Method of implanting a unicondylar knee prosthesis

A method of sizing a lateral unicondylar knee prosthesis for implantation in a lateral articulating portion of a femur having a lateral condyle for engagement with a tibia, the method comprising the steps of:

• bending a patient's knee such that the knee is not in full extension;
• making an incision through the skin, muscle, and other soft tissue until the damaged bone surfaces are exposed;
• resecting an end portion of the lateral tibia;
• inserting a tibial template component and fully extending the knee to confirm sufficient tibia resection;
• resecting an end portion of the lateral femoral condyle;
• inserting a lateral femoral template component and fully extending the knee to confirm sufficient femoral resection;
• inserting a mobile bearing template member between the tibial template component and the lateral femoral template component and fully extending the knee to determine an appropriate mobile bearing template thickness so that a lateral collateral ligament is tight in full knee extension and is slack in knee flexion;
• and
• sizing the prosthesis based on the tibial template component, the lateral femoral template component, and the mobile bearing template member to provide free movement of the knee, wherein the step of resecting the end portion of the lateral tibia comprises:
• sawing vertically a cut through the center of a patella tendon positioned in line with the medial side of the lateral femoral condyle;
• and sawing horizontally a cut that removes bone to approximately 8 mm below the original tibial articular surface or 2 to 3 mm below the eburnated bone of the tibia to accommodate a tibial prosthetic component and a mobile bearing member with the knee in full extension.