High congruency MB insert design: stabilizing knee joint even with PCL deficiency
- 4 Downloads
PCL management and choice of insert design and mobility in total knee arthroplasty are still debated in the literature. Consequently, the purpose of this study was to analyze the biomechanics of a fixed and a mobile bearing total knee arthroplasty with conventional and ultra-congruent insert during walking and squat activities, using finite element analysis, and to check the performance in a knee with healthy and deficient PCL.
The study was based on an already validated and published knee model. Fixed bearing and mobile bearing cruciate-retain designs were selected for this study. Implant kinematics and kinetics were calculated, following previously experimental tests, during a walking cycle and a loaded squat in a knee with intact and with deficient PCL.
Mobile bearing design, due to its higher congruency, was able to complete the task in intact and deficient PCL conditions, with similar internal–external femoral rotation and with a slight higher anterior translation of the one of the intact knees. Such outcomes were also in agreement with the results of different experimental studies of native knee specimens under similar boundary conditions. Contrariwise, fixed bearing design was able to accomplish the task only in healthy PCL conditions.
Results demonstrated how the high congruency of the mobile bearing design is able to guarantee proper knee stability and kinematics even when the PCL is deficient. Instead, the fixed bearing insert, with lower congruency, is not able, in the absence of the PCL, to stabilize the joint inducing irregular kinematic pattern and component dislocation. Surgeons will have to consider these findings to guarantee the best outcome for the patient and the related change in stability in case of PCL deficiency.
KeywordsInsert design Biomechanics TKA PCL Kinematics Contact pressure
The author would like to thank Mr. Edoardo Bori for his precious help during the writing of the study.
This work was supported by FNRS (Fonds National de la Recherche Scientifique): CDR 19545501 and CDR 29155446 and by FER ULB (Fonds d’Encouragement à la Recherche): FER 2014 and FER 2017. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Compliance with ethical standards
Conflict of interest
The author is a paid consultant and receive research support from Link Orthopaedic.
NA, No IRB approval is needed for this study.
- 2.Arnout N, Vanlommel L, Vanlommel J, Luyckx JP, Labey L, Innocenti B, Victor J, Bellemans J (2015) Post-cam mechanics and tibiofemoral kinematics: a dynamic in vitro analysis of eight posterior-stabilized total knee designs. Knee Surg Sports Traumatol Arthrosc 23(11):3343–3353PubMedCrossRefGoogle Scholar
- 5.Brihault J, Navacchia A, Pianigiani S, Labey L, De Corte R, Pascale V, Innocenti B (2016) All-polyethylene tibial components generate higher stress and micromotions than metal-backed tibial components in total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 24(8):2550–2559PubMedCrossRefGoogle Scholar
- 27.Kelman GJ, Biden EN, Wyatt MP, Ritter MA, Colwell CW Jr (1999) Gait laboratory analysis of a posterior cruciate-sparing total knee arthroplasty in stair ascent and descent. Clin Orthop Relat Res 248:21–25Google Scholar
- 32.Luyckx T, Didden K, Vandenneucker H, Labey L, Innocenti B, Bellemans J (2009) Is there a biomechanical explanation for anterior knee pain in patients with patella alta? Influence of patellar height on patellofemoral contact force, contact area and contact pressure. J Bone Jt Surg (Br) 91(3):344–350CrossRefGoogle Scholar