Periprosthetic Fractures Following Total Knee Arthroplasty

Abstract

Periprosthetic fractures following total knee arthroplasty are a potentially devastating complication to both the patient and the surgeon. Complication rates of treatment reported in the literature range widely, from 25 to 75 percent, even in the hands of both skilled and experienced surgeons1-4. A meta-analysis of 195 fractures in twelve published reports of ipsilateral supracondylar femoral fractures demonstrated complication rates of 30 percent with both nonoperative and operative treatment methods5. Various treatment modalities have been utilized to manage these challenging fractures. The purpose of this review is to analyze the prevalence, pathogenesis, mechanism of injury, risk factors, classification, and treatment of these fractures. ### Prevalence and Pathogenesis The reported prevalence of supracondylar femoral fracture following total knee arthroplasty has ranged from 0.3 to 2.5 percent3,6-12. Various factors have been implicated in the pathogenesis of this fracture. These include stress-shielding from the anterior flange of the femoral component, inadequate osseous remodeling due to postoperative hypovascularity, a relative difference in elastic modulus between the implant-covered distal part of the femur and the femoral cortex, endosteal ischemia from metal or bone cement13,14, and osteolysis of the distal part of the femur secondary to polyethylene wear debris15. The majority of these fractures result from a combination of axial and torsional loads10,16,17. Most occur following minimal falls, whereas others are secondary to motor-vehicle accidents, seizures, or closed manipulation of a stiff knee after total knee arthroplasty18. ### Risk Factors A review of the literature shows that patients with conditions associated with osteopenia are clearly at greater risk of sustaining a supracondylar femoral fracture after total knee arthroplasty4-7,10,19-24. Patients with rheumatoid arthritis2,4,7 …