Particulate debris presenting as radiographic dense masses following total knee arthroplasty

Two cases of failed total knee arthroplasty associated with significant titanium debris that created massive radiographic densities are reported. The similarities of the failed total knee arthroplasties are that both involve titanium femoral components with failed metal-backed patellar components. At the time of surgical intervention, patellar polyethylene dissociation from metal-backed patellar components was noted with excessive burnishing and wear of the remaining metal-backed patellar component and of the titanium femoral component. Wear of the tibial polyethylene was noted in both cases. The titanium-on-titanium wear couple produced significant debris, resulting in large mass formation about the total knee arthroplasty. Additionally, there were loculated, fluid-filled sacks of titanium debris. Histologic sections performed for both cases revealed significant deposits of titanium in combination with polyethylene. In both cases, radiographs revealed the presence of large, radiodense masses. These cases illustrate that when considering etiologies for radiodense masses about total joint arthroplasty, particulate titanium debris resulting in mass formation must be added to the differential diagnosis.