Clinical Outcomes of Fixed-Bearing Medial Unicompartmental Knee Arthroplasty in Patients Older than 80 Years: A Matched Control Study.

BACKGROUND

Unicompartmental knee arthroplasty (UKA) has a proven track record of success in patients who have medial knee osteoarthritis. However, it is still unclear whether outcomes in elderly patients are as satisfactory five years postoperatively and beyond as those in younger patients. In this study, we compared these two groups undergoing fixed-bearing cemented medial UKA.

METHODS

Prospectively collected data from cemented fixed-bearing medial UKAs collected between 2004 and 2017. Patients older than 80 years of age were matched with a control group of patients 70 years old or younger. The primary outcome was the Oxford Knee Score, and secondary outcome measures were complication rate, revision rate, and mortality within the first 10 years. A total of 160 patients were included who had a 1:1 ratio between the study and the body mass index- and sex-matched control groups. The mean follow-ups were 97.3 months (range, six to 180) and 123 months (range, zero to 180) for the 80-plus-year-old and control groups, respectively.

RESULTS

Excellent clinical improvement was demonstrated in both groups (mean difference in Oxford Knee Score five years postoperatively was 0.1 (95% CI [confidence interval], -4.06 to 4.26, P = 0.962)). There were four and seven revisions performed in the 80 years and above and control groups, respectively (relative risk of 0.57 (95% CI, 0.174 to 1.876, P = 0.356)). There were no deaths related to the index procedure.

CONCLUSIONS

This study shows comparable clinical outcomes five years postoperatively between patients aged above 80 and 70 years of age or below following fixed-bearing medial UKA. Comparable implant survivorship, revision rates, and surgical and medical complication profiles were documented in the immediate postoperative period. Fixed-bearing medial UKA appears to be a safe and effective option for more elderly patients who have medial knee OA.