The Free-Gliding screw for slipped capital femoral epiphysis : is it safe, does it glide, and does age matter?

AIMS: Fixation techniques used in the treatment of slipped capital femoral epiphysis (SCFE) that allow continued growth of the femoral neck, rather than inducing epiphyseal fusion in situ, have the advantage of allowing remodelling of the deformity. The aims of this study were threefold: to assess whether the Free-Gliding (FG) SCFE screw prevents further slip; to establish whether, in practice, it enables lengthening and gliding; and to determine whether the age of the patient influences the extent of glide. METHODS: All patients with SCFE who underwent fixation using FG SCFE screws after its introduction at our institution, with minimum three years' follow-up, were reviewed retrospectively as part of ongoing governance. All pre- and postoperative radiographs were evaluated. The demographics of the patients, the grade of slip, the extent of lengthening of the barrel of the screw and the restoration of Klein's line were recorded. Subanalysis was performed according to sex and age. RESULTS: A total of 19 hips in 13 patients were included. The mean age of the patients at the time of surgery was 11.5 years (9 to 13) and the mean follow-up was 63 months (45 to 83). A total of 13 FG SCFE screws were used for the fixation of mild or moderate SCFE, with six contralateral prophylactic fixations. No hip with SCFE showed a further slip after fixation and there were no complications. Lengthening occurred in 15 hips (79%), with a mean lengthening of the barrel of 6.8 mm (2.5 to 13.6) at final follow-up. Remodelling occurred in all hips with lengthening of the barrel. There was statistically more lengthening in patients who were aged < 12 years, regardless of sex (p = 0.002). CONCLUSION: The FG SCFE screw is effective in preventing further slip in patients with SCFE. Lengthening of the barrel occurred in most hips, and thus allowed remodelling. This was most marked in younger children, regardless of sex. Based on this study, this device should be considered for use in patients with SCFE aged < 12 years instead of standard pinning in situ.Cite this article: Bone Joint J 2023;105-B(2):215-219.

Alcohol-related acute medical reviews in an acute hospital before and immediately after the introduction of minimum unit pricing.

BACKGROUND: Minimum unit pricing (MUP) is one aspect of the Public Health (Alcohol) Act 2018 to limit the detrimental health impacts of alcohol use. Alcohol withdrawal syndrome (AWS) can occur within hours to days after alcohol cessation. This audit assesses two periods to see if the introduction of MUP had a significant impact on acute alcohol-related medical reviews mediated through a change in the incidence of AWS. METHODS: The medical inpatient handover documents all acute medical reviews of patients in Tipperary University Hospital in the preceding 24 h. Documents were retrospectively reviewed for two 28-day time periods 5th January to 1st February 2021 and 2022. Patients were assessed for presentations related to alcohol. RESULTS: 518 patients were reviewed by the acute medical service between 5th January and 1st February 2021. 28 patients presented with alcohol-related medical complaints. 637 patients were reviewed by the acute medical service between 5th January and 1st February 2022. 24 patients presented with alcohol-related medical complaints. The proportion of patients presenting with alcohol-related medical conditions, 5.41% for the first assessment period and 3.77% for the second period, was compared using MedCalc software. This demonstrated a difference of 1.64% (95% confidence interval - 0.78 to 4.24%, P = 0.18). CONCLUSION: At this institution, the introduction of MUP did not result in increased presentations with alcohol-related medical complaints. It is unlikely that it leads to an increase in the incidence of AWS.

Thermal transport in beta-gallium oxide thin-films using non-gray Boltzmann transport equation.

Phonon transport inß-Ga2O3thin films and metal-oxide field effect transistors (MESFETs) are investigated using non-gray Boltzmann transport equations (BTEs) to decipher the effect of ballistic-diffusive phonon transport. The effects of domain size, and energy dissipation to various phonon modes and subsequent phonon-phonon energy exchange on the thermal transport and temperature distribution is investigated using non-gray BTE. Our analysis deciphered that domain size plays a major role in thermal transport inß-Ga2O3but energy dissipation to various phonon modes and subsequent phonon-phonon energy exchange does not affect the temperature field significantly. Phonon transport inß-Ga2O3MESFETs on diamond substrate is investigated using coupled non-gray BTE and Fourier model. It is established that the ballistic effects need to be considered for devices withß-Ga2O3layer thickness less than 1 µm. A non-gray phonon BTE model should be used near hotspot in the thinß-Ga2O3layer as the Fourier model may not give accurate temperature distribution. The results from this work will help in understanding the mechanism of phonon transport in theß-Ga2O3thin films and energy efficient design of its FETs.

Voxelized Atomic Structure Potentials: Predicting Atomic Forces with the Accuracy of Quantum Mechanics Using Convolutional Neural Networks.

This paper introduces voxelized atomic structure (VASt) potentials as a machine learning (ML) framework for developing interatomic potentials. The VASt framework utilizes a voxelized representation of the atomic structure directly as the input to a convolutional neural network (CNN). This allows for high-fidelity representations of highly complex and diverse spatial arrangements of the atomic environments of interest. The CNN implicitly establishes the low-dimensional features needed to correlate each atomic neighborhood to its net atomic force. The selection of the salient features of the atomic structure (i.e., feature engineering) in the VASt framework is implicit, comprehensive, automated, scalable, and highly efficient. The calibrated convolutional layers learn the complex spatial relationships and multibody interactions that govern the physics of atomic systems with remarkable fidelity. We show that VASt potentials predict highly accurate forces on two phases of silicon carbide and the thermal conductivity of silicon over a range of isotropic strain.

A three body problem: a genuine heterotrimetallic molecule vs. a mixture of two parent heterobimetallic molecules.

This work raises a fundamental question about the "real" structure of molecular compounds containing three different metals: whether they consist of genuine heterotrimetallic species or of a mixture of parent heterobimetallic species. Heterotrimetallic complex Li2CoNi(tbaoac)6 (1, tbaoac = tert-butyl acetoacetate) has been designed based on the model tetranuclear structure featuring two transition metal sites in order to be utilized as a molecular precursor for the low-temperature preparation of the LiCo0.5Ni0.5O2 battery cathode material. An investigation of the structure of 1 appeared to be very challenging, since the Co and Ni atoms have very similar atomic numbers, monoisotopic masses, and radii as well as the same oxidation state and coordination number/environment. Using a statistical analysis of heavily overlaid isotope distribution patterns of the [Li2MM'L5]+ (M/M' = Co2, Ni2, and CoNi) ions in DART mass spectra, it was concluded that the reaction product 1 contains both heterotrimetallic and bimetallic species. A structural analogue approach has been applied to obtain Li2MMg(tbaoac)6 (M = Co (2) and Ni (3)) complexes that contain lighter, diamagnetic magnesium in the place of one of the 3d transition metals. X-ray crystallography, mass spectrometry, and NMR spectroscopy unambiguously confirmed the presence of three types of molecules in the reaction mixture that reaches an equilibrium, Li2M2L6 + Li2Mg2L6 ↔ 2Li2MMgL6, upon prolonged reflux in solution. The equilibrium mixture was shown to have a nearly statistical distribution of the three molecules, and this is fully supported by the results of theoretical calculations revealing that the stabilization energies of heterotrimetallic assemblies fall exactly in between those for the parent heterobimetallic species. The LiCo0.5Ni0.5O2 quaternary oxide has been obtained in its phase-pure form by thermal decomposition of heterometallic precursor 1 at temperatures as low as 450 °C. Its chemical composition, structure, morphology, and transition metal distribution have been studied by X-ray and electron diffraction techniques and compositional energy-dispersive X-ray mapping with nanometer resolution. The work clearly illustrates the advantages of heterometallic single-source precursors over the corresponding multi-source precursors.

Expanding the Structural Motif Landscape of Heterometallic ß-Diketonates: Congruently Melting Ionic Solids.

The first example of ionic ß-diketonates in which both the cation and anion are octahedral coordinatively saturated metal diketonate moieties are reported. Heterometallic tin-transition-metal heteroleptic diketonates were obtained through solid-state redox reactions and are formulated as {[SnIV(thd)3]+[MII(hfac)3]-} (MII = Mn (1), Fe (2), Co (3); thd = 2,2,6,6-tetramethyl-3,5-heptanedionate, hfac = hexafluoroacetylacetonate). X-ray single-crystal structural investigations along with DART mass spectrometry, multinuclear NMR, and magnetic susceptibility measurements have been used to confirm an assignment of metal oxidation states in compounds 1-3. Ionic compounds were found to melt congruently at temperatures below the decomposition point. As such, they represent prospective materials that can be utilized as ionic liquids as well as reagents for the soft transfer of diketonate ligands. An unexpected volatility of ionic compounds 1-3 was proposed to occur through a transport reaction, in which the transport agent is one of the products of their partial decomposition in the gas or condensed phase.

Paediatric pelvic fractures: A review of 2 cohorts over 22 years.

AIMS: The aim of this retrospective review was to identify all children that presented to our institution with a pelvic or acetabular fracture and to compare these children to a previous cohort of paediatric pelvic fractures that we have reported. PATIENTS: 53 children under the age of 16 were identified over a ten year period. METHODS: We reviewed our trauma database, hospital records and radiological imaging to determine the age, gender, fracture pattern, associated injuries and management of the pelvic fracture. RESULTS: There were 32 boys and 21 girls. Mean age of the boys was 8.8 years and the girls 10.7 years. In seven children the pelvic fracture was an isolated injury and in the remaining 46 children, there were 113 additional injuries. 56% of the additional injuries was either a fracture/dislocation (37%) or a head injury (19%). Compared to our first cohort, we had a larger number of children in the second cohort. Age, sex distribution, mechanism of injury was similar in the two groups. In this current cohort, use of CT scan imaging was more frequent, there were more unstable pelvic fracture patterns identified, ISS scores were higher and mortality was lower. CONCLUSION: We have seen more children with more severe injuries, higher ISS scores but a lower mortality rate.

Position Assignment and Oxidation State Recognition of Fe and Co Centers in Heterometallic Mixed-Valent Molecular Precursors for the Low-Temperature Preparation of Target Spinel Oxide Materials.

A series of mixed-valent, heterometallic (mixed-transition metal) diketonates that can be utilized as prospective volatile single-source precursors for the low-temperature preparation of MxM'3-xO4 spinel oxide materials is reported. Three iron-cobalt complexes with Fe/Co ratios of 1:1, 1:2, and 2:1 were synthesized by several methods using both solid-state and solution reactions. On the basis of nearly quantitative reaction yields, elemental analyses, and comparison of metal-oxygen bonds with those in homometallic analogues, heterometallic compounds were formulated as [FeIII(acac)3][CoII(hfac)2] (1), [CoII(hfac)2][FeIII(acac)3][CoII(hfac)2] (2), and [FeII(hfac)2][FeIII(acac)3][CoII(hfac)2] (3). In the above heteroleptic complexes, the Lewis acidic, coordinatively unsaturated CoII/FeII centers chelated by two hexafluoroacetylacetonate (hfac) ligands maintain bridging interactions with oxygen atoms of acetylacetonate (acac) groups that chelate the neighboring FeIII metal ion. Preliminary assignment of Fe and Co positions/oxidation states in 1-3 drawn from X-ray structural investigation was corroborated by a number of complementary techniques. Single-crystal resonant synchrotron diffraction and neutron diffraction experiments unambiguously confirmed the location of Fe and Co sites in the molecules of dinuclear (1) and trinuclear (2) complexes, respectively. Direct analysis in real time mass spectrometry revealed the presence of FeIII- and CoII-based fragments in the gas phase upon evaporation of precursors 1 and 2 as well as of FeIII, FeII, and CoII species for complex 3. Theoretical investigation of two possible "valent isomers", [FeIII(acac)3][CoII(hfac)2] (1) and [CoIII(acac)3][FeII(hfac)2] (1'), provided an additional support for the metal site/oxidation state assignment giving a preference of 6.48 kcal/mol for the experimentally observed molecule 1. Magnetic susceptibility measurements data are in agreement with the presence of high-spin FeIII and CoII magnetic centers with weak anti-ferromagnetic coupling between those in molecules of 1 and 2. Highly volatile heterometallic complexes 1-3 were found to act as effective single-source precursors for the low-temperature preparation of iron-cobalt spinel oxides FexCo3-xO4 known as important materials for diverse energy-related applications.

Heterometallic molecular precursors for a lithium-iron oxide material: synthesis, solid state structure, solution and gas-phase behaviour, and thermal decomposition.

Three heterometallic single-source precursors with a Li : Fe = 1 : 1 ratio for a LiFeO2 oxide material are reported. Heterometallic compounds LiFeL3 (L = tbaoac (1), ptac (2), and acac(3)) have been obtained on a large scale, in nearly quantitative yields by one-step reactions that employ readily available reagents. The heterometallic precursor LiFe(acac)3 (3) with small, symmetric substituents on the ligand (acac = pentane-2,4-dionate), maintains a 1D polymeric structure in the solid state that limits its volatility and prevents solubility in non-coordinating solvents. The application of the unsymmetrical ligands, tbaoac (tert-butyl acetoacetate) and ptac (1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedionate), that exhibit different bridging properties at the two ends of the ligand, allowed us to change the connectivity pattern within the heterometallic assembly. The latter was demonstrated by structural characterization of heterometallic complexes LiFe(tbaoac)3 (1) and LiFe(ptac)3 (2) that consist of discrete heterocyclic tetranuclear molecules Li2Fe2L6. The compounds are highly volatile and exhibit a congruent sublimation character. DART mass spectrometric investigation revealed the presence of heterometallic molecules in the gas phase. The positive mode spectra are dominated by the presence of [M - L]+ peaks (M = Li2Fe2L6). In accord with their discrete molecular structure, complexes 1 and 2 are highly soluble in nearly all common solvents. In order to test the retention of the heterometallic structure in solution, the diamagnetic analog of 1, LiMg(tbaoac)3 (4), has been isolated. Its tetranuclear molecular structure was found to be isomorphous to that of the iron counterpart. 1H and 7Li NMR spectroscopy unambiguously confirmed the presence of heterometallic molecules in solutions of non-coordinating solvents. The heterometallic precursor 1 was shown to exhibit clean thermal decomposition in air that results in phase-pure α-modification of layered oxide LiFeO2, the prospective cathode material for lithium ion batteries.

Volatile Single-Source Precursors for the Low-Temperature Preparation of Sodium-Rare Earth Metal Fluorides.

Heterometallic single-source precursors for the preparation of sodium-rare earth metal fluorides are reported. Fluorinated ß-diketonates NaRE(hfac)4 (RE = Y (1), Er (2), and Eu (3); hfac = hexafluoroacetylacetonate) have been obtained on a large scale, in high yield, via one-pot reaction that utilizes commercially available starting reagents. The solid-state structures of the title complexes consist of 1D polymeric chains with alternating [Na] and [RE(hfac)4] units. Compounds 1-3 are highly volatile and exhibit a fair stability in open air. Mass spectrometric investigation indicates the presence of heterometallic fragments in the gas phase. The presence of heterometallic species in solutions of coordinating solvents has also been confirmed. Decomposition of heterometallic precursors in argon atmosphere was shown to yield phase-pure sodium-rare earth metal fluorides. Low decomposition temperature effectively allows for a high degree of control over the formation of both kinetic α-phases and thermodynamic ß-phases of target NaREF4 (RE = Y, Er, and Eu) materials.

The Good, the Bad, and the Ugly of Dendritic Cells during Prion Disease.

Prions are a unique group of proteinaceous pathogens which cause neurodegenerative disease and can be transmitted by a variety of exposure routes. After peripheral exposure, the accumulation and replication of prions within secondary lymphoid organs are obligatory for their efficient spread from the periphery to the brain where they ultimately cause neurodegeneration and death. Mononuclear phagocytes (MNP) are a heterogeneous population of dendritic cells (DC) and macrophages. These cells are abundant throughout the body and display a diverse range of roles based on their anatomical locations. For example, some MNP are strategically situated to provide a first line of defence against pathogens by phagocytosing and destroying them. Conventional DC are potent antigen presenting cells and migrate via the lymphatics to the draining lymphoid tissue where they present the antigens to lymphocytes. The diverse roles of MNP are also reflected in various ways in which they interact with prions and in doing so impact on disease pathogenesis. Indeed, some studies suggest that prions exploit conventional DC to infect the host. Here we review our current understanding of the influence of MNP in the pathogenesis of the acquired prion diseases with particular emphasis on the role of conventional DC.

The role of external fixators in paediatric trauma.

We report a retrospective review of all paediatric trauma patients managed with an external fixator admitted to our institution over a 7-year period. We identified 30 fractures in 28 children. The fractures included 20 tibiae, 5 femurs, 2 humerii, 2 radii and 1 phalanx. The indications were 23 open fractures, 4 comminuted fractures and 3 closed fractures in poly-traumatised patients. It was the definitive treatment in 13 fractures. The mean length of total time with an external fixator was 9.6 weeks (range 1-38 weeks.) Difficulties encountered were eight problems, one obstacle and two true complications. There were no cases of re-fracture following removal of the external fixator. This review confirms that there is a role for the use of external fixation in selected paediatric fractures with a low complication rate.

Medial radial head dislocation associated with a proximal olecranon fracture: a bado type v?

The Monteggia fracture is relatively rare. We present an unreported configuration of a traumatic olecranon fracture with a concomitant medial radial head dislocation in a 3-year-old male. This injury was initially missed and required a subsequent operative intervention. Following surgery, there was evident fracture union, articular congruency, and a full functional recovery. Medial radial head dislocation is not accounted for in the Bado (1967) classification of the Monteggia lesion and hence we propose the addition of a Bado V category.

What makes a great resident? The programme director perspective.

A career in orthopedic surgery in the United Kingdom is highly competitive. Great residents are trainees who understand that ultimately, they are responsible for their own training. They need to work with their Training Program Director to plan their career, to develop as surgeons, to reflect on their performance and any feedback they receive, be flexible, and plan ahead. There is competition but it is fair for everyone and the great resident will excel within this environment and will be successful in the long term.

Limb lengthening for post-traumatic shortening over a pre-implanted femoral locking plate.

Attempts have been made to refine techniques involved in distraction osteogenesis to improve patient compliance and reduce complications. The prolonged use of external fixators for limb lengthening is associated with a number of problems, and in addition patient satisfaction with a cumbersome external fixator may be low. To reduce the complication rate and facilitate early removal of the external fixator by protecting the regenerate bone, lengthening over an intramedullary nail is being increasingly described. These techniques have limitations when used in skeletally immature patients and carry a risk of deep intramedullary infection. Post-traumatic limb length discrepancy is not uncommon after high-energy injuries are fixed in a shortened position secondary to bone loss. The plate applied at the time of injury may be incorporated into any subsequent lengthening process. A detailed description of the technique of lengthening over a pre-implanted distal femoral plate is followed by presentation of 2 case examples.

Primary subacute osteomyelitis of the talus in children: a case series and review.

Subacute haematogenous osteomyelitis of the talus in children is a rare condition. All previously reported cases have been managed by hospital admission with surgical debridement and antibiotics or by intravenous antibiotic therapy followed by oral antibiotics. This case series documents the management of the condition at our institution and reviews the current published literature. We conclude that with appropriate patient selection, primary subacute haematogenous osteomyelitis of the paediatric talus can be managed on an out-patient basis with oral antibiotic therapy.

Marginal excision and Ilizarov hemicallotasis for osteofibrous dysplasia of the tibia: a case report.

The surgical management of osteofibrous dysplasia (OFD), a rare developmental tumour-like condition of childhood that has a predilection for the tibia, ranges from curettage or subperiosteal resection to extraperiosteal wide resection followed by reconstruction. En-bloc excision followed by distraction osteogenesis has been described earlier for OFD. We describe a novel technique in which marginal excision was performed but instead of excising an entire segment of tibia, only the anterior portion containing the lesion was excised, sparing the uninvolved posterior cortex. Distraction osteogenesis was carried out on the anterior portion of the tibia (hemicallotasis) after acute correction of the deformity. Although the potential advantage is a decrease in time required for consolidation of the bone regenerate, this technique is dependent on the anatomical characteristics of the lesion. We describe a case in which this technique was adopted on a child with tibial OFD with resultant disease-free excision margins and deformity correction.

Use of consumer survey data to target cessation messages to smokers through mass media.

OBJECTIVES: We identified the mass media channels that reach the most cigarette smokers in an attempt to more effectively target smoking cessation messages. METHODS: Reach estimates and index scores for smokers were taken from 2002-2003 ConsumerStyles and HealthStyles national surveys of adults (N=11660) to estimate overall and demographic-specific exposure measures for television, radio, newspapers, and magazines. RESULTS: Smokers viewed more television, listened to more radio, and read fewer magazines and newspapers than did nonsmokers. Nearly one third of smokers were regular daytime or late-night television viewers. Selected cable television networks (USA, Lifetime, and Discovery Channel) and selected radio genres, such as classic rock and country, had high reach and were cost-efficient channels for targeting smokers. CONCLUSIONS: Certain mass media channels offer efficient opportunities to target smoking cessation messages so they reach relatively large audiences of smokers at relatively low cost. The approach used in this study can be applied to other types of health risk factors to improve health communication planning and increase efficiency of program media expenditures.