INTERPRETATION There was a clinical ly relevant association between early migration of acetabular cups  and late revision due to loosening .
BACKGROUND AND PURPOSE The association between excessive early migration of acetabular cups  and late aseptic revision has been scantily reported .
We therefore performed 2 parallel systematic review s and meta-analyses to determine the association between early migration of acetabular cups  and late aseptic revision .
Does early micromotion of femoral stem prostheses matter? 4-7-year stereoradiographic follow-up of 84 cemented prostheses.
Roentgen stereophotogrammetry was used to measure the migration of the centre of the femoral head in 84 cemented Lubinus SP I hip arthroplasties ( 58 primary operations , 26 revisions ) . Four to seven years later , seven femoral components had been revised because of painful loosening . These implants showed greater subsidence , medial migration and posterior migration during the first two postoperative years than did the hips which had not been revised . Six months after operation , subsidence of more than 0.33 mm combined with a total migration of more than 0.85 mm predicted an increased risk of subsequent revision ; the amount of subsidence at two years was an even better predictor . The probability of revision was greater than 50 % if the subsidence at two years was 1.2 mm or more
INTERPRETATION There was a clinical ly relevant association between early migration of acetabular cups  and late revision due to loosening .
BACKGROUND AND PURPOSE The association between excessive early migration of acetabular cups  and late aseptic revision has been scantily reported .
We therefore performed 2 parallel systematic review s and meta-analyses to determine the association between early migration of acetabular cups  and late aseptic revision .