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Evaluation of 2D Biomechanical Models of the Knee of One-Leg Stand for Total Knee Arthroplasty Planning

5 pagesPublished: June 13, 2017


Biomechanical models of the knee have the potential to predict joint mechanics and improve the therapeutic outcome. In case of total knee arthroplasty (TKA) knowledge on post-operative acting joint forces and its consideration in pre-operative planning might increase implant longevity and patient satisfaction. The goal of this study was to evaluate 2D biomechanical models of the knee suitable for pre-operative TKA planning and to validate them based on in vivo measurements of 9 patients treated with instrumented knee implants.
An extensive literature research on 2D biomechanical models of the knee with the requirement that patient-specific model adaption can be performed with data available in the conventional clinical workflow revealed the models of Maquet and Minns. Both models require one-leg stand AP long-leg radiographs and they output the resultant tibiofemoral joint force. For model validation, data from the freely accessible OrthoLoad database ( containing forces acting in orthopaedic implants have been used.
Looking at the results, Minns’s model was in the same range as the reference forces (deviation: -55 %BW to +80 %BW) as well as Maquet’s (deviation: -80 %BW to +50 %BW). Overall, the root-mean-square error (RMSE) was smallest for Minns’ model (48.36 %BW against 51.48 %BW). The patient-specific adaptation process plus simulation took 7 to 8 minutes making the models applicable in the conventional clinical workflow with acceptable costs.
In terms of clinical application, the models’ output might be consulted, e.g. to minimize the magnitude of the resultant joint force, target a specific orientation or load distribution in order to consider mechanical factors which might be associated with premature implant failure.

Keyphrases: Biomechanical Modelling, Biomechanics, Total knee arthroplasty, mathematical models, knee

In: Klaus Radermacher and Ferdinando Rodriguez Y Baena (editors). CAOS 2017. 17th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery, vol 1, pages 228--232

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