In this procedure multiple 'plugs' of cartilage are removed from areas that are not needed (i.e. where the cartilage is not on a weight bearing area of the bone). Cartilage covers the joint areas where two bones contact each other. However, areas of cartilage also cover some non-contact points. This cartilage can be removed from the non weight-bearing surfaces. Corresponding holes are drilled in the damaged area to remove the unhealthy cartilage and replaced with the plugs. This gives the appearance of a mosaic.

