Instructional Course Lectures, The American Academy of Orthopaedic Surgeons - Periprosthetic Fractures Adjacent to Total Knee Implants. Treatment and Clinical Results*†

The unique characteristics that predispose patients to periprosthetic fractures make treatment difficult and unpredictable. Severe osteoporosis makes fracture fixation precarious. The typical elderly and debilitated patient must be mobilized rapidly to avoid medical complications brought on by prolonged bed rest and inactivity. However, walking with protected weight-bearing often is impossible because of multiple-joint involvement, neurological disorders, and systemic illness. In most instances, early and definitive treatment is preferable to a prolonged period of bed rest and inactivity. Periprosthetic fractures may occur intraoperatively or postoperatively. The best treatment technique depends on whether the fracture is identified intraoperatively or postoperatively as well as on its location and severity. Common fracture-repair techniques, such as those involving use of a plate and screws, intramedullary rods, and external fixators, have been associated with variable rates of success. This paper examines the role of different techniques for management of the fracture and revision of the component in the treatment of periprosthetic fractures. Periprosthetic fractures that occur during a knee-replacement arthroplasty are rarely as challenging to treat as fractures that occur in the postoperative period. Most intraoperative fractures are neither displaced nor comminuted, the stability of the components is rarely altered, and the fractures are not associated with soft-tissue trauma. Treatment techniques that permit the patient to exercise safely during the early postoperative period should lead to an optimum clinical outcome. Usually, screws are adequate for stabilizing the fracture, and the patient may safely proceed with an unaltered rehabilitation protocol. ### Femoral Fractures When a fracture that splits the condyles occurs while the surgeon is making the box cut for a posterior stabilized component (Fig. 1-A), a transcondylar cancellous-bone screw can be used to stabilize the fracture. One screw usually is sufficient because the cement and the femoral component provide additional stability. If the metaphyseal bone is soft, a washer …