Extension limitation in standing affects weight-bearing asymmetry after unilateral total knee arthroplasty

The aim of this study was to evaluate weight-bearing condition after unilateral total knee arthroplasty (TKA) during standing and to examine whether the condition affects knee kinetics during gait in both limbs. Twenty-five patients, who underwent unilateral TKA for symptomatic bilateral osteoarthritis and who were on average 74 years old, participated. As a result, operated limbs became dominant in 80% of the patients. The other 20%, who had lack of knee extension during standing, showed more weight bearing in nonoperated knees. Furthermore, extension limitation in the operated knee in standing led to mechanical overload in the contralateral limb during gait. Therefore, to avoid progression of the osteoarthritis in the contralateral knee, it is important to acquire full extension in the operated knees during standing after unilateral TKA.