Most common cause of THR failure
Acetabular loosening incereases with time
Improvement in technque have reduced femoral lossening
Radiography:
Lucency between cement and bone more than 2 mm
Prosthetic migration
Cement fracture
Peristeal reaction
Arthrography:
Acetabular loosening: 90% sensitive, 70% specific
Contrast in all zones, I & II, II & III, or I & III with pseudocapsule or bursa (there are 3 zones divided by 2 perpendicular lines drawn from the centre of the acetabulur line; the lateral is zone I, middle zone II and medial zone III)
Contrast more than 2 mm thick in any zone
Femoral lossening: 90% sensitive and specific
Contrast below intertrochontric line
References:
Resnick et al, Bone and joint imaging, 3rd edition, Elsevier Saunders publications
