63 the surgeon may make the decision either upon manual review of the patient 39 s 3d bone geometry 69 or using the surgical plan database 58 or any similar data storage alternatively module b 46 may perform similar decision making based on a comparison with the data stored in the surgical plan database 60 if there is a past case that involves a bone having similar 3d geometry as the current patient 39 s bone 63 then the surgeon may instruct at step 142 module b 46 to read the surgical data associated with the past case from the surgical plan database 60 alternatively upon finding a matching or similar past case module b 46 may automatically perform a search of the surgical plan database 60 to retrieve and send pertinent past surgical data to the surgeon at the remote site 32 so that the surgeon may determine whether to follow the steps performed earlier in another case or to alter or improve the earlier executed surgical plan whether there is a past similar case or not the surgical planner module 46 generates a specification of the osteotomy site s and of the target geometry e g the mounting arrangement 75 in fig4 at.