Factors associated with failure of fixation of Vancouver B fractures around a cemented polished tapered stem: A 5 to 14 year follow up study.

AIMS: There is increasing evidence for fixation as opposed to revision for Vancouver B fractures around polished taper slip stems, however it is remains unclear whether fixation is associated with stem loosening in the longer term. This study aims to assess survival of plate-fixation of Vancouver-B-fractures around a polished-taper- slip cemented stem and identify factors associated with failure. METHODS: Retrospective cohort study assessed 129 consecutive unilateral Vancouver-B-fractures around cemented Exeter stems at a minimum of 5 years following open-reduction-internal-fixation (ORIF) with unilateral non-locked unilateral plating+/-cerclage cables. The primary outcome measure was reoperation for any reason. Kaplan Meier survival analysis was performed. RESULTS: Fractures (B1 n = 31 (24%); B2 n = 91 (71%); and B3 n = 7 (5%)) occurred at median of 6 years (IQR 1.2-9.2) after primary surgery. Mean patient age was 78.2 (SD10.56, range 46-96) and 54 (42.9%) were female. Mean follow up was 8.7 years (SD 2.48, 5.7 to 14.4). Symptomatic femoral stem loosening requiring revision occurred in two B2 fractures of metaphyseal split and short spiral patterns. The most common mode of failure was non-union (n = 7, 5%). Both fixation failure (n = 6/31 Vs n = 3/91 vs n = 0/7, p = 0.008) and reoperation (n = 8/31 vs n = 6/91 vs n = 0/7, p = 0.008) were significantly higher following fixation of B1 fractures compared to B2 and B3 fractures. Overall 5year survival free from reoperation was 88.8% (82.0-94.7 95%CI). B1 fracture types were associated with an increase risk of failure (endpoints fixation failure p = 0.010; and reoperation p = 0.016). Transverse fractures (B1) were associated with a relative risk of reoperation of 4.22 (1.63-10.9 95% CI, p = 0.008). CONCLUSION: Fixation of Vancouver-B fractures around cemented Exeter stems, when the bone-cement interface is intact and the fracture is anatomically reducible, had an excellent 5-year survival. Only 2 (1.6%) cases of late femoral stem loosening occurred, however, B1 type transverse fractures were associated with a higher rate of reoperation.

A multicentre comparative analysis of fixation versus revision surgery for periprosthetic femoral fractures following total hip arthroplasty with a cemented polished taper-slip femoral component.

AIMS: The aim of this study was to compare open reduction and internal fixation (ORIF) with revision surgery for the surgical management of Unified Classification System (UCS) type B periprosthetic femoral fractures around cemented polished taper-slip femoral components following primary total hip arthroplasty (THA). METHODS: Data were collected for patients admitted to five UK centres. The primary outcome measure was the two-year reoperation rate. Secondary outcomes were time to surgery, transfusion requirements, critical care requirements, length of stay, two-year local complication rates, six-month systemic complication rates, and mortality rates. Comparisons were made by the form of treatment (ORIF vs revision) and UCS type (B1 vs B2/B3). Kaplan-Meier survival analysis was performed with two-year reoperation for any reason as the endpoint. RESULTS: A total of 317 periprosthetic fractures (in 317 patients) with a median follow-up of 3.6 years (interquartile range (IQR) 2.0 to 5.4) were included. The fractures were type B1 in 133 (42.0%), B2 in 170 (53.6%), and B3 in 14 patients (4.4%). ORIF was performed in 167 (52.7%) and revision in 150 patients (47.3%). The two-year reoperation rate (15.3% vs 7.2%; p = 0.021), time to surgery (4.0 days (IQR 2.0 to 7.0) vs 2.0 days (IQR 1.0 to 4.0); p < 0.001), transfusion requirements (55 patients (36.7%) vs 42 patients (25.1%); p = 0.026), critical care requirements (36 patients (24.0%) vs seven patients (4.2%); p < 0.001) and two-year local complication rates (26.7% vs 9.0%; p < 0.001) were significantly higher in the revision group. The two-year rate of survival was significantly higher for ORIF (91.9% (standard error (SE) 0.023%) vs 83.9% (SE 0.031%); p = 0.032) compared with revision. For B1 fractures, the two-year reoperation rate was significantly higher for revision compared with ORIF (29.4% vs 6.0%; p = 0.002) but this was similar for B2 and B3 fractures (9.8% vs 13.5%; p = 0.341). The most common indication for reoperation after revision was dislocation (12 patients; 8.0%). CONCLUSION: Revision surgery has higher reoperation rates, longer surgical waiting times, higher transfusion requirements, and higher critical care requirements than ORIF in the management of periprosthetic fractures around polished taper-slip femoral components after THA. ORIF is a safe option providing anatomical reconstruction is achievable.Cite this article: Bone Joint J 2023;105-B(2):124-134.

Intervention rates are low after direct discharge from the Edinburgh trauma triage clinic: Outcomes of 6,688 patients.

AIM: The Edinburgh Trauma Triage clinic (TTC) is an established form of Virtual Fracture clinic (VFC) that permits the direct discharge of simple, isolated fractures from the Emergency Department (ED). Small, short-term cohort studies of similar systems have been published, but to detect low rates of complications requires a large study sample and longer-term follow-up. This study details the outcomes of all patients with injuries suitable for a direct discharge protocol over a four-year period, reviewed at a minimum of three years after attendance. PATIENTS: All TTC records between February 2014 and December 2017 were collated from a prospective database. Fractures of the radial head, little finger metacarpal, fifth metatarsal, toe phalanges and mallet finger injuries were included. TTC outcome, including any deviations from a well-established direct discharge protocol, were noted. All records were re-assessed at a minimum of 36 months after TTC triage (mean 54 months) to ascertain which injuries attended the trauma clinic after initial discharge. Reasons for attendance, the source of referral and any subsequent surgical procedures were identified. RESULTS: There were 6688 patients with fractures of the radial head (1861), little finger metacarpal (1621), fifth metatarsal (1916), toe phalanges (920) and mallet finger injuries (370). 298 (6%) patients were re-referred after direct discharge and attended trauma clinic at a mean time after injury of 11.9 weeks, of whom 11 (0.2%) underwent a surgical intervention. Serious adverse events, defined as those in which a patient may not have come to harm if early clinical review had been undertaken, occurred in 1 patient (0.01%). CONCLUSION: Intervention after direct discharge of simple pre-defined injuries of the elbow, hand and foot is low. Within a TTC system, patients with these injuries can be safely discharged without routine follow-up.

Effect of COVID-19 lockdown on regional pollution in Ireland.

This study examines the regional impact of the COVID-19 lockdown restrictions on pollution in Ireland by comparing the 2020 measurements of ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM) from monitoring stations around the country to the previous 3-year average. Results indicate that O3 was 5.6% lower and 13.7% higher than previous years during the lockdown at rural and suburban sites, respectively. NO2 decreased by 50.7% in urban areas, but increased slightly in agricultural regions, consistent with satellite observations. PM concentrations did not change significantly compared to previous years; however, a reduction in the signal variability in the smaller size particle measurements may be the result of different emission sources. The reduction in NO2 likely increased the ratio of volatile organic compounds (VOCs) to NOx (nitrogen oxides), creating a NOx limited environment, which resulted in an initial increase in O3 in suburban areas, and the lower than usual levels observed at rural sites. Meteorology showed higher than average wind speeds prior to lockdown, which likely acted to disperse PM and NO2.

Incidence and risk factors for incisional hernia and recurrence: Retrospective analysis of the French national database.

AIM: The aim of this work was to determine the rate of incisional hernia (IH) repair and risk factors for IH repair after laparotomy. METHOD: This population-based study used data extracted from the French Programme de Médicalisation des Systèmes d'Informations (PMSI) database. All patients who had undergone a laparotomy in 2010, their hospital visits from 2010 to 2015 and patients who underwent a first IH repair in 2013 were included. Previously identified risk factors included age, gender, high blood pressure (HBP), obesity, diabetes and chronic obstructive pulmonary disease (COPD). RESULTS: Among the 431 619 patients who underwent a laparotomy in 2010, 5% underwent IH repair between 2010 and 2015. A high-risk list of the most frequent surgical procedures (>100) with a significant risk of IH repair (>10% at 5 years) was established and included 71 863 patients (17%; 65 procedures). The overall IH repair rate from this list was 17%. Gastrointestinal (GI) surgery represented 89% of procedures, with the majority of patients (72%) undergoing lower GI tract surgery. The IH repair rate was 56% at 1 year and 79% at 2 years. Risk factors for IH repair included obesity (31% vs 15% without obesity, p  < 0.001), COPD (20% vs 16% without COPD), HBP (19% vs 15% without HBP) and diabetes (19% vs 16% without diabetes). Obesity was the main risk factor for recurrence after IH repair (19% vs 13%, p < 0.001). CONCLUSION: From the PMSI database, the real rate of IH repair after laparotomy was 5%, increasing to 17% after digestive surgery. Obesity was the main risk factor, with an IH repair rate of 31% after digestive surgery. Because of the important medico-economic consequences, prevention of IH after laparotomy in high-risk patients should be considered.

Emissions and Marine Boundary Layer Concentrations of Unregulated Chlorocarbons Measured at Cape Point, South Africa.

Unregulated chlorocarbons, here defined as dichloromethane (CH2Cl2), perchloroethene (C2Cl4), chloroform (CHCl3), and methyl chloride (CH3Cl), are gases not regulated by the Montreal Protocol. While CH3Cl is the largest contributor of atmospheric chlorine, recent studies have shown that growth in emissions of the less abundant chlorocarbons could pose a significant threat to the recovery of the ozone layer. Despite this, there remain many regions for which no atmospheric monitoring exists, leaving gaps in our understanding of global emissions. Here, we report on a new time series of chlorocarbon measurements from Cape Point, South Africa for 2017, which represent the first published high-frequency measurements of these gases from Africa. For CH2Cl2 and C2Cl4, the majority of mole fraction enhancements were observed from the north, consistent with anthropogenically modified air from Cape Town, while for CHCl3 and CH3Cl, we found evidence for both oceanic and terrestrial sources. Using an inverse method, we estimated emissions for south-western South Africa (SWSA). For each chlorocarbon, SWSA accounted for less than 1% of global emissions. For CH2Cl2 and C2Cl4, we extrapolated using population statistics and found South African emissions of 8.9 (7.4-10.4) Gg yr-1 and 0.80 (0.64-1.04) Gg yr-1, respectively.

Atmospheric HCFC-22, HFC-125, and HFC-152a at Cape Point, South Africa.

One hydrochlorofluorocarbon and two hydrofluorocarbons (HCFC-22, HFC-125, and HFC-152a) were measured in air samples at the Cape Point observatory (CPT), South Africa, during 2017. These data represent the first such atmospheric measurements of these compounds from southwestern South Africa (SWSA). Baseline atmospheric growth rates were estimated to be 8.36, 4.10, and 0.71 ppt year-1 for HCFC-22, HFC-125, and HFC-152a, respectively. The CPT measurements were combined with an inverse model to investigate emissions from SWSA. For all three halocarbons, Cape Town was found to be the dominant source within SWSA. These estimates were extrapolated, based on population statistics, to estimate emissions for the whole of South Africa. We estimate South Africa's 2017 emissions to be 3.0 (1.6-4.4), 0.8 (0.5-1.2), and 1.1 (0.6-1.6) Gg year-1 for HCFC-22, HFC-125, and HFC-152a, respectively. For all three halocarbons, South Africa's contribution to global emissions is small (<2.5%), but future monitoring is needed to ensure South Africa's compliance with regulation set out by the Montreal Protocol and its Amendments.

Urban Pollutant Transport and Infiltration into Buildings Using Perfluorocarbon Tracers.

People spend the majority of their time indoors and therefore the quality of indoor air is worthy of investigation; indoor air quality is affected by indoor sources of pollutants and from pollutants entering buildings from outdoors. In this study, unique perfluorocarbon tracers were released in five experiments at a 100 m and ~2 km distance from a large university building in Manchester, UK and tracer was also released inside the building to measure the amount of outdoor material penetrating into buildings and the flow of material within the building itself. Air samples of the tracer were taken in several rooms within the building, and a CO2 tracer was used within the building to estimate air-exchange rates. Air-exchange rates were found to vary between 0.57 and 10.90 per hour. Indoor perfluorocarbon tracer concentrations were paired to outdoor tracer concentrations, and in-out ratios were found to vary between 0.01 and 3.6. The largest room with the lowest air-exchange rate exhibited elevated tracer concentrations for over 60 min after the release had finished, but generally had the lowest concentrations, the room with the highest ventilation rates had the highest concentration over 30 min, but the peak decayed more rapidly. Tracer concentrations indoors compared to outdoors imply that pollutants remain within buildings after they have cleared outside, which must be considered when evaluating human exposure to outdoor pollutants.

The reversal of pulmonary vascular remodeling through inhibition of p38 MAPK-alpha: a potential novel anti-inflammatory strategy in pulmonary hypertension.

The p38 mitogen-activated protein kinase (MAPK) system is increasingly recognized as an important inflammatory pathway in systemic vascular disease but its role in pulmonary vascular disease is unclear. Previous in vitro studies suggest p38 MAPKα is critical in the proliferation of pulmonary artery fibroblasts, an important step in the pathogenesis of pulmonary vascular remodeling (PVremod). In this study the role of the p38 MAPK pathway was investigated in both in vitro and in vivo models of pulmonary hypertension and human disease. Pharmacological inhibition of p38 MAPKα in both chronic hypoxic and monocrotaline rodent models of pulmonary hypertension prevented and reversed the pulmonary hypertensive phenotype. Furthermore, with the use of a novel and clinically available p38 MAPKα antagonist, reversal of pulmonary hypertension was obtained in both experimental models. Increased expression of phosphorylated p38 MAPK and p38 MAPKα was observed in the pulmonary vasculature from patients with idiopathic pulmonary arterial hypertension, suggesting a role for activation of this pathway in the PVremod A reduction of IL-6 levels in serum and lung tissue was found in the drug-treated animals, suggesting a potential mechanism for this reversal in PVremod. This study suggests that the p38 MAPK and the α-isoform plays a pathogenic role in both human disease and rodent models of pulmonary hypertension potentially mediated through IL-6. Selective inhibition of this pathway may provide a novel therapeutic approach that targets both remodeling and inflammatory pathways in pulmonary vascular disease.

The Application of TD/GC/NICI-MS with an Al2O3-PLOT-S Column for the Determination of Perfluoroalkylcycloalkanes in the Atmosphere.

A modified method for the quantitative determination of atmospheric perfluoroalkylcycloalkanes (PFCs) using thermal desorption coupled with gas chromatography and detection by negative ion chemical ionization-mass spectrometry was developed. Using an optimized analytical system, a commercially available Al2O3 porous layer open tubular (PLOT) capillary column (30 m × 0.25 mm) deactivated with Na2SO4 was used for separation of PFCs. Improvements in the separation of PFCs, the corresponding identification and the limit of detection of PFCs using this method and column are presented. The method was successfully applied to determine the atmospheric background concentrations of a range of PFCs from a number of samples collected at a rural site in Germany. The results of this study suggest that the method outlined using the Al2O3-PLOT-S capillary column has good sensitivity and selectivity, and that it can be deployed in a routine laboratory process for the analysis of PFCs in the future research work. In addition, the ability of this column to separate the isomers of one of the lower boiling PFCs (perfluorodimethylcyclobutane) and its ability to resolve perfluoroethylcyclohexane offer the opportunity for single-column analysis for multiple PFCs.

Determination of gas-phase ozonolysis rate coefficients of a number of sesquiterpenes at elevated temperatures using the relative rate method.

The rates of ozonolysis of four sesquiterpenes, ß-caryophyllene, α-humulene, isolongifolene and α-cedrene, are determined in the gas phase at an elevated temperature of 366 ± 3 K and a pressure of ~780 Torr using the EXTreme RAnge chamber (EXTRA). The experimentally obtained rate coefficients agree with extrapolated room temperature rate coefficients for isolongifolene and α-cedrene but not for ß-caryophyllene and α-humulene, which were found to be three orders of magnitude slower than this in the literature. These new measurements support the hypothesis that operating under ambient conditions, kinetic measurements of condensable species can be influenced adversely by heterogeneous processes and should therefore be treated with caution.

Use of reactive tracers to determine ambient OH radical concentrations: application within the indoor environment.

The hydroxyl radical (OH) plays a key role in determining indoor air quality. However, its highly reactive nature and low concentration indoors impede direct analysis. This paper describes the techniques used to indirectly quantify indoor OH, including the development of a new method based on the instantaneous release of chemical tracers into the air. This method was used to detect ambient OH in two indoor seminar rooms following tracer detection by gas chromatography-mass spectrometry (GCMS). The results from these tests add to the small number of experiments that have measured indoor OH which are discussed with regard to future directions within air quality research.