INTERPRETATION There was a clinical ly relevant association between early migration of TKPs and late revision for loosening .
PURPOSE We performed two parallel systematic review s and meta-analyses to determine the association between early migration of tibial components and late aseptic revision .
Flat vs. concave tibial joint surface in total knee arthroplasty: Randomized evaluation of 39 cases using radiostereometry
40 patients with non-inflammatory arthrosis and minor preoperative deformity ( / 5 ° ) were operated on with an AMK type ( DePuy , Johnson & Johnson ) total knee arthroplasty ( TKA ) . The posterior cruciate ligament was retained . The patients were divided into those with a flat ( terminology of the manufacturer : st and ard ) or a concave ( terminology of the manufacturer : constrained ) polyethylene insert ( 20 in each group ) .  Radiostereometric ( RSA ) examinations were done postoperatively and after 3 , 12 and 24 months . The median absolute rotations of the tibial inserts varied between 0.12 and 0.24 ( range 0.00 - 1.54 ) degrees , with no differences between the 2 groups . The median maximum totalpoint motions ( flat/concave = 0.41/0.42 mm ) , the maximum subsidence or lift-off did not differ . The Hospital for Special Surgery knee score and the patients ' opinion about the operation , based on their preoperative expectations , showed little , if any , differences . At 2 years , 10 of 20 patients with flat and 13 of 19 with concave inserts regarded their knee function as normal or almost so
INTERPRETATION There was a clinical ly relevant association between early migration of TKPs and late revision for loosening .
PURPOSE We performed two parallel systematic review s and meta-analyses to determine the association between early migration of tibial components and late aseptic revision .