ARTICULAR SURFACE REPAIR

1 . Apparatus for repairing a bone, the apparatus comprising a prosthesis:

having:

a first face shaped to conform to a native articular bone surface and defining a perimeter; and

a second face shaped to conform to a bone surface prepared for receiving the prosthesis; and

defining two or more screw-holes adjacent the perimeter.

2 . The apparatus of claim 1 wherein the prosthesis defines, other than the screw-holes, no anchor pass-through.

3 . The apparatus of claim 1 wherein:

the prosthesis comprises a thickness between the first face and the second face;

a normal to the first face points in a first direction;

a normal to the second face points in a second direction; and

the first and second directions diverge.

4 . The apparatus of claim 1 wherein the prosthesis does not include an anchoring stem.

5 . The apparatus of claim 1 wherein the prosthesis does not include a fixture for receiving an anchoring stem.

6 - 7 . (canceled)

8 . The apparatus of claim 1 wherein the two or more holes are sized to receive a screw.

9 - 10 . (canceled)

11 . The apparatus of claim 1 wherein each of the two or more holes define a first opening on the first face and a second opening on the second face, the first opening being larger than the second opening.

12 . The apparatus of claim 1 wherein the second face is smooth.

13 . The apparatus of claim 1 wherein the prosthesis is dome-shaped.

14 . The apparatus of claim 13 wherein the prosthesis defines a truncated sphere.

15 . The apparatus of claim 1 wherein the first surface has a topography that includes one or more valleys and one or more hills.

16 . The apparatus of claim 1 wherein:

the two or more holes include:

a first hole having a diameter and a centroid that is at a first distance from the perimeter;

a second hole having a diameter and a centroid that is at a second distance from the perimeter;

a third hole having a diameter and a centroid that is at a third distance from the perimeter; and

each of the first, second and third distances is no less than 1.5 times the diameter.

17 - 33 . (canceled)

34 . The apparatus of claim 1 wherein the two or more holes are positioned, along a path that contours the perimeter, at uniform offsets from each other.

35 . The apparatus of claim 1 further comprising:

an anchoring hull defining a plurality of openings;

wherein:

the prosthesis and the anchoring hull are configured to be fixed together by screws or one or more tension-applying members; and

direct physical contact between the prosthesis and the anchoring hull, therapeutically in situ, does not effect an anchoring of the prosthesis to the anchoring hull.

36 . The apparatus of claim 35 wherein the prosthesis is not configured to mate with the anchoring hull.

37 . The apparatus of claim 35 wherein the prosthesis is not configured to snap into the anchoring hull.

38 . The apparatus of claim 35 wherein an abutment of the prosthesis against the anchoring hull does not rigidly couple the prosthesis to the anchoring hull.

39 . The apparatus of claim 35 wherein the plurality of openings are sized to receive screws having a length in the range 10 mm to 120 mm and a diameter in the range 1.1 mm to 10 mm.

40 . The apparatus of claim 35 wherein:

the plurality of openings defined by the anchoring hull has a first number of openings;

the two or more holes defined by the prosthesis have a second number of openings; and

the first number is at least ten times the second number.

41 . Apparatus for repairing a bone, the apparatus comprising:

first means for performing a function of native bone tissue;

second means for anchoring the first means to the bone; and

third means for fastening the first means to the second means.

42 . (canceled)

43 . A method for repairing a bone, the method comprising:

implanting an anchoring hull in an interior of the bone;

removing native articular bone to provide a prepared surface upon which to seat a prosthesis; and

seating the prosthesis on the prepared surface in a position in which the prosthesis is entirely spaced apart from the anchoring hull by a layer of native bone.

44 - 109 . (canceled)

110 . A method for repairing a bone the method comprising:

implanting, in an interior of the bone, an anchoring hull;

preparing an articular surface of the bone for receiving a prosthesis; and

placing a prosthesis on the prepared surface;

wherein:

the prosthesis abuts the anchoring hull; and

the abutment does not provide engagement between the prosthesis and the hull.

111 - 114 . (canceled)