Implementation of Outpatient Parenteral Antimicrobial Therapy (OPAT) in Patients with Complicated Periprosthetic Joint Infections. / Etablierung der ambulanten intravenösen Antibiotikatherapie (APAT) bei Patienten mit komplizierten Periimplantatinfektionen.

Periprosthetic joint infections (PJI) are a serious complication of arthroplasty with high morbidity. With growing bacterial resistance and limited disposability of oral antibiotics with sufficient bioavailability, the need for intravenous antibiotic application is raising. This causes long-term hospital stays and rising costs. In the course of transferring procedures into an outpatient setting as well as coping with pressures on hospital capacity, outpatient parenteral antimicrobial therapy (OPAT) can build a bridge for the treatment of such infections.In a single centre analysis, 47 cases treated with OPAT were studied in relation to pathogen, antimicrobial resistance, indication for OPAT and follow up. Furthermore, the patients received an anonymised questionnaire with 4 clusters of interest in terms of internal quality assessment on the success and evaluation of this therapeutic procedure. Special attention was paid to the descriptive analysis of patients with periprosthetic joint infections (n = 30).Between May 2021 and October 2022 out of 47 patients with OPAT, 30 cases with periprosthetic joint infections were identified. For infected hip- and knee arthroplasties, a remarkable spectrum of pathogens was found. In hip infections highly resistant strains of Staphylococcus epidermidis and Enterococci were detected. In knee infections, the pathogens were more susceptible, but however highly virulent Staphylococcus aureus and Streptococci. Difficult to treat, mixed infections were found in both locations. The indication for OPAT was based in half of the cases on the high level of antimicrobial resistance, with availability of only parenteral applicable antibiotics. Further indications were mixed infections and difficult to treat pathogens, with flucloxacillin therapy as well as OPAT as the last therapeutic option. The questionnaire showed 96% patient satisfaction in terms of organisation and acceptance of this kind of therapy. Complications or unexpected outpatient/ hospital treatments were very rare in connection with OPAT. Two thirds of patients reported completion of the treatment. In the clinical follow up (average of 5.7 months), 96.6% of cases were declared free of infection. In one patient the infection persisted.OPAT is a safe and reliable therapeutic option for outpatients to continue parenteral antimicrobial treatment in joint infections. Due to increasing pressure on hospitals in terms of costs and capacity, this therapy offers an alternative to inpatient treatment. The indication for OPAT should be set individually, risk adjusted and not generalised for all patients. The outpatient sector needs financial and structural support for comprehensive roll-out of this treatment in Germany. A further focus should be on the prevention of periprosthetic joint infections. With the knowledge of the expected pathogens and the surgical resources, the standards should be adapted. The choice of the antibiotic should be specified and the intervals of application be shortened, according to the surgical course, in order to yield high levels of agent concentration in the surgical area. Further investigations are required to test the superiority of OPAT versus the oral administration of antibiotics in long-term observations as well as to define the necessary duration of OPAT.

Management of osteoporosis-related bone fractures: an integrated concept of care.

INTRODUCTION: Multidisciplinary medical management of osteoporosis and osteoporosis-related fractures is still an important treatment issue today. In view of ethiopathology of osteoporosis and the future demographic development an increasing socioeconomic burden has to be estimated. A prerequisite for an effective secondary prophylaxis of osteoporotic fractures is the implementation of a treatment network, with inclusion of all partners involved in patient's care. Therefore, special attention should be paid to formation and establishment of centres with multidisciplinary and integrated treatment concepts. This paper outlines the concept of a clinical centre for diagnosis and therapy of osteoporosis established 4 years ago. Furthermore, a concept of integrated care of osteoporosis-related fractures is introduced and the obtained data of a 2-year follow-up analysis will be presented. METHODS: The establishment of an osteoporosis centre at a university teaching hospital as well as certification according to the Dachverband Osteologie (DVO) guidelines were necessary. Recruitment of contract partners on both sides, health insurances and outpatient general practitioners as well as specialist doctors, was also essential. The implementation of an osteoporosis coordinator was a step to put the treatment concept into practice. RESULTS AND DISCUSSION: Based on the recommendations of DVO guidelines, all diagnostic and therapeutic requirements of osteoporosis can be met by the team of consultant specialists at a clinical osteoporosis centre. In the described treatment concept of integrated care, 44 patients suffering of osteoporosis with a consecutive fracture could be included. Mean age was 77. Inclusion criteria were spinal fractures (61%), proximal femoral fractures (27%) and peripheral fractures (12%). Fifty percent of patients included into the contract had not received previous osteoporosis medication. Sixty-eight patients who met the inclusion criteria could not be included due to the lack of compliance (42%), patients' disapproval (34%) or incomplete treatment and documentation algorithm (24%). Special attention should focus on the completion of standardised diagnosis and documentation. The high amount of time and personnel required has proven the importance of the introduction of an osteoporosis coordinator to be essential.

Treatment strategies for proximal femur fractures in osteoporotic patients.

Fractures of the proximal end of the femur, together with vertebral fractures, are greatly exacerbated by osteoporosis and can be regarded as the most typical and most serious complications of this disease. The demand for prompt mobilisation with full loading of the affected limb, combined with a desire for the gentlest of treatments, becomes increasingly difficult to meet in ageing patients with advanced osteoporosis. The advantages of osteosynthesis in respect to these demands when operating on elderly patients with fractures do not apply due to the inability of the osteoporotic bone to hold the osteosynthetic components sufficiently until fracture healing occurs. This inability is related to the anatomy of the proximal end of the femur and its loading patterns. Under eccentric loading, high bending loads occur, leading to failure of the osteosynthetic anchorage at the center of the femoral head. This leads subsequently to stressful revision operations for the patient. The prosthetic replacement is a good option in cases of dislocated intracapsular fractures, but in cases of trochanteric fractures it is still debated. Therefore, it is vital for the trauma surgeon to have specific knowledge of the patient's bone quality in order to optimise the result of the preferred procedure. With reference to our own experimental research and a study of the current literature, this knowledge can be summarised as follows: the most stable anchorage for the implant is achieved by placing the implant through the midpoint of the femoral head (highest bone mineral density) or just below ("best backing"). Anchoring femoral head implants so that they are stable in rotation within the head-neck fragment will significantly raise their load bearing capacity. This is also true for intramedullary load bearing devices in trochanteric fractures. The distance between the load-bearing device in the femoral neck and the articular surface is inversely correlated to the stability at yield, as other studies have already shown. There seems to be a limit for a successful realisation of an osteosynthesis that lies at a femoral head bone mineral density of 250 mg/cm(3) calcium-hydroxyapatite (CaHAp). Nevertheless, high precision surgery in regard to fracture reduction and implant placement is a essential requirement for a successful osteosynthesis. Reproducible local measurements of bone mineral density and trabecular alterations, as well as quick screening methods, are very much desired by the authors.

Do vitamins C and E attenuate the effects of reactive oxygen species during pulmonary reperfusion and thereby prevent injury?

BACKGROUND: We established an in vivo pig model of standardized lung ischemia to analyze pulmonary reperfusion injury. Enhanced chemiluminescence measurement (CM) allowed immediate quantification of reactive oxygen species (ROS) and subsequent lipid peroxidation. In such model we analyzed efficacy of vitamins C and E to prevent reperfusion injury. METHODS: After left lateral thoracotomy in group I (n = 6), normothermic lung ischemia was maintained for 90 minutes followed by a 5-hour reperfusion period. In group II, animals (n = 6) underwent ischemia as in group I, but received vitamins (preoperative IV bolus C = 1 g, E = 0.75 g, then continuous infusion (125 mg/h) each throughout the study). In Group III, animals (n = 6) underwent sham surgery and served as controls. Hemodynamic variables and gas exchange were assessed. The CM was performed for injury quantification in blood samples and to determine activation of isolated PMNs. The Wilcox rank test was used for statistical analysis. RESULTS: During reperfusion, all animals in group I developed significant pulmonary edema with significant loss of pulmonary function. The addition of vitamins (group II) improved oxygenation and almost abolished pulmonary inflammatory cell infiltration; however, as in group I, pulmonary compliance still tended to decline and the number of circulating leucocytes increased. The CM showed that, compared with group I, vitamins reduced O2- basic release by PMNs significantly (460% to 170%, p < 0.05; control 165%), but could not prevent an increase of free ROS in whole blood similar to group I (443% to 270%, p = ns, control 207%). With regard to lipid peroxidation only a trend of reduction was observed (117% to 105%, p = ns, control 100%). CONCLUSIONS: Differentiated analysis by CM demonstrated that vitamins C and E inhibited PMN activation but were not able to prevent radical production by other sources. This offers a potential explanation why radical scavengers like vitamins only attenuate but ultimately do not prevent reperfusion injury.