Deep infection following total knee arthroplasty (TKA) is a devastating complication for the patient and a costly one for patients, surgeons, hospitals and payers. The aim of this study is to compare revision TKA for infection, revision TKA for aseptic loosening and primary TKA with respect to their impact on hospital and surgeon resource utilisation. The evaluation of hospital cost was carried out on a microeconomic basis in order to best evaluate the true cost. Demographic, clinical and economic data were obtained for 25 consecutive patients with an infection after TKA who underwent a two-stage revision arthroplasty (Group 1), 25 consecutive patients who underwent revision of both components because of aseptic loosening (Group 2) and 25 consecutive patients who underwent a primary TKA (Group 3), all of which where admitted at our institution between January 2000 and December 2005. The economic evaluation included both surgical treatment and hospitalisation cost. Because fixed charges do not depict accurately real resource consumption, total cost was calculated through direct cost analysis. All direct health sector costs such as medical supplies, drugs, implants, laboratory and radiology tests, salaries and wages and overhead expenses, including equipment and plant depreciation were calculated. All patients were followed up for a twelve-month period. Revision procedures for infection were associated with longer operative time, more blood loss and a higher total number of operations compared with both revisions for aseptic loosening and primary TKA. Furthermore, revisions for infection compared to revisions due to aseptic loosening and primary TKAs were associated with twofold and 2.6 times higher total number of hospitalisations, 2.5 and 5.6 times higher total number of inpatient days, 10.2 and 53.8 times higher cost of inpatient drugs and 1.2 and 2.37 times higher cost of implants, respectively. The costing evaluation of the three operative techniques is still on progress. Patients’ treatment with an infection after TKA is associated with significantly greater hospital and physician resource utilisation compared with that used for patients with a revision due to aseptic loosening or a primary TKA.
