Effect of variability in anatomical landmark location on knee kinematic description

Abstract

Small variability associated with identifying and locating anatomical landmarks on the knee has the potential to affect the joint coordinate systems and reported kinematic descriptions. The objectives of this study were to develop an approach to quantify the effect of landmark location variability on both tibiofemoral and patellofemoral kinematics and to identify the critical landmarks and associated degrees of freedom that most affected the kinematic measures. The commonly used three-cylindric open-chain kinematic description utilized measured rigid body kinematics from a cadaveric specimen during simulated gait. A probabilistic analysis was performed with 11 anatomical landmarks to predict the variability in each kinematic. The model predicted the absolute kinematic bounds and offset kinematic bounds, emphasizing profile shape, for each kinematic over the gait cycle, as well as the range of motion. Standard deviations of up to 2 mm were assumed for the anatomical landmark locations and resulted in significant variability in clinically relevant absolute kinematic parameters of up to 6.58 and 4.4 mm for tibiofemoral and 7.68 and 6.5 mm for patellofemoral kinematics. The location of the femoral epicondylar prominences had the greatest effect on both the tibiofemoral and patellofemoral kinematic descriptions. A quantitative understanding of the potential changes in kinematic description caused by anatomical landmark variability is important not only to the accuracy of kinematic gait studies and the evaluation of total knee arthroplasty implant performance, but also may impact component placement decisionmaking in computer-assisted surgery. ß

The effect of coordinate system variation on in vivo patellofemoral kinematic measures

“…For example, the patellofemoral 195 flexion angle was dictated by the landmarks that were selected to define the long axis, and patellofemoral tilt was affected by flexion axis definition. These correspondences were also found by Morton et al in their probabilistic analysis examining the sensitivity of patellofemoral kinematics to anatomical landmark locations in a cadaver model [28].…”

“…However, the effect of the variation of the patellar coordinate system was not investigated. Several 30 investigators have quantified the repeatability [2, 12,[26][27][28] and sensitivity [11] of the creation of their particular patellar coordinate systems. Katchburian et al [29] conducted a thorough review of patellar kinematics and recommended the coordinate system described by Lafortune [30] as being the 'most useful', possibly because it follows the method suggested by Grood and Suntay [31].…”

Determination of a reproducible flexion axis of the knee joint

“…lengőtengely körül történik, ez utóbbi a mozgás minden pillanatában vándorol, és kölcsönösen merőleges a fenti két tengelyre. A tibia keresztirányú tengelye a rotáció kiindulási állapotát határozza meg, viszont a görbék alakjára nincs hatással, 8,9 ezért nem okozott problémát a vizsgálataink során, hogy ennek meghatározása hasonlóan bizonytalan, mint a TEA.…”

Mean-shifted surface curvature algorithm for automatic bone shape segmentation in orthopedic surgery planning: a sensitivity analysis

“…In this domain, automatic shape analysis is strongly advocated because it offers the opportunity to detect morphological and clinical landmarks (MCL) with superior repeatability in comparison to human operators. It has been shown that manual interaction is commonly time consuming, and that the results are mostly dependent upon the examiner's individual expertise and are affected by noticeable inter-observer variability [22][23][24][25].…”