The Application of the Reference Finite Helical Axis for Characterizing Knee Joint Kinematics

Date
2022-01
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Abstract
Altered knee kinematics are an important biomechanical marker for the development of tibiofemoral osteoarthritis (OA). They are associated with altered cartilage contact areas, resulting in forces acting on unadapted cartilage that may degrade over time. The conventional approach to quantify knee kinematics is with Cardan angles, but the uncommon helical axis (HA) approach may provide supplementary information. However, the HA is susceptible to stochastic errors when angular displacements are small. To alleviate this error, a reference position may be used that permits larger angular displacements. However, more assessments are required to determine the utility of this reference finite helical axis (rFHA) method to provide biomechanical markers of tibiofemoral OA. The purpose of this thesis was to technically evaluate the rFHA and demonstrate its ability to distinguish knee kinematics of high tibiofemoral OA risk individuals. Technical evaluations consisted of 1) determining the effect of different smoothing techniques on rFHA accuracy, 2) assessing the sensitivity of the rFHA to reference position misalignments, and 3) comparing rFHA measures between an optical motion camera system (OMCS) and highspeed biplanar videoradiography system (HSBV). The utility of the rFHA was demonstrated by applying it to high tibiofemoral OA risk populations, specifically anterior cruciate ligament repaired (ACLR) knees and older knees. A spline filter with outlier removal process was the top performing smoothing technique for rFHA accuracy, providing a 72.2-80.1% improvement in rotational speed differences. Substantial differences of the rFHA measures were determined with misaligned reference positions, ranging from 1.17-19.53 mm and 0.77-5.45 deg. rFHA measure differences were also found between the OMCS and HSBV, ranging from 10.19-58.03 mm and 3.39-13.63 deg. Finally, kinematic trends were found in ACLR knees during a vertical drop jump, showing greater magnitudes of rFHA dispersion and helical internal rotation than healthy knees (dispersion: 0.46 deg; helical internal rotation: 2.18 deg). Additionally, significantly different rFHA path lengths were found between older and younger asymptomatic knees during walking (10.60 mm, p = 0.01). These findings demonstrate the utility of the rFHA in biomechanics, providing a supplementary method of characterizing knee kinematics and distinguishing the movement patterns of healthy individuals from tibiofemoral OA prone individuals.
Description
Keywords
Finite Helical Axis, Aging, Knee Injury, Kinematics, Knee, Osteoarthritis, Highspeed Biplanar Videoradiography
Citation
Bugajski, T. (2022). The application of the reference finite helical axis for characterizing knee joint kinematics (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.