JPH0614943B2 - Artificial prosthetic implant and method of constructing the same - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to prosthetic implant devices, and more particularly to such implants having a porous surface thereon. The present invention is particularly, but not exclusively, suitable for use as a femoral component for a hip prosthesis.

[Conventional technology]

To date, various types of porous surfaces have been incorporated into prosthetic implants. Such porous implants are often implanted without the use of any type of bone cement material, which results in the porous surface coming into direct contact with the surface of the bone. After a period of time, bone ingrowth has occurred at and around the porous surface, allowing the implant to be biologically affixed or further affixed to the bone. In addition, implants having a porous surface are implanted with an osteosynthesis agent such that penetration of the osteosynthesis agent into the porous surface of the prosthesis enhances fixation of the prosthesis. There is.

The following U.S. patents disclose prosthetic implants that include various types of porous surfaces.

U.S. Pat. No. 3,906,550 to Rostoker et al. Discloses a porous fiber metallographic structure adapted for attachment to prosthetic devices. This fiber metal material is directly formed into a desired precise shape by using a die or a punch.

U.S. Pat. No. 4,479,271 to Bolesky et al. Discloses a prosthesis that includes a porous surface that is molded and immediately pressed into the required shape or compressed and immediately cut into the required shape.

U.S. Pat.No. 4,536,894 to Galante et al. Discloses an artificial prosthesis that includes a porous surface that is compressed, cut directly into the desired shape, and adhered to a substantially flat surface. It is a porous pad.

U.S. Pat.No. 4,570,271 to Sump discloses an artificial prosthesis having a porous surface, the porous coating being directly preformed into a desired shape to match the preselected surface of the prosthesis. It is something. The preformed porous coating is then overlaid on the preselected surface, compressed and heated to adhere the preform to the prosthesis. This preforming is carried out by known multi-layer knitting, braiding, winding, weaving, or other continuous wire manufacturing method.

U.S. Pat. No. 4,589,883 to Kenna discloses a prosthesis that includes a porous surface and the porous coating is composed of spherical particles that appear to be in direct contact with the prosthesis mandrel.

U.S. Pat. No. 4,636,219 to Pratt et al. Discloses a prosthesis that includes a porous surface composed of a layered metal network. This net is a thin substrate (0.010 to 0.012 inches,
This thin substrate is then cut or formed and applied to the body of the prosthesis on a flat surface as shown in FIG. 3 of the Pratt et al. Patent. Alternatively, it is made into a specific shape by a process such as creep.

U.S. Pat. No. 4,660,755 to Farling is adhered to a substrate via electrodes when the porous layer is in the absence of a furnace. A method of constructing a surgical implant is disclosed.

Ducheyne's UK patent application GB 20 59267A discloses a type of porous metal wire mesh suitable for use in prostheses.

British patent application GB 2142 830A to Brown et al. Discloses an artificial prosthesis having a porous surface obtained by perforated microfabricated sheets.

Ducheyne's European Patent Application EP 0 178 650 A2 relates to an artificial prosthesis in which an osteosynthesis agent is placed between the implant and the porous pad material and one or more porous pad materials are pressed against the surface of the bone. Discloses a pad flexible metal fiber material for implantation.

[Problems to be Solved by the Invention]

SUMMARY OF THE INVENTION The primary object of the present invention is a prosthetic implant that includes a porous pad separate from the prosthetic mandrel, the porous pad being adapted to be wrapped around for attachment to the prosthetic mandrel. Is to provide.

Another object of the invention is to provide a prosthetic implant that includes a porous pad separate from the fixed surface substrate portion, such that the porous pad has a first preliminary preformed shape. Is. The porous pad is adapted to be wrapped around the fixed surface substrate portion such that it has a second final shape that matches the shape of the fixed surface substrate portion wrapped around it.

Yet another object of the invention is to provide such a prosthetic implant in which the pad is wrapped around at least two adjacent sides.

Yet another object of the present invention is a method of wrapping a porous pad around a prosthesis mandrel, the pad being subsequently wrapped around the mandrel for a second final shape for attachment to the mandrel. To provide a method of wrapping a porous pad having a first preliminary substantially flat preformed shape that becomes.

[Means for Solving the Problems]

The present invention achieves the above objects and is therefore preformed in a first shape and is wrapped and / or formed around the mandrel of the implant to conform to the shape of the implant in the second final shape. An artificial prosthetic implant is provided that includes a quality pad. The pad is then glued to the mandrel. The present invention further provides a method for providing a porous pad and conveniently winding the pad around the mandrel.

These and other features and objects of the present invention, as well as other features and objects, will be apparent to those skilled in the art by reference to the accompanying drawings.

〔Example〕

1 to 13 show a particularly advantageous embodiment of the prosthetic implant according to the invention. The present invention has been described and shown as being particularly suitable for the femoral component 10 of a hip prosthesis. However, it is understood that the principles of the present invention are compatible with other implants having elongated fixed mandrels. further,
For reference, the specific thigh component 1 described here
0 is configured as a right femoral implant, but a corresponding femoral component as a left femoral implant (not shown)
Can be seen to be a mirror image of the femoral component shown as the right femur.

The femoral component 10 of FIGS. 1-6 includes a distal end 12 and a continuous end 14. As is well known,
The femoral component 10 is adapted to fit within the intramedullary canal of the femur (not shown) such that its continuous end extends outwardly from the intramedullary canal of the femur and is carried by the continuous end 14. Through a ball or the like to cooperate with the acetabulum or acetabular prosthesis component. The end portion 16 can include a plurality of longitudinally extending grooves 18. Base 24
Is the porous surface or pad 2 surrounding the thigh component 10.
Includes 6. The distal portion 16 and the base 24 comprise the mandrel portion of the femoral component 10. Neck 28 is base 2
4 to carry a ball 30 shown in phantom in FIG. The opening 31 near the neck 28 is
It accepts a removal tool when it is necessary to remove this femoral component 10 from the intramedullary canal. The porous pad 26 passes through the adjacent smooth surface of the base 24 to about 0.
It is designed to extend outwardly from this base 24, although in a small range of 5 mm.

Figures 2, 3 and 4 show the front chamfer 3 of the thigh component.
2, the chamfer is adapted to avoid the distal end 12 from colliding with the bone surrounding the intramedullary canal in that position.

As shown in FIGS. 1 to 4, the base 24 includes a lateral side surface 34, a rear side surface 36, an intermediate side surface 38, and a front side surface 4.
Contains 0. The porous pad 26 is wrapped around the base 24 of the mandrel portion 20 as shown in FIGS. The pad 26 is adapted to be pre-compressed into a first shape and subsequently wrapped around the mandrel portion 20 to a second shape that matches the shape of the mandrel portion 20. It is formed of any suitable porous material. One of these suitable materials is Rostoker and Ga
The fibrous metal texture disclosed in U.S. Pat. No. 3,906,550 to Lante, Rostoker et al., which was subsequently wrapped around a prosthetic implant to obtain the second final shape of the invention. It teaches that the fibrous metal material is formed directly into the desired shape, rather than obtaining a first preformed shape that is applied or formed. It will be appreciated that any suitable porous material adapted to be practiced in accordance with the present invention may be used, particularly fibrous (wire-type) porous tissue. The material for the porous pad is a 0.010 inch (0.254 mm) diameter titanium wire, and the material for the thigh component is also titanium. It is further understood that any suitable material may be obtained.

The shape of the porous pad 26 is preferably formed or compressed into a substantially flat sheet 126 (FIGS. 9-11), although the pad may be of any desired shape. The outer peripheral edge of the pad 26 can have any shape. The porous pad 26 is separated from the mandrel portion 20. The pad 26 is adapted to be wrapped around the mandrel portion 20 for attachment. The porous pad 26 has a first preformed shape as shown in FIG. 11 and is then wrapped and / or formed about the mandrel portion 20 and attached to the mandrel portion. It has a second final shape that matches the shape of the mandrel portion 20 as shown in FIGS. The porous pad 26 is preferably wrapped around all four sides 34, 36, 38 and 40 to wrap around the mandrel portion 20 to form a continuous porous surface. , Wrapped around at least two or three adjacent flanks.

A porous material, such as twisted titanium fiber metal, is compression formed into a sheet 126 of porous material. This sheet126
Have any desired thickness or dimensions. The size of the sheet 126 is such that a single pad 26 having the desired outer shape is cut out or multiple pads 2 are cut from a single sheet.
The size is such that 6 is cut out. Sheet 126
Is prebonded in a vacuum oven by holding the sheet at a temperature sufficient to cause metallurgical bonding at the contact points of the fibers of the porous material within the sheet 126 for a suitable length of time. It The porous pad 26 having the desired outer shape is then cut from the sheet, leaving a corresponding cutout 226 in the sheet 126. The pre-bonding of the fiber metal sheet prior to cutting out provides mechanical integrity to the sheet 126, which allows the fiber material to be more easily formed and better retain its shape.

The porous pad 26 shown in FIG. 11 and subsequently applied to the thigh component 10 of FIGS. 1 to 4 has an intermediate pad side surface 138 corresponding to an intermediate mandrel side surface 38, and an intermediate pad side surface 138, respectively. Extending from or proximate to the side surface 138 and to the rear and front mandrel side surfaces 36 and 40, respectively, and to the rear and front pad side surfaces 136 and 140, and extending from the rear and front side surfaces, respectively. Includes first and second tabs 121 and 122 that exit. Both of these two tabs have lateral pad sides 134, which will correspond to the lateral mandrel sides 34 of the femoral component 10.
Pad 26 is asymmetric as shown, with back porous pad surface 136 having a larger surface area than front porous pad surface 140 and intermediate pad surface 138 longer than lateral pad surface 134. However, the pad 26 can easily be symmetrical, if desired, as any suitable shape is used as the pad 26.

The pad 26 is then ready to be wrapped around the mandrel portion 20. The base 24 of the mandrel portion 20 includes a recess 74 (FIG. 6) which conforms to the pad 26 and is shaped to receive the pad 26 for subsequent attachment. The pad 26 can be shaped to match any desired suitable implant mandrel or fixed surface shape. The base 24 of the mandrel portion 20 of the illustrated thigh component is shown in FIGS.
It has an asymmetric non-circular cross section as shown.

7 and 8 during the process of winding the porous pad 26.
As shown, the thigh component 10 is placed in the forming device 60.
This is done by placing (excluding the pad 26). The device 60 includes a plurality of forming jaws 61, 62, 63, and 6
Have four. These forming jaws are in the cylinder 26
Actuated by corresponding rods 161, 162, 163 and 164 which operatively connect these jaws to 1, 262, 263 and 264, respectively. These cylinders 261, 262, 263 and 2
64 can be an air or hydraulic cylinder or any other suitable actuating mechanism. The jaws, rods and cylinders are made of tool steel or a material that is strong enough to form a porous pad 26 around the thigh component 10.

The neck 28 of the femoral component 10 is placed within a cylindrical bush 66 inside the base plate 68 of the device 60 to hold the femoral component 10 in place.
The sliding locating pin 69 is placed through the opening 31 to prevent the thigh component 10 from rotating during the forming action. Bushing 66 is suitably made from a non-metallic material such as Delrin to prevent scratching neck 28. The base plate is made of aluminum or steel.
Other suitable means for securely holding the femoral component 10 within the forming device 60 may also be used.

The jaws 61, 62, 63 and 64 are each the thigh component 10
It is in a retracted position around. A pre-cut substantially flat pad 26 is placed between the jaws and the implant 10 with the intermediate pad portion 138 aligned with the corresponding intermediate side surface 38 of the mandrel portion 20. These jaws, having facing surfaces that match the contours of the desired pad and mandrel, are then activated in a predetermined order to pad 26 the shape of implant 10 as shown in FIGS. 8a, 8b and 8c. A pad 26 is formed around the implant to match. In FIG. 8a, the first forming jaw 61 is pressed against the intermediate porous pad surface 138, which in turn presses against the corresponding intermediate side surface 38 of the mandrel portion 20 which forms and positions each portion of the pad 26. To be The first jaw 61 is then held in its activated position with respect to the mandrel portion 20.

Alternatively, the intermediate porous pad surface 138 (rather than forming the intermediate side using the continuous device 60).
By using another forming die (not shown) made in the same shape for this intermediate side only, the intermediate side 3
It can be preformed in the shape of 8. This alternate die includes a substantially U-shaped recess, as shown in cross section of jaw 61 in FIG. 8a, and a U-shaped projection that conforms to the contour of the medial side of the thigh component, and these recesses. And preform the pad 26 into a substantially U-shaped configuration, as was done with the first jaw 61 of the continuous forming device 60 when the pad and protrusion are moved such that the pad 26 is placed therebetween. . If such another die is used, pad 2 having a preformed (U-shaped) intermediate pad surface 138
6 is placed in position in the forming device 60 between the jaws and the implant 10 with the preformed intermediate pad 138 aligned with the intermediate side surface 38 of the mandrel portion 20. The jaws 61 are actuated to hold the pad 26 with the preformed intermediate pad surface against the mandrel portion 20. The continued operation of the rest of Joe continues.

The second and third jaws 62 and 63 are then simultaneously actuated as shown in Figure 8b to provide a rear and front porous pad surface.
136 and 140 are pressed against the back and front sides 36 and 40 of the mandrel portion 20, respectively, so that portions of the pad are formed against each side of the mandrel. The jaws 61, 62 and 63 are then held in this operating position with respect to the mandrel portion 20.

The fourth jaw 64 is activated as shown in FIG. 8c and the first and second tabs 121 and 12 of the lateral porous pad surface 134.
The 2 is pressed against the lateral side 34 of the mandrel portion 20, thereby forming the respective parts of the pad against this side 34. The tabs 121 and 122 together fit on the lateral side surface 34 to form a flat contact surface 27, thereby providing a continuous peripheral porous surface connecting the front, middle, rear and lateral sides.

The forming jaws are then released from their operative position and retracted away from the mandrel portion 20. It is removed from the femoral component 10 forming device 60 with the matching pad 26 surrounding it. The femoral component 10 is then placed in a suitable adhesive device 80, such as in FIGS. 12 and 13, where the porous pad is held firmly in place relative to the mandrel portion 20. The pad 26 is firmly positioned in a recess that conforms to the wrapped shape of the pad 26. Porous pad 26 is adhered to and securely attached to mandrel portion 20. This bonding action is accomplished by diffusion bonding the pad to the mandrel portion by holding the pad firmly against the mandrel at a sufficient temperature and for a sufficient time to provide a secure bond. However, it is understood that other bonding processes such as sintering and other suitable bonding methods can be used.

Although any suitable adhesive device or retention mechanism may be used to adhere the pad 26 to the mandrel portion 20, FIG. 12 and FIG. 13 show such a suitable device 80. The device 80 includes a plurality of holding or adhesive blocks or jaws.
Includes a support frame 86 having 81, 82, 83 and 84, which jaws surround the porous pad 26 on the base 24 and conform to the shape of the mandrel portion 20 around which the jaws are located. ing. The adhesive block that holds the pad 26 in place with respect to the mandrel portion 20 is suitably made of carbon material, such as frame 86. The adhesive blocks 81, 82, 83 and 84 are placed against the mandrel portion 20 under sufficient pressure to evenly support the pad 26 via screws 88.

Instead of forming a substantially flat first pre-shaped pad 26 around its mandrel portion 20 in its second final shape, the pad 26 is instead of the implant to which it is to be attached. Can be formed around a mandrel (not shown) having a shape that matches the portion of the. This formation around the mandrel is accomplished with a device 60, such as the device described above, used to form a substantially flat or intermediate preformed pad 26 around the implant itself. This forming pad 26 formed around the mandrel is then removed from the mandrel and placed around the thigh component 10. The pad 26 can be firmly adhered to the mandrel portion 20 as described above.

Another embodiment for the thigh component 400 is shown in FIGS. 14-16, where the porous pad 426 fits within the recess 474. 14 and 1
FIG. 5 shows component 400 without porous pad 426 around it. The pad 426 has side, middle and front side surfaces 36,
It is wrapped around three adjacent sides including 38 and 40 to form a continuous porous surface interconnecting these three sides. Since the pad 426 does not completely surround all sides of the implant, the pad 426 is conveniently made in the same shape (substantially U-shaped as in the embodiment shown in FIGS. 14-16). By means of another single forming die (not shown) or by using a forming device 60 having a number of continuously actuated forming jaws as described above. It is formed from its preliminary shape (as shown in FIG. 16) to its second final contour that matches the shape of the recess 474 of the mandrel portion 20. This forming pad
The 426 can then be adhered to the mandrel portion 20 in a manner similar to that described above for the pad 26 surrounding the mandrel portion.

The prosthetic implant of the present invention provides a graft having a rolled porous pad and a method of wrapping the pad around the prosthetic mandrel portion. The present invention has a predetermined peripheral shape that conforms to and is attached to the prosthesis mandrel such that it is subsequently wrapped around the mandrel.
Provides a substantially flat pad. While the present invention has been described and illustrated with respect to particularly advantageous embodiments,
Those skilled in the art will appreciate that various changes can be made without departing from the spirit and scope of the invention.

[Brief description of drawings]

FIG. 1 is a perspective view of a thigh component for a hip prosthesis according to the present invention, FIG. 2 is a front view of the same as above, FIG. 3 is a front view of the same as above, and FIG. Fig. 5, Fig. 5 is a sectional view taken along line 5-5 of Fig. 2, Fig. 6 is a sectional view taken along line 6-6 of Fig. 2, and Fig. 7 is taken along line 7-7 of Fig. 8c. Shown in cross section. FIG. 8 is a side view of the thigh component of the present invention placed in the forming device, FIG. 8 is a cross-sectional view of the forming device taken along line 8-8 of FIG. 7, and FIGS. 8A, 8B and 8C are Of the forming device showing the various jaws in the actuated position about the mandrel of the thigh component,
7 is a cross-sectional view taken along line 8-8 of FIG. 7, FIG. 9 is a top view of a compressed and pre-bonded sheet of porous material, and FIG. 10 is a cutaway portion of the sheet of FIG. Top view, FIG. 11 is a top view of the porous pad formed from the cut-out portion of FIG. 10, and FIG. 12 is a section of the bonding apparatus shown in FIG. 13 taken along the line 12-12. FIG. 13 is a side view of the thigh component of the present invention arranged, FIG. 13 is a sectional view of the bonding device taken along line 13-13 of FIG. 12, and FIG. 14 is another embodiment of the thigh component. FIG. 15 is a front front view of FIG. 14, FIG. 15 is a rear front view of the component shown in FIG. 14, and FIG. 16 shows another embodiment of the porous pad used in connection with the component shown in FIG. . 10 ... thigh component, 12 ... distal end, 14 ... connecting end portion, 16 ... distal end portion, 20 ... mandrel portion, 24 ... base portion, 26 ... pad, 28 ... neck portion, 34 ... lateral side, 36 ... rear side, 38 ... middle side, 40 ... front side, 60 ... forming device, 61, 62, 63, 64 ... jaw, 80 ... connecting device, 81, 82, 83,84 …… Joe, 126 …… Sheet.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Steven Tee. Bain United States, Indiana 46580, Warsaw, Earl Dee 225 West 1806 (56) Reference JP 61-226038 (JP, A) JP 61-106147 (JP, A) JP 60-96247 (JP, A) ) JP-A-61-290126 (JP, A)

Claims (23)

[Claims] 1. A prosthetic implant including a mandrel portion having a plurality of sides, the implant including a porous pad separate from the mandrel portion, the pad having a shape of a portion of the mandrel portion. Wrapped around and conforming to this shape for attachment to the mandrel portion, said porous pad being made of a fibrous metal material and pre-bonded prior to wrapping said porous pad around the mandrel portion. Artificial implants. 2. A porous pad of fibrous metal material having a desired thickness and being a substantially flat canopy that is pre-bonded prior to the pad being wound around the mandrel portion.
The prosthetic implant of claim 1, which is precompressed. 3. The prosthetic implant of claim 1, wherein the mandrel portion includes a recess that conforms to the shape of the porous pad to allow the pad to be placed in the recess. 4. The prosthetic implant according to claim 1, wherein a part of the mandrel around which the pad is wound has a non-circular, asymmetric cross-sectional shape. 5. The prosthetic implant of claim 1, wherein the implant is a thigh component for a hip prosthesis. 6. The thigh component of claim 5, wherein the mandrel portion has a base and a distal end, and the mandrel portion has intermediate, posterior, anterior and lateral sides. 7. The femoral component of claim 6, wherein the porous pad is located substantially at the base of the hip prosthesis. 8. The thigh component according to claim 7, wherein the base has a non-circular cross-sectional shape. 9. The femoral component of claim 7, wherein the porous pad is wrapped around each of the anterior, medial, and posterior sides to form a continuous porous surface connecting the three sides. . 10. A porous pad is wrapped around a portion of front, middle, rear and lateral sides which connects the four sides to form a continuous porous surface around the mandrel portion. The thigh component according to claim 7, wherein 11. The prosthetic implant of claim 2, wherein the separate porous pad has a predetermined outer perimeter that defines the desired shape for the porous pad. 12. The prosthetic implant according to claim 1, wherein the porous pad is a single pad. 13. A thigh component for a hip prosthesis having a fixed surface substrate portion having a plurality of different sides, wherein the implant is a porous pad separate from the substrate portion. Including a first preliminary preformed shape, the porous pad being wrapped around a portion of at least two sides of the plurality of sides and attached to the sides. A thigh component that is intended to have a second final shape. 14. A method of constructing a prosthetic implant, comprising: (a) providing a substrate implant including a mandrel portion having a plurality of sides (b) a separate body having a first desired shape. Preforming a porous pad, (c) wrapping this pad around the mandrel portion and attaching it to the mandrel portion into a second shape that matches the shape of the mandrel around which the pad is wound. A method of constructing an artificial prosthetic implant comprising :. 15. The method of claim 14 further comprising the step of adhering the pad to the mandrel portion and holding the pad against the mandrel portion to obtain a suitable adhesive bond. 16. The method of claim 14 further comprising the step of compression forming and prebonding a sheet of porous material prior to preforming the shape of the pad. 17. A method of constructing a prosthetic implant, comprising: (a) providing a base metal implant including mandrel portions having intermediate, posterior, anterior and lateral sides; and (b). Forming a sheet of porous fibrous metal material, (c) pre-adhering this sheet and adhering the fibrous metal material together, (d) cutting a porous pad from this sheet to circularly form the desired shape Obtaining a pad with an outer peripheral edge, (e) wrapping this pad around a mandrel and matching this pad to the shape of the mandrel around which this pad is wrapped and attached. A method of constructing an artificial prosthetic implant comprising. 18. The step of wrapping a pad around the mandrel portion further comprises first forming the pad to conform to the shape of one side of the mandrel portion and then conforming the pad to the shape of the remaining sides. 18. The method of claim 17 including forming.
The method described in. 19. The step of wrapping the pad around the mandrel portion further comprises placing the prosthetic implant in a device having a plurality of forming jaws each in a retracted position away from the prosthetic implant. Thereby forming the pad to conform to the shape of the mandrel portion to which it is attached, placing the porous pad in the desired location between the jaws and the implant, and then placing the jaws on the fiber metal and implant. 18. The method of claim 17, comprising actuating in a predetermined sequence to form a porous pad around the implant and conforming the pad to the shape of the implant. 20. The step of wrapping a pad around the mandrel portion further comprises four forming jaws, the jaws being (a) pressed against one of the sides of the implant with a porous pad. Actuating the first jaw so as to hold the first jaw in this actuated position, and (b) press the porous pad against the two sides of the implant adjacent to the one side. Actuating the second and third jaws, holding the second and third jaws in their actuated position, and (c) actuating the fourth jaw to press the porous pad against the remaining sides. 20. The method of claim 19 including the steps of actuating the porous pad to conform to the shape of the mandrel portion and to fully surround the mandrel portion in the order described above. 21. (a) Releasing the jaw from its actuated position, (b) removing the mandrel from the device with a matching pad surrounding the mandrel, (c) the porous pad in the correct position relative to the mandrel. 21. The method of claim 20 further comprising the steps of placing the mandrel in a suitable adhesive device that is held securely in the mandrel, and (d) adhering the porous pad to the mandrel and securely attaching the pad to the mandrel. Method. 22. (a) Matching the shape of the mandrel portion to which the pad is attached by forming the porous pad around a mandrel having a shape that matches the portion of the implant to which the pad is attached. Forming the pad, (b) removing the formed pad from the mandrel, (c) placing the formed pad around the prosthetic implant, and (d) securely attaching the pad to the mandrel. 18. The method of claim 17, further comprising: 23. An artificial prosthetic implant having a non-planar fixation surface, the graft comprising a porous pad separate from the fixation surface, the porous pad being a first preliminary parenchyma. Has a pre-formed shape that is substantially flat and the porous pad is then formed around the anchoring surface for attachment to the non-planar anchoring surface to the shape of the anchoring surface to which the pad is attached. A prosthetic implant that is adapted to have a matching non-planar second final shape.