein like numerals are used 10 for like and corresponding parts of the drawings. According to the present invention (although not presently claimed) and referring now to FIGS. 10 and 11, a glenoid component 100 for use with a prosthesis humeral component 102 for use in shoulder arthroplasty is shown. 15 The glenoid component 100 is fitted at least partially into a cavity 104 formed in the glenoid vault 106 of the scapula 110. The glenoid component 100 includes a body 112 having a stem portion 114 for inserting at least partially into the cavity 104 formed in the glenoid vault 106. The stem 20 portion 114 cooperates with the interior wall 116 of the cavity 104 formed in the glenoid vault 106. The body 112 also includes a bearing portion 120 for articulating cooperation with the prosthetic humeral component 102. The glenoid component 100 may be made of any suitable 25 durable material. For example, the glenoid component 100 may be made of a plastic. For example, the glenoid component 100 may be made of a polyethylene. One particular polyethylene that is well suited for a bearing portion is a high molecular weight polyethylene, for example 30 ultra-high molecular weight polyethylene (UHMWPE). One such 00s089168v4 15 UHMWPE is sold by the assignee of the instant application or MarathonTm UHMWPE and more fully described in US Patents 6,228,900 and 6,281,264 to McKellop incorporated herein in their entireties by reference. 5 The glenoid component 100 may have any suitable shape capable of filling a substantial portion of the cavity 104. The glenoid cavity 104 may vary substantially from patient to patient. Generally, however, the cavity 104 has a generally inverted dome shape and has a generally oval 10 cross-section. Preferable the glenoid component 104 likewise has a oval domed shape to correspondence to that of the cavity 104. For example, referring to FIG. 10, the stem portion 114 of the glenoid component 100 has a generally domed shape with a larger width WT adjacent the bearing 15 portion 112 and a small diameter WB at the stem portion 112 opposed to the bearing portion 120. Referring to FIG. 11, the glenoid component 100 is preferably generally oval with a major diameter MD that is substantially larger than the minor diameter ID. While the 20 glenoid component 110 preferably has a shape similar to that of the cavity 104, it should be appreciated that the glenoid component 100 may completely fill the cavity 104 or the somewhat smaller than the cavity 104. As shown in FIGS. 10 and 11, the glenoid component 100 25 is in intimate contact with the glenoid vault 106 to assist in the secure location of the glenoid component 100. Exact sizing of the glenoid component 100 to the cavity 104 maybe somewhat difficult due to the unique anatomy of every individual. It should be appreciated that a series of 30 glenoid components 100 may be provided for accommodating the 005089168v4 16 most common sizes of the glenoid cavity for various patients. Referring now to FIG. 12, an alternative embodiment is shown as glenoid component 200 for use with humeral 5 component 102. The glenoid component 200 of FIG. 12 is similar to the glenoid component 100 of FIGS. 10 and 11, except that the glenoid component 200 includes a stem portion 214 which is sized relatively smaller than the stem portion 114 of the glenoid component 110 of FIGS. 10 and 11 10 so that cement 250 may be positioned between internal wall 116 of the glenoid vault 106 and stem periphery 252 of the stem portion 214 of the glenoid component 200. The cement 250 may be any suitable cement capable of assisting and securing the glenoid component 200 to the glenoid vault 106. 15 For example the cement may be polymethylmenthacrylate(PMMA). The glenoid component 200 may as shown in FIG. 12 be an integral component such as glenoid component 100 and may, for example be made of a plastic for example high molecular weight polyethylene or ultra high molecular weight 20 polyethylene. The glenoid component 200 includes a body 212 having a stem portion 214 and a bearing portion 220. The use of the cement 250 permits the use of a common glenoid component 200 for varying sizes of the glenoid vault. Referring now to FIGS. 13, 13A, and 14, another 25 embodiment is shown as glenoid component 300. Glenoid component 300 is similar to the glenoid component 200 except that the glenoid 300 further includes a support layer 354 surrounding a portion of body 312 of the glenoid component 300.

oo5o89168v4 17 The glenoid component 300 includes a body 312 having a stem portion 314 and a bearing portion 320. The support layer 354 extends outwardly from stem periphery 352 of the stem portion 314 of the body 312 of the glenoid component 5 300. As shown in Figure 13, the support layer 354 may include a lip 353 which extend outwardly from the distal end of the support layer 354. The lip 353 rests on cortical wall 355 and provides support for the glenoid component 300. The support layer 354 may be made of any suitable durable 10 material and may be made as a metal compatible with the human anatomy, for example, a cobalt chromium alloy, a stainless stell alloy or a titanium alloy. Support layer periphery 360 of the support layer 354 may, as shown in FIG. 13, be in intimate contact with inner 15 wall 116 of the glenoid vault 106. The support layer periphery 360 may include a porous coating 362 to assist in the bone ingrowth of the glenoid component 300 to the glenoid vault 106. The coating 362 may be any suitable porous coating and 20 may for example be Porocoat@, a product of the assignee of the instant application and more fully described in US Patent 3,855,638 to Pilliar hereby incorporated by reference in its entireties. As shown in FIG. 13, the glenoid component 300 may 25 further include a fastener 364 in the form of, for example, a screw. The screw 364 may be any screw capable of assisting and securing the glenoid component 300 to the glenoid vault 106. For example, the screw 364 may be in the form of a cortical 30 screw, for example, a cortical screw available from DePuy 005089168v4 18 Orthopaedics, Inc. the Assignee of the instant application. One such cortical screw is DePuy Ace catalog number 8150-36 030. The screw 364 has a diameter SD of sufficient diameter 5 to properly secure the glenoid component 300 to the glenoid vault 106 and may, for example, have a diameter SD of about two to five millimeters. The screw 364 may have any suitable length capable of properly securing the glenoid component 300 to the glenoid vault 106 and reaching 10 sufficient bone in the scapula 110 to properly secure the glenoid component 300. For example, the screw 364 may have a length of SL of from 10 to 60 millimeters. The screw 364 may be secured to the glenoid component 300 in any suitable fashion and may, as shown in FIG. 13, be 15 secured to the support layer 354 of the glenoid component 300. The support layer 354 may include an opening 366 through which the screw 364 partially passes. The support layer 354 may be secured to the body 312 in any suitable manner. For example, the support layer 354 may 20 be bonded to the body 312. For example, the support layer 354 could be made of polyethylene and compression molded to the body 312. Alternately the support layer 354 may be glued to the body 312 by, for example, an adhesive. Alternatively the support layer 354 may be mechanically 25 interlocked to the body 312. For example, the support layer 354 may include surface features, for example, ribs (not shown)or perhaps a porous coating to mechanically interlock the support layer 354 to the body 312. Alternatively and as shown in FIGS. 13 and 13A, the 30 glenoid component 300 may include a locking feature 370.

ooso8918v4 19 The locking feature 370 may have any shape capable of mechanically locking the support layer 354 to the body 312. For example, the support layer 354 may include a lip 372 that forms a groove 374 in the support layer 354. The body 5 312 may include a protrusion 376 that matingly fits with the groove 374 to secure the body 312 and the support layer 354 to each other. It should be appreciated that the protrusion 376 may be in the form of separate spaced- apart detents or may be in the form of a circular ring. 10 When installing the glenoid component 300, the support layer 354 is first placed in the glenoid vault 106 and the screw 364 is positioned through the opening 366 and engages the scapula 110. After the screw 364 is fully inserted, the body 312 may be placed into the support layer 354 with the 15 protrusion 376 being snapped into the groove 374 of the support layer 354. As shown in FIG. 13 when viewing the glenoid vault 106 from above, the support layer 354 may closely conform to the glenoid vault 106. Further, when viewing the glenoid 20 component 300 and the glenoid vault 106 in the medial lateral view of FIG. 14, the glenoid vault 106 curves inwardly in the proximal direction with a shape that could be described as that of a wine glass.. During the revision shoulder arthroplasty surgery, the 25 cancellous bone within the cavity 104 is generally removed and the glenoid cavity 104 is cleaned to the inner wall 116 of the glenoid vault 106. It is thus desirable to support the glenoid component 300 between the support layer 354 and the inner wall 116 of the glenoid vault 106. A material 30 suitable for supporting the glenoid component 300 is 005089168v4 20 preferably positioned in the glenoid vault 106. Such a material is graft mineralized bone fragments that are commercially available or created from the patient's available bone. 5 Continuing to refer to FIG. 14, the cavity 104 between inner wall 116 of glenoid vault 106 and body support layer surface 380 of the support layer 354 of the glenoid component 300 is preferably filled with a mineralized bone graft material 382. 10 Referring now to FIG. 15, the glenoid vault 106 is shown with the mineralized bone graft material 382 in position in the cavity 104. The mineralized bone graft material 382 is preferably positioned with an outer contour 384 that conforms to the body support layer surface 380 of 15 the glenoid component 300. Referring now to FIGS. 16 and 17, an embodiment of the present invention is shown as tamp 386. The tamp 386 is for use in forming the grafting material 382 (see FIG. 15) into the cavity 104 of the glenoid vault 106 to prepare the vault 20 106 for the glenoid component 300 for performing shoulder arthroplasty. The tamp 386 includes a body 390. The body 390 may have any suitable shape and may as is shown in FIGS. 16 and 17 have a generally cylindrical elongated shape. The tamp 25 386 further includes a forming portion 392 extending in a first direction from the body 390. The forming portion 392 includes a surface 394 of the forming portion 392 that is shaped to receive the glenoid component 300 (see FIGS. 13 and 14). Preferably, the outer surface 394 of the forming 30 portion 392 has a shape that is substantially similar to 005089168v4 21 that of the outer surface 380 of the glenoid component 300 (see FIG. 14). As shown in FIGS. 16 and 17, the tamp 386 may further include a handle 396 which may be located opposed to the 5 forming portion 392. The handle 396 may serve to provide a place to hold the tamp 386 when it is being used to position and tamp the graft material 382. Further, the handle 396 may include a surface 398 for striking the tamp 386 to properly secure the graft material 382. The tamp 386 may 10 further include a stop 399 positioned between the body 390 and the forming portion 392. The stop 399 may be used to limit the motion of the tamp 386 and to provide for an accurate shape of the graft material 382 by resting the stop 399 against the glenoid vault 106. 15 While the forming portion 392 may have any suitable shape, the forming portion 392 preferably conforms to the shape of the glenoid component 300. While the glenoid component 300 may be circular, preferably to conform to the shape of the glenoid vault 106, the glenoid component 300 is 20 generally oval. Therefore, as shown in FIGS. 16 and 17, the forming portion 392 has an outer periphery 394 that is generally oval. The tamp 386 may be made of any suitable durable material and may, for example, be made of a titanium alloy, 25 a cobalt chromium metal alloy, or a stainless steel alloy. The tamp 386 may be integral or may be made of various components which are mechanically interlocked to each other. Referring now to FIGS. 18 and 19, another embodiment is shown as glenoid component 400. Glenoid component 400 is 30 similar to glenoid component 300 of FIGS. 13 and 14 except 005089168v4 22 that glenoid component 400 is designed to accommodate those patients in whom at least a portion of the glenoid vault 106 is damaged or missing. Referring now to FIG. 19, the glenoid vault 106 of the 5 scapula 110 is shown having a void 165 in the vault periphery 167 of the glenoid vault 106. A purpose of the glenoid component 400 is to replace at least a portion of the void 165 in the vault periphery 167. The glenoid component 400 thus includes a vault replacement portion 475. 10 The vault replacement portion 475 extends downwardly from bearing portion 420 of the glenoid component 400. The vault replacement portion 475 extends from bearing portion periphery 421 of the bearing portion 420 of the glenoid component 400. The outer surface 477 of the vault 15 replacement portion 475 extends from the bearing portion periphery 421 and is aligned with vault periphery 167 of the glenoid vault 106. In order to provide a glenoid component 400 that is commercially available, the glenoid component 400 includes a 20 vault replacement portion 475 that has a vault replacement portion edge periphery 479 that is smaller and extends within edge periphery 169 of the void 165 in the glenoid vault 165. The glenoid component 400 includes the bearing portion 420 that is similar to the bearing portion 320 of 25 the glenoid component 300 of FIGS. 13 and 14. The bearing portion 420 mates with the humeral head 132 of the humeral component 102. The glenoid component 400 also includes a body 412 that is similar body 312 of the glenoid component 300 of 30 FIGS. 13 and 14. The body 412 also includes a stem portion 005089168v4 23 414 that is similar to stem portion 314 of the bearing component 300 of FIGS. 13 and 14, except that the stem portion 414 further includes the vault replacement portion 475. 5 To accommodate the space between the void 165 in the glenoid vault 106 and the vault replacement portion 475, the gap 157 between the vault replacement portion 475 and the glenoid vault 106 may be filled with, for example, graft material 482 similar to the graft material 382 of the 10 glenoid component 300 of FIGS. 13 and 14. Referring again to FIG. 18, the glenoid component 400 includes, in addition to the body 412, a support surface 454 similar to the support layer 354 of the glenoid component 300 of FIGS. 13 and 14, except that the support layer 454 15 does not extend into the vault replacement portion 475 of the body 412. The glenoid component 400 may further include a screw 464 similar to the screw 364 of the glenoid component 300 of FIGS. 13 and 14. The screw 464 may be secured to the 20 support layer 454 by means of, for example, a screw head 465 which mates with the support layer 454 of the glenoid component 400. The screw 464 passes through opening 466 in the support layer 454. The screw 464 is similar to the screw 364 of the glenoid component 300 of FIGS. 13 and 14. 25 The body 412 may be made of any suitable material and may for example be made of materials similar to that of the body 312 of the glenoid component 300 of FIGS. 13 and 14. The body 412 may be secured to the support layer 454 in any suitable method and may, for example, be secured in a method 30 similar to that of the glenoid component 300 and may, for 005089168v4 24 example, include a locking feature 470 similar to the locking feature 370 of the glenoid component 300. While the vault replacement portion 475 of the glenoid component 400 of FIGS. 18 and 19 may be a portion of the 5 body 412 and be made of, for example, a plastic, it should be appreciated that the vault replacement portion 475 may be a part of the support layer 454. Referring now to FIGS. 20, 21 and 22, another embodiment is shown as glenoid component 500. Glenoid 10 component 500 is similar to glenoid component 100 of FIGS. 10 and 11 except that glenoid component 500 includes a resilient integral portion 507 which is conformable to be positionable within the glenoid vault 106 and expands on being positioned in the glenoid vault 106 to conform to the 15 inner walls 116 of the glenoid vault 106. As shown in FIG. 20, the glenoid component 500 includes a body 512, which body 512 includes a stem portion 514 and a bearing portion 520. The bearing portion 520 is similar to the bearing portion 120 of the glenoid component 100 of 20 FIGS. 10 and 11. The stem portion 514 includes a resilient integral portion 507 that expands to conform to the inner walls 116 of the glenoid vault 106. The resilient integral portion 507 may, as shown in FIG. 20, be in the form of a lip 507. 25 Referring now to FIG. 22, the glenoid component 500 is shown positioned between the prosthetic humeral component 102 and the glenoid vault 106. The bearing portion 520 of the glenoid component 500 mates with head 132 of the prosthetic humeral component 102. The lip 507 of the 005089168v4 25 glenoid component 500 is shown in solid in a relaxed position 511 and in phantom in a constrained position 513. When in the constrained position 513, the lip 507 has a constrained diameter CD.that is equal to or smaller than 5 the vault diameter VD of the glenoid vault 106. Therefore, the stem portion 514 of the glenoid component 500 can be positioned in the glenoid cavity 104 of the scapular 110. Upon insertion into the glenoid cavity 104, the lip 507 returns to the relaxed diameter RD that is larger than the 10 vault diameter VD of the glenoid cavity 104. Thus, the glenoid component 500 is constrained within the glenoid vault 106. The glenoid component 500 may be made of any suitable durable material and may, as shown in FIGS. 21 and 22 be 15 integrally molded of a plastic. For example, the glenoid component 500 may be made of a polyethylene, for example ultra-high molecular weight polyethylene. It should be appreciated that the stem portion 514 may include one or more slit 521 to permit the stem portion 514 to have greater 20 flexibility to permit the expansion and contraction of the lip 507 to fit within the glenoid vault 106. Referring now to FIG. 21, the lip 507 is shown in greater detail. The lip 507 has a relaxed diameter RD that is larger than the stem diameter SD of the stem 514 of the 25 glenoid component 500. Referring now to FIG. 23, an alternate embodiment is shown as glenoid component 600. Glenoid component 600 is similar to glenoid component 500 of FIGS. 20, 21 and 22, except that glenoid component 600 includes a plurality of 30 fingers 607 which serve the purpose of the lip 507 of the 005089168v4 26 glenoid component 500. The glenoid component 600 thus includes a body 614 which includes a bearing portion 620 similar to the bearing portion 520 of the glenoid component 500 of FIGS. 20, 21 and 22, as well as a stem portion 614 5 which is different than the stem portion 514 of the glenoid component 500 of FIGS. 20, 21 and 22 in that the stem portion 614 includes the fingers 607. Under the present invention and referring now to FIG. 24, another embodiment is shown as glenoid component 700. 10 The glenoid component 700 is similar to the glenoid component 300 of FIGS. 13 and 14 except that the stem component 714 is in the form of an expander 740. The glenoid component 700 includes a body 712, which includes a stem portion 714 and a bearing portion 720. 15 The bearing portion 720 may be integral with the body 712 or, as shown in FIG. 24, the bearing component 720 may be a separate component. If the body 712 and the bearing component 720 are made of a integral component, the body 712 is preferably made of a plastic, for example ultra-high 20 molecular weight polyethylene. It should be appreciated, however, that the body 712 may likewise be made of a durable metal compatible with the human body. If the body 712 and the bearing component 720 are made of separable components as shown in FIG. 24, the body 712 is 25 preferably made of a metal. For example, the body 712 may be made of a cobalt chromium alloy, a titanium alloy, or a stainless steel alloy. The bearing component 720, if made of a separable component, is preferably made of a plastic, for example an ultra-high molecular weight polyethylene.

005089168v4 27 A locking feature 770 that is similar to the locking feature 370 of the glenoid component 300 of FIGS. 13 and 14 may be used for securing the bearing portion 720 to the body 712. The expander 470 is operably connected to the body 712 5 through, for example, a opening 766 in the body 712. The expander 740 is positioned at least partially within the cavity 104 of the glenoid vault 106. A portion of the expander 740 may be urged against inner walls 116 of the glenoid vault 106. The expander 740 may, as shown in 10 FIG. 24, include a screw 764 that is fitted through opening 766 in the body 712. The screw 764 may be any commercially available bone screw similar to bone screw 364 of the glenoid component 300 of FIGS. 13 and 14. The screw 764 engages cortical bone in the scapula 110. 15 The screw 764 is threadably secured to a tube 768 at threaded end 772 of the tube 768. The tube 768 is in clearance with the screw 764 on bearing end 774 of the tube 768. Longitudinal slits 776 are formed in the tube 768 and form staves 778 between the threaded end 772 and the bearing 20 end 774 see (FIG. 24A). Referring again to FIG. 24, the staves 778 have crimped portions 780 equidistant from the bearing end 774 and the threaded end 772. The crimped portions 780 separate upper stave portions 782 from lower stave portions 784. As the 25 threaded end 772 is moved upwardly in the direction of arrow 786, the staves 778 are bent with the upper stave portion 782 and the lower stave portions 784 forming an angle a there between. When the glenoid component 700 is positioned in vault 30 106, the screw 764 is rotated causing the screw 764 to oo5o89168v4 28 engage the scapula 110 and causing the threaded end 772 of the tube 768 to move in the direction of arrow 786 causing the crimped sections 780 of the staves 778 to move in the direction of arrows 788 toward inner walls 116 of the 5 glenoid vault 106, thereby securing the glenoid component 700 to the glenoid vault 106. The tube 768 may be made of any suitable durable material and may, for example, be made of a flexible metal compatible with the human body, for example a titanium 10 alloy. It should be appreciated that the tube 768 may be made of a stainless steel alloy or a cobalt chromium alloy. Referring now to FIGS. 25 and 26, another embodiment is shown as glenoid component 800. Glenoid component 800 is 15 similar to glenoid component 700 of FIG. 24. For example, the glenoid component 800 includes a body 812 similar to the body 712 of the glenoid component 700 of FIG. 24. Further, the glenoid component 800 includes a bearing portion 820 similar to the bearing portion 720 of the glenoid component 20 700 of FIG. 24. The glenoid component 800 also includes a stem portion 814. The stem portion 814 is similar to the stem portion 714 of the glenoid component 700 in that the stem portion 814 includes an expander 840, similar to the stem portion 714 including an expander 740. 25 The expander 840 is somewhat different than the expander 740 of the glenoid component 700. The expander 840 includes a screw 864 similar to the screw 764 of the glenoid component 700. The expander 840 also includes a wedge shaped nut 868. The wedge-shaped nut 868 has a clearance 30 fit to the screw 864. The wedge-shaped nut 868 includes a 005089168v4 29 wedge-shaped outer periphery 870 that is threadably engaged with a spider 872. The spider 872 includes a series of spaced apart bars 874 which include outer edges 876 that engage inner walls 5 116 of the glenoid vault 106. The spider 872 further includes an inner band 878 that is threadably engaged with the outer periphery 870 of the wedge-shaped nut 868. As the screw 864 is rotated to engage the cortical bone of the scapula 110, shoulder 179 of screw 864 engages top 10 869 of nut 869. Upon contact by the screw 864, the wedge shaped nut 868 is advanced in the direction of arrow 880, causing the bars 874 to advance outwardly in the direction of arrow 882 until the outer periphery 876 of the bars 874 engage the inner walls 116 of the glenoid vault 106. 15 The wedge-shaped nut 868 and the spider 872 may be made of any suitable durable material that is compatible with the human body. For example, the spider 872 and the wedge shaped nut 868 may be made of a titanium alloy, a cobalt chrome alloy, or a stainless steel alloy. 20 Referring now to FIG. 27, surgical procedure 900 is shown. The surgical procedure 900 includes a first step 910 of resecting a glenoid vault. The procedure 900 further includes a second step 920 of providing a tool for forming a cavity in the glenoid vault. The surgical method 900 25 further includes a third step 930 of forming a cavity in the glenoid vault with a tool. The method 900 further includes a fourth step 940 providing a glenoid prosthetic component for at least partially fitting into the cavity in a glenoid vault. The method 900 further includes a fifth step 950 of 30 implanting the glenoid prosthetic component in the cavity.

005089168v4 30 Referring now to FIGS. 28 and 29, a template 1010 is shown for preparing the edge 1020 of the cortical bone of the glenoid vault 106. Such a template is particularly useful in connection with the use of the glenoid component 5 400 of FIG. 18 to prepare edge 473 when a portion of the cortical wall has been lost. The template includes a pilot portion 1030 which mates with the inner wall of the glenoid vault 106 and serves to position the template with respect to the vault 106. The template 1010 also includes a guiding 10 groove 1040 that guides a tool 1050 as it removes bone from the edge 1020 of the glenoid vault 106 to provide a surface for proper support of the glenoid component. The tool 1050 may for example be translated along groove 1040 in the direction of arrow 1060 from first position 1070 as shown in 15 phantom to second position 1080 as shown in solid and then to third position 1090 as shown in phantom. The template 1010 may be made of any suitable durable material that may be sterilized and may, for example, be made of a metal, for example, cobalt chromium alloy, a 20 titanium alloy or a stainless steel. Referring now to FIG. 30 the tool 1050 is shown in greater detail. The tool 1050 may include a cutting surface 1100 for cutting the bone. The tool 1050 may also include a stop 1110 for limiting the travel of the tool along its 25 longitudinal axis. The tool 1050 may also include a shank 1120 for connection with a power tool (not shown). The tool 1050 may be made of any suitable durable material that may be sterilized and may, for example, be made of a metal, for example, a steel alloy, a titanium 30 alloy or a stainless steel. The cutting surface 1100 may be 31 made of a separate material that has improved wear properties such as carbide or diamond. Although the present invention and its advantages have been described in detail, it should be understood that 5 various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the present invention as defined by the appended claims. As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, 10 such as "comprising", "comprises" and "comprised", are not intended to exclude other additives, components, integers or steps.

Claims (21)

1. A tamp for use in forming grafting material into a cavity in a glenoid vault to prepare the vault for a glenoid component for performing shoulder arthroplasty, said tamp 5 comprising: a body; a forming portion extending in a first direction from said body, said forming portion including a surface thereof shaped to assist in preparing the glenoid vault to receive 10 the glenoid component; and a stop positioned between the body and the forming portion.

2. The tamp of claim 1, wherein the surface of said forming portion has a shape substantially similar to a 15 surface of the glenoid component.

3. The tamp of claim 2, wherein said body has a generally cylindrical elongated shape.

4. The tamp of claim 2, further comprising a handle extending from said body in a second direction opposed to 20 the first direction.

5. The tamp of claim 4, wherein said handle further includes a striking surface for striking the tamp, the striking surface being perpendicular to a longitudinal axis of said handle. 33

6. The tamp of claim 2, wherein the surface of said forming portion has an oval shape.

7. The tamp of claim 2, wherein said body and said forming portion are integral with each other. 5

8. A tamp for use in forming grafting material into a cavity in a glenoid vault to prepare the vault for a glenoid component for performing shoulder arthroplasty, said tamp comprising: a body; 10 a forming portion extending in a first direction from said body, said forming portion including a surface thereof shaped to assist in tamping the graft material into a shape to matingly receive the glenoid component; a handle extending from said body in a second direction 15 opposed to the first direction; and a stop positioned between the body and the forming portion.

9. The tamp of claim 8, wherein the surface of said forming portion has a shape substantially similar to a 20 surface of the glenoid component.

10. The tamp of claim 8, wherein the surface of said forming portion has an oval shape.

11. The tamp of any one of claims 8 to 10, wherein said body has a generally cylindrical elongated shape. 34

12. The tamp of any one of claims 8 to 11, wherein said handle further includes a striking surface for striking the tamp, the striking surface being perpendicular to a longitudinal axis of said handle. 5

13. The tamp of any one of claims 4 to 12, wherein said body, said forming portion, and said handle are integral with each other.

14. A tamp for use in forming grafting material into a cavity in a glenoid vault to prepare the vault for a glenoid LO component for performing shoulder arthroplasty, said tamp comprising: a body; a forming portion extending in a first direction from said body, said forming portion including a surface thereof 15 having a shape matching the glenoid component; a handle extending from said body in a second direction opposed to the first direction; and a stop positioned between the body and the forming portion. 20

15. The tamp of claim 14, wherein said forming portion has a generally inverted dome shape including a generally oval cross-section.

16. The tamp of claim 14, wherein said forming portion has a continuously decreasing width in a direction opposed to 25 said handle. 35

17. The tamp of claim 14, wherein said body has a generally cylindrical elongated shape.

18. The tamp of claim 14, wherein said handle further includes a striking surface for striking the tamp, the 5 striking surface being perpendicular to a longitudinal axis of said handle.

19. The tamp of claim 14, wherein the surface of said forming portion has an oval shape.

20. The tamp of claim 14, wherein said body, said forming 10 portion, and said handle are made of a material selected from the group including a titanium alloy, a cobalt chromium alloy, and a stainless steel alloy.

21. A tamp substantially as described herein with reference to Figures 16 and 17 of the accompanying drawings.