Economic Analysis in a Diagnosis Related Groups System for Two-stage Exchange of Prosthetic-joint Infections

Background: There is a constant increase of joint arthroplasties performed, with an infectious risk of 1-2%. Different therapeutic options for prosthetic-joint infections exist, but surgery remains essential. With a two-stage exchange procedure, a success rate above 90% can be expected. Currently, there is no consensus regarding the optimal interval duration between explantation and reimplantation. This retrospective study aimed to assess the economic impact of a two-stage exchange from a single-hospital perspective. Methods: 21 patients who have undergone a two-stage exchange of a hip or knee prosthetic-joint infection at the University Hospital of Lausanne (Switzerland) from 2012 to 2013 were included. The revenues earned according to the Swiss Diagnosis Related Groups (SwissDRG) system introduced in 2012 and the costs were compared for each hospital stay. Results: The remuneration ranged from 26'806 to 42'978 Swiss francs (CHF) (~ 22'905-36'723 EUR, median 36'338 CHF, ~ 31'049 EUR). The median total cost per patient was 76'000 CHF (~ 65'000 EUR) (51'151 to 118'263; hip median 79'744, knee median 66'708). The main determinant of the costs was the length of the hospital stay. Revenues never covered all the costs, even with a short-interval procedure. The hospital lost a median of 35'000 CHF per patient (~ 30'000 EUR) (22'280 to 64'666). Conclusion: The current DRG system may not be specific enough for rewarding prosthetic-joint infections. Several options could be considered to act on the length of the hospital stay. In order to cover costs in complicated cases, such as prosthetic-joint infections, more specific DRGs are needed.