Patients aged 80 and above who suffer from end-stage osteoarthritis may benefit from total knee arthroplasty (TKA), but at high potential risk. Additionally, there is controversy about whether functional improvement in patients above age 80 is similar to younger patients. We compared functional improvement, length of stay (LOS), and facility discharge rates after TKA between this cohort and patients less than 80 years of age.
We completed a retrospective cohort study comparing TKA patients aged 80 and above with all patients younger than 80. We utilized data from a prospectively collected institutional repository of 2308 TKAs performed from April 2011 through July 2016 at an academic medical center in the United States. We performed multivariable logistic regression to determine the association between age group and clinically significant improvement in the Patient-Reported Outcome Measurement Information System (PROMIS)-10 physical component summary (PCS) score. Secondary outcomes included the magnitude of PCS change, LOS, and facility discharge.
There were 175 (7.6%) TKAs in patients older than 80 years compared with 2133 TKAs in patients younger than 80. Patients over 80 had similar adjusted odds of achieving clinically significant PCS improvement following TKA (P = .366), and there was no statistical difference in adjusted postoperative PCS improvement between the 2 age groups. Age 80 and above was associated with a longer adjusted LOS and demonstrated increased odds of facility discharge (odds ratio 4.11, P < .001) after TKA.
Following TKA, patients older than 80 years demonstrate similar adjusted functional improvement in comparison to younger patients. However, older patients did require substantially more resources as they remained in the hospital longer and were discharged to rehabilitation more often.