Traumatic events and their relative PTSD burden in Northern Ireland: a consideration of the impact of the ‘Troubles’

Purpose

Over a 30-year period in its recent history, daily life in Northern Ireland (NI) was characterised by civil violence, colloquially termed as the ‘Troubles’. The current report examines exposure to 29 traumatic event types and the associated conditional prevalence of post-traumatic stress disorder (PTSD) among the Northern Ireland population, with a focus on the impact of traumatic events that were characteristic of the NI ‘Troubles’.

Method

Results presented are based on analysis of data from the Northern Ireland Study of Health and Stress (NISHS). The NISHS is a representative epidemiological study of mental health among the NI adult population (N = 4,340) and part of the World Mental Health Survey Initiative.

Results

Perpetration of violence, physical assault by a spouse or partner and private events were the event types associated with the highest conditional prevalence of PTSD. Despite this elevated risk, collectively these events accounted for just 16.8 % of the overall public burden of PTSD, given their low prevalence among the general population. Events that were characteristic of civil conflict, including unexpected death of a loved one, witnessing death or a dead body or someone seriously injured and being mugged or threatened with a weapon accounted for the highest proportion of the overall public health burden of PTSD (18.6, 9.4 and 7.8 %, respectively). These findings are a feature of the higher prevalence of these events among the general population coupled with their moderate to above average risk of PTSD.

Conclusions

Despite the formal end to conflict in NI in 1999, a substantial proportion of the adult population continue to suffer the adverse mental health effects of chronic trauma exposure. Given rates of recovery of PTSD in the absence of evidence-based treatments, it is likely that the legacy of mental ill health associated with conflict, if not adequately addressed, will endure for many years.     

Volume expansion with albumin compared to gelofusine in children with severe malaria: results of a controlled trial

Objectives:     

How Does a Novel Monoplanar Pedicle Screw Perform Biomechanically Relative to Monoaxial and Polyaxial Designs?

Background

Minimally invasive spinal fusions frequently require placement of pedicle screws through small incisions with limited visualization. Polyaxial pedicle screws are favored due to the difficulty of rod insertion with fixed monoaxial screws. Recently, a novel monoplanar screw became available that is mobile in the coronal plane to ease rod insertion but fixed in the sagittal plane to eliminate head slippage during flexion loads; however, the strength of this screw has not been established relative to other available screw designs.

Questions/purposes

We compared the static and dynamic load to failure in polyaxial, monoaxial, and monoplanar pedicle screws.

Methods

Six different manufacturers’ screws (42 total) were tested in three categories (polyaxial, n = 4; monoaxial, n = 1; monopolar, n = 1) utilizing titanium rods. An additional test was performed using cobalt-chromium rods with the monopolar screws only. Screws were embedded into polyethylene blocks and rods were attached using the manufacturers’ specifications. Static and dynamic testing was performed. Dynamic testing began at 80% of static yield strength at 1 Hz for 50,000 cycles.

Results

In static testing, monoaxial and monoplanar screws sustained higher loads than all polyaxial screw designs (range, 37%–425% higher; p < 0.001). The polyaxial screws failed at the head-screw interface, while the monoaxial and monoplanar screws failed by rod breakage in the static test. The dynamic loads to failure were greater with the monoplanar and monoaxial screws than with the polyaxial screws (range, 35%–560% higher; p < 0.001). With dynamic testing, polyaxial screws failed via screw-head slippage between 40% and 95% of static yield strength, while failures in monoaxial and monoplanar screws resulted from either screw shaft or rod breakage.

Conclusions

All polyaxial screws failed at the screw-head interface in static and dynamic testing and at lower values than monoaxial/monoplanar screw designs. Monoplanar and monoaxial screws failed at forces well above expected in vivo values; this was not the case for most polyaxial screws.

Clinical Relevance

Polyaxial screw heads slip on the screw shank at lower values than monoaxial or monoplanar screws, and this results in angular change between the rod and pedicle screw, which could cause loss of segmental lordosis. The novel monoplanar screw used in this study may combine ease of rod placement with sagittal plane strength.     

A Low‐Cost,Small Volume Circuit for Autologous Blood Normothermic Perfusion of Rabbit Organs

We have designed a laboratory extracorporeal normothermic blood perfusion system for whole organs (e.g., kidney) that achieves pulsatile flow, low levels of hemolysis, and a blood priming volume of 60 mL or less. Using this uniquely designed extracorporeal circuit, we have achieved perfusion of two isolated ex vivo constructs. In the first experiment, we successfully perfused a rabbit epigastric flap based on the femoral vessels. In the second experiment, we were able to perfuse the isolated rabbit kidney for 48 h (range for all kidneys was 12–48 h) with excellent urine output, normal arterial blood gasses at 24 h, and normal ex vivo kidney histology at the conclusion of the experiments. These parameters have not been achieved before with any known or previously published laboratory extracorporeal circuits. The study has implications for prolonged organ perfusion prior to transplantation and for tissue engineering of vascularized tissues, such as by the perfusion of decellularized organs.     

Studying Variations in Bone Composition at Nano-Scale Resolution: A Preliminary Report

Bone has a hierarchical structure extending from the micrometer to the nanometer scale. We report here the first analysis of non-human primate osteonal bone obtained using a spectrometer coupled to an AFM microscope (AFM-IR), with a resolution of 50–100 nm. Average spectra correspond to those observed with conventional FTIR spectroscopy. The following validated FTIR parameters were calculated based on intensities observed in scans covering ~60 µm from the osteon center: mineral content (1030/1660 cm^?1), crystallinity (1030/1020 cm^?1), collagen maturity (1660/1690 cm^?1), and acid phosphate content (1128/1096 cm^?1). A repeating pattern was found in most of these calculated IR parameters corresponding to the reported inter- and intra-lamellar spacing in human bone, indicating that AFM-IR measurements will be able to provide novel compositional information on the variation in bone at the nanometer level.     

Skeletal muscle fibrosis and stiffness increase after rotator cuff tendon injury and neuromuscular compromise in a rat model

Rotator cuff tears can cause irreversible changes (e.g., fibrosis) to the structure and function of the injured muscle(s). Fibrosis leads to increased muscle stiffness resulting in increased tension at the rotator cuff repair site. This tension influences repairability and healing potential in the clinical setting. However, the micro‐ and meso‐scale structural and molecular sources of these whole‐muscle mechanical changes are poorly understood. Here, single muscle fiber and fiber bundle passive mechanical testing was performed on rat supraspinatus and infraspinatus muscles with experimentally induced massive rotator cuff tears (Tenotomy) as well as massive tears with chemical denervation (Tenotomy + BTX) at 8 and 16 weeks post‐injury. Titin molecular weight, collagen content, and myosin heavy chain profiles were measured and correlated with mechanical variables. Single fiber stiffness was not different between controls and experimental groups. However, fiber bundle stiffness was significantly increased at 8 weeks in the Tenotomy + BTX group compared to Tenotomy or control groups. Many of the changes were resolved by 16 weeks. Only fiber bundle passive mechanics was weakly correlated with collagen content. These data suggest that tendon injury with concomitant neuromuscular compromise results in extra‐cellular matrix production and increases in stiffness of the muscle, potentially complicating subsequent attempts for surgical repair. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1111–1116, 2014.