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 .
In vivo deep-flexion kinematics in patients with posterior-cruciate retaining and anterior-cruciate substituting total knee arthroplasty.
BACKGROUND Posterior-cruciate ligament retaining total knee arthroplasty design s have long been used with excellent clinical success , but often have shown kinematics and flexion performance that are significantly different from the natural knee . The purpose of this study was to compare deep-flexion knee kinematics in patients with two types of posterior-cruciate ligament retaining total knee arthroplasty .  METHODS One group received a traditional curved symmetric articular configuration , and one group received a design incorporating a lateral compartment which constrains the lateral condyle to the antero-posterior center of the tibial plateau in extension , but allows translation in flexion -- roughly approximating the role of the anterior cruciate ligament . In vivo kinematics were analyzed using three-dimensional model registration and plain radiographs of kneeling and squatting activities in 20 knees in 18 patients . FINDINGS Knees with the anterior cruciate ligament substituting design exhibited greater flexion , femoral antero-posterior translation and tibial internal rotation . INTERPRETATION Geometric features intended to improve knee flexion , including greater antero-posterior stability , a more posterior tibial sulcus , and reshaped femoral condyles , do provide measurable and significant differences in deep-flexion knee kinematics
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 .