Knee varus-valgus motion during gait--a measure of joint stability in patients with osteoarthritis?
OBJECTIVE
To determine the validity of varus-valgus motion as a measure of knee joint stability by establishing the relationship of varus-valgus motion with muscle strength, joint proprioception, joint laxity and skeletal alignment in patients with knee osteoarthritis (OA).


METHODS
Sixty-three patients with OA of the knee were tested. Varus-valgus motion was determined with a video-based optoelectronic gait analysis system. Muscle strength was measured using a computer-driven isokinetic dynamometer. Proprioceptive acuity was assessed by establishing the joint motion detection threshold in the anterior-posterior direction. Laxity was assessed using a device which measures the passive angular deviation of the knee in the frontal plane. Alignment was assessed using a goniometer. Regression analyses were performed to assess the relationship between varus-valgus motion, muscle strength, joint proprioception, joint laxity and skeletal alignment.


RESULTS
Varus-valgus motion was not related to muscle strength, joint proprioception, joint laxity and skeletal alignment.


CONCLUSIONS
Knee joint stability cannot be measured as varus-valgus motion. Rather, a number of independent factors seem to contribute to the process of stabilization of the knee joint.
van der Esch
M
M
Jan van Breemen Institute, Center for Rheumatology and Rehabilitation, Amsterdam, The Netherlands. M.vd.Esch@janvanbreemen.nl
Steultjens
M
M
Harlaar
J
J
Wolterbeek
N
N
Knol
D L
DL
Dekker
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000503:physiopathology; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology; D011859:Radiography; D016059:Range of Motion, Articular; D012044:Regression Analysis; D016138:Walking / Q000502:physiology