OBJECTIVES: Chronic prosthetic joint infections (PJI) are a serious complication in arthroplasty leading to potential significant costs for health systems. Patients are at risk of a new infection, following prosthesis reimplantation. This study assessed the cost of knee or hip chronic PJI managed in 2-stage exchange at the Lyon university hospitals, France. A threshold analysis was also conducted to determine the reimbursement tariff of a bone cement loaded with antibiotics (gentamicin + vancomycin) that would prevent infections while allowing French health insurance to save money.

METHODS: Patients aged 18 and over, admitted for a hip or knee chronic PJI managed with 2-stage exchange, between January 1, 2013 and December 31, 2015 were retrospectively identified. Following resource consumptions were collected from patients record and taken into account in the evaluation: hospital stays, antibiotic treatments, imagery and biological acts, consultations, hospitalization at home and follow-up and rehabilitation care. Costs were assessed from the French health insurance viewpoint over 2-year from prosthesis reimplantation.

RESULTS: The study included 116 patients (median age 67y; 51% female; 47% hip prosthesis). Mean cost of knee or hip chronic PJI was estimated over 2 years from prosthesis reimplantation at 21,324 euros for all patients, at 51,697 euros for patients with a new infection after reimplantation (n=18) and at 15,745 euros for patients without a new infection after reimplantation (n=98). If all patients had benefited from an antibiotic-loaded (gentamicin + vancomycin) bone cement to fix the prosthesis at the time of reimplantation, at a reimbursement tariff between 2,980 and 3,984 euros (depending on hypothesis), the cost avoided by infections avoided would have been higher than the additional cost related to the medical device.

CONCLUSIONS: These first cost estimates of knee or hip chronic PJI managed in 2-stage exchange in France underline the economic interest of preventing new infections.