Medicaid Insurance Is Associated With Increased Readmissions and Mortality After Surgery for Periprosthetic Joint Infection.

Background: Patients with Medicaid insurance are at an increased risk of postoperative complications following total knee arthroplasty and total hip arthroplasty (TJA); however, their outcomes following revision TJA for periprosthetic joint infection (PJI) requires further study.

Methods: A retrospective query was conducted for adult patients undergoing implant explantation and antibiotic spacer placement for TJA PJI from the Premier Healthcare Database between December 1, 2016, and December 31, 2021. Patients were then grouped by Medicaid or non-Medicaid insurance status and were age matched through exact caliper matching. Multivariable regression models addressed potential confounding. Adjusted risks of 90-day postoperative complications were reported.

Results: Of the 40,346 patients identified, 2,711 Medicaid patients were matched to 10,844 non-Medicaid patients on age (56.1 vs. 56.1 years, P = 1.000). Patients with Medicaid experienced higher risk of sepsis (adjusted odds ratio [aOR] = 1.20, P = 0.010), readmission (aOR = 1.12, P = 0.022), being discharged to a skilled nursing facility (aOR = 1.13, P = 0.031), and had longer length of stay (9.48 vs. 6.67 days, P < 0.001), compared with patients with non-Medicaid. Medicaid patients had a higher rate of inpatient mortality (0.81% vs. 0.48%, P = 0.038); however, the risk was similar after accounting for differences in comorbidities.

Conclusion: Following revision TJA for PJI, patients with Medicaid were at an increased risk for postoperative complication, including sepsis and readmission. They experienced a higher rate of inpatient mortality that may be driven by differences in comorbidities. Insurers and policy makers should consider this information to develop risk stratification-based payment strategies that take into account the healthcare burden of this high-risk patient population.

Level of evidence: IV.