Elsevier

The Journal of Arthroplasty

Volume 18, Issue 8, December 2003, Pages 1048-1055
The Journal of Arthroplasty

Tibial axis and patellar position relative to the femoral epicondylar axis during squatting

https://doi.org/10.1016/S0883-5403(03)00449-2Get rights and content

Abstract

A laboratory-based study was performed to describe the tibial axis and patellar position relative to the femoral epicondylar (FE) axis during squatting. During the squat, the angle between the tibial and FE axes averaged 90.5°, and 66% of internal rotation of the tibia occurred before 15° flexion. In the mid-sagittal plane of the femur, the patella followed a circular arc, and mediolateral patellar shift averaged 4.3 mm. These findings can be used as the basis for development of new total knee arthroplasty components that recreate normal patellofemoral kinematics, and may provide important guidelines for alignment of the tibial and femoral components. The perpendicular relationship between the tibial and the FE axes may be useful in locating the FE axis intraoperatively. The reduced mediolateral shift of the patella suggests that alignment of the femoral component with the FE axis will aid patellar tracking about a circular arc with small deviations in the medial-lateral direction.

Section snippets

Materials and methods

Ten whole-leg, fresh-frozen human cadaver specimens were tested in a fixture designed to simulate squatting (Fig. 1) [4]. All specimens were examined grossly and radiographically and appeared normal. The quadriceps extensor mechanism, the biceps femoris, and the semimembranosus muscle bellies were dissected free approximately 10 cm proximal to their insertions and were sutured to loading straps. Intermedullary rods were cemented into the distal tibia and femoral neck and then secured to the

Results

The tibia rotated an average of 13° (SD, 3; range, 8°–17°) internally as the knee was moved from full extension (0°) to 90° (Fig. 3). Flexion of the knee from full extension to 15° produced, on average, 8° (SD, 3; range, 2°–11°) of internal rotation of the tibia, whereas movement from full extension to 30° of flexion, created 11° of internal rotation of the tibia (SD, 3; range, 5°–14°). On average, 60% and 81% of the internal rotation was produced by movement of the knee from full extension to

Discussion

The findings from this study are based on the “compound hinge model of knee kinematics” described previously [4]. A more suitable term might be the “two-axis theory” of tibiofemoral kinematics, because knee motion can be described by rotations about two axes carefully located and fixed in bone: the femoral epicondylar axis (flexion-extension) and the anatomic tibial axis (internal-external rotation). This is not to say that there are only 2 degrees of freedom in the tibiofemoral joint, but

References (27)

  • D.G Eckhoff et al.

    Malrotation associated with implant alignment technique in total knee arthroplasty

    Clin Orthop

    (1995)
  • R.A Berger et al.

    Malrotation causing patellofemoral complications after total knee arthroplasty

    Clin Orthop

    (1998)
  • R.A Berger et al.

    Determining the rotational alignment of the femoral component in total knee arthroplasty using the epicondylar axis

    Clin Orthop

    (1993)
  • Cited by (83)

    • In-vivo tibiofemoral kinematics of the normal knee during closed and open kinetic chain exercises: A comparative study of box squat and seated knee extension

      2022, Medical Engineering and Physics
      Citation Excerpt :

      The accuracy of this system in determining knee-joint kinematics has been evaluated and described in previous articles and was shown to be less than 1 mm in translation and 1° in orientation [35]. Since knee kinematics change dramatically before and after 20° to 30° of knee flexion angle because of the “screw-home” mechanism, [22,23] the knee extension was further divided into two phases: screw-home phase (0°−25°) and femoral rollback phase (25°−75°) [24].. Descriptive statistics are presented as means with standard deviations.

    • It Is Time to Consider a Philosophical Change From Mechanical to Kinematic Alignment

      2021, Calipered Kinematically aligned Total Knee Arthroplasty: Theory, Surgical Techniques and Perspectives
    • Implant Survival and Function Ten Years After Kinematically Aligned Total Knee Arthroplasty

      2018, Journal of Arthroplasty
      Citation Excerpt :

      The concept of KA and the surgical technique that uses PSI to align the femoral and tibial components coincident to the native joint lines of the knee after compensating for wear has been described [6,37]. Briefly, KA coaligns the rotational axes of the components with the 3 kinematic axes of the knee without ligament release, which are either parallel or perpendicular to the native joint lines [5,7,9]. The femoral and tibial components are introduced in such a way that the angle and level of the distal and posterior femoral joint lines and the tibial joint line are restored to the natural alignment for each patient using PSI.

    View all citing articles on Scopus

    Benefits or funds were received in partial or total support of the research material described in this article from Stryker Howmedica Osteonics.

    View full text