Tangential Fit of Patient-Specific Guides

A bone preparation guide comprising:

• a plurality of first patient-specific bone contacting members customized based on two-dimensional image data of a specific patient to match the patient's specific bone geometry and provide a first bone coupling surface;
• a plurality of second patient-specific bone contacting members customized based on two-dimensional image data of the specific patient to match the patient's specific bone geometry and provide a second bone coupling surface;
• and
• a patient-generic portion configured as a bone-facing surface to be supported by the first and the second patient-specific bone contacting members at a portion of the patient's bone surface not imaged during preparation of a preoperative plan.

A method of customizing a bone preparation guide to correspond to specific bone geometry of a specific patient comprising:

• analyzing two-dimensional image data of the specific patient's own bone geometry;
• developing a pre-operative plan based on the patient's own two-dimensional image data, first and second patient-specific bone contacting members of the guide are configured pursuant to the pre-operative plan to match the patient's specific bone surface and couple the guide to the patient's own bone geometry, the first and the second patient-specific bone contacting members are further configured to support a patient-generic portion of the bone preparation guide over the bone such that the patient-generic portion faces a portion of the patient's bone surface not imaged during preparation of the pre-operative plan;
• coupling the guide to the patient's bone with the first and the second patient-specific bone contacting members;
• and
• guiding at least one of a first cutting instrument or a first guide member to the patient's bone using the guide.