Wear of acrylic cement (methylene-polymethacrylate) can manifest as extraosseous cement granuloma or false aneurysm of the popliteal artery after total knee arthroplasty.

Wear particles of acrylic cement, similar to other biomaterials, can cause periprosthetic osteolysis and formation of extraosseous cement granuloma (ECG). Expansive granuloma can manifest as a tumorous mass adjacent to the knee prosthesis, or it even can damage the popliteal artery and lead to false aneurysm formation. Suspicion of these two conditions requires a complex diagnostic approach and eventually revision of the endoprosthesis itself or reparation of the popliteal artery. Despite the beneficial fixative properties of acrylic cement (methylene-polymethacrylate), which are important for implantation of joint prostheses, the acrylic cement can also cause severe complications related to the wear process.