Osteochondral autograft or allograft?
For smaller defects autograft can be used, where the plug of cartilage and bone is harvested from the patient rather than a donor. Small plugs are harvested along the outer edges of the groove where there is less weight being borne. If the defect is too large for a single plug (OATS) then smaller plugs can be packed like a mosaic into the prepared area (mosaicplasty). For larger defects, cadaver femur can be purchased (pre-sterilised) and the plugs can be taken from that source (allograft).