Total hip arthroplasty revision due to infection: a cost analysis approach.

INTRODUCTION: The treatment of total hip arthroplasty (THA) infections is long and costly. However,the number of studies in the literature analysing the real cost of THA revision in relation to their etiology, including infection, is limited. The aim of this retrospective study was to determine the cost of revision of infected THA and to compare these costs to those of primary THA and revision of non-infected THA.

MATERIALS AND METHODS: We performed a retrospective cost analysis for the year 2006 using an identical analytic accounting system in each hospital department (according to internal criteria) based on allotment of direct costs and receipts for each department. From January to December 2006, 424 primary THA, 57 non-infected THA revisions and 40 THA revisions due to infection were performed. The different cost areas of the patient's treatment were identified.This included preoperative medical work-up, medicosurgical management during hospital stay,a second stay in an orthopedic rehabilitation hospital (ORH) and post-hospitalisation antibiotic therapy after revision due to infection, as well as home-based hospitalisation (HH) costs, if this was the selected alternative option. We used the national health insurance fee schedule found in the "Common classification of medical procedures" and the "General nomenclature of professional procedures" applicable in France since September 1, 2005. Hospital costs included direct costs (hospital overhead costs) and indirect costs, (medical, surgical, technical settings and net general service expenses). The calculation of HH costs and ORH costs were based on the average daily charge of these departments. The cost of primary THA was used as the reference.We then compared our surgical costs with those found for the corresponding comparable hospital stay groups (Groupes homogènes de séjour).

RESULTS: The average hospital stay (AHS) was 7.5 +/- 1.8 days for primary THA, 8.9 +/- 2.2 days for non-infected revisions and 30.6 +/- 14.9 days for revisions due to infection. The rate of transfer to a rehabilitation hospital (ORH) was 55% for primary THA, 77% in non infected revision cases and 65% in revisions due to infection. Moreover, 30% of these infected THA were prescribed HH. Non-infected THA revisions cost 1.4 times more than primary THA. THA revisions due to infection cost 3.6 times more than primary THA.

DISCUSSION: The economic impact of THA infections is considerable. The extra costs are mainly due to an extended hospital stay and to longer rehabilitation consuming significant substantial human and material resources.

CONCLUSION: The cost of treating infected THA is high. Treatment strategies should therefore be optimised to increase the success rate and minimise total costs.

LEVEL OF EVIDENCE: Level IV. Economic and decision analyses, retrospective study