Periprosthetic osteolysis in total knee arthroplasty (TKA) has become a significant problem. Routine surveillance is warranted to detect problems that may not be symptomatic. The goal of these radiographs is to detect arthroplasty-related bone loss at an early stage to implement strategies to limit its extension. The purpose of this study was to show the extent to which condylar osteolysis can be underestimated on routine radiographs. Two cadaveric femurs were prepared to receive a posterior stabilized (PS) femoral component. A simulated osteolytic lesion was created using acetabular reamers. Lesions of 36 mm not easily discernible on standard anteroposterior and lateral images were easily recognized on oblique films. The oblique radiographs described can help with the early recognition of retrofemoral osteolysis about a posterior-stabilized implant.