Cemented and uncemented tibial components had different migration patterns .
For cemented tibial components there was no difference in migration between all-poly and metal-backed components , between mobile bearing and fixed bearing , between cruciate retaining and posterior stabilized .
Furthermore , no difference existed between TKR measured with model-based RSA or marker-based RSA methods .
For uncemented TKR there was some variation in migration with the highest migration for uncoated TKR .
Interpretation - The results from this meta- analysis on  RSA migration of TKR  are in line with both the survival analyses results from joint registries of these TKRs as well as revision rates results from meta-analyses , thus providing further proof for the association between early migration and late revision for loosening .
Purpose - We performed a systematic review and meta-analyses to evaluate the early and long-term migration patterns of  tibial components of TKR of all known RSA studies .
Mobile Bearings Do Not Improve Fixation in Cemented Total Knee Arthroplasty
Mobile bearings were introduced to improve wear and knee kinematics . By uncoupling the forces generated at the articulation from the implant-bone interface this would , theoretically , also improve the fixation of the implant to bone . We did this study to evaluate whether mobile bearings  improve the fixation of the tibial component to bone .  Fifty-two consecutive knees in 47 patients ( average age , 72 years ; range , 62 - 84 years ) with primary osteoarthrosis were r and omized into two groups to receive a cemented total knee arthroplasty with either a fixed-bearing or mobile-bearing tibial component . The quality of fixation was analyzed with radiostereometric analysis for up to 2 years . Mobile bearings did not improve fixation . Both magnitudes and directions of component rotations were similar , and the number of implants with continuous migration was almost identical . Both implant types had a combination of subsidence and lift-off , but where the mobile bearing implants displayed more of subsidence , the fixed bearing knees showed more lift-off . It might be that the somewhat stiffer cobalt-chromium baseplate or the different joint conformity used in the mobile-bearing knees counteracts any potential effects of the mobile bearing . Level of Evidence : Therapeutic Level I. See the Guidelines for Authors for a complete description of levels of evidence
Cemented and uncemented tibial components had different migration patterns .
For cemented tibial components there was no difference in migration between all-poly and metal-backed components , between mobile bearing and fixed bearing , between cruciate retaining and posterior stabilized .
Furthermore , no difference existed between TKR measured with model-based RSA or marker-based RSA methods .
For uncemented TKR there was some variation in migration with the highest migration for uncoated TKR .
Interpretation - The results from this meta- analysis on  RSA migration of TKR  are in line with both the survival analyses results from joint registries of these TKRs as well as revision rates results from meta-analyses , thus providing further proof for the association between early migration and late revision for loosening .
Purpose - We performed a systematic review and meta-analyses to evaluate the early and long-term migration patterns of  tibial components of TKR of all known RSA studies .