A method for producing a customised orthopaedic implant is provided. The method involves scanning a bone from which a diseased region of bone will be resected to obtain a three dimensional digital image of an unresected volume of bone; scanning the bone after a diseased region of bone has been resected to obtain a corresponding three dimensional digital image of a resected volume of bone; and comparing the three dimensional digital image of the unresected volume of bone to the corresponding three dimensional digital image of the resected volume of bone to estimate a volume of bone that has been resected. The estimate of the volume of bone that has been resected is used to design a customised orthopaedic implant that substantially corresponds to the configuration of the resected volume of bone, the implant being configured to substantially restore a biomechanical function of the bone. Finally the customised orthopaedic implant is manufactured and provided for insertion into the resected region of bone.