The sclerotic line: Why it appears under knee replacements (a study based on the Oxford Knee)

Abstract

Background: Radiolucent lines and sclerotic margins are often seen on knee radiographs taken a year or longer after knee replacement surgery. Histology has shown that the radiolucent zone is predominantly fibrocartilage and the sclerotic margin is lamellar bone. The reasons for their existence are not clearly understood. Methods: A three-dimensional finite element model of the medial half of the proximal 75 mm of a tibia implanted with a knee replacement was created and run over 365 iterations simulating 1 year of in vivo post implant remodelling. After each iteration, new material properties were calculated for all elements of the model using established bone remodelling and tissue differen..