Change in Limb Length After Total Knee Arthroplasty

Abstract

The clinical outcome of total knee arthroplasty (TKA) remains suboptimal in some patients. One of the factors that might hinder improved functionality may be postoperative limb length discrepancy due to increase in limb length of the operative limb. The objective of this cross-sectional prospective study was to examine the extent to which limb length change occurs after TKA and to compare the change in limb length to the degree of valgus or varus joint position preoperatively. The role of body mass index and Kellgren-Lawrence grade in limb length change was also assessed. The data of 137 TKAs were analyzed and separated into categories to compare change in limb length pre- versus postoperatively. In all, 59.1% of patients experienced an increase in limb length with an average increase of 0.438 cm, but overall, there was no statistically significant difference in limb length pre- versus postoperatively (P value 0.598). Similar trends were seen within all other groups. It is the conclusion of this study that limb lengthening after TKA does not frequently occur to a statistically significant extent, regardless of preoperative joint state.