AIDS but not asymptomatic HIV is associated with higher 2-10-year implant survivorship following total knee arthroplasty.

INTRODUCTION: Prior studies have demonstrated HIV does not increase the risk of 2-year complications following TKA; however, the literature is sparse regarding the impact of HIV and AIDS on long-term implant survivorship. The purpose of this study was to compare the 10-year cumulative incidence and risk of revision TKA in patients with and without asymptomatic HIV, and with and without AIDS.

METHODS: Patients with HIV who underwent elective TKA were identified using a national database and divided into subgroups of asymptomatic HIV (AHIV) and acquired immunodeficiency syndrome (AIDS). These patients with HIV were propensity matched based on age, sex, and Charlson Comorbidity Index (CCI) to a control group of elective TKA patients without HIV in a 1:2 ratio. Patients were also compared to an unmatched control group.

RESULTS: The 10-year risk for all-cause revision TKA was higher in the HIV group compared to unmatched controls (HR 1.40, 95% CI 1.02-1.93, p = 0.038) but not matched controls (HR 1.13, 95% CI 0.77-1.63, p = 0.594). When compared to both control groups (unmatched; matched), the AIDS group had a higher risk of 10-year all-cause revision (HR 2.74, 95% CI 1.51-4.99, p < 0.001; HR 2.19, 95% CI 1.17-4.11, p = 0.014), dislocation/instability (HR 4.89, 95% CI 1.54-15.51, p = 0.007; HR 3.86, 95% CI 1.12-13.34, p = 0.033), and periprosthetic fracture [PPF] (HR 0.67, 95% CI 0.16-2.74, p = 0.002; HR 3.82, 95% CI 1.08-13.45, p = 0.037). However, patients with AIDS were not at increased risk of PJI or mechanical loosening compared to unmatched controls or matched controls.

DISCUSSION: This study expands on current literature by following a nationwide cohort of HIV/AIDS patients for 10 years after TKA. Although a diagnosis of asymptomatic HIV was not associated with increased risk of 10-year revision rates following TKA, a diagnosis of AIDS was. Surgeons should ensure patients' serum CD4 level is sufficient, ideally in the normal range of 500-1500 cells per mm3 , before undergoing TKA.