A surgical aiming instrument for a lining and guiding a piercing tool used to make a tunnel through a tibia which intersects two predefined points of the knee joint includes at its distal end a tip to be temporarily inserted in the bone. The instrument further includes means for positioning the instrument...http://www.google.ca/patents/US5743909?utm_source=gb-gplus-sharePatent US5743909 - Radiological method for preoperative determination of isometric attachment points of an ACL graft, surgical aiming instrument and method of use 
