Influence of component design on in vivo tibiofemoral contact patterns during kneeling after total knee arthroplasty: a systematic review and meta-analysis

Abstract

Purpose Modern TKR prostheses are designed to restore healthy kinematics including high fexion. Kneeling is a demanding high-fexion activity. There have been many studies of kneeling kinematics using a plethora of implant designs but no comprehensive comparisons. Visualisation of contact patterns allows for quantifcation and comparison of knee kinematics. The aim of this systematic review was to determine whether there are any diferences in the kinematics of kneeling as a function of TKR design. Methods A search of the published literature identifed 26 articles which were assessed for methodologic quality using the MINORS instrument. Contact patterns for diferent implant designs were compared at 90° and maximal fexion using quality-efects meta-analysis models. Results Twenty-fve diferent implants using six designs were reported. Most of the included studies had small-sample sizes, were non-consecutive, and did not have a direct comparison group. Only posterior-stabilised fxed-bearing and cruciateretaining fxed-bearing designs had data for more than 200 participants. Meta-analyses revealed that bicruciate-stabilised fxed-bearing designs appeared to achieve more fexion and the cruciate-retaining rotating-platform design achieved the least, but both included single studies only. All designs demonstrated posterior–femoral translation and external rotation in kneeling, but posterior-stabilised designs were more posterior at maximal fexion when compared to cruciate retaining. However, the heterogeneity of the mean estimates was substantial, and therefore, frm conclusions about relative behaviour cannot be drawn. Conclusion The high heterogeneity may be due to a combination of variability in the kneeling activity and variations in implant geometry within each design category. There remains a need for a high-quality prospective comparative studies to directly compare designs using a common method. Level of evidence Systematic review and meta-analysis Level IV