Abstract
As the population requiring revision total knee arthroplasty (rTKA) grows, varying
preoperative conditions may need to be considered when attempting to predict postoperative
outcomes. Considering preoperative activity levels may help manage the expectations
of patients. The purpose of this study was to analyze the outcomes of low- and high-activity
subgroups of patients receiving a contemporary rTKA. One hundred and eighty-one rTKA
patients enrolled in a prospective multicenter study were evaluated over a minimum
follow-up of 2 years postoperatively. Patients were divided into two groups based
on the preoperative activity level using the Lower Extremity Activity Scale. Patients
scoring between 1 and 7 were classified as “Low Activity” (LA; N = 105) and patients scoring 8 to 18 were classified as “High Activity” (HA; N = 76). Clinical outcomes were evaluated, with an additional quality-of-life analysis
completed utilizing SF-6D (6-dimension short form) scores obtained through a method
described by Brazier et al and analyzed for effect size. There were no significant
differences in age or body mass index between the groups. Postoperative improvement
in both groups were similar in the Knee Society score (KSS), but the LA group showed
larger increases in the KSS functional assessment at 6 months (16.2) and 2 years (34.8).
There was a statistically significant effect (0.96, p = 0.0006) seen in the LA group at 1 year, in conjunction with a higher SF-6D outcome.
The current study population displayed significant improvement in functional patient
outcomes following rTKA regardless of preoperative activity level and function. Patients
with lower preoperative activity levels demonstrated greater cumulative functional
and quality-of-life improvements. This suggests that a lower preoperative activity
level may be related to a poorly functioning knee and that rTKA has the potential
to improve overall activity levels and function. Low preoperative function should
not disqualify patients for rTKA.
Keywords
revision total knee arthroplasty - functional outcomes - activity levels
