United States Trends in Utilization and One-Year Revision Risk of Cementless Total Knee Arthroplasty: An Analysis of American Joint Replacement Registry Data.

BACKGROUND: Cementless total knee arthroplasty (TKA) has emerged as an alternative to cemented fixation. We used the American Joint Replacement Registry (AJRR) to assess trends in cementless TKA utilization and associated one-year revision rates.

METHODS: We analyzed primary TKAs recorded in the AJRR from 2012 to 2024 with available fixation data. Annual proportions of cementless fixation were calculated, and trend analyses were performed using Kendall Tau-b tests. The one-year revision risk was evaluated in cases linkable to Centers for Medicare and Medicaid Services (CMS) data among patients aged 65 years and older with at least two years of potential follow-up. A multivariable generalized linear model was used to estimate one-year revision risk, adjusting for patient and hospital characteristics and clustering by institution. A sub-analysis examined specific reasons for revision.

RESULTS: Of 1,178,783 primary TKAs from 2012 to 2024, 127,781 (10.8%) were cementless. Use increased from 1.6 to 19.0% across all regions (P < 0.002). In the CMS-linked cohort (n = 685,274), 52,742 (7.7%) were cementless. The one-year revision rates were 1.61% for cementless and 1.53% for cemented TKAs (P = 0.162). After adjustment, cementless fixation was associated with increased revision risk (adjusted odds ratio (aOR) = 1.12; 95% confidence interval (CI): 1.00 to 1.25; P = 0.05). Revision risk was more strongly associated with age greater than 75 years (aOR = 0.76), men (aOR = 1.49), body mass index greater than 40 (aOR = 1.64), Charlson Comorbidity Index greater than 5 (aOR = 2.66), and hospital versus ambulatory surgery center (aOR = 4.78). Sub-analysis revealed higher risk of revision with cementless fixation for aseptic loosening (0.11 versus 0.06%; aOR = 2.37) and instability (0.14 versus 0.09%; aOR = 1.64).

CONCLUSIONS: Cementless TKA utilization has grown in the AJRR. While associated with a modestly higher one-year revision risk, the absolute difference is small and may not be clinically meaningful.