Abstract. Background: There is a constant increase of joint arthroplasties to improve the quality of life of an ever-aging population. Although prosthetic-joint infections are rare, with an incidence of 1-2%, they represent a serious complication in terms of morbidity and mortality. Infection related mortality is known to be approaching 8% at one year. The aim of this retrospective study is to reassess the one and two-year mortality over the last ten years.Methods: Patients treated for prosthetic joint infection at the University Hospital of Lausanne (Switzerland) between 2006 and 2016 were included. The one and two-year cumulative mortality depending on sex, age, type of prosthesis, infecting organism and type of surgical treatment were computed.Results: 363 patients (60% hips, 40% knees) were identified with a median age of 70 years. The one-year cumulative mortality was 5.5% and it was 7.3% after two years. No difference was seen between hip and knee prostheses, but the mortality was higher in men than in women and increased with age. Furthermore, there was a significant difference depending of the germ with enterococci infections associated with a higher risk of death. Finally, patients treated with a one-stage or two-stage exchange had a lower mortality than those treated with debridement and retention.Conclusion: The mortality is still high and differs according to sex, age, infecting organism and type of surgical treatment. There is a need of studies to improve the management of patients at risk of increased mortality.

A 75-year-old diabetic man with a cardiac history of pacemaker implantation and mechanical prosthetic valve (PV) replacement, also known for chronic osteitis of the first left metatarsophalangeal joint (MTP I), was treated with oral antibiotic on an outpatient basis with poor compliance when he developed intermittent fever (39.8°C) and left foot pain. Laboratory testing revealed a slight elevation of the white blood cell count (10.7 G/L) and a significant elevation of the C-reactive protein (235 mg/L). Hemocultures turned positive for multi-sensitive Staphylococcus aureus and Proteus mirabilis. A left foot CT showed MTP I osteoarthritis without collection. Transoesophageal echocardiography (TOE) showed no evidence of endocarditis. A double antibiotic regimen was started, but the patient developed persistent fever. Repeated TOE raised endocarditis suspicion. Because of a newly developed cough, a search for respiratory pathogens was performed and turned positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. An 18 F-FDG PET/CT was requested for investigating the suspicion of PV infection with a 72-h low-carbohydrate diet preparation.The 18 F-FDG PET maximum-intensity projection image shows (a) bilateral metabolic lung lesions, the foot infection (*), and one metabolically active draining sentinel lymph node (arrowhead). (b) Free-breathing lung CT and 18 F-FDG with hypermetabolic (SUV max 7.6 g/mL) focal ground-glass opacities with partial consolidation and mild bronchial dilatation with a peripheral distribution in the subpleural and periscissural regions of the apical and posterior segments of both upper lobes and right middle lobe, as previously described on CT [1]. (c) Hypermetabolic lymphadenopathies in the right lower paratracheal, subcarinal, and bilateral hilar stations (SUV max 6.

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.

Purpose Knee arthrodesis is an established procedure for limb salvage in cases of recurrent infection, total knee arthroplasty soft tissue defect, poor bone stock or a deficient extensor mechanism. Surgical options include compression plate, external fixator and arthrodesis nail. Different types of nail exist: long fusion nail, short modular nail and bridging nail. This study presents the results on knee arthrodesis using different types of intramedullary nails. The aim is to assess if a specific type of nail has a better fusion rate, clinical outcome and lower complication rate. Methods A mono-centric retrospective study of 48 knees arthrodesis was performed between 2000 and 2018. 15 T2™ Arthrodesis Nail, 6 OsteoBridge® Knee Arthrodesis and 27 Wichita® fusion nail were used. The mean clinic and radiological follow-up was 9.8 ± 3.8 years (2.6–18 years). Results Fusion rate was 89.6%. Time to fusion was 6.9 months. Mean Parker score was 6.9/9 points. Visual Analogic Scale was 1.9. The Wichita® fusion nail showed better results in terms of fusion, time to fusion and clinical outcome measured by Parker score and VAS but without statistical significance. The early revision rate was 10.4% and 20.8% presented a late complication requiring a surgery, due to nonunion or infection. 93.3% of infection was cured. Two patients live with a fistula (4.2%) and 1 was amputated (2.1%). Conclusion Although burdened by a big complication rate, knee arthrodesis with an intramedullary nail provides satisfactory results and is a good alternative to above-knee-amputation. The Wichita® fusion nail shows a tendency to better results compared to the two other nails. Level of evidence Case series, level IV