The aetiology of posterior glenohumeral dislocations and occurrence of associated injuries: a systematic review.

AIMS: The glenohumeral joint is the most frequently dislocated articulation, but possibly due to the lower prevalence of posterior shoulder dislocations, approximately 50% to 79% of posterior glenohumeral dislocations are missed at initial presentation. The aim of this study was to systematically evaluate the most recent evidence involving the aetiology of posterior glenohumeral dislocations, as well as the diagnosis and treatment. MATERIALS AND METHODS: A systematic search was conducted using PubMed (MEDLINE), Web of Science, Embase, and Cochrane (January 1997 to September 2017), with references from articles also evaluated. Studies reporting patients who experienced an acute posterior glenohumeral joint subluxation and/or dislocation, as well as the aetiology of posterior glenohumeral dislocations, were included. RESULTS: A total of 54 studies met the inclusion criteria. In total, 182 patients were included in this analysis; study sizes ranged from one to 66 patients, with a mean age of 44.2 years (sd 13.7). There was a higher proportion of male patients. In all, 216 shoulders were included with 148 unilateral injuries and 34 bilateral. Seizures were implicated in 38% of patients (n = 69), with falls, road traffic accidents, electric shock, and iatrogenic reasons also described. Time to diagnosis varied across studies from immediate up to a delay of 25 years. Multiple associated injuries are described. CONCLUSION: This review provides an up-to-date insight into the aetiology of posterior shoulder dislocations. Our results showed that seizures were most commonly implicated. Overall, reduction was achieved via open means in the majority of shoulders. We also found that delayed diagnosis is common.

Bulk Flow and Near Wall Hemodynamics of the Rabbit Aortic Arch and Descending Thoracic Aorta: A 4D PC-MRI Derived Computational Fluid Dynamics Study.

Animal models offer a flexible experimental environment for studying atherosclerosis. The mouse is the most commonly used animal, however, the underlying hemodynamics in larger animals such as the rabbit are far closer to that of humans. The aortic arch is a vessel with complex helical flow and highly heterogeneous shear stress patterns which may influence where atherosclerotic lesions form. A better understanding of intraspecies flow variation and the impact of geometry on flow may improve our understanding of where disease forms. In this work, we use magnetic resonance angiography (MRA) and 4D phase contrast magnetic resonance imaging (PC-MRI) to image and measure blood velocity in the rabbit aortic arch. Measured flow rates from the PC-MRI were used as boundary conditions in computational fluid dynamics (CFD) models of the arches. Helical flow, cross flow index (CFI), and time-averaged wall shear stress (TAWSS) were determined from the simulated flow field. Both traditional geometric metrics and shape modes derived from statistical shape analysis were analyzed with respect to flow helicity. High CFI and low TAWSS were found to colocalize in the ascending aorta and to a lesser extent on the inner curvature of the aortic arch. The Reynolds number was linearly associated with an increase in helical flow intensity (R = 0.85, p < 0.05). Both traditional and statistical shape analyses correlated with increased helical flow symmetry. However, a stronger correlation was obtained from the statistical shape analysis demonstrating its potential for discerning the role of shape in hemodynamic studies.

70,489 primary care encounters: retrospective analysis of morbidity at a primary care centre in Ireland.

BACKGROUND: While considerable changes are happening in primary care in Ireland and considerable potential exists in intelligence derived from practice-based data to inform these changes, relatively few large-scale general morbidity surveys have been published. AIMS: To examine the most common reasons why people attend primary care, specifically 'reasons for encounter' (RFEs) among the general practice population and among specific demographic groups (i.e., young children and older adults). METHODS: We retrospectively examined clinical encounters (which had a diagnostic code) over a 4-year time period. Descriptive analyses were conducted on anonymised data. RESULTS: 70,489 RFEs consultations were recorded (mean 13.53 recorded RFEs per person per annum) and consultations involving multiple RFEs were common. RFE categories for which codes were most commonly recorded were: 'general/unspecified' (31.6 %), 'respiratory' (15.4 %) and 'musculoskeletal' (12.6 %). Most commonly recorded codes were: 'medication renewal' (6.8 %), 'cough' (6.6 %), and 'health maintenance/prevention' (5.8 %). There was considerable variation in the number of RFEs recorded per age group. 6239 RFEs (8.9 %) were recorded by children under 6 years and 15,295 RFEs (21.7 %) were recorded by adults aged over 70. RFEs recorded per calendar month increased consistently through the study period and there was a marked seasonal and temporal variation in the number of RFEs recorded. CONCLUSIONS: Practice databases can generate intelligence on morbidity and health service utilisation in the community. Future research to optimise diagnostic coding at a practice level and to promote this activity in a more representative sample of practices is a priority.

Does eliminating fees at point of access affect Irish general practice attendance rates in the under 6 years old population? A cross sectional study at six general practices.

With the introduction of free point of access GP care for children aged under six imminent, we sought to determine consultation rates among this group. We interrogated data from practice management systems at six general practices (total patient population 27080). A total of 1931 children aged under six were responsible for 5814 surgery consultations. The mean annual consultation rate was 3.01; 4.91 for GMS' patients, 5.07 for 'Doctor Visit' patients and 2.03 for private patients. Our findings suggest the introduction of free GP care for children under six will considerably increase GP consultations. We also highlight the value of routinely collected general practice data in facilitating health services planning. We estimate that there will be an additional 750,000 GP consultations annually.

Are Irish adult general practice consultation rates as low as official records suggest? A cross sectional study at six general practices.

Accurate data on primary care activity is key to health services planning and reconfiguration. Official data estimate general practice adult consultation rates to be 3.2 visits annually, based on patient self reports. We aim to estimate the consultation rate using practice based data and compare this to official estimates. We interrogated six general practices' information systems and estimated consultation rates based on practice, telephone, domiciliary and out of hours consultations by patients aged 18 years or older. The study population (20,706 patients) was representative of the national population in terms of age and GMS status. The mean consultation rate was 5.17, though this was higher among GMS-eligible patients and among older age groups. Estimates of consultation rates derived from practice based data are likely to be higher than that derived from other approaches. Using multiple sources of data will enhance accuracy of workload estimates and this will benefit service planning.

Patient-reported outcomes after Silastic replacement of the trapezium for osteoarthritis.

This retrospective study evaluated 69 Swanson trapezium replacements performed between 1990 and 2009 for trapeziometacarpal osteoarthritis in 58 patients. Pain and function were assessed using the Michigan Hand Questionnaire and the Disability of the Arm, Shoulder and Hand questionnaire. Patients had a mean age of 62 years at the time of surgery, with a mean time of 7.7 years (range 9 months to 19 years) from surgery to follow-up interview. There was no association between outcome scores and the length of follow-up, suggesting that the results are maintained over time (Spearman's rank correlation test < ±0.2). Scores for activities of daily living and work-related activities were higher when surgery was on the dominant hand (p < 0.05). Silicone trapezium replacement remains a good option for patients with painful trapeziometacarpal osteoarthritis that has not responded to nonoperative management.

The effect of vessel material properties and pulsatile wall motion on the fixation of a proximal stent of an endovascular graft.

Migration is a serious failure mechanism associated with endovascular abdominal aortic aneurysm (AAA) repair (EVAR). The effect of vessel material properties and pulsatile wall motion on stent fixation has not been previously investigated. A proximal stent from a commercially available stent graft was implanted into the proximal neck of silicone rubber abdominal aortic aneurysm models of varying proximal neck stiffness (ß=25.39 and 20.44). The stent was then dislodged by placing distal force on the stent struts. The peak force to completely dislodge the stent was measured using a loadcell. Dislodgment was performed at ambient pressure with no flow (NF) and during pulsatile flow (PF) at pressures of 120/80 mmHg and 140/100 mmHg to determine if pulsatile wall motions affected the dislodgement force. An imaging analysis was performed at ambient pressure and at pressures of 120 mmHg and 140 mmHg to investigate diameter changes on the model due to the radial force of the stent and internal pressurisation. Stent displacement forces were ~50% higher in the stiffer model (7.16-8.4 N) than in the more compliant model (3.67-4.21 N). The mean displacement force was significantly reduced by 10.95-12.83% from the case of NF to the case of PF at 120/80 mmHg. A further increase in pressure to 140/120 mmHg had no significant effect on the displacement force. The imaging analysis showed that the diameter in the region of the stent was 0.37 mm greater in the less stiff model at all the pressures which could reduce the fixation of the stent. The results suggest that the fixation of passively fixated aortic stents could be comprised in more compliant walls and that pulsatile motions of the wall can reduce the maximum stent fixation.

Age-specific incidence of hip fracture in the elderly: a healthy decline.

Hip fractures in the elderly are an important source of morbidity and mortality. The predicted increase in the number of hip fractures due to the increasing elderly population has not been universally observed. The purpose of this study was to examine the incidence of hip fractures over a twenty year period to determine if this rise is occurring in our region. All hip fractures from the unit over 20 years were identified. Population data for those over 65 in the catchment area of our hospital was acquired. The rate of fractures occurring each year relative to the population was determined. The results were split into age groups. There was a strong correlation between the population rise and number of fractures (p = 0.77). But there was no significant difference in the rate of fracture over time (p = 0.41). However, the average age at which fracture occurred increased by two years. In addition we show the overall trend in the rate of fractures decreases in the younger age groups and increases in the older age groups. Therefore, the predicted rapid increase in rate is not occurring. This probably reflects the strengthening of the economy in Ireland from the 1930's onwards, leading to a healthier population.

A computational study of the magnitude and direction of migration forces in patient-specific abdominal aortic aneurysm stent-grafts.

OBJECTIVES: Endovascular aneurysm repair for abdominal aortic aneurysm (AAA) is now a widely adopted treatment. Several complications remain to be fully resolved and perhaps the most significant of these is graft migration. Haemodynamic drag forces are believed to be partly responsible for migration of the device. The objective of this work was to investigate the drag forces in patient-specific AAA stent-grafts. METHODS: CT scan data was obtained from 10 post-operative AAA patients treated with stent-grafts. 3D models of the aneurysm, intraluminal thrombus and stent-graft were created. The drag forces were determined by fluid-structure interaction simulations. A worst case scenario was investigated by altering the aortic waveforms. RESULTS: The median resultant drag force was 5.46 N (range: 2.53-10.84). An increase in proximal neck angulation resulted in an increase in the resultant drag force (p = 0.009). The primary force vector was found to act in an anterior caudal direction for most patients. The worst case scenario simulation resulted in a greatest drag force of 16 N. CONCLUSIONS: Numerical methods can be used to determine patient-specific drag forces which may help determine the likelihood of stent-graft migration. Anterior-posterior neck angulation appears to be the greatest determinant of drag force magnitude. Graft dislodgement may occur anteriorally as well as caudally.

Normal variants in the paediatric orthopaedic population.

Normal variations of lower limb development are a common source of parental concern and are commonly referred to paediatric orthopaedic clinics. To determine the proportion of children referred to a paediatric orthopaedic outpatients with potentially normal developmental variations, referral letters and case notes of children attending the paediatric orthopaedic clinic at our institution over three months were analysed and categorized according to the main reason for referral. The number with true orthopaedic pathology was documented. Variations of normal anatomy and physiology accounted for 53.1% of all new referrals seen at the clinic with intoeing and flexible flat feet being the commonest referrals in this category. The rate of true primary pathology was only 16.3%. Normal developmental variations form a significant proportion of all new referrals to paediatric orthopaedic clinics. These take time and resources to process. Strategies to minimise these referrals are needed.

Immunosuppressive agents for treating IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is a world-wide disease and the cause of end-stage renal failure (ESRF) in 15 to 20% of patients within 10 years and in 30 to 40% of individuals within 20 years from the apparent onset of disease. No specific treatment has yet been established but many approaches have been investigated. OBJECTIVES: To assess the benefits and harms of immunosuppressive treatment for IgAN. SEARCH STRATEGY: We searched The Cochrane Renal Group's specialized register (May 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2002) MEDLINE (1966 - September 2002), EMBASE (1988 - September 2002) and handsearched reference lists of retrieved articles and conference proceedings. SELECTION CRITERIA: Randomized controlled trials (RCTs) and quasi-RCTs comparing treatment of IgAN with immunosuppressive agents against placebo, no treatment, other immunosuppressive or non-immunosuppressive agents. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes, with 95% confidence intervals (CI). MAIN RESULTS: Thirteen eligible RCTs involving 623 patients were identified. All identified RCTs had a placebo, no treatment or warfarin/dipyridamole control group. Seven trials used steroids, three used alkylating agents/cyclosporin and three used combinations of steroids and alkylating agents/cyclosporin. No trial directly compared steroids versus alkylating agents/cyclosporin. Quality was sub-optimal. Steroids were associated with a lower risk of progression to ESRF (RR 0.44, 95% CI 0.25 to 0.80) and lower urinary protein excretion (WMD -0.49 g/24h, 95% CI -0.72 to -0.12). Urinary protein excretion was lower for patients treated with alkylating agents/cyclosporin compared to placebo/no treatment (WMD -0.94 g/24h, 95% CI -1.43 to -0.46). There was no significant reduction of urinary protein excretion with combination treatment of steroids and alkylating agents compared with placebo/no treatment. REVIEWER'S CONCLUSIONS: The optimal management of IgAN remains uncertain. The RCTs identified were small, of sub-optimal methodological quality and tended to only report favorable and surrogate outcomes without a thorough reporting of treatment harms. All outcomes favor the use of immunosuppressive interventions, with steroids appearing to be the most promising. Further study, in the form of RCTs, is necessary to ascertain which patients would benefit from these interventions, whether they are the ones with early signs of renal dysfunction or those with more advanced renal impairment.

Effective clearance of methotrexate using high-flux hemodialysis membranes.

We report the first series demonstrating effective clearance of methotrexate using acute intermittent hemodialysis with a high-flux dialyzer. The study was performed on six patients, two females and four males aged 13 to 72 years. All were patients at M.D. Anderson Cancer Center. Patients were dialyzed for 4 to 6 hours daily using a Fresenius F-80 membrane (Fresenius Inc, Walnut Creek, CA). Following the initiation of dialysis, there was a reduction in arterial and venous serum concentration of methotrexate with time. Mean plasma clearance of methotrexate during dialysis in these six patients was 92.1 +/- 10.3 mL/min. One patient who was nearly functionally anephric was studied in detail. In this patient, following a high dose of methotrexate (7.2 g/m2), approximately 63% of this dose was cleared with 6 hours of hemodialysis. With subsequent dialysis performed daily for 6 hours, the drug was cleared completely in 5.6 +/- 0.3 days (n = 7 separate methotrexate treatments). A reduction in plasma methotrexate concentration from 1,733 +/- 40 micromol/L 1 hour postinfusion to less than 0.3 micromol/L in 5 to 6 days was observed for these seven separate treatments. We conclude that significant clearance of methotrexate can be achieved with high-flux dialyzers, making methotrexate therapy a viable treatment option in patients with responsive malignancies despite the presence of renal failure.

Should hypertension be treated after acute stroke? A randomized controlled trial using single photon emission computed tomography.

OBJECTIVE: To determine if previously hypertensive patients with acute ischemic stroke should be treated with antihypertensive medication in the immediate poststroke period. DESIGN: Randomized double-blind, placebo-controlled trial. SETTING: Sixteen consecutive hypertensive patients (four men and 12 women; mean age, 66 years [age range, 46 to 83 years]) with middle cerebral artery infarction within 72 hours of onset and blood pressure between 170 and 220 mm Hg(systolic) and 95 and 120 mm Hg (diastolic). INTERVENTION: Placebo (n = 6), nicardipine hydrochloride (20 mg [n = 5]), captopril (12.5 mg [n = 3]), or clonidine hydrochloride (0.1 mg [n = 2]) given every 8 hours for 3 days. MAIN OUTCOME MEASURES: Decline in blood pressure, change in cerebral blood flow as measured by single photon emission computed tomography, and clinical change as determined by the National Institutes of Health Stroke Scale. RESULTS: Blood pressure fell significantly in both the drug-treated group as a whole and in those patients receiving placebo (P < .001). There was no difference in blood pressure levels between these two groups throughout the study period. Patients receiving nicardipine had a consistently lower pressure than the other groups. A significant negative relationship was noted between the maximum blood pressure fall and improvement in cerebral blood flow. There were four patients whose blood pressure dropped by more than 16% of the baseline value on any 24 hours in the first 3 days. All either failed to increase or actually decreased their cerebral blood flow to the affected area. Three of these patients were treated with nicardipine. There was no significant difference in clinical course between the placebo-and drug-treated groups as a whole. CONCLUSIONS: Hypertensive ischemic stroke patients with a moderate elevation of blood pressure in the first few days may not require antihypertensive therapy. Nicardipine and possibly other calcium channel blockers may cause an excessive fall in blood pressure and impair cerebral blood flow in these patients and should therefore be used with caution.

Interactions of cadmium and nickel with K channels of vascular smooth muscle.

Previous studies have shown that environmentally significant concentrations (< 1 microM) of large divalent cations increased vascular tone in resistance arteries. Because K channels are important regulators of vasoactivity, we studied the interactions of Cd and Ni on K channels of smooth muscle from bovine mesenteric artery using the planar bilayer method. We describe one type of small, Ca-insensitive K channel (Ks), and two types of large, Ca-activated K channels ([BK(Ca)], Kc1 and Kc2, that were identical with respect to single-channel conductance and K/Cl selectivity, but differed in Ca/voltage sensitivity. Neither metal affected the open probability (po) of Ks but both Cd and Ni, in concentrations greater than or equal to 100 nM, similarly decreased po of Kc1 and Kc2 from the intracellular side of the channel in the presence of 1 microM Ca. The effects of both Cd and Ni were reversed by 0.1 mM Ca. It is concluded that Cd and Ni, in concentrations less than 1 microM, can interact with the Ca/voltage sensor and inhibit BK(Ca) channels of vascular smooth muscle. These effects may partially explain the vascular tension induced by large divalent cations.

Diluting power of thick limbs of Henle. III. Modulation of in vitro diluting power.

This paper considers the quantitative interplay of various factors in modulating diluting power of in vitro medullary and cortical thick ascending limbs of Henle (MTAL and CTAL, respectively) segments from mouse and rabbit. Experimentally, the measured diluting power of the in vitro rabbit CTAL is greater than that of the rabbit MTAL, although the inherent rate of net Cl- absorption at high perfusion rates is considerably greater in the rabbit MTAL than in the rabbit CTAL. Similar results apply when comparing the rabbit CTAL to the mouse MTAL exposed to antidiuretic hormone (ADH). Our calculations show that, in the rabbit CTAL, the measured static head luminal salt concentration can be accounted for quantitatively by the measured rate of net salt absorption at a high perfusion rate together with the passive permeability coefficients for Na+ and Cl-. Moreover, with perfusion rates of 10% of single-nephron glomerular filtration rate, the transport properties of the CTAL predict that, at the end of the CTAL, the static head luminal Cl- concentration occurs if the initial perfusate contains either 50 or 150 mM Cl-. Thus one can argue that, in vivo the CTAL may be the cardinal determinant of the TAL contribution to diluting power and to external salt balance. The relatively blunted diluting power of in vitro MTAL segments can be accounted for quantitatively by assuming that luminal dilution, and the attendant osmotic gradient from lumen to cell, suppresses the inherent rate of transcellular Cl- transport. Our calculations also show that prostaglandin E2 and peritubular osmolality increases blunt tubular diluting power. Thus in vivo, the MTAL segment may be the cardinal determinant of TAL contribution to concentrating power and to intrarenal salt balance.

Diluting power of thick limbs of Henle. I. Peritubular hypertonicity blocks basolateral Cl- channels.

This paper provides the results of experiments intended to assess the mechanism responsible for the suppression of net salt absorption and the attendant spontaneous voltage (Ve, mV) that occurs when isolated thick ascending limbs of Henle (TAL) are exposed to a hypertonic environment. In isolated mouse medullary (MTAL) and cortical (CTAL) segments, as well as in rabbit MTAL segments, increases in peritubular osmolality with urea produced a graded suppression of Ve. This effect was evaluated in further detail in isolated mouse MTAL segments, where 600 mM peritubular urea produced a reversible reduction in Ve and a reversible reduction in the transcellular electrical conductance (Gc; mS.cm-2). There was no detectable effect on the paracellular conductance (Gs; mS.cm-2). Simultaneously, 600 mM peritubular urea also produced hyperpolarization of the voltage across basolateral membranes (mV). Moreover, 600 mM peritubular urea produced virtually the same magnitude reduction in Gc either in the absence or presence of 10(-4) M luminal furosemide. Thus we conclude that peritubular urea hypertonicity directly suppresses the Cl- conductance of basolateral membranes (mS.cm-2).