Extreme ultraviolet-excited time-resolved luminescence spectroscopy using an ultrafast table-top high-harmonic generation source.

We present a table-top extreme ultraviolet (XUV) beamline for measuring time- and frequency-resolved XUV-excited optical luminescence (XEOL) with additional femtosecond-resolution XUV transient absorption spectroscopy functionality. XUV pulses are generated via high-harmonic generation using a near-infrared pulse in a noble gas medium and focused to excite luminescence from a solid sample. The luminescence is collimated and guided into a streak camera where its spectral components are temporally resolved with picosecond temporal resolution. We time-resolve XUV-excited luminescence and compare the results to luminescence decays excited at longer wavelengths for three different materials: (i) sodium salicylate, an often used XUV scintillator; (ii) fluorescent labeling molecule 4-carbazole benzoic (CB) acid; and (iii) a zirconium metal oxo-cluster labeled with CB, which is a photoresist candidate for extreme-ultraviolet lithography. Our results establish time-resolved XEOL as a new technique to measure transient XUV-driven phenomena in solid-state samples and identify decay mechanisms of molecules following XUV and soft-x-ray excitation.

Dynamics of an orthopaedic team: Insights to improve teamwork through a design thinking approach.

BACKGROUND: Supporting teamwork in healthcare is a way to foster both the quality and safety of care, and better working conditions for all the team members. Although increasing attention is paid to this topic on a general level, there is less knowledge about its unfolding in orthopaedic units and its translation to interventions. OBJECTIVE: To identify concrete opportunities for teamwork intervention through a design thinking approach by analysing the teamwork dynamics of an orthopaedic team. METHODS: An adaptation of the learning history method, comprising shadowing, observations and interviews involving 26 orthopaedic team members at a top clinical teaching hospital in the Netherlands, was applied. A thematic analysis was conducted to derive themes that describe team dynamics and to subsequently extrapolate opportunities for intervention. RESULTS: We identified five themes and translated them into four design opportunities for intervention, namely: a) Improve daily rounds by reducing cognitive overload and promoting confidence; b) Improve collaboration by building empathy; c) Connect the patient with the professional team; and d) Support changes by fostering learning. Suggestions for concrete actions are presented for each opportunity. CONCLUSIONS: Opportunities to improve teamwork among healthcare professionals, specifically those in orthopaedics, revolve around the creation of common knowledge, the fostering of mutual understanding, and the design of tools and activities that support these processes.

Anxiety and depressive symptoms before and after total hip and knee arthroplasty: a prospective multicentre study.

BACKGROUND: A subset of patients with total hip arthroplasty (THA) or total knee arthroplasty (TKA) has suboptimal postoperative results in terms of Patient Reported Outcomes (PROs), and psychological factors could contribute to these suboptimal results. OBJECTIVES: To examine the prevalence of anxiety and depressive symptoms in patients undergoing primary THA or TKA preoperatively and postoperatively, and the relationship between preoperative anxiety and depressive symptoms on PROs of THA and TKA. DESIGN: In this prospective study patients were measured preoperatively, and 3 and 12 months postoperatively. Patients filled in the Hospital Anxiety and Depression Scale, Knee injury and Osteoarthritis Outcome Score (KOOS) or Hip disability and Osteoarthritis Outcome Score (HOOS) and a satisfaction questionnaire. RESULTS: Data were obtained from 149 hip and 133 knee patients. The prevalence of anxiety symptoms decreased significantly from 27.9% to 10.8% 12 months postoperatively in hip patients, and from 20.3% to 14.8% in knee patients. Depressive symptoms decreased significantly from 33.6% to 12.1% 12 months postoperatively in hip patients, and from 22.7% to 11.7% in knee patients. In hip and knee patients, preoperative depressive symptoms predicted smaller changes in different HOOS or KOOS subscales and patients were less satisfied 12 months postoperatively. CONCLUSIONS: Preoperatively, the prevalence of anxiety and depressive symptoms was high. At 3 and 12 months postoperatively, the prevalence of anxiety and depressive symptoms was decreased in both hip and knee patients. However, patients with preoperative anxiety and depressive symptoms had worse PROs 3 and 12 months after THA and TKA and were less satisfied than patients without anxiety or depressive symptoms.

Risk factors for the displacement of fractures of both bones of the forearm in children.

Forearm fractures in children have a tendency to displace in a cast leading to malunion with reduced functional and cosmetic results. In order to identify risk factors for displacement, a total of 247 conservatively treated fractures of the forearm in 246 children with a mean age of 7.3 years (sd 3.2; 0.9 to 14.9) were included in a prospective multicentre study. Multivariate logistic regression analyses were performed to assess risk factors for displacement of reduced or non-reduced fractures in the cast. Displacement occurred in 73 patients (29.6%), of which 65 (89.0%) were in above-elbow casts. The mean time between the injury and displacement was 22.7 days (0 to 59). The independent factors found to significantly increase the risk of displacement were a fracture of the non-dominant arm (p = 0.024), a complete fracture (p = 0.040), a fracture with translation of the ulna on lateral radiographs (p = 0.014) and shortening of the fracture (p = 0.019). Fractures of both forearm bones in children have a strong tendency to displace even in an above-elbow cast. Severe fractures of the non-dominant arm are at highest risk for displacement. Radiographs at set times during treatment might identify early displacement, which should be treated before malunion occurs, especially in older children with less potential for remodelling.

Comparison of contamination of femoral heads and pre-processed bone chips during hip revision arthroplasty.

With bone impaction grafting, cancellous bone chips made from allograft femoral heads are impacted in a bone defect, which introduces an additional source of infection. The potential benefit of the use of pre-processed bone chips was investigated by comparing the bacterial contamination of bone chips prepared intraoperatively with the bacterial contamination of pre-processed bone chips at different stages in the surgical procedure. To investigate baseline contamination of the bone grafts, specimens were collected during 88 procedures before actual use or preparation of the bone chips: in 44 procedures intraoperatively prepared chips were used (Group A) and in the other 44 procedures pre-processed bone chips were used (Group B). In 64 of these procedures (32 using locally prepared bone chips and 32 using pre-processed bone chips) specimens were also collected later in the procedure to investigate contamination after use and preparation of the bone chips. In total, 8 procedures had one or more positive specimen(s) (12.5 %). Contamination rates were not significantly different between bone chips prepared at the operating theatre and pre-processed bone chips. In conclusion, there was no difference in bacterial contamination between bone chips prepared from whole femoral heads in the operating room and pre-processed bone chips, and therefore, both types of bone allografts are comparable with respect to risk of infection.

Epidiaphyseal versus other intercalary allografts for tumors of the lower limb.

Epidiaphyseal intercalary reconstruction has become possible for bone tumors that extend into the epiphysis because advances in magnetic resonance imaging and chemotherapy allow close resection while sparing the juxtaarticular bone and joint. In a retrospective study, we questioned whether epidiaphyseal reconstructions around the knee had a clinical outcome (measured as long-term survival, complication rate, and functional score) comparable with metadiaphyseal and diaphyseal reconstructions. Between 1988 and 1999, 14 epidiaphyseal, nine metaphyseal, and 12 diaphyseal reconstructions were done, and the median followup was 7.2 years. Kaplan-Meier analysis showed a 10-year survival rate of 79% for epidiaphyseal reconstructions, which did not differ from an 89% rate for metadiaphyseal and a 75% rate for diaphyseal reconstructions. Epidiaphyseal complications included two infections, five fractures, and three nonunion treatments. Complications for all 35 grafts included three infections, 12 fractures, and nine nonunion treatments. Ultimately, six grafts failed, with infection and length of resection as predisposing factors. All epiphyseal osteotomies had tumor-free margins and no local recurrences. The mean Musculoskeletal Tumor Society score for each type of intercalary reconstruction was between 23 and 24. Because the epidiaphyseal reconstruction avoids complications associated with joint reconstruction and the results are comparable with those of other types of intercalary grafts, these reconstructions should be considered if at least 1 cm of tumor-free juxtaarticular bone can be maintained.

Hemicortical allograft reconstruction after resection of low-grade malignant bone tumours.

Low-grade surface tumours of bone may theoretically be treated by hemicortical resection, retaining part of the circumference of the cortex. An inlay allograft may be used to reconstruct the defect. Since 1988 we have performed 22 hemicortical procedures in selected patients with low-grade parosteal osteosarcoma (6), peripheral chondrosarcoma (6) and adamantinoma (10). Restricted medullary involvement was not a contraindication for this procedure. There was no evidence of local recurrence or distant metastasis at a mean follow-up of 64 months (27 to 135). Wide resection margins were obtained in 19 patients. All allografts incorporated completely and there were no fractures or infections. Fractures of the remaining hemicortex occurred in six patients and were managed successfully by casts or by osteosynthesis. The functional results were excellent or good in all except one patient. Hemicortical procedures for selected cases of low-grade surface tumours give excellent oncological and functional outcomes. There was complete remodelling and fewer complications when compared with larger intercalary procedures. The surgery is technically demanding but gives good clinical results.

Microbiological screening of post-mortem bone donors - two case reports.

This study assesses the value of blood cultures in combination with swab culturing techniques in association with bone banking procedures. The results of blood and swab cultures of two postmortem bone donors were compared with procured grafts, cultured in their entirety. In one donor, who died of drowning, three of the 12 entire graft cultures were positive with the same microorganism of high pathogenicity as the blood culture, whilst the swab culture of only one graft was positive. In the second donor, who died from myocardial infarction, four entire cultures were positive with the same organism of high pathogenicity as the blood culture, whilst the swab cultures of three grafts were positive. In both donors identical organisms were cultured from the myocardium of the pulmonary or aortic heart valve. The results confirm the limited sensitivity of swab culturing techniques. Especially micro-organisms inside a graft, disseminated through the bloodstream, can remain unnoticed. Blood cultures seem to provide additional information on micro-organisms that have spread haematogenously pre-mortem and may even provide information on the source from which they have spread.

[A structured pain interview for geriatric patients]. / Ein strukturiertes Schmerzinterview für geriatrische Patienten.

BACKGROUND: In old age, assessment of pain often is hampered by sensory and cognitive deficits that do not allow the patients to fill in standardized questionnaires without help from significant others. Therefore, as an alternative, we developed a structured pain interview, and examined its properties and acceptance in a sample of geriatric patients with pain. METHODS: The interview covers site of pain, intensity of pain, its duration and persistency, pain related disability and, finally, emotional and cognitive variables. In addition, the interviewer addresses significant others to get information about medication, previous treatment, and residence, and administers the Mini-Mental-State-Examination (MMSE). The analysis includes 128 patients of pain centers older than 74 years, of whom 80% are female. RESULTS: Forty percent of the subjects score below the critical MMSE value < or =23 indicative of cognitive impairment. These patients are responsible for 36 out of a total of 39 missing values. A significant increase of missing values is observed in patients with a MMSE score below 10. Cognitive impairment goes along with greater functional and social disability. On the other hand, cognitive impairment is unrelated to localization, intensity, and duration of pain. The memory item of the MMSE can be used as a screening tool for cognitive impairment. Patients, who are unable to recall any of the three objects, comprise 80% of the total of missing values and demonstrate a low MMSE score. CONCLUSION: As long as geriatric patients are able to communicate verbally, they are most likely to profit from the structured pain interview in spite of existing cognitive impairment. A MMSE score <10 indicates that the interpretation of the data obtained may be difficult, especially due to a high frequency of missing values.

A comparative study of blood and bone marrow cultures in cadaveric bone donation.

The results of blood cultures taken from cadaveric bone donors were compared with bone marrow and also swab cultures of the procured grafts. In eight of the 95 donors evaluated, pathogenic micro-organisms were detected in the blood sample. In two, identical micro-organisms were cultured from the blood and bone marrow sample whilst the swab cultures were negative. Considering the low sensitivity of the swab culture, the organisms detected in the blood culture were likely to have spread haematogenously and considered to be present in the explanted grafts. Bacteriological screening of bone donors is extremely important since the transmission of micro-organisms via an allograft can lead to serious complications in the recipient. Positive blood cultures provide important information on the presence of pathogenic micro-organisms in grafts obtained from cadaveric bone donors and are therefore essential in deciding whether a graft is bacteriologically acceptable for transplantation.

[Negative priming designs: comparison and improvement of measurements for detection of cognitive inhibition]. / Negative-Priming-Designs: Vergleich und Optimierung von Messverfahren zur Erfassung kognitiver Hemmungsprozesse.

Ignoring a distractor on a prime trial generally impairs responses to that stimulus on a subsequent probe trial. This so called negative-priming (NP) effect supports the view that the representations of distracting stimuli underly a cognitive inhibition during target selection (Tipper, 1985). Aiming at the optimization of NP designs for analyzing cognitive inhibition the present paper investigates two open questions within this context: Which classical designs using words, letters, or pictures as stimuli are most accepted by subjects and at the same time result in possibly strong NP effects? What is the time course of NP, and at which interstimulus interval (ISI) the maximum is reached? In experiment 1, three "classical" NP designs were compared within one sample of subjects and a picture design was selected as the most suitable one. In experiment 2 the ISI was varied within subjects; the maximal NP effect was found at an ISI of around 1000 ms.

Successful excision of a pseudotumour in a congenitally factor V deficient patient.

We report a patient with congenital homozygous factor V deficiency in whom a large pseudotumour in the right upper leg was successfully surgically excised under continuous substitution with fresh-frozen plasma.

Contamination of bone allografts: analysis of incidence and predisposing factors.

We analysed the bacterial contamination of 1999 bone allografts retrieved from 200 cadaver donors under sterile operating conditions. The effect of various factors on the relative risk of contamination was estimated using a multiple logistic regression model. Organisms of low pathogenicity were cultured from 50% of the grafts and of high pathogenicity from 3%. The risk of contamination with low pathogenic organisms (mainly skin commensals) increased by a factor of 1.6 for each member added to the procurement team. The risk of contamination with high pathogenic organisms (mainly contaminants from the gastrointestinal tract) was 3.4 times higher in donors with a traumatic cause of death and 5.2 times higher in those with a positive blood culture. Preceding organ procurement did not significantly influence the risk of contamination. Rinsing the graft with an antibiotic solution was not an effective decontamination method. The major source of contamination is exogenous and is strongly influenced by the procurement team. Contamination from endogenous sources can be controlled by donor selection. We discuss methods that can be used to decrease contamination and the rate of discarding of bone allografts.

[5-year experience with a central bone bank]. / Vijf jaar ervaring met een centrale botbank.

Since December 1988 the Leiden Bone Bank Foundation, in cooperation with the BIS Foundation, makes allogeneic bone and related soft tissue available for transplantation. Bone banking has become a scientifically high level medical activity in which international standards are established in order to provide safe and effective allografts. Careful donor selection and extensive laboratory testing are the cornerstones for the prevention of disease transmission. In the first 5 years of the existence of the Leiden Bone Bank 450 deep frozen massive bone allografts, of which 221 osteoarticular and intercalary allografts, were shipped to different clinics inside and outside the Netherlands. Furthermore, 322 deep frozen soft tissues, 1877 units of freeze dried bone grafts and 5629 units of demineralized grafts were distributed. The number of transplants with allogeneic bone and related soft tissue from the Leiden Bone Bank increased each year by at least 30% Bone and related soft tissue allografts were used in orthopaedic surgery, neurosurgery and maxillofacial surgery. There are no known cases of transmission of infectious diseases by grafts distributed by the Leiden Bone Bank.

Sensitivity and negative predictive value of swab cultures in musculoskeletal allograft procurement.

Seventy-five fibular specimens were obtained from postmortem donors using aseptic surgical techniques. All specimens were swabbed following the same technique as routinely used for retrieved musculoskeletal grafts. After swabbing, the specimens were placed in BHI-culture medium. Three different protocols were subsequently followed: (1) culture of the entire bone specimen in BHI-culture medium, (2) culture of the swab incubated on blood agar and chocolate plates, and (3) culture of the swab in BHI-culture medium. A control group included 20 sterilized bone specimens that were cultured entirely in BHI-culture medium according to Protocol 1. The sensitivity and negative predictive value were found to be 10% and 9% in Protocol 2 and 13% in Protocol 3. These findings imply that swab cultures are inadequate to detect bacterial contamination of musculoskeletal allografts in all cases. However, the instances of infection after transplantation of allografts bacteriologically screened according to Protocols 1 and 2 do not exceed those reported in other similar series. This suggests an acceptable bioburden.

Paget's disease with osteolytic lesions: combining medical and surgical treatments.

A patient with extensive Paget's disease of bone presented with severe bone pain, hypercalcaemia and a large osteolytic lesion of the femur which developed during long-term therapy with etidronate. Treatment with pamidronate normalized serum calcium concentration and induced a complete biochemical remission. The osteolytic lesion was grafted with bone chips. A recurrence of the Paget's disease was associated with clear autonomous hypercalcaemic hyperparathyroidism. Five years after removal of 3 1/2 hyperplastic parathyroid glands, the patient remains in complete clinical and biochemical remission. These findings illustrate the pitfalls encountered in the management of Paget's disease and the value of combining medical and surgical interventions.

[The use of allogeneic bone and tendon tissue from a central bone bank]. / Het gebruik van allogeen bot- en peesweefsel uit een centrale botbank.

During the period January 1989 to December 1990 the use of bone and related soft tissue allografts from our bone bank was reviewed retrospectively. Data were complete for 278 patients, who received 403 allografts in total. Forty-nine patients were transplanted with a massive deep frozen bone allograft, 41 patients received a deep frozen soft tissue allograft, while 313 units of freeze dried bone allografts were transplanted into 188 patients. Massive deep-frozen bone allografts were used mainly in patients with bone tumours, fibrous dysplasia of the neck of the femur and for revision arthroplasty. Soft tissues were used mainly for reconstruction of ruptured cruciate ligaments. Freeze dried bone allografts such as cancellous chips as well as cortical cancellous chips were used for spinal fusion, arthroplasty, treatment of pseudarthrosis, fractures, tumours and fibrous dysplasia, and in maxillofacial defects. Cancellous blocks were used specifically for spinal fusion. Demineralized cortical dust was used mainly in maxillofacial surgery.

Sequential magnetic resonance imaging in Perthes' disease.

Forty-eight images using magnetic resonance imaging (MRI) in 16 hips with Perthes' disease were evaluated over a mean period of two years. MRI depicted exactly the infarcted zone in the femoral head before typical radiological changes were evident. Early determination of the extent of the infarcted bone on MRI benefits those patients who require treatment. Follow-up MRI scans at six-monthly intervals, reflected the chronological stages of the repair process in each group classified according to Catterall.