All design s demonstrated posterior – femoral translation and external rotation in kneeling , but posterior-stabilised design s were more posterior at maximal flexion when compared to cruciate retaining .
Modern  TKR prostheses are design ed to restore healthy kinematics including high flexion .
Kneeling is a dem and ing high-flexion activity .
There have been many studies of kneeling kinematics using a plethora of implant design s but no comprehensive comparisons .
Visualisation of contact patterns allows for quantification and comparison of knee kinematics .
The aim of this systematic review was to determine whether there are any differences in the kinematics of kneeling as a function of TKR design .
Contribution of geometric design parameters to knee implant performance: Conflicting impact of conformity on kinematics and contact mechanics.
BACKGROUND Articular geometry of knee implant has a competing impact on kinematics and contact mechanics of total knee arthroplasty ( TKA ) such that geometry with lower contact pressure will impose more constraints on knee kinematics . The geometric parameters that may cause this competing effect have not been well understood . This study aim ed to quantify the underlying relationships between implant geometry as input and its performance metrics as output . METHODS Parametric dimensions of a fixed-bearing cruciate retaining implant were  r and omized to generate a number of perturbed implant geometries . Performance metrics ( i.e. , maximum contact pressure , anterior-posterior range of motion [ A-P ROM ] and internal-external range of motion [ I-E ROM ] ) of each r and omized design were calculated using finite element analysis . The relative contributions of individual geometric variables to the performance metrics were then determined in terms of sensitivity indices ( SI ) . RESULTS The femoral and tibial distal or posterior radii and femoral frontal radius are the key parameters . In the sagittal plane , distal curvature of the femoral and tibial influenced both contact pressure , i.e. , SI=0.57 ; SI=0.65 , and A-P ROM , i.e. , SI=0.58 ; SI=0.6 , respectively . However , posterior curvature of the femoral and tibial implants had a smaller impact on the contact pressure , i.e. , SI=0.31 ; SI=0.23 and a higher impact on the I-E ROM , i.e. , SI=0.72 ; SI=0.58 . It is noteworthy that in the frontal plane , frontal radius of the femoral implant impacted both contact pressure ( SI=0.38 ) and I-E ROM ( SI=0.35 ) . CONCLUSION Findings of this study highlighted how changes in the conformity of the femoral and tibial can impact the performance metrics
All design s demonstrated posterior – femoral translation and external rotation in kneeling , but posterior-stabilised design s were more posterior at maximal flexion when compared to cruciate retaining .
Modern  TKR prostheses are design ed to restore healthy kinematics including high flexion .
Kneeling is a dem and ing high-flexion activity .
There have been many studies of kneeling kinematics using a plethora of implant design s but no comprehensive comparisons .
Visualisation of contact patterns allows for quantification and comparison of knee kinematics .
The aim of this systematic review was to determine whether there are any differences in the kinematics of kneeling as a function of TKR design .