Gelenkbelastung & Muskel-Skelett-Analyse
Die Belastung künstlicher Gelenke und anderer orthopädischer Implantate ist noch immer teilweise unbekannt. Die auf diese Implantate einwirkenden Kräfte müssen daher für viele Zwecke ermittelt werden.
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Autoren:Trepczynski A, Kutzner I, Schutz P, Dymke J, List R, von Roth P, Moewis P, Bergmann G, Taylor WR, Duda GN
Titel:Tibio-Femoral Contact Force Distribution is Not the Only Factor Governing Pivot Location after Total Knee Arthroplasty
Total knee arthroplasty aims to mimic the natural knee kinematics by optimizing implant geometry, but it is not clear how loading relates to tibio-femoral anterior-posterior translation or internal-external pivoting. Tibio-femoral loading was measured using an instrumented tibial component in six total knee arthroplasty patients (aged 65-80y, 5-7y post-op) during 5-6 squat repetitions, while knee kinematics were captured using a mobile video-fluoroscope. In the range of congruent tibio-femoral contact the medial femoral condyle remained approximately static while the lateral condyle translated posteriorly by 4.1 mm (median). Beyond the congruent range, the medial and lateral condyle motions both abruptly changed to anterior sliding by 4.6 mm, and 2.6 mm respectively. On average, both the axial loading and pivot position were more medial near extension, and transferred to the lateral side in flexion. However, no consistent relationship between pivoting and load distribution was found across all patients throughout flexion, with R(2) values ranging from 0.00 to 0.65. Tibio-femoral kinematics is not related to the load distribution alone: medial loading of the knee does not necessarily imply a medial pivot location.
Zeitschrift (Journal):Sci Rep Jahr:2019; Jahrgang (Volume):9Ausgabe (Issue):(1):Seiten (Pages):182.
Autoren:Trepczynski A, Kutzner I, Schwachmeyer V, Heller MO, Pfitzner T, Duda GN
Titel:Impact of antagonistic muscle co-contraction on in vivo knee contact forces
BACKGROUND: The onset and progression of osteoarthritis, but also the wear and loosening of the components of an artificial joint, are commonly associated with mechanical overloading. Mechanical forces acting at the joints and understanding of the key factors that can alter them are critical to develop effective treatments for restoring joint function. While static anatomy is usually the clinical focus, less is known about the impact of dynamic factors, such as individual muscle recruitment, on joint contact forces. CONCLUSIONS: Treatment of diseased and failed joints should not only be restricted to anatomical reconstruction of static limb axes alignment. The dynamic activation of muscles, as a key modifier of lower limb biomechanics, should also be taken into account and thus also represents a promising target for restoring function, patient mobility, and preventing future joint failure. German Clinical Trials Register: ID: DRKS00000606
Zeitschrift (Journal):J Neuroeng Rehabil Jahr:2018; Jahrgang (Volume):15Ausgabe (Issue):(1):Seiten (Pages):101.