Ten-year mortality risk predictors after primary total knee arthroplasty for osteoarthritis

Purpose

To determine predictors of mortality up to 10 post-operative years.

Methods

A cohort of 1,569 consecutive patients who underwent primary cementless total knee arthroplasty (TKA) for osteoarthritis was prospectively evaluated. Patient mortality was compared to the general population using standardized mortality ratios (SMR). The effects on patient mortality and surgical data, as well as post-operative outcomes, were analysed using Cox regression analysis.

Results

The 10-year survival was 88.9 % in females and 73.4 % in males (p = 0.001). The SMR were higher for females under 50 years (213.1 %) and for males over 70 years (170.5 %). Aged 70 or older and male gender were predictive for mortality in any post-operative time. Lengthening of the follow-up time showed different patterns of other risk mortality factors. Within 8 years, high Charlson index, poorer post-operative clinical status, and quality of life were also associated with an increased mortality risk, and obesity was protective factor. However, 10-year mortality was only associated with age, female gender, post-operative walking disability, and increasing post-operative WOMAC pain score.

Conclusion

In this study, patient-related factors that can help identify patients at risk were only age and gender, while recovery of walking ability, WOMAC pain, and SF-12 mental component were important survival factors among post-operative factors. This study identified important patient-related predictors of mortality after TKA, which may be useful in order to inform the patients of the potential risks.

Level of evidence

IV.