INTRODUCTION

This study investigates whether primary knee arthroplasty (KA) restores health-related quality of life (HRQoL) to levels expected in the general population.

METHODOLOGY

This retrospective case-control study utilises two sources: patients undergoing primary KA from a University Teaching hospital; and individual-level data from the Health Survey for England which was used to represent the General Population.

Propensity score matching was used to balance covariates (sex, age and body mass index (BMI)) and facilitate group comparisons. Two matched cohorts with 3029 patients each were obtained for the adjusted analyses (median age 70.3 interquartile range (IQR) 64–77; Female sex 3233 (53.4%); median BMI 29.7 IQR 26.5-33.7). HRQoL was measured using the three-level version of the EuroQol 5-Dimensions’ (EQ-5D-3L) Index and EQ-VAS scores.

RESULTS

Patients awaiting KA had significantly lower EQ-5D-3L Index scores than the General Population (median 0.620 (IQR 0.16-0.69) vs median 0.796 (IQR 0.69-1.00), p<0.001). By one-year post-operation, the median EQ-5D-3L Index score improved significantly in the KA cohort (mean change 0.32 (Standard deviation 0.33), p<0.001), and demonstrated no significant differences when compared to the General Population (0.796 (IQR 0.69-1.00) vs 0.796 (0.69-1.00), p=1.0). Older age-groups had statistically better Index scores than matched peers in the General Population. Compared to the General Population cohort, the post-operative EQ-VAS was significantly higher in the KA cohort (p<0.001).

CONCLUSION

Patients awaiting KA for osteoarthritis have significantly poorer HRQoL than the General Population. However, within one year of surgery, primary KA restored HRQoL to levels expected for patient's age, BMI and sex-matched peers.