We found moderate to strong evidence that no adverse effects on subsidence and osseous integration of the femoral stem after uncemented THA occur after immediate UWB .
The aim of this systematic review was to find evidence -based support in the literature to allow immediate unrestricted weight bearing after  primary uncemented total hip arthroplasty ( THA ) .
Accelerated rehabilitation programs for THA are becoming increasingly popular to shorten hospital stay and to facilitate rapid restoration of function .
The goals of these rehabilitation programs could be more easily achieved if immediate unrestricted weight bearing ( UWB ) could be allowed after a THA .
So far , however , immediate weight bearing is frequently contraindicated in widely accepted protocol s for uncemented THA due to fear for subsidence and absence of osseous integration of the femoral stem .
Thus , frequently protected weight bearing and restricted activities are still advocated for at least 6 weeks after surgery .
In addition , we analyzed the literature to come to a recommendation on gait pattern and walking aid .
Early migration and late aseptic failure of proximal femoral prostheses.
The  vertical migration of four configurations of a proximal femoral prosthesis , followed for up to nine years , was measured on st and ard radiographs . The same implant was used without cement ( group 1 ) and with cement ( group 2 ) . The migration of both groups was linear from six months onwards . The mean migration rate and the incidence of late aseptic loosening were both greater in group 1 . Survival analysis of the two groups , however , showed no statistically significant difference . In both groups , hips later destined for revision migrated more rapidly from the initial postoperative period onwards , than did the remainder . A threshold migration of 1.2 mm/year during the first two years after implantation detected hips likely to fail with a specificity of 86 % and a sensitivity of 78 % . This ' migration test ' was applied to the results in two further groups of patients in which a modified femoral prosthesis had been implanted without hydroxyapatite coating ( group 3 ) and with hydroxyapatite coating  ( group 4 ) . The test distinguished between the four groups and suggested that at least two fixation procedures should be ab and oned . We conclude that vertical migration measured on st and ard radiographs in the first two years after implantation can be used to predict late aseptic loosening . New prosthetic configurations should be evaluated by migration measurements before their general release . Our observations support the view that one cause of late aseptic loosening is imperfect initial fixation
We found moderate to strong evidence that no adverse effects on subsidence and osseous integration of the femoral stem after uncemented THA occur after immediate UWB .
The aim of this systematic review was to find evidence -based support in the literature to allow immediate unrestricted weight bearing after  primary uncemented total hip arthroplasty ( THA ) .
Accelerated rehabilitation programs for THA are becoming increasingly popular to shorten hospital stay and to facilitate rapid restoration of function .
The goals of these rehabilitation programs could be more easily achieved if immediate unrestricted weight bearing ( UWB ) could be allowed after a THA .
So far , however , immediate weight bearing is frequently contraindicated in widely accepted protocol s for uncemented THA due to fear for subsidence and absence of osseous integration of the femoral stem .
Thus , frequently protected weight bearing and restricted activities are still advocated for at least 6 weeks after surgery .
In addition , we analyzed the literature to come to a recommendation on gait pattern and walking aid .