The impact of future sea-level rise on the global tides

Tides are a key component in coastal extreme water levels. Possible changes in the tides caused by mean sea-level rise (SLR) are therefore of importance in the analysis of coastal flooding, as well as many other applications. We investigate the effect of future SLR on the tides globally using a fully global forward tidal model: OTISmpi. Statistical comparisons of the modelled and observed tidal solutions demonstrate the skill of the refined model setup with no reliance on data assimilation. We simulate the response of the four primary tidal constituents to various SLR scenarios. Particular attention is paid to future changes at the largest 136 coastal cities, where changes in water level would have the greatest impact. Spatially uniform SLR scenarios ranging from 0.5 to 10 m with fixed coastlines show that the tidal amplitudes in shelf seas globally respond strongly to SLR with spatially coherent areas of increase and decrease. Changes in the M2 and S2 constituents occur globally in most shelf seas, whereas changes in K1 and O1 are confined to Asian shelves. With higher SLR tidal changes are often not proportional to the SLR imposed and larger portions of mean high water (MHW) changes are above proportional. Changes in MHW exceed ±10% of the SLR at ~10% of coastal cities. SLR scenarios allowing for coastal recession tend increasingly to result in a reduction in tidal range. The fact that the fixed and recession shoreline scenarios result mainly in changes of opposing sign is explained by the effect of the perturbations on the natural period of oscillation of the basin. Our results suggest that coastal management strategies could influence the sign of the tidal amplitude change. The effect of a spatially varying SLR, in this case fingerprints of the initial elastic response to ice mass loss, modestly alters the tidal response with the largest differences at high latitudes

Секция 16-ти этажного монолитно-кирпичного жилого дома по ул. Норильская в г. Красноярске

Background: Epileptic patients have increased risk of fractures. This is related to the traumatic event itself and to concomitant factors. Clear fracture related complaints are not always present at primary survey of these patients. This indicates a thorough primary evaluation of the complete individual post-seizure. We present a unique case of abdominal pain due to bilateral acetabular fracture after an epileptic seizure. Case Report: A 66-year old patient, who chose to live solitary and was in suboptimal hygienic condition, was admitted to the neurological department after two epileptic seizures. Three days after admission, an abdominal radiograph revealed bilateral acetabular and pubic fractures as chance findings. Treatment was challenging due to patient and fracture specific conditions. Conservative treatment options were limited and eventually failed. Eventually, bilateral total hip prosthesis with bone impaction grafting were performed. At one-year follow up, no restriction in active daily living was noted. Conclusion: Seizure induced bilaterally acetabular fractures are very rare. Thorough physical examination after an epileptic seizure is imperative to identify fractures. Abdominal pain can be the only symptom of a fractured acetabulum. Treatment options are dependent of patient’s morbidity, bone quality and surgeon’s preference. Primary total hip arthroplasty might be indicated and can offer good results even in case of bilateral acetabular fractures

Natural language processing for automated quantification of bone metastases reported in free-text bone scintigraphy reports

Background The widespread use of electronic patient-generated health data has led to unprecedented opportunities for automated extraction of clinical features from free-text medical notes. However, processing this rich resource of data for clinical and research purposes, depends on labor-intensive and potentially error-prone manual review. The aim of this study was to develop a natural language processing (NLP) algorithm for binary classification (single metastasis versus two or more metastases) in bone scintigraphy reports of patients undergoing surgery for bone metastases. Material and methods Bone scintigraphy reports of patients undergoing surgery for bone metastases were labeled each by three independent reviewers using a binary classification (single metastasis versus two or more metastases) to establish a ground truth. A stratified 80:20 split was used to develop and test an extreme-gradient boosting supervised machine learning NLP algorithm. Results A total of 704 free-text bone scintigraphy reports from 704 patients were included in this study and 617 (88%) had multiple bone metastases. In the independent test set (n = 141) not used for model development, the NLP algorithm achieved an 0.97 AUC-ROC (95% confidence interval [CI], 0.92-0.99) for classification of multiple bone metastases and an 0.99 AUC-PRC (95% CI, 0.99-0.99). At a threshold of 0.90, NLP algorithm correctly identified multiple bone metastases in 117 of the 124 who had multiple bone metastases in the testing cohort (sensitivity 0.94) and yielded 3 false positives (specificity 0.82). At the same threshold, the NLP algorithm had a positive predictive value of 0.97 and F1-score of 0.96. Conclusions NLP has the potential to automate clinical data extraction from free text radiology notes in orthopedics, thereby optimizing the speed, accuracy, and consistency of clinical chart review. Pending external validation, the NLP algorithm developed in this study may be implemented as a means to aid researchers in tackling large amounts of data

Less invasive surgical treatment of traumatic thoracolumbar fractures

Less invasive surgical treatment of traumatic thoracolumbar fractures. In this thesis various strategies were employed to evaluate the posibilities of reducing the invasiveness of the surgical treatment of traumatic thoracolumbar fractures. A systematic review of the literature suggested that adequate immobilization (as opposed to rigid fixation) of the fractured spine will, in the end lead, to good functional results regardless of the technique used. Previous work demonstrated that insufficient anterior column support can lead to (late onset) kyphosis, mechanical instability, pain and neurological deficit. In a human cadaveric thoracolumbar burst fracture study we demonstrated the feasibility and relative safety of adding balloon vertebroplasty with calcium phosphate cement as a means of reinforcing the anterior column, to the regular treatment of pedicle screw instrumentation. By using a new imaging modality (3D rotational X-ray imaging) we were also able to demonstrate the usefulness and safety of balloon vertebroplasty in fractures where damage to the longitudinal ligaments can be expected. Furthermore, we were able to validate this imaging technique by quantitatively comparing reconstructed (3D) images with corresponding anatomical sections. A high accuracy in displaying the spinal anatomy was found with low interobserver and intraobserver differences. The histological and thermal effects of injecting polymethyl methacrylate and calcium phosphate cement, in artificially created defects in the vertebral body of the goat spine, were investigated. No signs of degeneration to the surrounding tissues could be detected six weeks and six months after surgery and the temperature elevation caused by polymerization of the polymethyl methacrylate cement was not found to reach critical levels. A clinical trial was performed in which twenty patients with traumatic thoracolumbar (burst) fractures but without neurological deficit were included. Balloon vertebroplasty with calcium phosphate cement was performed after internal reduction and fixation with pedicle screw instrumentation. It was found that a significant reduction of the endplate fracture could be achieved after the experimental procedure. Leakage of cement was observed in some patients but did not lead to clinically relevant conditions. The follow-up of the patients was too short to draw solid conclusions yet but the feasibility of the experimental procedure was demonstrated. A randomized controlled clinical trial is currently under consideration. In another human cadaveric study, we demonstrated the feasibility of percutaneous treatment of traumatic fractures by combining balloon vertebroplasty with reduction and fixation using the AO external spine fixator. The external fixator was removed after curing of the cement (typically within 24 hours) and biomechanical tests were performed. It was found that a significant reduction of the fractured endplate could be achieved and at least 60% of the reduced height remained after loading the treated fractures with the maximum values that are sustained during in vivo conditions. This percutaneous treatment could be performed using six small stabwounds instead of a midline incision with the associated soft tissue damage. In the last chapter a device that can be inserted percutaneously, is proposed that could be used as standalone reduction/fixation device for the treatment of traumatic thoracolumbar fractures. This device is currently in the prototype stage and has already undergone some human cadaveric testing

Histologic changes after vertebroplasty.

Item does not contain fulltextBACKGROUND: Vertebroplasty with use of polymethylmethacrylate cement is gaining popularity in the treatment of some specific painful lesions of the spine. It remains unclear, however, what possible side effects this type of cement might have upon the vertebral body. We performed a histologic and radiographic analysis of the end plate and disc to determine whether there was a difference between vertebroplasty with polymethylmethacrylate cement and vertebroplasty with calcium phosphate cement in the surrounding tissue of the goat spine. Furthermore, we assessed whether a defect in the end plate, simulating end-plate fracture and allowing for direct contact of cement with disc tissue, had any effect on end-plate or disc degeneration. METHODS: Twenty-four mature goats were divided between two follow-up periods (six weeks and six months). All animals underwent a bilateral transpedicular vertebroplasty at two lumbar levels, where one of the following treatments was applied: vertebroplasty with calcium phosphate cement with or without an end-plate defect, and vertebroplasty with polymethylmethacrylate cement with or without an end-plate defect. The effect of the various treatments on the integrity of the intervertebral disc, end plate, and surrounding tissue was examined with semiquantitative histologic analysis and radiography. RESULTS: No sign of disc or end-plate degeneration was seen in any of the analyzed sections. The mean disc height did not decrease from the postoperative period to the time that the animals were killed in any group, thereby supporting the histologic findings. A mild inflammatory reaction was found in four vertebral bodies in the polymethylmethacrylate groups only. CONCLUSIONS: Calcium phosphate cement and polymethylmethacrylate cement both seem to be adequate bone-void fillers in terms of biological behavior in the vertebral body

Clinical outcome after traumatic spinal fractures in patients with ankylosing spinal disorders compared with control patients.

Background context The clinical outcome of patients with ankylosing spinal disorders (ASDs) sustaining a spinal fracture has been described to be worse compared with the general trauma population. Purpose To investigate clinical outcome (neurologic deficits, complications, and mortality) after spinal injury in patients with ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) compared with control patients. Study design Retrospective cohort study. Patient sample All patients older than 50 years and admitted with a traumatic spinal fracture to the Emergency Department of the University Medical Center Utrecht, the Netherlands, a regional level-1 trauma center and tertiary referral spine center. Outcome measures Data on comorbidity (Charlson comorbidity score), mechanism of trauma, fracture characteristics, neurologic deficit, complications, and in-hospital mortality were collected from medical records. Methods With logistic regression analysis, the association between the presence of an ASD and mortality was investigated in relation to other known risk factors for mortality. Results A total of 165 patients met the inclusion criteria; 14 patients were diagnosed with AS (8.5%), 40 patients had DISH (24.2%), and 111 patients were control patients (67.3%). Ankylosing spinal disorder patients were approximately five years older than control patients and predominantly of male gender. The Charlson comorbidity score did not significantly differ among the groups, but Type 2 diabetes mellitus and obesity were more prevalent among DISH patients. In many AS and DISH cases, fractures resulted from low-energy trauma and showed a hyperextension configuration. Patients with AS and DISH were frequently admitted with a neurologic deficit (57.1% and 30.0%, respectively) compared with controls (12.6%; p=.002), which did not improve in the majority of cases. In AS and DISH patients, complication and mortality rates were significantly higher than in controls. Logistic regression analysis showed the parameters age and presence of DISH to be independently, statistically significantly related to mortality. Conclusions Many patients with AS and DISH showed unstable (hyperextension) fracture configurations and neurologic deficits. Complication and mortality rates were higher in patients with ASD compared with control patients. Increasing age and presence of DISH are predictors of mortality after a spinal fracture

The influence of diffuse idiopathic skeletal hyperostosis on bone mineral density measurements of the spine

Rheumatology Advance Access originally published online on July 14, 2009 Rheumatology 2009 48(9):1133-1136; doi:10.1093/rheumatology/kep177 © The Author 2009. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: [email protected] The influence of diffuse idiopathic skeletal hyperostosis on bone mineral density measurements of the spine L. Anneloes Westerveld1, Jorrit-Jan Verlaan1, Marnix G. E. H. Lam2, Wendy P. Scholten2, Ronald L. A. W. Bleys3, Wouter J. A. Dhert1,4 and F. Cumhur Oner1 1Department of Orthopaedics, 2Department of Radiology and Nuclear Medicine, 3Department of Anatomy, University Medical Center Utrecht and 4Faculty of Veterinary Medicine, University of Utrecht, Utrecht, The Netherlands. Correspondence to: Jorrit-Jan Verlaan, Department of Orthopaedics, University Medical Center Utrecht, G 05.228, PO Box 85500, 3508 GA Utrecht, The Netherlands. E-mail: [email protected]

Extraspinal manifestations of diffuse idiopathic skeletal hyperostosis

DISH is a condition characterized by calcification and/or ossification of soft tissues, mainly entheses, ligaments and joint capsules. Its prevalence increases with age and, therefore, DISH is a relatively common entity in the elderly. The classical site of involvement is the spinal column with right anterolateral soft tissue ossification being the most characteristic feature. However, DISH is not limited to the spine, and may affect multiple peripheral sites independently. Extraspinal entheseal ossifications are common and observing their isolated presence may lead to the diagnosis of DISH. Furthermore, hypertrophic or atypical OA observed in joints usually not affected by primary OA has frequently been reported in DISH. Several metabolic derangements and concomitant diseases have been suggested to be associated with DISH including obesity, increased waist circumference, hypertension, dyslipidaemia, diabetes mellitus (DM), hyperuricaemia, metabolic syndrome and an increased risk for cardiovascular diseases. Witnessing the present increase in lifespan, obesity, DM and metabolic syndrome in the Western population, the prevalence of DISH should be expected to rise. In order to increase the awareness for DISH, this review focuses on the extraspinal features of the condition

Sparing the posterior surgical site when planning radiation therapy for thoracic metastatic spinal disease

Clinical Oncolog