Adults with incident accelerated knee osteoarthritis are more likely to receive a knee replacement: data from the Osteoarthritis Initiative

Julie E. Davis, Shao-Hsien Liu, Kate Lapane, Matthew S. Harkey, Lori Lyn Price, Bing Lu, Grace H. Lo, Charles B. Eaton, Mary F. Barbe, Timothy E. McAlindon, Jeffrey B. Driban

We aimed to determine if knees with incident accelerated knee osteoarthritis (AKOA) were more likely to receive a knee replacement (KR) than those with common knee osteoarthritis (KOA) or no KOA. We conducted a nested cohort study using data from baseline and the first 9 years of the Osteoarthritis Initiative (OAI). Eligible knees had no radiographic KOA at baseline (Kellgren-Lawrence [KL] < 2). We classified 3 groups using KL grades from the first 8 years of the OAI: 1) AKOA: knee progressed to advance-stage KOA (KL 3/4) in ≤ 4 years, 2) common KOA: knee increased in KL grade (excluding AKOA), and 3) No KOA: no change in KL grade by 8 years. The outcome was a KR (partial or total) at or before the 9-year OAI visit. We conducted a logistic regression with generalized linear mixed model and adjusted for age, body mass index, and sex. Overall, 14% of knees with AKOA received a KR by the 9th year compared with 1% and < 1% of those with common or no KOA, respectively. Knees that developed AKOA were > 80x and ~ 25x more likely to receive a KR than knees with no KOA or incident common KOA (adjusted odds ratio = 25.08; 95% confidence interval = 9.63-65.34). In conclusion, approximately 1 in 7 knees that develop AKOA received a KR; however, KRs were rare in the OAI among other knees with no radiographic KOA at baseline. Urgent steps are needed to identify adults at high-risk for AKOA and develop prevention strategies regarding the modifiable risk factors.