The "replication crisis" in the public eye: Germans' awareness and perceptions of the (ir)reproducibility of scientific research.

Several meta-analytical attempts to reproduce results of empirical research have failed in recent years, prompting scholars and news media to diagnose a "replication crisis" and voice concerns about science losing public credibility. Others, in contrast, hoped replication efforts could improve public confidence in science. Yet nationally representative evidence backing these concerns or hopes is scarce. We provide such evidence, conducting a secondary analysis of the German "Science Barometer" ("Wissenschaftsbarometer") survey. We find that most Germans are not aware of the "replication crisis." In addition, most interpret replication efforts as indicative of scientific quality control and science's self-correcting nature. However, supporters of the populist right-wing party AfD tend to believe that the "crisis" shows one cannot trust science, perhaps using it as an argument to discredit science. But for the majority of Germans, hopes about reputational benefits of the "replication crisis" for science seem more justified than concerns about detrimental effects.

Evaluation of an interdisciplinary therapy algorithm in patients with prosthetic joint infections.

PURPOSE: Current concepts in the treatment of prosthetic joint infections include prosthetic retention and exchange strategies according to published recommendations. A useful algorithm should fit for each type of prosthetic joint infection, even the most complicated situations. We present the outcome of 147 patients with prosthetic joint infections of the hip or the knee joint in an unselected population in clinical routine. METHODS: Between November 2006 and November 2009, 147 consecutive patients with prosthetic joint infections of the hip or knee were treated according to an algorithm based on the concept published by Zimmerli et al. in 2004. Causative organism, duration of infection, patient comorbidities, surgical treatment, antibiotic treatment, and outcome of treatment were analysed retrospectively. According to the criteria duration of infection, stability of prosthesis, local and systemic risk factors, and susceptibility of the causative pathogen, patients were treated either with debridement and retention or a long-interval two-stage procedure. RESULTS: A pathogen could be detected in 82.8% of the patients, gram-positive cocci being most common. Twenty-seven patients were treated with debridement and retention and 120 were treated with a two-stage procedure. In 68 cases difficult-to-treat pathogens could be detected, a polymicrobial infection was found in 51 patients. Definitely free of infection were 71.6% after a two-stage procedure, and 70.4% after debridement and retention. CONCLUSIONS: Our data indicates that the applied algorithm is suitable to be applied as a day-to-day routine, and we confirmed that published results from the literature can be reproduced in an inhomogeneous patient cohort.

Intravertebral pressure gradient during vertebroplasty.

OBJECTIVE: Intravertebral pressure (IP) is considered a possible factor influencing cement leakage in vertebroplasty (VP). Reports of measuring IP during the injection of the cement reveal rather low values in the periphery of the vertebral body but fail to determine the situation in the center. Hypothesizing there is a significant IP gradient between both areas intravertebral pressure measurements were conducted in a comparative biomechanical study. METHODS: VP was performed in ten lumbar cadaveric spines. A pressure sensor was either placed in the center or in the periphery of the vertebral body, while bone cement was delivered in 1.5-cc increments. Volume flow, cement mixing time, and room temperature were standardized and kept constant during cement injection. RESULTS: During the administration of the first 1.5 cc of bone cement, the central IP (C-IP) increased to 23.6 kPa and the peripheral IP (P-IP) to 0.9 kPa on average. With the second injection, the mean C-IP was 42.8 kPa while the mean P-IP was 3.8 kPa. During the 3rd filling, C-IP averaged 69.9 kPa and P-IP 12.8 kPa, respectively. At the last increment, C-IP was at 70.7 kPa and P-IP at 24.5 kPa on average. CONCLUSIONS: A centroperipheral IP gradient (∆IP) was monitored during cement delivery in VP. ∆IP decreases with increasing bone cement charge of the vertebra, but C-IP stays significantly higher than P-IP at all times. C-IP was consistently higher than IP values reported for VP so far.

Computer-assisted fluoroscopic navigation of percutaneous spinal interventions.

PURPOSE: Percutaneous spine procedures may occasionally be difficult and subject to complications. Navigation using a dynamic reference base (DRB) may ease the procedure. Yet, besides other shortcomings, its fixation demands additional incisions and thereby defies the percutaneous character of the procedure. METHODS: A new concept of atraumatic referencing was invented including a special epiDRB. The accuracy of navigated needle placement in soft tissue and bone was experimentally scrutinised. Axial and pin-point deviations from the planned trajectory were investigated with a CT-based 3D computer system. Clinical evaluation in a series of ten patients was also done. RESULTS: The new epiDRB proved convenient and reliable. Its fixation to the skin with adhesive foil provided a stable reference for navigation that improves the workflow of percutaneous interventions, reduces radiation exposure and helps avoid complications. CONCLUSIONS: Percutaneous spine interventions can be safely and accurately navigated using epiDRB with minimal trauma or radiation exposure and without additional skin incisions.

Intravertebral pressure during vertebroplasty and balloon kyphoplasty: an in vitro study.

STUDY DESIGN: Intravertebral pressure (IP) measurements were conducted on human cadaveric lumbar spines in a biomechanical study. OBJECTIVE: To assess the pressure that is generated in the center of the vertebral body during the cement fill in vertebroplasty (VP) and balloon kyphoplasty (BKP). SUMMARY OF BACKGROUND DATA: High IP during polymethylmethacrylate (PMMA) injection have frequently been raised as a reason for the higher cement leakage rate during VP in contrast to BKP. The IP recorded in the periphery of the vertebral body is much lower than the injection syringe pressure. The pressure ratios in the central region of the vertebrae close to the injection cannula are not known. METHODS: VP and BKP were performed in 8 lumbar cadaveric spines. A pressure sensor was placed in the center of the vertebral body. In the VP subgroup a total volume of 6 mL of polymethylmethacrylate cement was delivered in 1.5 mL increments. In the BKP subgroup balloon dilation up to a volume of 4 mL was made before cement injection of 6 mL (1.5 mL increments). Room temperature, cement mixing time, and constant volume flow during cement injection were recorded. RESULTS: During the administration of the first 1.5 mL of bone cement the average IP for VP was 18.5 versus 1.2 kPa for BKP. For the second filling an average pressure of 34.9 kPa (VP) and 3.4 kPa (BKP) was recorded. The average IP during the third injection was 53.0 kPa (VP) and 14.8 kPa (BKP). The pressure of the last 1.5 mL averaged in 56.6 kPa (VP) and 25.5 kPa (BKP). CONCLUSION: The IP measured during cement augmentation in cadaveric spines was lower in BKP than in VP. In the BKP group a relative increase of the IP was registered at the end state of cement delivery when the cavity was overfilled.

Epithelioid sarcoma in the thoracic spine.

Epithelioid sarcoma is a rare and highly malignant soft tissue tumor that is commonly found in the extremities and rarely in the trunk area. This malignant tumor often mimics granuloma or nodular fasciitis, which causes a delay in establishing the diagnosis. This type of cancer has a high recurrence rate. Surgical treatment requires wide radical resection. The objective of this case report is to highlight the unique location of a rare neoplasm and to illustrate the relentless course of epithelioid sarcoma despite initial radical resection. A 14-year-old boy was admitted to our facility with a soft tissue mass on the right lower thoracic spine. The large tumor mass had deeply penetrated into the muscles, infiltrated the neuroforamen of T9-T10 level, and compressed the dural sac. Immunohistological study of the biopsy was highly consistent with an epithelioid sarcoma. Wide excision of the mass, laminectomy and spine fusion with instrumentation was performed. The patient received chemotherapy and irradiation. The first recurrence of the neoplasm was seen as a contralateral metastasis 21 months after the resection. On the last follow-up, 3 years postoperatively, the patient was in a good general condition. However, further progression of the sarcoma had to be recognized. Our case encompasses multiple features that represent negative prognostic factors. Initial wide excision of the neoplasm and adjuvant therapy including chemotherapy and irradiation seem to slow down the relentless course of epithelioid sarcoma in the trunk.

Early polyethylene wear and excessive acetabular granuloma in an uncemented HA-coated total hip arthroplasty--midterm results of a prospective study.

This is a prospective review of 135 HA-coated ABG I total hip arthroplasty (THA) systems with a mean clinical and radiographic follow-up of 8.5 years. The 5-year survival rate was 85%, but 22% of the patients were dissatisfied. Revision THA was already indicated in 28% of the patients, with 26% indicated for cup loosening. PE wear was detected by x-ray in 42%. Disproportionate substantial wear with an average linear loss of 2.6 mm at the inner rim of the insert was observed in 23% of the cases. The mean annual wear rate was calculated 0.1-0.25 mm/year. Laboratory examination of the retrieved PE revealed polishing, cracks, and subsurface delamination. Radiographic evidence of acetabular cysts were found to be excessive granuloma during surgery. Polarization microscopy revealed debris particles phagocytized by reticuloendothelial cells. Results confirm the general opinion that aseptic osteolysis is a cell-mediated process driven by the presence of particles generated from wear debris. The findings also suggest that the main reasons for the failure of the first-generation ABG hip system were an insufficient locking mechanism and poor PE congruency, and not solely poor PE quality.

Therapeutic options and results following fixed atlantoaxial rotatory dislocations.

Atlantoaxial rotatory dislocation (AARD) represents a rare pathological condition of the upper cervical spine that is frequently misdiagnosed, leading to a delay in therapy. In a long-term assessment of clinical and radiological results, three different therapeutic options with regard to the length of the dislocation-therapy interval (DTI) were evaluated. Twenty-six patients were treated for AARD from December 1988 until April 2000. Proper diagnosis was established after an average interval of 15 months. Three different therapeutical protocols were followed in order to reduce the dislocation: (1) closed transoral reposition under general anesthesia; (2) temporary transoral fixation utilizing the Harms T-plate; (3) definitive transoral fusion. The eight patients treated by closed reduction had the best pain relief. The average visual analogue scale (VAS) score was 96.6 points, while the rotatory motion of the upper cervical spine, as assessed by dynamic MRI, was 25.3 degrees to each side. The length of the dislocation-therapy-interval (DTI) averaged 1.4 months. A mean VAS Score of 92.3 points was recorded in the ten patients treated with a temporary fixation of C1/C2. In this subgroup the DTI had an average length of 5.3 months. The mean rotation to each side was 13.9 degrees . In the eight patients who underwent definitive fusion the mean VAS score was 60.6 points, while the average length of the DTI was 40.5 months. In conclusion, the clinical outcome and the subjective well-being following AARD deteriorates with increasing length of the dislocation-therapy interval.