Abstract
INTRODUCTION
As the demographic of the patient population requiring revision total knee arthroplasty (rTKA) continues to expand, varying preoperative conditions and activity levels need to be taken into consideration when analyzing postoperative outcomes. Factoring in preoperative activity levels can help manage the expectations of patients. The purpose of this study was to analyze the outcomes of low and high activity patients receiving a contemporary rTKA.
METHODS
One hundred and eighty rTKA patients enrolled in a prospective, multicenter study were evaluated through 2 years postoperative. Patients were divided into groups based on preoperative activity level using the Lower Extremity Activity Scale (LEAS). Patients scoring between 1–7 were classified as ‘Low Activity’ (LA, N=104) and patients scoring 8–18 were classified as ‘High Activity’ (HA, N=76). Clinical and patient-reported outcomes were evaluated, with an additional quality of life analysis completed utilizing SF-6D scores obtained by transforming SF-36 scores through a method described by Brazier et al. and analyzed for effect size.
RESULTS
No differences were seen in age or BMI between the groups, with more females in the LA group (64%) and majority males in the HA group (58%). Both groups displayed statistically significant improvements through 2 years; however the degree of improvement varied based on outcome measure. Postoperative improvement in both groups were similar in the KSS, but patients in the LA group showed larger increases in the KSS Functional assessment at 6 weeks and 2 years (Figure 1). The effect of rTKA was analyzed through an SF-6D analysis (Figure 2). There was a statistically significant large effect seen in the LA group at 1 year (0.96), which was in conjunction with a higher SF-6D outcome (Figure 2).
CONCLUSION
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 not only greater cumulative functional improvements, but also had significant improvements in quality of life following rTKA. This suggests that the preoperative lower activity level may be in part related to the poorly functioning knee and that revision surgery has the potential to improve overall activity levels and function.
