Archives of Orthopaedic and Trauma Surgery - 2026-08-06 - Journal Article; Comparative Study
Patient mortality exceeds implant revision risk with equivalent survival following unicompartmental versus total knee arthroplasty in octogenarians.
Innocenti M, Leggieri F, Massenzi M, Stimolo D, Akkaya M, Matassi F, Civinini R
Topics
Key Takeaway
In octogenarians undergoing primary knee arthroplasty, all-cause mortality at minimum 5-year follow-up was 35.3% overall—3–5 times higher than registry-reported revision rates—with no significant difference between UKA (41.5%) and TKA (33.5%) (OR 1.41, 95% CI 0.75–2.63, p=0.329).
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Summary
This single-center retrospective cohort compared all-cause mortality between UKA and TKA in 238 consecutive octogenarians (age ≥80) at minimum 5-year follow-up. Overall mortality was 35.3%, with no significant difference between TKA (33.5%) and UKA (41.5%); multivariable logistic regression identified age as the only independent mortality predictor (adjusted OR 1.16 per year, p=0.013), while implant type was not significant. Patient mortality exceeded registry-reported implant revision rates by 3–5 fold across all age strata.
Key Limitation
Absence of comorbidity indices (ASA, Charlson Comorbidity Index) and functional outcome data means the study cannot determine whether mortality differences between groups reflect patient selection bias rather than a true implant-independent effect.
Original Abstract
BACKGROUND
While traditional surgical decision-making emphasizes long-term implant survivorship for octogenarians knee reconstruction, this paradigm may be inappropriate when patient mortality risk substantially exceeds revision risk. This study compared mid-term mortality between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) in octogenarians, hypothesizing that implant type would not significantly influence patient survival.
METHODS
A retrospective cohort study was conducted on 238 consecutive octogenarian patients (age ≥ 80 years) who underwent primary knee arthroplasty at a single tertiary orthopaedic center between January 2018 and December 2020. Patients with revision arthroplasty, fracture, tumor, inflammatory arthropathy, or incomplete data were excluded. The primary outcome was all-cause mortality at minimum 5-year follow-up. Secondary outcomes included age-stratified mortality (80-84, 85-89, ≥ 90 years) and identification of independent mortality predictors. Statistical analyses included independent t-tests, chi-square/Fisher's exact tests, standardized mean differences, and multivariable logistic regression adjusting for age, follow-up duration, and registry year.
RESULTS
Of 238 patients, 185 (77.7%) underwent TKA and 53 (22.3%) underwent UKA. Overall mortality was 35.3% (84/238): 33.5% in TKA versus 41.5% in UKA (OR = 1.41, 95% CI: 0.75-2.63, p = 0.329). Age-stratified mortality showed no significant differences: 80-84 years (31.2% TKA vs. 37.2% UKA, p = 0.467), 85-89 years (42.3% vs. 50.0%, p = 1.000). Multivariable analysis identified age as the only significant mortality predictor (adjusted OR = 1.16 per year, 95% CI: 1.03-1.32, p = 0.013), while implant type was not associated with mortality (adjusted OR = 1.40, 95% CI: 0.72-2.73, p = 0.319). Patient mortality exceeded registry-reported revision rates 3-5 fold.
CONCLUSIONS
In octogenarians, patient mortality substantially exceeds implant revision risk, with no significant difference between UKA and TKA. Surgeons should prioritize patient-specific clinical indications over theoretical implant durability concerns when selecting procedures in this population.
LEVEL OF EVIDENCE
III.