The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty

Marco Antonio Marra, Marta Strzelczak, Petra J.C. Heesterbeek, Sebastiaan A.W. van de Groes, Dennis W. Janssen, H.F.J.M. Koopman, A.B. Wymenga, N.J.J. Verdonschot

    Research output: Contribution to conferenceAbstract

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    Abstract

    Introduction/Aim: More posterior tibial slope (PTS) can potentially prevent flexion gap tightness in Total Knee Arthroplasty (TKA). However, the effects of more PTS on knee laxity remain unclear. The aim of this study was to investigate the effect of PTS on the anterior-posterior (AP) and varus-valgus (VV) laxity in TKA. We hypothesised that the effects also depend on whether an anterior tibial cortex-referencing (ACR) technique or a centre of tibial plateau-referencing (CPR) technique is used.
    Materials and Methods: A previous validated musculoskeletal model of cruciate-retaining TKA was configured to simulate AP and VV laxity tests [1]. First the model was simulated without any external loads applied, with the knee spanning a 0-90° flexion range of motion (ROM). Subsequently, anterior and posterior loads of 70 N were applied alternately to the proximal tibia, and the resulting AP tibial displacement recorded throughout the knee ROM. Similarly, varus and valgus loads of 15 Nm were applied alternately to the tibia, and the resulting knee VV rotation recorded. The simulations were repeated with -3°, +3°, +6°, +9° of PTS both with the ACR and CPR techniques (Fig. 1). Laxity were calculated as the unloaded case curves minus the loaded case curves.
    Results: More PTS with the ACR technique increased dramatically the anterior, varus and valgus laxities, throughout the knee flexion ROM. The anterior laxity was maximal (23 mm) at 60° of knee flexion in the +9° ACR case. Conversely, variations of PTS with the CPR technique hardly affected the AP and VV laxities.
    Discussion: More PTS with the ACR technique compromises the overall knee stability, throughout the knee flexion-extension ROM and, most interestingly, also in extension. This is due to an increase of the flexion gap. In contrast, the CPR technique preserves the translational and rotational laxities of the knee, throughout the ROM. CPR could be achieved by pre-planning the PTS and by accurately executing the tibial cut or by using inserts with built-in PTS.
    Conclusions: More PTS with the ACR technique has large effects on knee stability and laxity, therefore surgeons should avoid increasing PTS using the ACR technique and, instead, reference the tibial cut height and slope from the posterior one third of the tibia.
    References: [1] Marra MA, Vanheule V, Fluit R, et al. A Subject-Specific Musculoskeletal Modeling Framework to Predict In Vivo Mechanics of Total Knee Arthroplasty. ASME. J Biomech Eng. 2015;137(2):020904-020904-12
    Original languageEnglish
    Publication statusPublished - 20 Apr 2017
    EventEuropean Knee Society Conference 2017 - London, United Kingdom
    Duration: 20 Apr 201721 Apr 2017
    http://eks.congresses.medicongress.com/eks-2017/welcome

    Conference

    ConferenceEuropean Knee Society Conference 2017
    Abbreviated titleEKS 2017
    CountryUnited Kingdom
    CityLondon
    Period20/04/1721/04/17
    Internet address

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    Knee Replacement Arthroplasties
    Knee
    Articular Range of Motion
    Tibia
    Mechanics

    Cite this

    Marra, M. A., Strzelczak, M., Heesterbeek, P. J. C., van de Groes, S. A. W., Janssen, D. W., Koopman, H. F. J. M., ... Verdonschot, N. J. J. (2017). The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty. Abstract from European Knee Society Conference 2017, London, United Kingdom.
    Marra, Marco Antonio ; Strzelczak, Marta ; Heesterbeek, Petra J.C. ; van de Groes, Sebastiaan A.W. ; Janssen, Dennis W. ; Koopman, H.F.J.M. ; Wymenga, A.B. ; Verdonschot, N.J.J. / The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty. Abstract from European Knee Society Conference 2017, London, United Kingdom.
    @conference{3211e83c7bbe4e07a5310043ab57c888,
    title = "The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty",
    abstract = "Introduction/Aim: More posterior tibial slope (PTS) can potentially prevent flexion gap tightness in Total Knee Arthroplasty (TKA). However, the effects of more PTS on knee laxity remain unclear. The aim of this study was to investigate the effect of PTS on the anterior-posterior (AP) and varus-valgus (VV) laxity in TKA. We hypothesised that the effects also depend on whether an anterior tibial cortex-referencing (ACR) technique or a centre of tibial plateau-referencing (CPR) technique is used.Materials and Methods: A previous validated musculoskeletal model of cruciate-retaining TKA was configured to simulate AP and VV laxity tests [1]. First the model was simulated without any external loads applied, with the knee spanning a 0-90° flexion range of motion (ROM). Subsequently, anterior and posterior loads of 70 N were applied alternately to the proximal tibia, and the resulting AP tibial displacement recorded throughout the knee ROM. Similarly, varus and valgus loads of 15 Nm were applied alternately to the tibia, and the resulting knee VV rotation recorded. The simulations were repeated with -3°, +3°, +6°, +9° of PTS both with the ACR and CPR techniques (Fig. 1). Laxity were calculated as the unloaded case curves minus the loaded case curves.Results: More PTS with the ACR technique increased dramatically the anterior, varus and valgus laxities, throughout the knee flexion ROM. The anterior laxity was maximal (23 mm) at 60° of knee flexion in the +9° ACR case. Conversely, variations of PTS with the CPR technique hardly affected the AP and VV laxities.Discussion: More PTS with the ACR technique compromises the overall knee stability, throughout the knee flexion-extension ROM and, most interestingly, also in extension. This is due to an increase of the flexion gap. In contrast, the CPR technique preserves the translational and rotational laxities of the knee, throughout the ROM. CPR could be achieved by pre-planning the PTS and by accurately executing the tibial cut or by using inserts with built-in PTS.Conclusions: More PTS with the ACR technique has large effects on knee stability and laxity, therefore surgeons should avoid increasing PTS using the ACR technique and, instead, reference the tibial cut height and slope from the posterior one third of the tibia.References: [1] Marra MA, Vanheule V, Fluit R, et al. A Subject-Specific Musculoskeletal Modeling Framework to Predict In Vivo Mechanics of Total Knee Arthroplasty. ASME. J Biomech Eng. 2015;137(2):020904-020904-12",
    author = "Marra, {Marco Antonio} and Marta Strzelczak and Heesterbeek, {Petra J.C.} and {van de Groes}, {Sebastiaan A.W.} and Janssen, {Dennis W.} and H.F.J.M. Koopman and A.B. Wymenga and N.J.J. Verdonschot",
    year = "2017",
    month = "4",
    day = "20",
    language = "English",
    note = "European Knee Society Conference 2017, EKS 2017 ; Conference date: 20-04-2017 Through 21-04-2017",
    url = "http://eks.congresses.medicongress.com/eks-2017/welcome",

    }

    Marra, MA, Strzelczak, M, Heesterbeek, PJC, van de Groes, SAW, Janssen, DW, Koopman, HFJM, Wymenga, AB & Verdonschot, NJJ 2017, 'The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty' European Knee Society Conference 2017, London, United Kingdom, 20/04/17 - 21/04/17, .

    The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty. / Marra, Marco Antonio; Strzelczak, Marta; Heesterbeek, Petra J.C.; van de Groes, Sebastiaan A.W.; Janssen, Dennis W.; Koopman, H.F.J.M.; Wymenga, A.B.; Verdonschot, N.J.J.

    2017. Abstract from European Knee Society Conference 2017, London, United Kingdom.

    Research output: Contribution to conferenceAbstract

    TY - CONF

    T1 - The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty

    AU - Marra, Marco Antonio

    AU - Strzelczak, Marta

    AU - Heesterbeek, Petra J.C.

    AU - van de Groes, Sebastiaan A.W.

    AU - Janssen, Dennis W.

    AU - Koopman, H.F.J.M.

    AU - Wymenga, A.B.

    AU - Verdonschot, N.J.J.

    PY - 2017/4/20

    Y1 - 2017/4/20

    N2 - Introduction/Aim: More posterior tibial slope (PTS) can potentially prevent flexion gap tightness in Total Knee Arthroplasty (TKA). However, the effects of more PTS on knee laxity remain unclear. The aim of this study was to investigate the effect of PTS on the anterior-posterior (AP) and varus-valgus (VV) laxity in TKA. We hypothesised that the effects also depend on whether an anterior tibial cortex-referencing (ACR) technique or a centre of tibial plateau-referencing (CPR) technique is used.Materials and Methods: A previous validated musculoskeletal model of cruciate-retaining TKA was configured to simulate AP and VV laxity tests [1]. First the model was simulated without any external loads applied, with the knee spanning a 0-90° flexion range of motion (ROM). Subsequently, anterior and posterior loads of 70 N were applied alternately to the proximal tibia, and the resulting AP tibial displacement recorded throughout the knee ROM. Similarly, varus and valgus loads of 15 Nm were applied alternately to the tibia, and the resulting knee VV rotation recorded. The simulations were repeated with -3°, +3°, +6°, +9° of PTS both with the ACR and CPR techniques (Fig. 1). Laxity were calculated as the unloaded case curves minus the loaded case curves.Results: More PTS with the ACR technique increased dramatically the anterior, varus and valgus laxities, throughout the knee flexion ROM. The anterior laxity was maximal (23 mm) at 60° of knee flexion in the +9° ACR case. Conversely, variations of PTS with the CPR technique hardly affected the AP and VV laxities.Discussion: More PTS with the ACR technique compromises the overall knee stability, throughout the knee flexion-extension ROM and, most interestingly, also in extension. This is due to an increase of the flexion gap. In contrast, the CPR technique preserves the translational and rotational laxities of the knee, throughout the ROM. CPR could be achieved by pre-planning the PTS and by accurately executing the tibial cut or by using inserts with built-in PTS.Conclusions: More PTS with the ACR technique has large effects on knee stability and laxity, therefore surgeons should avoid increasing PTS using the ACR technique and, instead, reference the tibial cut height and slope from the posterior one third of the tibia.References: [1] Marra MA, Vanheule V, Fluit R, et al. A Subject-Specific Musculoskeletal Modeling Framework to Predict In Vivo Mechanics of Total Knee Arthroplasty. ASME. J Biomech Eng. 2015;137(2):020904-020904-12

    AB - Introduction/Aim: More posterior tibial slope (PTS) can potentially prevent flexion gap tightness in Total Knee Arthroplasty (TKA). However, the effects of more PTS on knee laxity remain unclear. The aim of this study was to investigate the effect of PTS on the anterior-posterior (AP) and varus-valgus (VV) laxity in TKA. We hypothesised that the effects also depend on whether an anterior tibial cortex-referencing (ACR) technique or a centre of tibial plateau-referencing (CPR) technique is used.Materials and Methods: A previous validated musculoskeletal model of cruciate-retaining TKA was configured to simulate AP and VV laxity tests [1]. First the model was simulated without any external loads applied, with the knee spanning a 0-90° flexion range of motion (ROM). Subsequently, anterior and posterior loads of 70 N were applied alternately to the proximal tibia, and the resulting AP tibial displacement recorded throughout the knee ROM. Similarly, varus and valgus loads of 15 Nm were applied alternately to the tibia, and the resulting knee VV rotation recorded. The simulations were repeated with -3°, +3°, +6°, +9° of PTS both with the ACR and CPR techniques (Fig. 1). Laxity were calculated as the unloaded case curves minus the loaded case curves.Results: More PTS with the ACR technique increased dramatically the anterior, varus and valgus laxities, throughout the knee flexion ROM. The anterior laxity was maximal (23 mm) at 60° of knee flexion in the +9° ACR case. Conversely, variations of PTS with the CPR technique hardly affected the AP and VV laxities.Discussion: More PTS with the ACR technique compromises the overall knee stability, throughout the knee flexion-extension ROM and, most interestingly, also in extension. This is due to an increase of the flexion gap. In contrast, the CPR technique preserves the translational and rotational laxities of the knee, throughout the ROM. CPR could be achieved by pre-planning the PTS and by accurately executing the tibial cut or by using inserts with built-in PTS.Conclusions: More PTS with the ACR technique has large effects on knee stability and laxity, therefore surgeons should avoid increasing PTS using the ACR technique and, instead, reference the tibial cut height and slope from the posterior one third of the tibia.References: [1] Marra MA, Vanheule V, Fluit R, et al. A Subject-Specific Musculoskeletal Modeling Framework to Predict In Vivo Mechanics of Total Knee Arthroplasty. ASME. J Biomech Eng. 2015;137(2):020904-020904-12

    M3 - Abstract

    ER -

    Marra MA, Strzelczak M, Heesterbeek PJC, van de Groes SAW, Janssen DW, Koopman HFJM et al. The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining total knee arthroplasty. 2017. Abstract from European Knee Society Conference 2017, London, United Kingdom.