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Undersizing the Tibial Baseplate in Cementless Total Knee Arthroplasty has Only a Small Impact on Bone-Implant Interaction: A Finite Element Biomechanical Study

Published:October 21, 2022DOI:https://doi.org/10.1016/j.arth.2022.10.032

      Abstract

      Background

      The tibial component in total knee arthroplasty (TKA) is often chosen to maximize coverage of the tibial cut, which can result in excessive internal rotation of the component. Optimal rotational alignment may require a smaller baseplate with suboptimal coverage that could threaten fixation. We asked: “does undersizing the tibial component of a cementless TKA to gain external rotation increase the risk of bone failure?”

      Methods

      We developed computational finite element (FE) analysis models from the computed tomography (CT) scans of 12 patients scheduled for primary TKA. The models were implanted with a cementless tibial baseplate that maximized coverage and one or two sizes smaller and externally rotated by 5°. We calculated the risk of bone collapse under loads representative of stair ascent.

      Results

      Undersizing the implant increased the area at risk of collapse for eight patients. However, the area at risk of collapse for the undersized implant (range, 5.2%-16.4%) was no different (P = .24) to the optimally sized implant (range, 4.5%-17.9%). The bone at risk of collapse was concentrated along the posterior edge of the implant. The area at risk of collapse was not proportional to implant size, and for four subjects undersizing the implant actually decreased the area at risk of collapse.

      Conclusion

      While implants should maximize coverage of the tibial cut and seek support on dense bone, undersizing the tibial component to gain external rotation had minimal impact on the load transfer to the underlying bone. This FE analysis model of a cementless tibial baseplate may require further validation and additional studies to investigate the long-term biomechanical effects of undersizing the tibial baseplate. In conclusion, while surgeons should strive to use the appropriate tibial baseplate for each patient, our model identified only minor biomechanical consequences of undersizing the implant for the immediate postoperative bone-implant interaction and implant subsidence.

      Keywords

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      References

        • Ryd L.
        • Albrektsson B.E.J.
        • Carlsson L.
        • Dansgard F.
        • Herberts P.
        • Lindstrand A.
        • et al.
        Roentgen stereophotogrammetric analysis as a predictor of mechanical loosening of knee prostheses.
        J Bone Joint Surg. 1995; 77-B: 377-383
        • Pijls B.G.
        • Plevier J.W.M.
        • Nelissen R.G.H.H.
        RSA migration of total knee replacements.
        Acta Orthop. 2018; 89: 320-328
        • Martin S.
        • Saurez A.
        • Ismaily S.
        • Ashfaq K.
        • Noble P.
        • Incavo S.J.
        Maximizing tibial coverage is detrimental to proper rotational alignment.
        Clin Orthop Relat Res. 2014; 472: 121-125
        • Berend M.E.
        • Ritter M.A.
        • Hyldahl H.C.
        • Meding J.B.
        • Redelman R.
        Implant migration and failure in total knee arthroplasty is related to body mass index and tibial component size.
        J Arthroplasty. 2008; 23: 104-109
        • Fehring T.K.
        • Fehring K.A.
        • Anderson L.A.
        • Otero J.E.
        • Springer B.D.
        Catastrophic varus collapse of the tibia in obese total knee arthroplasty.
        J Arthroplasty. 2016; 32: 1625-1629
        • Dunbar M.J.
        • Wilson D.A.J.
        • Henningar A.W.
        • Amirault J.D.
        • Gross M.
        • Reardon G.P.
        Fixation of a trabecular metal knee arthroplasty component.
        J Bone Joint Surg. 2009; 91: 1578-1586
        • Andersen M.R.
        • Winther N.
        • Lind T.
        • Schroder H.
        • Flivik G.
        • Petersen M.M.
        Monoblock versus modular polyethylene insert in uncemented total knee arthroplasty.
        Acta Orthop. 2016; 87: 607-614
        • Wojtowicz R.
        • Henricson A.
        • Nilsson K.G.
        • Crnalic S.
        Uncemented monoblock trabecular metal posterior stabilized high-flex total knee arthroplasty: similar pattern of migration to the cruciate-retaining design — a prospective radiostereometric analysis (RSA) and clinical evaluation of 40 patients (49 knees) 60 years or younger with 9 years’ follow-up.
        Acta Orthop. 2019; 90: 460-466
        • Wong J.
        • Steklov N.
        • Patil S.
        • Flores-Hernandez C.
        • Kester M.
        • Colwell Jr., C.W.
        • et al.
        Predicting the effect of tray malalignment on risk for bone damage and implant subsidence after total knee arthroplasty.
        J Orthop Res. 2011; 29: 347-353
        • Perillo-Marcone A.
        • Ryd L.
        • Johnsson K.
        • Taylor M.
        A combined RSA and FE study of the implanted proximal tibia: correlation of the post-operative mechanical environment with implant migration.
        J Biomech. 2004; 37: 1205-1213
        • Quevedo González F.J.
        • Lipman J.D.
        • Lo D.
        • De Martino I.
        • Sculco P.K.
        • Sculco T.P.
        • et al.
        Mechanical performance of cementless total knee replacements: it is not all about the maximum loads.
        J Orthop Res. 2019; 37: 350-357
        • Morgan E.F.
        • Keaveny T.M.
        Dependence of yield strain of human trabecular bone on anatomic site.
        J Biomech. 2001; 34: 69-577
        • Dendorfer S.
        • Maier H.J.
        • Taylor D.
        • Hammer J.
        Anisotropy of the fatigue behaviour of cancellous bone.
        J Biomech. 2008; 41: 636-641
        • Tuncer M.
        • Hansen U.N.
        • Amis A.A.
        Prediction of structural failure of tibial bone models under physiological loads: effect of CT density-modulus relationships.
        Med Eng Phys. 2014; 36: 991-997
        • Morgan E.F.
        • Bayraktar H.H.
        • Keaveny T.M.
        Trabecular bone modulus-density relationships depend on anatomic site.
        J Biomech. 2003; 36: 897-904
        • Snyder S.M.
        • Schneider E.
        Estimation of mechanical properties of cortical bone by computed tomography.
        J Orthop Res. 1991; 9: 422-431
        • Tuncer M.
        • Cobb J.P.
        • Hansen U.N.
        • Amis A.A.
        Validation of multiple subject-specific finite element models of unicompartmental knee replacement.
        Med Eng Phys. 2013; 35: 1457-1464
        • Bergmann G.
        • Bender A.
        • Graichen F.
        • Dymke J.
        • Rohlmann A.
        • Trepczynski A.
        • et al.
        Standardized loads acting in knee implants.
        PLoS One. 2014; 9: e86035
        • Lemaire P.
        • Pioletti D.P.
        • Meyer F.M.
        • Meuli R.
        • Dorfl J.
        • Leyvraz P.F.
        Tibial component positioning in total knee arthroplasty: bone coverage and extensor apparatus alignment.
        Knee Surg Sports Traumatol Arthrosc. 1997; 5: 251-257
        • Bonin M.P.
        • Schmidt A.
        • Basiglini L.
        • Bossard N.
        • Dantony E.
        Mediolateral oversizing influences pain, function, and flexion after TKA.
        Knee Surg Sports Traumatol Arthrosc. 2013; 21: 2314-2324
        • Mielsen C.S.
        • Nbergall A.
        • Huddleston J.
        • Kallemose T.
        • Malchau H.
        • Troelsen A.
        Medial overhang of the tibial component is associated with higher risk of inferior knee injury and osteoarthritis outcome score pain after knee replacement.
        J Arthroplasty. 2018; 33: 1394-1398
        • Quevedo González F.J.
        • Meyers K.N.
        • Schraut N.
        • Mehrotra K.G.
        • Lipman J.D.
        • Wright T.M.
        • et al.
        Do metaphyseal cones and stems provide any biomechanical advantage for moderate contained tibial defects in revision TKA? A finite-element analysis based on a cadaver model.
        Clin Orthop Relat Res. 2021; 479: 2534-2546