Method and apparatus for arthroscopically replacing a bone joint

A method and apparatus for arthroscopically replacing a joint between two bones utilizes a plurality of joint surface members which are attached to a prepared surface arthroscopically formed on the end of a bone, and the joint surface members are inserted through an arthroscopic portal adjacent to the joint to be repaired.

FIELD OF THE INVENTION 
The present invention relates to a method of providing a low friction bone 
joint replacement by arthroscopic surgery and an apparatus for 
arthroscopically repairing damaged or diseased joints. 
BACKGROUND OF THE INVENTION 
It has been known for several years that prosthetic devices can be used for 
joints to replace defective natural joints. In the patent issued to 
Johnson and Vegell on May 29, 1979, U.S. Pat. No. 4,156,296, there is 
described an endoprosthetic device for replacement of the joint in fingers 
and toes. This device requires removal of part of the bone and the 
insertion of a device to replace the joint. 
The patent issued to Weber on Sept. 30, 1980, U.S. Pat. No. 4,224,699, 
describes a cap-shaped endoprosthesis and anchoring pin for the 
replacement of the femoral head. 
In the patent issued to Rehder and Rusdea on Jun. 23, 1981, U.S. Pat. No. 
4,274,164, there is described an endoprosthesis for replacement of a hip 
joint including a cap shaped femur head shell device. This device includes 
a convex surface used for insertion into the hip joint to form a complete 
replacement of the hip joint. 
In a patent issued to Steffee on Feb. 10, 1987, U.S. Pat. No. 4,642,122, 
there is described a device for an implantable joint replacing a human toe 
joint. 
All of the foregoing patents describe methods and apparatus for replacement 
of damaged or diseased bone joints with a prosthesis. The major 
disadvantage associated with these methods of replacing bone joints is 
that major surgery is required. The bone joint replacement requires a 
large incision to expose and partially amputate the bone ends so that the 
joint can be capped. These procedures usually require major surgery 
performed in a hospital and may require blood transfusions. Recovery after 
surgery takes weeks and typically requires post operative therapy. 
In contrast to these prior art methods and apparatus, the present invention 
is directed to a method and apparatus for providing low friction bone 
joint replacement through arthroscopic surgery. A major advantage of the 
present invention is that the surgical procedure required is considered 
minor when compared with the prior art methods and apparatus, in that no 
large incisions are necessary. Additionally, no blood transfusion is 
typically required. Furthermore, because the procedure is less traumatic, 
the recovery time should be shorter; and it is believed that the procedure 
may be performed on an out-patient basis. 
SUMMARY OF THE INVENTION 
In accordance with the invention, the foregoing advantages have been 
achieved through the present apparatus for arthroscopically replacing a 
joint between two bones, each bone having at least one planar surface 
formed thereon, at least one of the planar surfaces of each bone being 
disposed opposite each other in a spaced relationship. The present 
invention includes: a plurality of joint surface members, each joint 
surface member including an upper bearing surface formed of a 
bio-compatible, low friction material, and a lower surface; means for 
attaching the plurality of joint surface members to a prepared bone 
surface, the attachment means being associated with the lower surface of 
each joint surface member; each of the joint surface members having three 
external dimensions including height, width and length, and at least two 
of the external dimensions of each joint surface member are equal to, or 
less than, one centimeter, whereby the joint surface members may be passed 
through an arthroscopic portal adjacent to the joint and a portion of the 
plurality of the joint surface members may be attached to one prepared 
bone surface and the remaining portion of the plurality of joint surface 
members may be attached to the other prepared bone surface to form a 
replacement joint between the two bones. A feature of the invention is 
that the attachment means may be either: a screw, pin, nail, or staple 
member associated with the lower surface of the joint surface members; a 
bio-compatible glue or bone cement; or may include a porous coating into 
which the bone may grow. 
Another feature of the present invention is that the attachment means may 
include a plurality of scaffold members upon which are disposed a 
plurality of joint surface members; the scaffold members having an upper 
and a lower surface, the lower surface of each joint surface member being 
disposed upon an upper surface of one of the scaffold members, and the 
lower surface of each scaffold member may be attached to a prepared bone 
surface. 
Another feature of the present invention is that one of the bones may be a 
femur having a plurality of prepared planar bone surfaces formed thereon, 
and the scaffold members which are attached to the planar surfaces of the 
femur have a J,C, or U-shaped configuration which conforms to the shape of 
the planar surfaces on the femur. A further feature of the present 
invention is that the joint surface members may be the scaffold members, 
and the upper bearing surface of each joint surface may be formed as an 
integral part of the upper surface of each scaffold member. 
An additional feature of the present invention is that the cross-sectional 
configuration of some of the joint surface members may be circular, 
triangular, rectangular, or hexagonal. A further feature of the present 
invention is that the upper bearing surfaces of the joint surface members 
attached to one bone may have a concave configuration, and the upper 
bearing surfaces of the joint surface members attached to the other bone 
may have a convex figuration, whereby opposing upper bearing surfaces are 
matingly received within one another. Alternatively, the upper bearing 
surfaces of each joint surface member may be planar or convex. 
In accordance with another aspect of the invention, the foregoing 
advantages have also been achieved through the present method for 
arthroscopically replacing a joint between two bones. The present 
invention includes the steps of: forming a plurality of arthroscopic 
portals adjacent to the joint; inserting an arthroscope through one of the 
arthroscopic portals; arthroscopically preparing at least one surface on 
each bone with at least one of the prepared surfaces of each bone being 
disposed opposite each other in a spaced relationship; inserting a 
plurality of joint surface members through at least some of the 
arthroscopic portals, each joint surface member including an upper bearing 
surface formed of a bio-compatible, low friction material, and a lower 
surface; attaching a plurality of joint surface members to the prepared 
bone surfaces to cover a substantial portion of each prepared bone 
surface, whereby a replacement joint between the two bones is formed by 
the upper bearing support surfaces of the joint surface members which 
upper bearing surfaces abut oppositely disposed upper bearing surfaces as 
one bone moves with respect to the other bone. 
A further feature of the present invention may include the steps of: 
inserting a plurality of scaffold members through some of the arthroscopic 
portals; attaching the scaffold members to the prepared bone surfaces, and 
attaching the joint surface members to the scaffold members. A further 
feature of the present invention is the step of forming the upper bearing 
surfaces as an integral part of each scaffold member. 
The method and apparatus for arthroscopically replacing a bone joint of the 
present invention, when compared with previously proposed prior art 
methods and apparatus, have the advantages of: not requiring a major 
surgical procedure which includes large incisions to expose the bone ends 
of the joint to be repaired; does not require blood transfusions; may be 
performed on a out-patient basis; and has a shorter recovery time.

DETAILED DESCRIPTION OF THE INVENTION 
In FIGS. 1A and 1B, a human knee joint 15 is illustrated, knee joint 15 
being representative of one type of joint which may be repaired or 
replaced by use of the method and apparatus for arthroscopically replacing 
a bone joint, in accordance with the present invention. Other 
representative joints for which the present invention may be useful 
include the elbow, shoulder joint and joints between toes and fingers, hip 
joint, ankle, and all other joints of the body which can be 
arthroscopically approached. 
Still with reference to FIGS. 1A and 1B, knee joint 15 generally comprises 
two bones, 16, 17; bone 16 being the tibia, or large lower leg bone, and 
bone 17 being the femur, or thigh bone. A person's leg is indicated in 
phantom lines at 18. The patella 19, or knee cap, has the quadraceps 
extensor femoris muscle 20 holding the patella 19 in place in alignment 
with a groove in the femur 17, whereby the patella 19 slides within the 
groove in femur 17 as the leg 18 is bent. Knee joint 15 also includes a 
fibula 21, or smaller leg bone. A natural knee joint 15 includes a lateral 
collateral ligament 22, a medial collateral ligament 23, anterior cruciate 
ligament 24, lateral meniscus 25, and medial meniscus 26. Knee joint 15 
has two layers of cartilage. Articular cartilage 27 covers the bone ends 
of bones 16, 17 or tibia 16 and femur 17. The other cartilage is the 
menisci, or lateral meniscus 25 and medial meniscus 26. The menisci 25, 26 
are thick pads of cartilage that form a rim inside the knee joint 15 and 
help absorb shock and stabilize the knee joint 15. Damage or disease to 
the various components of knee joint 15 may sometimes be alleviated 
through conventional arthroscopic surgery, such as arthroscopic meniscus 
surgery, arthroscopic surface cartilage surgery, or arthroscopic patella 
surgery. For such conventional arthroscopic surgery, a plurality of 
arthroscopic portals 30, or incisions, are made adjacent to knee joint 15 
to provide access to knee joint 15 by a conventional arthroscope (not 
shown), or through which arthroscopic surgical instruments (not shown) may 
be inserted into knee joint 15. As previously discussed, some damage and 
disease within a joint, such as knee joint 15, requires more than a repair 
by conventional arthroscopic surgery, and instead requires a replacement 
of the joint. The present invention permits knee joint 15 to be replaced 
by use of the conventional arthroscopic portals, or openings, 30 without 
the necessity of making major incisions upon leg 18 to expose knee joint 
15. It should be noted that conventional arthroscopic portals 30 have a 
size which is preferably one centimeter in diameter, but arthroscopic 
openings, or portals, 30 could have a size range from one-half to one and 
one-half centimeters in diameter. 
With reference now to FIGS. 2 and 10, the lower end 41 of femur 17 and the 
upper end 42 of tibia 16 are shown to illustrate how bones 16 and 17 are 
prepared for use with the joint surface members (not shown) of the present 
invention, as will be hereinafter described in greater detail. It is first 
necessary to remove portions of the upper end 42 of tibia 16 and lower end 
41 of femur 17 to arthroscopically form at least one planar surface 43,44 
on each bone 16,17 with at least one of the planar surface 43,44 of each 
bone being disposed opposite each other in a spaced relationship, as 
illustrated in FIGS. 2 and 10. The original configuration of tibia 16 and 
femur 17 are illustrated in phantom lines 45,46 and those portions 46 of 
tibia 16 and 45 of femur 17 are arthroscopically removed, as by use of 
arthroscopic burrs, drills, cutters or rasps (not shown), which are used 
along with arthroscopic rulers and depth guides (not shown) to form the 
desired planar surfaces 43,44. Preferably, the at least one planar surface 
43, 44, on each bone 16,17 are disposed parallel to each other when the 
longitudinal axes of tibia 16 and femur 17 are disposed parallel to each 
other as illustrated in FIGS. 2 and 10, whereby the cuts, or shaping, of 
the lower end 41 femur 17 and upper end 42 of tibia 16 are made parallel 
with each other. If necessary, a planar surface 47 may be formed on the 
back 48 of patella 19. As will be hereinafter described in greater detail, 
lower end 41 of femur 17 may be provided with additional planar surfaces, 
such as planar surfaces 49-52, as illustrated in FIG. 10. It should be 
noted that all of the shaping, or preparation of, lower end 41 of femur 17 
and upper end 42 of tibia 16 is accomplished by use of arthroscopic 
techniques, requiring only the formation of arthroscopic portals 30 being 
made adjacent joint 15. 
After bones 16 and 17 have planar surfaces 43 and 44 formed thereon, as 
previously described, a plurality of joint surface members 60 may be 
inserted into at least some of the arthroscopic portals 30, and attached 
to bone planar surfaces 43, 44, as illustrated in FIGS. 3 and 4. As seen 
in FIGS. 3-5, each joint surface member 60 preferably includes an upper 
bearing surface 61 formed of a bio-compatible, low friction material and a 
lower surface 62. Each joint surface member 60 also preferably includes a 
means for attaching 63 a plurality of joint surface members 60 to a bone 
planar surface 43, 44; the attachment means 63 being associated with a 
lower surface 62 of each joint surface member 60. The bio-compatible, low 
friction material can be any suitable material having the requisite 
biological compatibility qualities necessary for any prosthetic device 
implanted within the human body, as well as possess the requisite strength 
and durability qualities necessary for components used to replace a human 
joint. The upper bearing surface 61 may be a polished metal surface made 
from alloys of titanium, aluminum, vanadium, or stainless steel as 
examples. Alternatively, suitable plastic materials could be utilized, 
such as TEFLON or a high-molecular weight polyethylene, combinations of 
metal and plastics, ceramics, or composite materials, such as carbon fiber 
reinforced materials. As illustrated in FIG. 5, upper bearing surface 61 
may be formed integral with each joint surface member 60. Alternatively, 
upper bearing surface 61 of each joint surface member 60 may be a cap 
member 65 which is fixedly secured to the joint surface member 60 as 
illustrated in FIG. 6. cap member 60 may be snapped upon the top portion 
66 of joint surface member 60 and held in place by an outwardly extending 
flange member 67. Alternatively, cap member 65 may be molded upon the top 
portion 66 of joint surface member 60 and also fixedly secured thereto as 
by its engagement with flange member 67. 
As illustrated in FIGS. 3-6, the cross-sectional configuration of some of 
the joint surface members 60 may be circular with a diameter, D. 
Alternatively, as illustrated in FIGS. 7, 8A and 8B, the cross-sectional 
configuration of some of the joint surface members may be triangular, 
rectangular or hexagonal. As will be hereinafter described in greater 
detail, a plurality of joint surface members 60 having any of the 
foregoing cross-sectional configurations or combinations thereof, are 
attached to a bone planar surface 43, 44 to cover a substantial portion of 
each bone planar surface 43, 44 to form the desired replacement joint 70 
between bones 16, 17 (FIG. 3). As illustrated in FIG. 3, the upper bearing 
surfaces 61 of the joint surface members 60 may be a flat, planar surface. 
Alternatively, as illustrated in FIG. 5, the upper bearing surface 61 of 
the joint surface members 60 attached to one bone may have a concave 
configuration 71 (FIGS. 5 and 6), and the upper bearing surface 61 of the 
joint surface members 60 attached to another bone may have a convex 
configuration 72, whereby opposing upper bearing surfaces 61 are matingly 
received within one another. 
With reference to FIG. 5, attachment means 63 may be a screw 73, or a pin, 
nail or staple member 74 having the same general configuration as screw 
73; and attachment means 63 is received within a bone planar surface 43, 
44, and/or 47 and remains fixedly secured therein. Alternatively, 
attachment means 63 may be a conventional bio-compatible glue or bone 
cement 75 disposed on the lower surface 62 of each joint surface member 
60, as shown in FIG. 5, in which case screw 73, or pin, nail or staple 
member 74 would not be utilized. Alternatively, the conventional 
bio-compatible glue or bone cement 75 could be used on the lower surface 
62 of each joint surface member 60 in combination with screw 73 or pin, 
nail or staple member 74 to further insure the secure attachment of bone 
joint and/or surface member 60 to bone planar surfaces 43, 44, 47. 
Additionally, attachment means 63 could include a porous coated surface, 
such as titanium fiber pads 75, into which the bone 16, 17 may grow. 
Porous coated surface 75 may preferably be disposed on the lower surface 
62 of each joint surface member 60 shown in FIG. 5, if desired. Porous 
coated surface 75 could also be used in combination with any of the other 
previously described attachment means 63. 
With reference to FIGS. 4-8, it is seen that each joint surface member 60 
has three external dimensions including height H, width W, length L. In 
order for each of the joint surface members 60 to be inserted through the 
arthroscopic portals 30, at least two of the external dimensions H, W and 
L of each joint surface member 60 is equal to, or less than, one 
centimeter. Thus, if the diameter of joint surface member 60 of FIG. 6 is 
one centimeter, its height and width will each be equal to, or less than, 
one centimeter, and will be capable of being inserted through arthroscopic 
portals 30, even if its length exceeds one centimeter. After joint surface 
member 60 has been inserted through arthroscopic portal 30, it may then be 
manipulated by an arthroscopic tool and rotated to permit attachment means 
63 to be secured into bone planar surface 43, 44. 
As illustrated in FIGS. 3, 4, and 7, it is intended that a substantial 
portion of each bone planar surface 43, 44 and 47, if necessary, shall be 
covered with joint surface members 60, whereby replacement joint 70 
disposed between the two bones, 16, 17 is formed by the upper bearing 
surfaces 61 of the joint surface members 60, the upper bearing surfaces 61 
abutting oppositely disposed upper bearing surfaces 61 as one bone 16 
moves with respect to the other bone 17. All of the other joint surface 
pieces 60 may have the same cross-sectional configuration to form a mosaic 
pattern upon bone planar surfaces 43, 44, as illustrated in FIGS. 3, 4 and 
7; or alternatively, joint surface members 60 having different 
cross-sectional configurations, such as those illustrated in FIGS. 4, 7, 
8A and 8B, may be combined, so as to best cover a substantial portion of 
each bone planar surface 43, 44 and/or 47. It should be noted that as 
illustrated in FIGS. 4 and 7, the medullary canal 80 is preferably not 
covered by joint surface members 60. 
With reference to FIG. 9, a method for making mating upper bearing surfaces 
61 for joint surface members 60 is illustrated. If desired to have the 
upper bearing surfaces 61 of the joint surface members 60 attached to the 
tibia 16 have a concave configuration 71, as previously described in 
connection with FIG. 5, it may also be desirable to have all of the upper 
bearing surfaces 61 of joint surface members 60 formed from an integral 
block of bearing surface material 90 which has a flat, planar lower 
surface 91 and an upper surface 92 having a concave configuration 93 as 
illustrated, or on convex configuration. By selecting a block of material 
90 which substantially corresponds in size to the planar surface 44 of 
bone 16, it is then possible to form the plurality of upper bearing 
surfaces 61 for joint surface members 60 from the block of material 90 as 
by cutting or sawing the joint surface member 60 from the block of 
material 90. By then attaching joint surface members 60 upon planar 
surface member 44 in the same location and angular orientation that each 
joint member 60 originally had in block of material 90, a substantially 
continuous concave surface 71 will be formed above bone planar surface 44 
by the plurality of bone joint members 60. If a similar block of material 
having an upper convex surface is utilized to make the joint surface 
members 60 to be attached to the bone planar surface 43 of bone 17, the 
convex surface of the other block of material closely conforming to the 
concave surface 71 of the other block of bearing surface material 90, a 
substantially continuous convex surface will be formed upon bone planar 
surface 43 of bone 17, whereby the oppositely disposed upper bearing 
surfaces 61 of joint surface members 60 having a concave configuration 
will matingly receive the upper bearing surfaces 61 of joint surface 
members 60 having a convex configuration so as to form the desired 
replacement joint 70 between the two bones 16, 17. 
With reference to FIGS. 11-13, attachment means 63 may include a plurality 
of scaffold members, or supporting framework members, 100 upon which are 
disposed the plurality of joint surface members 60; the scaffold member 
100 having upper and lower surfaces 101, 102, the lower surface 62 of each 
joint surface member 60 being disposed upon an upper surface 101 of one of 
the scaffold members 100, and the lower surface 102 of each scaffold 
member 100 is attached to a bone planar surface 43, 44. Scaffold members 
100 may be utilized to strengthen the bone 16, 17 and to provide a 
stronger and more rigid surface upon which to attach the joint surface 
members 60. Scaffold members 100 can be attached to bone planar surfaces 
43, 44 in any manner previously described in connection with attaching a 
joint surface member 60 to planar surfaces 43, 44, as by: use of screws 
73; pin, nail or staple members 74, (staple member 104 being illustrated 
in FIG. 11, and nail members 105 being illustrated in FIG. 13); a 
bio-compatible glue or bone cement; a porous coating, all as previously 
described. The screw, pin, nail or staple members 73, 74, 104, 105, may be 
secured to the lower surface 102 of each scaffold member 100, or such 
members may be secured to the lower surface 62 of each joint surface 
member 60 and then passed through scaffold members 100 as illustrated in 
FIG. 11. 
As with joint surface members 60, each scaffold member 100 has three 
external dimensions, including height, width, and length as illustrated in 
FIG. 13. At least two of the three external dimensions H, W, L of each 
scaffold member 100 is equal to, or less than, one centimeter, in order to 
permit the insertion of scaffold members 100 through arthroscopic portals 
30, as previously described. Dependent upon the dimensions of scaffold 
members 100, joint surface members 60 may be already attached to scaffold 
members 100, before they are inserted through arthroscopic portals 30; or 
alternatively, joint surface member 60 may be attached to scaffold members 
100 after scaffold members 100 are already attached to bone planar 
surfaces 43, 44. Preferably, scaffold members 100 have a height H of 
approximately six millimeters, and can fall within a range of between four 
and ten millimeters. Preferably, the width W of each scaffold member 100 
is approximately five millimeters, with a range of from three to ten 
millimeters. Preferably, two to five scaffold members 100 would be used 
for each bone planar surface, 43, 44, if the joint being replaced were a 
large joint such as a knee joint 15. For smaller joints, a single scaffold 
member 100 could be utilized. For example, if the height H of scaffold 
member 100 is six millimeters thick, a joint surface member 60 could be 
attached to the upper surface 101 of scaffold member 100 having a distance 
between its upper bearing surface 61 and lower surface 67 of approximately 
four millimeters, whereby scaffold member 100 with joint surface member 60 
attached thereto, could be initially inserted through a one centimeter 
wide arthroscopic portal 30. Scaffold members 100 may be provided with an 
opening 130 (FIG. 13) at their ends to permit them to be manipulated and 
moved by a suitable arthroscopic tool (not shown). 
Still with reference to FIGS. 11-13, scaffold members 100 can be 
manufactured from any of the materials previously describe in connection 
with the manufacture of joint surface members 60. Alternatively, joint 
surface members 60 could comprise the scaffold members 100, and the upper 
bearing surface 61 of each joint surface member, or scaffold member 100, 
is formed as an integral part of the upper surface 101 of each scaffold 
member 100 as will hereinafter be discussed in greater detail in 
connection with FIGS. 15-18. If scaffold members 100 are utilized as an 
integral joint surface member 60, with the upper bearing surface 61 formed 
integral with scaffold member 100, the height H of each scaffold member 
100 would be increased to provide the requisite strength characteristics 
to permit scaffold members 100 to cooperate with a mating scaffold member 
100 to serve as the replacement joint 70. As illustrated in FIG. 13, the 
scaffold members 100 disposed upon bone planar surface 44 of tibia 16 are 
integral elongate members 110, and such members 110 could be utilized upon 
planar surface 43 of femur 17. Preferably, scaffold members 100 for femur 
17 include additional elongate members 111-114, whereby the scaffold 
member 100' for femur 17 has a generally J, C, or U-shaped configuration 
which conforms to the shape of the planar surfaces 43,49-52 formed on 
femur 17 as previously described in connection with FIG. 10. 
As illustrated in FIGS. 14A, 14B, scaffold members 100, 100', may include a 
positioning means 120 which cooperates with a mating surface 121 on each 
joint surface member 60. In the embodiment illustrated in FIG. 14A, 
positioning means 120 may comprise a circular opening 122 formed in the 
upper surface 101 of scaffold member 100, with opening 122 receives a 
correspondingly sized locating pin 123. Locating pin 123 could also have a 
key 126 which mates with a key shaped opening 127 in opening 122, to 
properly orientate joint surface member 80 on scaffold 100. In the 
embodiment illustrated in FIG. 14B, positioning means 120 may comprise a 
locating pin 124 which mates with a correspondingly sized opening 125 
formed in the lower surface 62 of joint surface member 60. Also, as 
illustrated in FIGS. 14A, 14B, scaffold members 100 can be formed as 
elongate members 110 formed of connected segments 110A, 110B, including 
means for connecting 130 the scaffold member segments 110A, 110B. 
Connecting means 130 can be any suitable connection means, such as 
illustrated in FIG. 14B or a mating dove tail connection, or any other 
suitable interlocking connection. 
It should be noted that the joint surface members 60 disposed upon scaffold 
members 100 on bone surface 44 in FIG. 13, and the joint surface members 
60 disposed upon the scaffold members 100 on bone planar surface 43 may be 
formed as previously described in connection with FIG. 9, whereby a 
substantially, continuous bearing surface is formed by the plurality of 
joint surface members 60 on tibia 16, which mate with the plurality of 
joint surface members 60 on femur 17. 
With referenced to FIGS. 15-18, joint surface members 60 are shown to be 
comprised of scaffold members 100, wherein the upper bearing surface 61 of 
each joint surface member 200, or scaffold 100, is formed as integral part 
of the upper surface 101 of each scaffold 100. The height H of each 
scaffold number 100, or joint surface member 200, has been increased to be 
equal to or less than one centimeter to provide the requisite strength 
characteristics to permit joint surface members 200 disposed upon femur 17 
to cooperate with mating joint surface members 200 disposed upon tibia 16, 
to serve as the replacement joint 70. 
The joint surface members 200 for femur 17 may have a generally C,U, or 
J-shaped configuration as previously described in connection with the 
scaffold members 100 of FIGS. 11 and 13. The planar surfaces 43, 44 on 
femur 17 and tibia 16 are formed as previously described in connection 
with FIG. 10, and the height H and width W of joint surface members 200 
are equal to, or less than one centimeter in length, whereby joint surface 
members 200 may be passed through the arthroscopic portal 30, as 
previously described The particular type of replacement joint 70 being 
formed determines the number of joint surface members 200 to be utilized. 
In FIG. 15, three joint surface members 200 are illustrated for tibia 16 
and femur 17, it being understood that at least two joint surface members 
200 would be utilized for forming a replacement joint 70 for a knee joint 
of an adult. More joint surface members 200 could be utilized if desired. 
The only limitation on the size of the joint surface members 200 is that 
two of its three dimensions, H,W, or L, must be equal to, or less than, 
one centimeter. 
Whereas FIG. 15 illustrates the joint surface members 200 being configured 
to substantially cover a major portion of the planar surface 44 of tibia 
16, the joint surface members 200 illustrated in FIGS. 16-18 are shaped to 
match the outer periphery 210 of the planar surface 44 formed on tibia 16, 
whereby substantially all of planar surface 44 of tibia 16 is covered by 
the joint surface members 200, as illustrated in FIG. 18. The joint 
surface members 200 in the foreground of FIGS. 16 and 17 are shaped to 
conform to the outer periphery 210 of planar surface 44 on tibia 16; the 
joint surface members 200 in the background of FIGS. 16 and 17 having the 
configuration of joint surface members 200 illustrated in FIG. 15. It 
should be noted that six joint surface members are illustrated in FIG. 16, 
with the joint surface members 200 abutting against each other along a 
planar side surface 211 of adjacent joint surface members 200. In FIG. 17, 
joint surface members 200 are connected by a joint surface member 220 
which has a configuration which interlocks with a mating portion 212 of 
side surfaces 211 of joint surface members 200. The joint surface members 
200 of FIG. 18 have an undulating configuration for the side surfaces 211 
of joint surface members 200, which undulating side surfaces 211 mate with 
those of adjacent joint surface members 200. 
As previously discussed, it is preferred that the lower surface 215 of each 
joint surface member 200 be planar to conform to the planar surfaces 43, 
44 formed on femur 17 and tibia 16. Preferably, the upper bearing surface 
61 of joint surface members 200 for femur 17 have a convex configuration 
as illustrated in FIG. 15, and the upper bearing surfaces 61 of joint 
surface members 200 disposed upon tibia 16 have a concave surface 71 as 
previously described. Joint surface members 200 for tibia 16 could be 
manufactured as previously described in connection with joint surface 
members 60 of FIG. 9, in that joint surface members 200 could be formed 
from an integral block of bearing surface material 90, having a concave 
surface 71, and the individual joint surface members 200 are formed from 
the block of bearing surface material 90. Joint surface members 200 may be 
attached to femur 17 and tibia 16 in any manner previously described, 
using any of the attachment means 63 previously described. 
With reference to FIGS. 19-21, joint surface members 200' are illustrated 
to form a replacement joint 70' between a femur head 230 disposed upon 
femur neck 231 on the upper end of femur 17 and an acetabulum 235. As 
illustrated in FIG. 19, hip joint 70' is prepared for use with joint 
surface members 200' in a manner similar to that previously described in 
connection FIG. 10. An outer surface portion 236 of femur head 230 is 
arthroscopically removed to form a spherical surface 237 on femur head 
230. A portion 238 of acetabulum 235 is likewise removed to form a 
spherical shaped cavity 239. Portions 236, 238 of femur head 230 and 
acetabulum 235 are arthroscopically removed, as by use of arthroscopic 
burrs, drills, cutters, or rasps (not shown), which are used along with 
arthroscopic rulers and depth guides (not shown) to form the desired 
spherical-shaped surface 237 on femur head 230 and spherical shaped cavity 
239 within acetabulum 235. After femur head 230 and acetabulum 235 have 
been arthroscopically prepared, joint surface members 200' are 
arthroscopically attached to femur head 230 and acetabulum 235. 
Joint surface members 200' may be formed of any of the same materials 
previously described in connection with joint surface members 60, scaffold 
members 100, and joint surface members 200, and joint surface members 200' 
can be attached to surfaces 237, 239 by use of any of the attachment means 
63 previously described. Preferably joint surface members 200' for femur 
head 230 each comprise an elongate member 240 having a generally 
semi-circular configuration, as illustrated in FIG. 21. Each elongate 
member 240 as in upper bearing surface 61' which is shaped to closely 
conform to the bearing surface 261 of the joint surface members 200' of 
acetabulum 235 as will be hereinafter described in greater detail. The 
lower surface 62 of each elongate member 240 which forms joint surface 
member 200' for femur head 230 is shaped to conform to the spherical 
surface 237 formed on femur head 230. An end cap piece 241 is also 
provided to cover the end most portion 242 of femur head 230. Joint 
surface members 200' for acetabulum 235 are likewise formed of a plurality 
of elongate members 240 which have an outer bearing surface 261 which 
closely conforms to the outer bearing surface 61' of joint surface members 
200' for femur head 230 after femur head 230 in disposed within acetabulum 
235. The joint surface members 200' or acetabulum 235 are likewise 
preferably formed to have a generally semi-circular configuration, the 
lower surface 262 of the joint surface members 200' for acetabulum 235 
being shaped to conform to the spherically shaped cavity surface 239 of 
acetabulum 235. 
By arthroscopically disposing two joint surface members 200' in an abutting 
relationship as shown at 250 in FIG. 21, the two generally semi-circular 
configured elongate members 240 form a ring-like member. By succesively, 
arthroscopically disposing joint surface members 200' upon femur head 230, 
substantially all of spherical surface 237 of femur head 230 is covered by 
joint surface members 200', so as to form the femur head portion of 
replacement hip joint 70'. Likewise, by attaching a plurality of joint 
surface members 200' within acetabulum 235, the acetabulum 235 is 
substantially covered by joint surface members 200' to form the acetabulum 
portion of hip replacement joint 70'. After hip replacement joint 70' has 
been formed, femur head 230 is urged into acetabulum 235, so that femur 
head 230, with joint surface members 200' disposed thereon, articulates 
within acetabulum 235, having joint surface members 200' disposed thereon. 
It should be readily apparent to one of ordinary skill in the art that more 
than two elongate members 240 could be utilized to form the ring-like 
structure of two abutting joint surface members 200'. For example, four 
joint surface members 200' are utilized to form one of the ring-like 
structures in FIG. 21. It should be noted that in order for joint surface 
members 200' to be arthroscopically disposed upon femur head 230 and 
within acetabulum 235, as previously described, the height H and width W 
of elongate members 240 which form joint surface members 200' must be 
equal to or less than one centimeter, so that joint surface members 200' 
may be passed through an arthroscopic portal 30, as previously described. 
It is to be understood that the invention is not limited to the exact 
details of construction, operation, exact materials, or embodiments shown 
and described, as obvious modifications and equivalents will be apparent 
to one skilled in the art; for example, other cross-sectional 
configurations of the upper bearing surfaces could be utilized. 
Accordingly, the invention is therefore to be limited only by the scope of 
the appended claims.