Search our Database of Scientific Publications and Authors

I’m looking for a

    Details and Download Full Text PDF:
    Malrotation in total knee arthroplasty: effect on tibial cortex strain captured by laser-based strain acquisition.

    Clin Biomech (Bristol, Avon) 2006 Jul 22;21(6):603-9. Epub 2006 Mar 22.
    STRYKER Europe, Department for Scientific Affairs, Florastrasse 13, 8800 Thalwil, Switzerland.
    Background: Malrotation of the tibial and femoral components has been recognized to be a clinical complication affecting the performance and durability of total knee arthroplasty. This study used a novel strain acquisition technique to determine the effect of tibio-femoral component malrotation on tibial torque and strain distribution of the proximal tibial cortex with a cemented fixed-bearing posterior-stabilized knee.

    Methods: Using electronic speckle pattern interferometry, strain on the proximal tibia of human cadaveric knees was obtained in response to 1500N axial loading for neutrally aligned tibial and femoral components, and for 10 degrees internal and external malrotation between the tibial and femoral components. Local strain gage measurements were combined with full-field optical strain measurements to quantify effects on tibial cortex strain and strain distributions caused by the 10 degrees malrotations. In addition, tibial torque was measured for incremental degrees of tibio-femoral malrotation.

    Findings: Tibio-femoral malrotations as small as 2 degrees caused tibial torque in excess of 4 Nm. At 10 degrees malrotation, tibial torque significantly increased to over 8 Nm (P<0.001) as compared to neutrally aligned components. Local strain gage results significantly increased from 500 muepsilon to 632 muepsilon compressive strain in response to 10 degrees external malrotation, and to 1000 muepsilon compressive strain in response to 10 degrees internal malrotation. Full-field optical strain reports yielded the highest strain of 2153 muepsilon for 10 degrees internal malrotation 30 mm below the joint line.

    Interpretation: Laser-based strain measurement technology provides novel capabilities to capture cortex strain fields. The sensitivity of cortex strain and torsion to small amounts of tibio-femoral malrotation may explain factors contributing to aseptic implant loosening of the tibial component.
    PDF Download - Full Text Link
    ( Please be advised that this article is hosted on an external website not affiliated with
    Source Status ListingPossible

    Similar Publications

    A mobile-bearing knee prosthesis can reduce strain at the proximal tibia.
    Clin Orthop Relat Res 2006 Jun;447:105-11
    Biomechanics Laboratory, Legacy Research & Technology Center, Portland, OR 97232, USA.
    Mobile and fixed-bearing knee prostheses are likely to generate distinct strain gradients in the proximal tibia. The resulting strain distribution in the proximal tibia governs bone remodeling and affects implant integration and stability. We determined the effects of fixed and mobile-bearing total knee prostheses on strain distribution at the proximal tibia. Read More
    Varus and valgus flexion laxity of total knee alignment methods in loaded cadaveric knees.
    Clin Orthop Relat Res 2002 Jan(394):243-53
    Department of Orthopaedic Surgery, University of Zurich, Switzerland.
    Both total knee alignment methods, the anatomic and classic, seek to achieve stability in flexion and extension. However, posterior femoral condyle referencing (anatomic alignment) combined with perpendicular tibial resection (classic alignment) results in a 3 degree relative internal rotation of the femoral component with lateral joint opening. The current cadaver study investigated the influence of total knee alignment methods and femoral component malrotation (3 degrees and 6 degrees internal and external malrotation) on femorotibial laxity. Read More
    The effect of femoral component malrotation on patellar biomechanics.
    J Biomech 2008 Dec 18;41(16):3332-9. Epub 2008 Nov 18.
    Scientific Affairs, Stryker Europe, Thalwil, Switzerland.
    Patellofemoral complications are among the important reasons for revision knee arthroplasty. Femoral component malposition has been implicated in patellofemoral maltracking, which is associated with anterior knee pain, subluxation, fracture, wear, and aseptic loosening. Rotating-platform mobile bearings compensate for malrotation between the tibial and femoral components and may, therefore, reduce any associated patellofemoral maltracking. Read More
    [Influence of rotatory malposition of femoral implant in failure of unicompartimental medial knee prosthesis].
    Rev Chir Orthop Reparatrice Appar Mot 2006 Sep;92(5):473-84
    Centre Orthos, 427, rue Paradis, 13008 Marseille.
    Purpose Of The Study: Rotatory malposition of the femoral component of a unicompartmental knee arthroplasty (UKA) is a key element of mechanical failure despite proper alignment and position of the tibial implant. The purpose of this study was to describe a method for measuring femoral implant rotation on the anteroposterior x-ray using an original geometric model.

    Material And Methods: 276 medial UKA (227 non-cemented Uni Goeland, Depuy; Uni, AMP) and 49 cemented (Miller-Galante, Zimmer) were reviewed and analyzed at a mean 11 years (range 7 - 15) using the Knee Society Score. Read More