An implant comprising a first, second, and third segment wherein the second and third segments partially overlap the first segment and define a load bearing surface comprising an anterior-posterior (AP) curvature including at least two tangential curves of the portion of the articular surface of the femoral condyle, the tangential curves having different radii of curvature. A drill guide comprises a body portion including a first, second and third bushing spaced along the body portion to establish a first, second and third axes, respectively. Each axis may be substantially normal to the articular surface at three different points along a curvature of the articular surface comprising the two tangential curves. A measuring device comprises a housing defining a longitudinally passageway and an outrigger. A guide pin may be received in the longitudinal passageway and a measuring device determines how far the guide pin is in the passageway.