Classification and preoperative radiographic evaluation: knee.

Preoperative radiographic planning for revision total knee arthroplasty begins with obtaining excellent quality AP and lateral radiographs that permit: 1. Evaluation of the extent of bone loss in the metaphyseal region of the femur and tibia. 2. Full visualization of the patient's intramedullary canal for determining appropriate stem size and length. The surgeon should then determine the appropriate bone defect classification, keeping in mind the provisions needed to address Type 2 and 3 defects. These provisions include any augments or allografts, stemmed components, and the degree of component constraint needed in the patient's revision surgery. Through preoperative templating, the surgeon can determine whether a particular implant system provides the options necessary to achieve an optimal surgical result. Whenever templating leaves unanswered questions regarding the extent of bone damage or the degree of knee instability, the surgeon must prepare for the worst case scenario to ensure that the appropriate components and graft material are made available.