Gesture and Posture As Important Factors in 3D Kinematic Assessment of the Knee Lavoie F 1, Laplante...

Gesture and Posture As Important Factors in

3D Kinematic Assessment of the Knee Lavoie F1, Laplante M2, Parent G1, Duval N1,3,

Doré S1,2, de Guise J1,2

1. Laboratoire de recherche en imagerie en orthopédie du CRCHUM (LIO)

2. École de Technologie Supérieure (ÉTS)3. Pavillon des Charmilles

Introduction

Accurate 3D kinematic assessment combined with computer-assisted surgery will bring a whole new dimension to knee arthroplasty and ligament reconstruction

• Diagnosis and surgical indications

• Surgical technique

• Follow-up

Current problem

Three-dimensional kinematics of the normal knee are still ill-defined

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•Differences between studies

•Differences between subjects of the same studies

Possible causes of kinematic differences between subjects and between studies

Artefact motionSkin-bone movement (up to 1 cm, Sati et al. 1996)Invasive methods not appliable to large populations

(Lafortune et al. 1992, Ishii et al. 1997)

Analysis of the movement recordedAxes system position (Marin et al. 2003)

Different Gesture = Different Movement?

Hypothesis

Knee kinematics are altered by the gesture accomplished when it is recorded

Knee-bend Standardizer

Knee-bend Standardizer

Purposes:Control the movement of the trunk along a fixed axis

Control the position of the feet

Rotation, DF/PF, AP position, Width

Allow to test in different predetermined positions

Weight-bearing normal, increased or decreased

Previous Findings

• Knee-bend standardization increases kinematic reproducibility

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Ascent phase Descent phase Ascent phase Descent phase

Tibial rotation Abduction/ adduction

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Unconstrained knee-bends

Wall-sliding knee-bends

Standardized knee-bends

Previous Findings

• Knee-bend standardization decreases between-subject kinematic variability

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Standardized Knee-bends Unconstrained Knee-bends

Objective of this Study

Evaluate the impact of different gesture parameters on measured knee kinematics:

Foot rotation Hip rotation

Knee excursionFoot A-P positionAnkle flexionWeight-bearingSpeed

Materials and Method

17 male participantsAvg 25.5 y.o. (21-30)No lower limb pathology

Optotrak position sensorsmounted on special harness

purpose: minimizing mvt between sensors and bone, allowing assessment of axial rotation at the knee

ref. Sati et al. 1996, Ganjika et al. 2000

Harness

Materials and Method

13 squat series for each subject

0-60 degrees of flexion

20 seconds recording

Speed controled

Left knee kinematics recorded

8 gesture parameters tested

Standard Gesture

Knee excursion

Knee In Knee Out

Foot Rotation

30 degreesinternal rotation

30 degreesexternal rotation

Hip Rotation

Ankle Flexion

30 degrees plantiflexion 10 degrees dorsiflexion

Foot A-P Position

Feet advanced (70% of femur length)

Ref.: Kvist et al. 2001

Load-bearing

25% weight increase

Ref.: Yack et al. 1994

25% weight decrease

Speed of gesture

Standard gesture: 2 seconds for each cycle

Slow gesture: 4 seconds for each cycle

Fast gesture: 1 second for each cycle

Analysis

3D Kinematics analyzed as rotationsTibial rotation vs Knee flexionLeg abduction/adduction vs Knee flexion

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Analysis

Comparison each gesture condition with standard gesture

Comparison with inverse gesture conditione.g. Slow pace vs Fast pace

Average of the differences were calculated

Results

Impact of Knee Excursion on Knee Kinematics

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Knees Projected Inwards Standard Gesture Knees Projected Outwards

Impact of Foot Rotation on Knee Kinematics

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External Rotation Standard Gesture Internal Rotation

Impact of Hip Rotation on Knee Kinematics

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Hips Externally Rotated Standard Gesture

Average Kinematic Differences Between Gesture Conditions

Gesture Parameter

ComparisonTranslations (mm) Rotations (degrees)

AP ML PD AdductionExternal Rotation

Knee excursion

Knee In vs Knee Out 1.37 -1.75 0.12 -1.68 4.70

Knee In 0.69 -0.85 0.33 -0.48 3.12

Knee Out -0.49 0.93 0.02 1.19 -1.31

Hip rotation External Rotation (Knee Neutral) 0.59 -0.02 -0.94 2.18 5.38

Foot rotation

External Rotation (Knee Neutral) vs External Rotation (Knee-In)

2.12 -2.34 -0.08 -1.26 6.16

External Rotation (Knee In) vs Internal Rotation

4.73 -2.75 -2.44 1.02 16.01

External Rotation (Knee In) 2.71 -1.95 -0.75 0.92 10.96

Internal Rotation -1.82 0.88 1.29 -0.17 -5.25

= Statistically Significant

= Scientifically Significant (>2mm or >2degrees)

Discussion

In the studied population, no significant effect found for:

Foot A-P positionAnkle flexionWeight-bearingSpeed

Discussion

Current studies of knee kinematics during a knee bend gesture don’t control for foot position, knee excursion and hip rotation

Our results show that these parameters affect knee kinematics

> 15 degrees of impact on tibial rotation for a ROM of 5-10 degrees

Conclusion

Gesture needs to be controled in kinematic studies of the knee:

Better reproducibility

Comparisons between studies

Follow-up comparisons

Financial Help

IRSC (Programme MENTOR) Fondation de Recherche et d’Éducation en Orthopédie

de Montréal (FRÉOM) Département de Chirurgie de l’Université de Montréal

CRSNGFonds Québécois pour la Recherche Nature et

Technologie (FQRNT)Chaire de recherche du Canada

Future Directions

Characterization of normal knee kinematicsAxes system

Residual skin movement

ACL-deficient participants:Kinematic effect of injury

Impact of ACL reconstruction on knee kinematics

Gesture and Posture As Important Factors in 3D Kinematic Assessment of the Knee Lavoie F 1, Laplante...

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