Effect of tibial re-alignment surgery on single leg standing balance in patients with knee osteoarthritis.

Abstract

Standing balance is impaired in individuals with knee osteoarthritis and is associated with disease severity. The effects of surgical interventions on standing balance have received little attention. The purpose of the present study was to examine measures of balance during tests of single-limb standing before and after medial opening wedge high tibial osteotomy--a lower limb re-alignment procedure for those with varus alignment and knee osteoarthritis. Standing balance was assessed in 49 individuals prior to and 12 months following medial opening wedge high tibial osteotomy. Participants performed three trials of single-limb balance lasting 10s each while standing on a force platform. Anteroposterior and mediolateral coordinates of the centre of pressure were obtained from the force platform and used to calculate the total centre of pressure path length as well as the range and variability (standard deviation) of the anteroposterior and mediolateral coordinates. Though all centre of pressure measures were lower following high tibial osteotomy, none reached statistical significance (P>0.05) and effect sizes were small (d<0.34). The largest mean improvement was 7.6% (95% confidence interval: -0.7-15.8%). Results indicate that standing balance in individuals with knee osteoarthritis is not significantly different following high tibial osteotomy surgery. Standing balance in this patient population is a complex process not entirely dictated by disease symptoms or structural factors such as alignment.