Systems and methods for determining the mechanical axis of a femur

A method of providing a patient-specific surgical item comprising:

• gathering patient-specific anatomical data of a limb;
• using the patient-specific anatomical data to determine a three dimensional mechanical axis of the limb by:
• identifying a first anatomical landmark and a second anatomical landmark of the limb;
• defining a first spatial relationship as a line extending between the first and second anatomical landmarks of the limb;
• identifying a third anatomical landmark of the limb;
• defining a second spatial relationship as a line that runs through the third anatomical landmark parallel to the first spatial relationship;
• and
• identifying a fourth anatomical landmark of the limb;
• manufacturing the patient-specific surgical item based at least partially on the determined three dimensional mechanical axis of the limb;
• and
• orienting the patient-specific surgical item on the limb using at least the first and second spatial relationships and the fourth anatomical landmark.

A method of determining anatomical orientations with respect to a limb, the method comprising:

• identifying a first anatomical landmark and a second anatomical landmark of the limb;
• defining a first spatial relationship as a line extending between the first and second anatomical landmarks of the limb;
• identifying a third anatomical landmark of the limb;
• defining a second spatial relationship as a line extending through the third anatomical landmark parallel to the first spatial relationship;
• and
• determining a positioning of a profile of a prosthetic component with respect to the limb using at least the first spatial relationship and the second spatial relationship.