In cases of prosthetic joint infections the sensitivity of bacterial cultivation of tissue samples is not 100%. In fact, the reported sensitivity based on standardized criteria and rigorous tissue sampling technique probably differs between 86 to 89%. It has been claimed that sonication of explanted prostheses with subsequent culturing of sonication fluid can increase the sensitivity of the test compared to culturing of tissue samples. To what degree bacteria embedded in biofilm is dislodged during the sonication process has to our knowledge not been fully elucidated. We studied the effect of sonication as a method to dislodge biofilm embedded 46 steel plates were colonized with biofilm forming Three steel plates acted as negative controls.Aim
Method
The incidence of prosthetic joint infections can be severe to monitor, as they are rare events. Recent publications from National registries points toward a significant underestimation of reported infections. The aim of this project was to develop a complication register that could report the “true” and momentaneous incidence of prosthetic infections after total knee and hip arthroplasty. All patients operated with total hip arthroplasty (THA) or total knee arthroplasty (TKA) at our hospital were included in a local quality registry. All complications were reported at follow-up at 2 and 3 months for total knee and hip arthroplasties respectively, and at 1-year follow up. Both primary and revision surgeries were included. In order to monitor complications of special interest, such as deep postoperative infections, key variables were presented in a g-chart. This chart shows the number of uncomplicated surgeries between each complication (such as infection) in a bar diagram. This diagram is easily read as high bars indicate a low incidence of complications and low bars indicate a high incidence. The diagram is updated and distributed for information every month.Aim
Method
Computer-assisted techniques are developed to optimise the positioning of acetabular cups in total hip replacement. However, ordinary guiding devices are still most commonly used. The aim of this study was to evaluate the accuracy when using a simple mechanical guiding device. 30 patients were operated by an experienced hip surgeon. A lateral position and a lateral approach were used. An un cemented press fit cup (Trilogy AB) was inserted using the guiding device for this type of pros-thesis, aiming 45 degrees abduction and 20 degrees ante-version. Radiological investigations were performed one week and three months postoperatively. Frontal views of the pelvis and of the operated hip were obtained. After scanning the contour of the opening of the acetabular prosthesis was identified and digitised using an edge detecting technique. The axes of the ellipsis of the acetabular opening served for calculation of the version of the cup. A lateral view clarified whether the cup was ante- or retroverted. The abduction related to the teardrop-line was measured on the scanned pelvic radiograph. One week postoperatively mean abduction was 50 degrees (37–62), SD 5 degrees. Mean anteversion measured on the pelvic view was 9 degrees (2–23), SD 5 degrees, compared to 11 degrees (4–24), SD 5 degrees, on the frontal view of the hip joint 50 per cent of the cups showed a deviation of more than 10 degrees from the aimed anteversion.. At average the anteversion was 2 degrees lower when measured on the pelvic view compared to that measured on the AP-view of the hip. There were no significant differences between the measurements at one week and three months. The anteversion of uncemented press fit acetabular components tends to be lower than intended when using a simple guiding device. The risk of an unacceptable abduction seems negligible. The inaccuracy in acetabular positioning may be due to inadequate positioning of the pelvis or inaccurate insertion technique.
