The effect of movement on the holding power of screws in bone.
Movement between screw threads and bone inhibits bone formation, revascularization and remodeling of dead bone. Movement causes the screw to become enveloped by fibrous tissue in response to necrosis and resorption of adjacent dead cortical bone. This results in a radiologically discernible radiolucent "halo" about the screw, a certain sign of screw loosening.
D000818:Animals; D001863:Bone Screws; D001842:Bone and Bones / Q000000981:diagnostic imaging; D004285:Dogs; D005593:Fracture Fixation, Internal; D009038:Motion; D011859:Radiography; D013314:Stress, Mechanical; D013997:Time Factors