TY - JOUR
T1 - The relationship between toe-out angle during gait and progression of medial tibiofemoral osteoarthritis
AU - Chang, Alison
AU - Hurwitz, Debra
AU - Dunlop, Dorothy
AU - Song, Jing
AU - Cahue, September
AU - Hayes, Karen
AU - Sharma, Leena
PY - 2007/10
Y1 - 2007/10
N2 - Background: A greater knee adduction moment increases risk of medial tibiofemoral osteoarthritis (OA) progression. Greater toe-out during gait shifts the ground reaction force vector closer to the centre of the knee, reducing the adduction moment. The present study was designed to test whether greater toe-out is associated with lower likelihood of medial OA progression. Methods: Baseline assessments included: kinematic/kinetic gait parameters using an optoelectronic camera system, force platform and inverse dynamics to calculate three-dimensional external knee moments; toe-out angle (formed by the line connecting heel strike and toe-off plantar surface centres of pressure and the forward progression line; knee pain; and full-limb alignment. Knee x-rays (semi-flexed) were obtained at baseline and at 18 months, with progression noted as medial joint space grade worsening. With logistic regression, odds ratios (ORs) for progression/5° toe-out were estimated. Results: In the 56 subjects (59% women, mean age 66.6 years, body mass index (BMI) 29), baseline toe-out angle was less in knees with than without progression (difference -4.4, 95% CI -8.5 to -0.3). Greater toe-out was associated with reduced likelihood of progression (OR 0.60, 95% CI 0.37 to 0.98). Adjusting for age, gender, BMI, pain severity and disease severity, the OR was 0.62, 95% CI 0.36 to 1.06. Adjusting for adduction moment (second peak), the OR was 0.72, 95% CI 0.40 to 1.28. Conclusions: Osteoarthritic knees that progressed had less toeing-out than knees without progression. Greater toe-out was associated with a lower likelihood of progression. Adjustment for covariates did not alter the OR, although the 95% CI included 1. Further adjustment for adduction moment did alter the OR, consistent with the possibility that a mechanism of the effect may be via lowering of the adduction moment.
AB - Background: A greater knee adduction moment increases risk of medial tibiofemoral osteoarthritis (OA) progression. Greater toe-out during gait shifts the ground reaction force vector closer to the centre of the knee, reducing the adduction moment. The present study was designed to test whether greater toe-out is associated with lower likelihood of medial OA progression. Methods: Baseline assessments included: kinematic/kinetic gait parameters using an optoelectronic camera system, force platform and inverse dynamics to calculate three-dimensional external knee moments; toe-out angle (formed by the line connecting heel strike and toe-off plantar surface centres of pressure and the forward progression line; knee pain; and full-limb alignment. Knee x-rays (semi-flexed) were obtained at baseline and at 18 months, with progression noted as medial joint space grade worsening. With logistic regression, odds ratios (ORs) for progression/5° toe-out were estimated. Results: In the 56 subjects (59% women, mean age 66.6 years, body mass index (BMI) 29), baseline toe-out angle was less in knees with than without progression (difference -4.4, 95% CI -8.5 to -0.3). Greater toe-out was associated with reduced likelihood of progression (OR 0.60, 95% CI 0.37 to 0.98). Adjusting for age, gender, BMI, pain severity and disease severity, the OR was 0.62, 95% CI 0.36 to 1.06. Adjusting for adduction moment (second peak), the OR was 0.72, 95% CI 0.40 to 1.28. Conclusions: Osteoarthritic knees that progressed had less toeing-out than knees without progression. Greater toe-out was associated with a lower likelihood of progression. Adjustment for covariates did not alter the OR, although the 95% CI included 1. Further adjustment for adduction moment did alter the OR, consistent with the possibility that a mechanism of the effect may be via lowering of the adduction moment.
UR - http://www.scopus.com/inward/record.url?scp=34848889931&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34848889931&partnerID=8YFLogxK
U2 - 10.1136/ard.2006.062927
DO - 10.1136/ard.2006.062927
M3 - Article
C2 - 17267516
AN - SCOPUS:34848889931
SN - 0003-4967
VL - 66
SP - 1271
EP - 1275
JO - Annals of the rheumatic diseases
JF - Annals of the rheumatic diseases
IS - 10
ER -