Impact of neighborhood socioeconomic deprivation on implant complications after unicompartmental knee arthroplasty: a propensity-matched cohort study

INTRODUCTION: Although previous studies have examined total joint arthroplasties (TJA), research on the association between the Area Deprivation Index (ADI) and outcomes following unicompartmental knee arthroplasty (UKA) remains limited. This study evaluates outcomes following UKA and whether patients with higher ADIs (indicating greater socioeconomic disadvantage) are at increased risk for implant-related complications. METHODS: A retrospective analysis was performed using a nationwide claims database from 2010 to 2022. The ADI was used to categorize patients into high and low ADI groups. A total of 26,058 primary UKA patients for osteoarthritis were 1:1 propensity-score matched by age, gender, and Elixhauser Comorbidity Index (ECI). Primary endpoints included 2-year implant-related complications and costs. Multivariable logistic regression models computed the odds ratios (OR) for the association between ADI and 2-year implant complications. P values < 0.001 were significant. RESULTS: Patients undergoing UKA with higher ADIs experienced no difference in the incidence and odds of implant-related complications within 2 years compared to those with lower ADIs. Periprosthetic fractures were less common in the high ADI group (0.21% versus 0.40%; OR: 0.53, P = 0.008). Periprosthetic joint infections (PJIs) (1.27% versus 1.33%; OR: 0.95, P = 0.701), aseptic loosening (1.14% versus 1.05%; OR: 1.08, P = 0.512), manipulations under anesthesia (MUA) (1.10% versus 0.92%; OR: 1.20, P = 0.153), or all-cause revisions (3.04% versus 2.86%; OR: 1.07, P = 0.378) were similar between groups. Patients in the higher ADI cohort had significantly higher day of surgery ($5,336 vs. $4,118;P < 0.0001) and 90-day costs ($7,462 vs. $6,431; P < 0.0001) after propensity-matching and adjustment for measured comorbidities. CONCLUSION: Patients undergoing UKA of higher ADIs did not experience significant differences in implant-related complications compared to those of lower ADIs. Socioeconomic disadvantage alone is not a major determinant of early implant-related outcomes following UKA. These findings support equitable patient selection and treatment decisions based on clinical indications rather than socioeconomic proxies of patient complexity. LEVEL OF EVIDENCE: III.