Aim

Debridement, antibiotics, and implant retention (DAIR) is a viable treatment option for acute periprosthetic joint infections (PJI). The landmark DATIPO trial of Bernard et al. concluded that six weeks is not non-inferior to 12-week antibiotic therapy for DAIR. However, it is unknown if suppressive antibiotic treatment (SAT) would improve patient outcomes. Therefore, our study aims to evaluate the utility of SAT after 12 weeks of therapy.

Background

The duration and extent of postoperative wound leakage after joint arthroplasty in patients with or without a complicated course, like a prosthetic joint infection (PJI), is currently unknown. Adequate differentiation between normal postoperative wound leakage and wound leakage due to a postoperative PJI is important and prevents unnecessary surgical procedures. We investigated the association between postoperative wound leakage and development of PJI in patients who used a previously developed mobile wound care app.

Aim

Rifampin is considered as the antibiotic corner stone in the treatment of acute staphylococcal periprosthetic joint infections (PJI). However, if, when, and how to use rifampin has been questioned. We evaluated the outcome of patients treated with and without rifampin, and analysed the influence of timing, dose and co-antibiotic.

Aim

Treatment success of debridement, antibiotics and implant retention (DAIR) is in early periprosthetic joint infection (PJI) is largely dependent on the presence or absence of a mature biofilm. In what time interval a mature biofilm develops is still unclear, and therefore, the time point at which DAIR should be disrecommended remains to be established. This large multicenter trial evaluated the failure rates of DAIR for different time intervals from index arthroplasty to DAIR in early PJI.

Aim

Obese patients are not only more likely to receive total joint arthroplasty, but are also more prone to postoperative complications. The most severe complication is a prosthetic joint infection (PJI), occurring two to four times more often in severely obese patients (BMI ≥ 35kg/m²) compared to non-obese patients. This higher risk for PJI may be attributed to higher glucose levels in case of diabetes mellitus, diminished wound healing or inadequate antibiotic prophylaxis. To ultimately improve the prevention measures for this specific patient category, we aimed to describe the clinical and microbiological characteristics of early acute PJI in severely obese patients.

Aim

Debridement, antibiotics and implant retention (DAIR) is a widely used treatment modality for early acute prosthetic joint infection (PJI). A preoperative risk score was previously designed for predicting DAIR failure, consisting of chronic renal failure (K), liver cirrhosis (L), index surgery (I), cemented prosthesis (C) and C-reactive protein >115mg/L (KLIC). The aim of this study was to validate the KLIC score in an external cohort.

Introduction: Gait before and after total hip arthroplasty (THA) is often determined by walking at preferred speed. However gait function comprises more than just walking at preferred speed. The objective is to describe recovery of gait after THA based on the assessment of spatio-temporal gait parameters determined with an ambulatory system whereby an extended test protocol is used.

Materials and Methods: Sixty-three patients participating in a short-stay program for primary unilateral THA were assessed preoperatively and at 6 weeks and 6 months postoperatively. The spatiotemporal gait parameters walking speed, step length, step duration and variability coefficient (VC) were determined with an ambulatory system using accelerometers. The test protocol contained walking at different speeds, walking while performing an additional cognitive task, and an endurance test.

Results: Patients improved significantly over time; however, the extent and speed of recovery of gait parameters was different for each test part. The relation between walking speed and step length showed systematic improvement when analyzed over a range of speeds. At 6 months, the VC of the additional cognitive task part was comparable with the preferred walking VC. The endurance test results could be predicted from the results of preferred walking.

Conclusion: The assessment of the recovery of gait function requires more than only the assessment of ‘normal’ walking. Particularly, an analysis of walking at different speeds and walking while performing an additional cognitive task demonstrate different aspects of gait recovery after THA.

Introduction: Despite growing awareness of the beneficial effects of physical activity on health, little is known about the amount of physical activity after THA. Although the WOMAC does not give direct information about the amount of physical activity it can be hypothesized that when patients experience limitations this will have an adverse effect on the amount of physical activity they are involved in. In this way the WOMAC can be predictive for the amount of physical activity. The aim of this study is to determine the correlation between the WOMAC and the amount of physical activity and to determine the predictive value of the WOMAC on meeting the (inter-) national guidelines of health -enhancing physical activity.

Materials and Methods: 364 patients with a THA (minimal one year postoperative) were included. Self-reported physical functioning was assessed by means of the WOMAC and the amount of physical activity by means of the SQUASH. Correlations between the WOMAC and SQUASH-scores were assessed using Pearson’s correlation coefficient. Binary logistic regression modelling was used to determine to which extent the score on the WOMAC was predictive in meeting the (inter-)national guidelines.

Results: A significant, low correlation between the WOMAC and SQUASH-scores (range 0.14 – 0.24) was found. Although the WOMAC was a significant predictor to meet the (inter-) national guidelines of physical activity (p< 0.001), the odds-ratio was low (1.022, 95%CI 1.0121.033). The Nagelkerke R2 was 0.069, implicating that 6.9% of the variance could be explained.

Conclusion: The WOMAC is not suitable to predict the amount of physical activity after THA, necessitating the use of additional quantitative outcome measures.

Objectives: The development of effective fall prevention programs requires understanding of underlying causes of falls. Measurement tools are needed that predict the risk of falling and give objective assessment of balance function needed for daily life performance. The ultimate goal of the activities within this work package is to combine the expertise of different disciplines for the development of balance assessment tools that meet the requirements for large-scale intervention studies and routine-use in clinical settings. The knowledge needed to develop these instruments and measures is scattered over a wide range of disciplines (ranging from physiology to electrical engineering). The objectives of this work package are to combine expertise from different disciplines to transfer knowledge between disciplines, to co-operate in designing research and provide an intellectual environment for interdisciplinary projects and dissemination of knowledge into disciplines working in the clinical field.

Description of work: Recent technological developments allow for the measurement of human movement under real-life conditions by means of lightweight ambulatory equipment. This novel approach to the analysis of human movement can potentially fill the need for objective field instruments. However, suitable methods for balance assessment need to be developed. Activities of this work package are aimed at co-ordinating the development of methods that can be used in the clinical field for assessment of posture and gait. The work encompasses the organization of workshops, the co-ordination of research, and dissemination of knowledge through publications, teaching and training. Members co-ordinate their individual research efforts in such a way that the different research lines support and reinforce each other. The coordination of research will involve joint experiments and the definition of assessment protocols that can be used in the individual studies of all participating groups. The work focuses on the analysis of kinematic patterns during walking and standing in a natural environment by means of ambulatory equipment. Appropriate methods for signal acquisition and analysis are being developed. Protocols are being designed which specifically address different aspects of balance control (i.e. mental load, sensory dependence, and effects of mechanical manipulations). Laboratory tasks, which have proven to be sensitive for balance dysfunction, will be translated into valid, reliable and easy-to-use procedures for field use. These field instruments are based upon a sound theoretical framework against which the results can be understood and interpreted. In order to address the validity and predictive value of field instruments, longitudinal studies need to be performed that are in accordance with the work in other work packages. Apart from balance assessment procedures, activity levels, history of falls, and future falls need to be assessed. We expect this novel approach to give insight in the relation between objective measures of balance function, activity level and number of falls. Thus, the occurrence of falls can be related to (changes in) activity level.