Sharkey et al [13] found aseptic loosening to be the major cause of late stage (>2 years) TKA failure. Aseptic loosening may occur either because of inadequate primary fixation or because of failure after successful fixation. It is thought to result from mechanical stresses, osteolysis secondary to particle debris, or poor bone stock [21]. Loosening may be closely related to other forms of mechanical failure such as osteolysis, Imaging After Total Knee Arthroplasty instability, polyethylene liner wear, and periprosthetic fracture. Osteolysis is a leading cause of late TKA revision. Osteolysis, also known as particle disease and aggressive granulomatosis, occurs secondary to macrophage phagocytosis of particle debris. Debris originating from polyethylene, cement, and metal can all be causes of cell- mediated inflammatory response and osteolysis [113], but typically polyethylene is the most common cause. Areas of osteolysis contain granulation tissue with phagocytosed particulate debris [21]. The incidence of osteolysis is higher for cementless, compared with cemented TKA [114]. Osteolysis can occur anywhere but is more common in the region of the femoral condyles near the attachment of the collateral ligaments, along the periphery of the component, and along the access channels to the cancellous bone of the tibia, including screw holes [114,115]. Patients with osteolysis may be asymptomatic early on but can go on to develop pain, swelling, and acute synovitis. Although small areas of osteolysis may be monitored, the presence of large areas of osteolysis suggest component loosening and may require revision surgery [116]. Imaging can also help evaluate available bone stock in preparation for revision surgery. Instability refers to abnormal and excessive displacement of the articular surfaces of the prosthesis [21].
Imaging After Total Knee Arthroplasty. Sharkey et al [13] found aseptic loosening to be the major cause of late stage (>2 years) TKA failure. Aseptic loosening may occur either because of inadequate primary fixation or because of failure after successful fixation. It is thought to result from mechanical stresses, osteolysis secondary to particle debris, or poor bone stock [21]. Loosening may be closely related to other forms of mechanical failure such as osteolysis, Imaging After Total Knee Arthroplasty instability, polyethylene liner wear, and periprosthetic fracture. Osteolysis is a leading cause of late TKA revision. Osteolysis, also known as particle disease and aggressive granulomatosis, occurs secondary to macrophage phagocytosis of particle debris. Debris originating from polyethylene, cement, and metal can all be causes of cell- mediated inflammatory response and osteolysis [113], but typically polyethylene is the most common cause. Areas of osteolysis contain granulation tissue with phagocytosed particulate debris [21]. The incidence of osteolysis is higher for cementless, compared with cemented TKA [114]. Osteolysis can occur anywhere but is more common in the region of the femoral condyles near the attachment of the collateral ligaments, along the periphery of the component, and along the access channels to the cancellous bone of the tibia, including screw holes [114,115]. Patients with osteolysis may be asymptomatic early on but can go on to develop pain, swelling, and acute synovitis. Although small areas of osteolysis may be monitored, the presence of large areas of osteolysis suggest component loosening and may require revision surgery [116]. Imaging can also help evaluate available bone stock in preparation for revision surgery. Instability refers to abnormal and excessive displacement of the articular surfaces of the prosthesis [21].