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1.
Curr Biol ; 34(8): 1801-1809.e4, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38569544

RESUMEN

Neural oscillations reflect fluctuations in the relative excitation/inhibition of neural systems1,2,3,4,5 and are theorized to play a critical role in canonical neural computations6,7,8,9 and cognitive processes.10,11,12,13,14 These theories have been supported by findings that detection of visual stimuli fluctuates with the phase of oscillations prior to stimulus onset.15,16,17,18,19,20,21,22,23 However, null results have emerged in studies seeking to demonstrate these effects in visual discrimination tasks,24,25,26,27 raising questions about the generalizability of these phenomena to wider neural processes. Recently, we suggested that methodological limitations may mask effects of phase in higher-level sensory processing.28 To test the generality of phasic influences on perception requires a task that involves stimulus discrimination while also depending on early sensory processing. Here, we examined the influence of oscillation phase on the visual tilt illusion, in which a center grating has its perceived orientation biased away from the orientation of a surround grating29 due to lateral inhibitory interactions in early visual processing.30,31,32 We presented center gratings at participants' subjective vertical angle and had participants report whether the grating appeared tilted clockwise or counterclockwise from vertical on each trial while measuring their brain activity with electroencephalography (EEG). In addition to effects of alpha power and aperiodic slope, we observed robust associations between orientation perception and alpha and theta phase, consistent with fluctuating illusion magnitude across the oscillatory cycle. These results confirm that oscillation phase affects the complex processing involved in stimulus discrimination, consistent with its purported role in canonical computations that underpin cognition.


Asunto(s)
Percepción Visual , Humanos , Masculino , Adulto , Femenino , Percepción Visual/fisiología , Adulto Joven , Ilusiones/fisiología , Estimulación Luminosa , Electroencefalografía , Discriminación en Psicología/fisiología
2.
Cognition ; 242: 105631, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37820487

RESUMEN

Humans have well-documented priors for many features present in nature that guide visual perception. Despite being putatively grounded in the statistical regularities of the environment, scene priors are frequently violated due to the inherent variability of visual features from one scene to the next. However, these repeated violations do not appreciably challenge visuo-cognitive function, necessitating the broad use of priors in conjunction with context-specific information. We investigated the trade-off between participants' internal expectations formed from both longer-term priors and those formed from immediate contextual information using a perceptual inference task and naturalistic stimuli. Notably, our task required participants to make perceptual inferences about naturalistic images using their own internal criteria, rather than making comparative judgements. Nonetheless, we show that observers' performance is well approximated by a model that makes inferences using a prior for low-level image statistics, aggregated over many images. We further show that the dependence on this prior is rapidly re-weighted against contextual information, even when misleading. Our results therefore provide insight into how apparent high-level interpretations of scene appearances follow from the most basic of perceptual processes, which are grounded in the statistics of natural images.


Asunto(s)
Juicio , Percepción Visual , Humanos , Cognición
3.
Nat Commun ; 14(1): 5320, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37658039

RESUMEN

Perception is often modelled as a process of active inference, whereby prior expectations are combined with noisy sensory measurements to estimate the structure of the world. This mathematical framework has proven critical to understanding perception, cognition, motor control, and social interaction. While theoretical work has shown how priors can be computed from environmental statistics, their neural instantiation could be realised through multiple competing encoding schemes. Using a data-driven approach, here we extract the brain's representation of visual orientation and compare this with simulations from different sensory coding schemes. We found that the tuning of the human visual system is highly conditional on stimulus-specific variations in a way that is not predicted by previous proposals. We further show that the adopted encoding scheme effectively embeds an environmental prior for natural image statistics within the sensory measurement, providing the functional architecture necessary for optimal inference in the earliest stages of cortical processing.


Asunto(s)
Cognición , Motivación , Humanos , Interacción Social
4.
PLoS Comput Biol ; 19(7): e1011245, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37450502

RESUMEN

The mechanisms that enable humans to evaluate their confidence across a range of different decisions remain poorly understood. To bridge this gap in understanding, we used computational modelling to investigate the processes that underlie confidence judgements for perceptual decisions and the extent to which these computations are the same in the visual and auditory modalities. Participants completed two versions of a categorisation task with visual or auditory stimuli and made confidence judgements about their category decisions. In each modality, we varied both evidence strength, (i.e., the strength of the evidence for a particular category) and sensory uncertainty (i.e., the intensity of the sensory signal). We evaluated several classes of computational models which formalise the mapping of evidence strength and sensory uncertainty to confidence in different ways: 1) unscaled evidence strength models, 2) scaled evidence strength models, and 3) Bayesian models. Our model comparison results showed that across tasks and modalities, participants take evidence strength and sensory uncertainty into account in a way that is consistent with the scaled evidence strength class. Notably, the Bayesian class provided a relatively poor account of the data across modalities, particularly in the more complex categorisation task. Our findings suggest that a common process is used for evaluating confidence in perceptual decisions across domains, but that the parameter settings governing the process are tuned differently in each modality. Overall, our results highlight the impact of sensory uncertainty on confidence and the unity of metacognitive processing across sensory modalities.


Asunto(s)
Juicio , Metacognición , Humanos , Teorema de Bayes , Incertidumbre , Simulación por Computador , Estimulación Luminosa , Percepción Visual , Percepción Auditiva
5.
J Bone Joint Surg Am ; 105(7): 518-526, 2023 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-36763675

RESUMEN

BACKGROUND: Injuries are one of the leading causes of global death and disability and commonly have substantial economic implications. The economic impact of injuries is particularly pronounced in low- and middle-income countries, where 90% of injuries occur. In this study, we aimed to assess return-to-work rates of individuals who sustained a lower-limb long-bone fracture in South Africa and to identify factors that influence the ability to return to employment. METHODS: This prospective cohort study was conducted across 2 tertiary trauma centers in Cape Town, South Africa. Adults who received intramedullary nail fixation for a lower-limb fracture between September 2017 and December 2018 were recruited and followed for 18 months postoperatively. The participants' return to employment was assessed at 6 and 18 months post-injury. Multivariate logistic regression was used to identify factors that influence post-injury employment. RESULTS: Of the 194 participants enrolled, 192 completed follow-up. The study population had a median age of 33.0 years, and most of the participants (76.6%) were male. Seventy-five percent of the participants were employed before their injury. At 6 and 18 months post-injury, 34.4% and 56.3% of participants, respectively, were employed. Of those employed pre-injury, 70.1% had returned to work at 18 months. Multivariate regression identified increasing age, unemployment prior to injury, and working in the informal employment sector as factors that impede an individual's likelihood of working 18 months post-injury. For those in employment prior to injury, increasing age was the only factor found to impede the likelihood of returning to work following an injury. CONCLUSIONS: This study highlights the profound effect that lower-limb long-bone fractures may have on an individual's ability to return to work in South Africa, with the potential to cause substantial economic impact on an individual's livelihood and that of their dependents. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Fijación Intramedular de Fracturas , Fracturas Óseas , Traumatismos de la Pierna , Adulto , Humanos , Masculino , Lactante , Femenino , Reinserción al Trabajo , Sudáfrica , Estudios Prospectivos , Fracturas Óseas/epidemiología
6.
BMC Med Educ ; 23(1): 111, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36793036

RESUMEN

BACKGROUND: A key strategy to building surgical capacity in low income countries involves training care providers, particularly in the interventions highlighted by the Lancet Commission for Global Surgery, including the management of open fractures. This is a common injury, especially in areas with a high incidence of road traffic incidents. The aim of this study was to use a nominal group consensus method to design a course on open fracture management for clinical officers in Malawi. METHODS: The nominal group meeting was held over two days, including clinical officers and surgeons from Malawi and the UK with various levels of expertise in the fields of global surgery, orthopaedics and education. The group was posed with questions on course content, delivery and evaluation. Each participant was encouraged to suggest an answer and the advantages and disadvantages of each suggestion were discussed before voting through an anonymous online platform. Voting included use of a Likert scale or ranking available options. Ethical approval for this process was obtained from the College of Medicine Research and Ethics Committee Malawi and the Liverpool School of Tropical Medicine. RESULTS: All suggested course topics received an average score of greater than 8 out of 10 on a Likert scale and were included in the final programme. Videos was the highest ranking option as a method for delivering pre-course material. The highest ranking methods for each course topic included lectures, videos and practicals. When asked what practical skill should be tested at the end of the course, the highest ranking option was "initial assessment". CONCLUSION: This work outlines how a consensus meeting can be used to design an educational intervention to improve patient care and outcomes. Through combining the perspectives of both the trainer and trainee, the course aligns both agendas so that it is relevant and sustainable.


Asunto(s)
Oftalmología , Cirujanos , Humanos , Consenso , Curriculum , Países en Desarrollo
7.
Bone Joint J ; 104-B(12): 1362-1368, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36453043

RESUMEN

AIMS: Prior to the availability of vaccines, mortality for hip fracture patients with concomitant COVID-19 infection was three times higher than pre-pandemic rates. The primary aim of this study was to determine the 30-day mortality rate of hip fracture patients in the post-vaccine era. METHODS: A multicentre observational study was carried out at 19 NHS Trusts in England. The study period for the data collection was 1 February 2021 until 28 February 2022, with mortality tracing until 28 March 2022. Data collection included demographic details, data points to calculate the Nottingham Hip Fracture Score, COVID-19 status, 30-day mortality, and vaccination status. RESULTS: A total of 337 patients tested positive for COVID-19. The overall 30-day mortality in these patients was 7.7%: 5.5% in vaccinated patients and 21.7% in unvaccinated patients. There was no significant difference between post-vaccine mortality compared with pre-pandemic 2019 controls (7.7% vs 5.0%; p = 0.068). Independent risk factors for mortality included unvaccinated status, Abbreviated Mental Test Score ≤ 6, male sex, age > 80 years, and time to theatre > 36 hours, in decreasing order of effect size. CONCLUSION: The vaccination programme has reduced 30-day mortality rates in hip fracture patients with concomitant COVID-19 infection to a level similar to pre-pandemic. Mortality for unvaccinated patients remained high.Cite this article: Bone Joint J 2022;104-B(12):1362-1368.


Asunto(s)
COVID-19 , Fracturas de Cadera , Humanos , Masculino , Anciano de 80 o más Años , Vacunación , Pandemias , Recolección de Datos
8.
Wellcome Open Res ; 7: 204, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36110835

RESUMEN

Background: Open tibia fractures are a common injury following road traffic accidents in Malawi and can lead to long term disability. Very little is known about patients' experiences of the healthcare system and the disability in low-income countries following this injury. The aim of the study was to explore patient experiences of treatment and disability following an open tibia fracture in Malawi. Methods: A qualitative study was conducted using semi-structured interviews with ten patients with open tibia fractures at a central hospital in Blantyre, Malawi. A mixed deductive-inductive thematic analysis was used to identify broad themes of treatment and disability. Written informed consent was obtained from all participants. Results: Patient characteristics included an average age of 39.1 years old (22-63) and 80% were male. Broad themes found were delays in receiving treatment, change in individuals' societal role and delayed recovery associated with pain and immobility. Conclusions: Open tibia fractures in Malawi have a devastating impact on patients and their families. Further studies are required to explore the reasons for the delays in open fracture emergency treatment.

9.
Perception ; 51(4): 244-262, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35296165

RESUMEN

The THINGS database is a freely available stimulus set that has the potential to facilitate the generation of theory that bridges multiple areas within cognitive neuroscience. The database consists of 26,107 high quality digital photos that are sorted into 1,854 concepts. While a valuable resource, relatively few technical details relevant to the design of studies in cognitive neuroscience have been described. We present an analysis of two key low-level properties of THINGS images, luminance and luminance contrast. These image statistics are known to influence common physiological and neural correlates of perceptual and cognitive processes. In general, we found that the distributions of luminance and contrast are in close agreement with the statistics of natural images reported previously. However, we found that image concepts are separable in their luminance and contrast: we show that luminance and contrast alone are sufficient to classify images into their concepts with above chance accuracy. We describe how these factors may confound studies using the THINGS images, and suggest simple controls that can be implemented a priori or post-hoc. We discuss the importance of using such natural images as stimuli in psychological research.


Asunto(s)
Sensibilidad de Contraste , Visión Ocular , Bases de Datos Factuales , Humanos
10.
J Vis ; 22(1): 4, 2022 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-35006237

RESUMEN

The sensitivity of the human visual system is thought to be shaped by environmental statistics. A major endeavor in vision science, therefore, is to uncover the image statistics that predict perceptual and cognitive function. When searching for targets in natural images, for example, it has recently been proposed that target detection is inversely related to the spatial similarity of the target to its local background. We tested this hypothesis by measuring observers' sensitivity to targets that were blended with natural image backgrounds. Targets were designed to have a spatial structure that was either similar or dissimilar to the background. Contrary to masking from similarity, we found that observers were most sensitive to targets that were most similar to their backgrounds. We hypothesized that a coincidence of phase alignment between target and background results in a local contrast signal that facilitates detection when target-background similarity is high. We confirmed this prediction in a second experiment. Indeed, we show that, by solely manipulating the phase of a target relative to its background, the target can be rendered easily visible or undetectable. Our study thus reveals that, in addition to its structural similarity, the phase of the target relative to the background must be considered when predicting detection sensitivity in natural images.


Asunto(s)
Sensibilidad de Contraste , Visión Ocular , Humanos
11.
Cortex ; 146: 238-249, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34915394

RESUMEN

A person's ability to recognise familiar faces is critical to their participation in many aspects of society. Following an acquired brain injury or retinal disease, however, faces can appear distorted, a phenomenon known as prosopometamorphopsia. Although case reports have described a variety of changes in the appearance of faces during prosopometamorphopsia, the influence of the disorder on face recognition has not been rigorously investigated. In the present report, we quantify how well healthy observers can recognise familiar faces that have been distorted using a parametric model of prosopometamorphopsia. Our results reveal that face recognition varies systematically with the parameters of visual distortion, which, importantly, interact with the size of the face in a nonlinear but highly predictable manner. Our findings demonstrate that prosopometamorphopsia can lead to a surprising range of changes in the appearance of faces. The impact of visual distortion on face recognition thus depends critically on the distance at which the face is viewed, which is likely to change across social and clinical contexts.


Asunto(s)
Reconocimiento Facial , Cara , Humanos , Reconocimiento Visual de Modelos
12.
Artículo en Inglés | MEDLINE | ID: mdl-34746631

RESUMEN

In this observational study, we describe the medium-term outcomes of total joint arthroplasty (TJA) in human immunodeficiency virus (HIV)-positive patients in Malawi, a low-income country. With a high prevalence of HIV and increasing arthroplasty rates in low and middle-income countries, understanding the outcomes of TJA in this unique cohort of patients is essential to ensure that surgical practice is evidence-based. METHODS: Data for all HIV-positive patients who had TJA from January 2005 to March 2020 were extracted from the National Arthroplasty Registry of the Malawi Orthopaedic Association (NARMOA). From January 2005 to March 2020, a total of 102 total hip arthroplasties (THAs) and 20 total knee arthroplasties (TKAs) were performed in 97 patients who were HIV-positive and without hemophilia or a history of intravenous drug use. The mean length of follow-up was 4 years and 3 months (range, 6 weeks to 15 years) in the THA group and 4 years and 9 months (range, 6 weeks to 12 years) in the TKA group. The mean patient age was 50 years (range, 21 to 76 years) and 64 years (range, 48 to 76 years) at the time of THA and TKA, respectively. RESULTS: The primary indication for THA was osteonecrosis (66 hips). In the THA group, the mean preoperative Oxford Hip Score and Harris hip score were 14.0 (range, 2 to 33) and 29.4 (range, 1 to 64), respectively, and improved to 46.6 (range, 23 to 48) and 85.0 (range, 28 to 91) postoperatively. The primary indication for TKA was osteoarthritis (19 knees). The mean preoperative Oxford Knee Score was 14.9 (range, 6 to 31) and increased to 46.8 (range, 40 to 48) postoperatively. In patients who underwent THA, there was 1 deep infection (1 of 102 procedures), and 6 patients developed aseptic loosening (6 of 102). There was 1 postoperative superficial infection following TKA (1 of 20 procedures), and 1 patient developed aseptic loosening (1 of 20). Postoperative 6-week mortality among all patients was zero. CONCLUSIONS: To our knowledge this is the largest medium-term follow-up of HIV-positive patients, without hemophilia or a history of intravenous drug use, who have had TJA in a low-income country. This study demonstrated good medium-term results among HIV-positive patients undergoing TJA, low complication rates, and improvements in patient-reported outcome measures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

13.
Cognition ; 214: 104763, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34062339

RESUMEN

Accounts of working memory based on independent item representations may overlook a possible contribution of ensemble statistics, higher-order regularities of a scene such as the mean or variance of a visual attribute. Here we used change detection tasks to investigate the hypothesis that observers store ensemble statistics in working memory and use them to detect changes in the visual environment. We controlled changes to the ensemble mean or variance between memory and test displays across six experiments. We made specific predictions of observers' sensitivity using an optimal summation model that integrates evidence across separate items but does not detect changes in ensemble statistics. We found strong evidence that observers outperformed this model, but only when task difficulty was high, and only for changes in stimulus variance. Under these conditions, we estimated that the variance of items contributed to change detection sensitivity more strongly than any individual item in this case. In contrast, however, we found strong evidence against the hypothesis that the average feature value is stored in working memory: when the mean of memoranda changed, sensitivity did not differ from the optimal summation model, which was blind to the ensemble mean, in five out of six experiments. Our results reveal that change detection is primarily limited by uncertainty in the memory of individual features, but that memory for the variance of items can facilitate detection under a limited set of conditions that involve relatively high working memory demands.


Asunto(s)
Memoria a Corto Plazo , Percepción Visual , Humanos , Incertidumbre
14.
J Acquir Immune Defic Syndr ; 87(5): 1214-1220, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-33990496

RESUMEN

BACKGROUND: HIV reduces bone mineral density, mineralization, and turnover and may impair fracture healing. SETTING: This prospective cohort study in South Africa investigated whether HIV infection was associated with impaired fracture healing after trauma. METHODS: All adults with acute tibia and femur fractures who underwent intermedullary (IM) nailing for fracture fixation between September 2017 and December 2018, at 2 tertiary hospitals, were followed up for a minimum of 12 months postoperatively. The primary outcome was delayed bone union at 6 months (defined by the radiological union scoring system for the tibia score <9), and the secondary outcome was nonunion (defined as radiological union scoring system for the tibia score <9) at 9 months. Multivariable logistic regression models were constructed to investigate the associations between HIV status and impaired fracture healing. RESULTS: In total, 358 participants, who underwent 395 IM nailings, were enrolled in the study and followed up for 12 months. Seventy-one of the 358 (19.8%) participants were HIV-positive [83/395 (21%) IM nailings]. HIV was not associated with delayed fracture healing after IM nailing of the tibia or femur (multivariable odds ratio: 1.06; 95% confidence interval: 0.50 to 2.22). HIV-positive participants had a statistically significant lower odds ratio of nonunion compared with HIV-negative participants (multivariable odds ratio: 0.17; 95% confidence interval: 0.01 to 0.92). CONCLUSIONS: Fractures sustained in HIV-positive individuals can undergo surgical fixation as effectively as those in HIV-negative individuals, with no increased risk of delayed union or nonunion.


Asunto(s)
Curación de Fractura , Infecciones por VIH/fisiopatología , Adolescente , Adulto , Anciano , Densidad Ósea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sudáfrica , Adulto Joven
15.
Atten Percept Psychophys ; 83(6): 2377-2393, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33864204

RESUMEN

Spatial location is believed to have a privileged role in binding features held in visual working memory. Supporting this view, Pertzov and Husain (Attention, Perception, & Psychophysics, 76(7), 1914-1924, 2014) reported that recall of bindings between visual features was selectively impaired when items were presented sequentially at the same location compared to sequentially at different locations. We replicated their experiment, but additionally tested whether the observed impairment could be explained by perceptual interference during encoding. Participants viewed four oriented bars in highly discriminable colors presented sequentially either at the same or different locations, and after a brief delay were cued with one color to reproduce the associated orientation. When we used the same timing as the original study, we reproduced its key finding of impaired binding memory in the same-location condition. Critically, however, this effect was significantly modulated by the duration of the inter-stimulus interval, and disappeared if memoranda were presented with longer delays between them. In a second experiment, we tested whether the effect generalized to other visual features, namely reporting of colors cued by stimulus shape. While we found performance deficits in the same-location condition, these did not selectively affect binding memory. We argue that the observed effects are best explained by encoding interference, and that memory for feature binding is not necessarily impaired when memoranda share the same location.


Asunto(s)
Memoria a Corto Plazo , Percepción Visual , Atención , Señales (Psicología) , Humanos , Recuerdo Mental
16.
Injury ; 52(6): 1251-1259, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33691946

RESUMEN

BACKGROUND: Open tibia fractures are a common injury following road traffic collisions and place a large economic burden on patients and healthcare systems. Summarising their economic burden is key to inform policy and help prioritise treatment. METHODS: All studies were identified from a systematic search of Medline, Embase and the Cochrane Central Register of Controlled Trials. We included any human with a diagnosed open tibia fracture, following any intervention. The primary outcome was any costs reported or patient return to work status. Secondary outcomes included average length of stay, wage loss, absenteeism and complications such as infection, amputation and nonunion. Data was extracted and we performed a descriptive narrative summary. RESULTS: We reviewed 1,204 studies from our searches. A total of 34 studies were included from 14 different countries. The average age was 37.7 years old and 76% of the patients were male. 6.5% were Gustilo I, 12% Gustilo II and 82% Gustilo III. Initial direct hospitalisation costs were reported to be between £356 to £126,479 with an average length of stay of 56 days (3.1-244). 89% of participants were working pre-injury, 60% fully returned to work, 17% returned to work part time or changed profession and 22% did not return to work at one-year. The most common complications reported were 22% infection, 11% nonunion and 16% amputation. Mean follow-up duration for the studies was 25 months. CONCLUSION: The economic burden of open tibia fractures varies greatly, but it is costly for both hospitals and patients. The current evidence is predominantly from high-income countries (HICs), especially the USA. Further research is required to investigate the costs of open tibia fractures using validated costing tools, especially in low-income countries (LICs), to help inform and direct policy.


Asunto(s)
Fracturas Abiertas , Fracturas de la Tibia , Accidentes de Tránsito , Adulto , Amputación Quirúrgica , Costo de Enfermedad , Femenino , Fracturas Abiertas/cirugía , Humanos , Masculino , Tibia , Fracturas de la Tibia/cirugía
17.
Injury ; 52(6): 1473-1479, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33441253

RESUMEN

BACKGROUND: Hip fractures are a large burden on the health care systems of developed nations. Patients usually have multiple co-morbidities and the pre-injury use of anticoagulants and anti-platelet medication is common. MATERIALS AND METHODS: This study used a single hospital hip fracture database to facilitate a retrospective analysis of the impact of anti-coagulation and anti-platelet therapy on mortality and complications after surgical management of hip fractures. There were 92 patients on warfarin, 69 on DOAC, 260 antiplatelet patients and 617 control patients. RESULTS: Mortality rates at 30 days were 4.8% for the control group, 12.6% for the antiplatelet group, warfarin 7.0%, 9.5% for Direct Oral Anticoagulant (DOAC) group, p = 0.004. Mortality rates at 1 year were 22.4% for the control group, 32.3% for the antiplatelet group, 29.3% for the warfarin group and 29.0% for DOAC group (p=0.007). Amongst complications, significant differences were found in transfusion (DOAC) and wound ooze (warfarin) rates, but the study did not detect significant clinical consequences arising from these differences. A matched analysis for age, sex, and ASA was undertaken to look in more detail at mortality data. Some mortality differences remained between groups with anti-platelet medication associated with increased mortality, but the differences no longer appeared to be significant. Our data suggests that this is a non-causal association, which could be incorporated into predictive mortality risk scores such as the Nottingham hip fracture score. CONCLUSION: We believe that pre-injury antiplatelet therapy is a strong indicator for high risk patients with higher expected mortality after hip fracture surgery. We saw no evidence to support delayed surgery in patients taking DOACs.


Asunto(s)
Fracturas de Cadera , Warfarina , Anticoagulantes/efectos adversos , Estudios de Cohortes , Fracturas de Cadera/tratamiento farmacológico , Fracturas de Cadera/cirugía , Humanos , Estudios Retrospectivos
18.
J Orthop Res ; 38(3): 574-577, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31560130

RESUMEN

The dynamic hip screw (DHS) consists of a barrel-plate fixed to the relatively-straight proximal femoral shaft, and a screw which slides within the barrel at a fixed angle, usually 135°. The guide-wire is inserted using a guide at the set angle. Guide design varies between manufacturers, with some new guides being particularly short. We analysed the impact of guide design on the resulting trajectory of the guidewire, and its potential to cause a surgical error. Twenty AP hip radiographs were analysed. Trauma Cad (Brainlab, Munich, Germany) software was used to template a 4-hole 135° DHS onto the intact femur with the screw positioned in the center of the head. A template of a Stryker (Michigan, USA) 135° DHS guide (37 mm long) was then overlaid at the hip screw entry point, and the set trajectory marked. The divergence between the two trajectories was measured (α angle). The distance the guide would have to be moved inferiorly to attain the correct position in the head was then noted. The median divergence (α angle) caused by the guide relative to the ideal position was 6° (range 2-12). This led to the guidewire placement being a median of 9.1 mm (range 3-23) superior in the head (ß).To achieve the correct position of the wire in the head, the guide needed to be moved inferiorly a median of 8 mm (range 2-10). © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:574-577, 2020.


Asunto(s)
Placas Óseas , Tornillos Óseos , Fijación Interna de Fracturas/instrumentación , Fracturas de Cadera/diagnóstico por imagen , Fracturas de Cadera/cirugía , Cadera/diagnóstico por imagen , Cadera/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Cabeza Femoral/cirugía , Fijación Interna de Fracturas/métodos , Humanos , Masculino , Persona de Mediana Edad , Ortopedia/métodos , Radiografía/métodos , Reproducibilidad de los Resultados
19.
Injury ; 51(2): 142-146, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31767370

RESUMEN

BACKGROUND: Open tibia fractures are a common cause of admission following road traffic accidents in low and middle income countries (LMICs), resulting in substantial mortality and disability. It is important to summarise the clinical course of this injury using patient reported scores in order to assess best treatment in LMICs. OBJECTIVES: To summarise the disability after sustaining an open tibia fracture in LMICs METHODS: All studies were identified from a systematic search of Medline, Embase and the Cochrane Central Register of Controlled Trials. We included any human with a diagnosed open tibia fracture, following any intervention. Studies were performed in a low or middle income country. The primary outcome was any validated patient reported outcome score reported after three months. Secondary outcomes included economic impact and complications such as infection, non-union and amputation. Data was extracted and summarised. RESULTS: We reviewed 3,593 articles from our search. A total of 18 studies were included from 10 countries with 8 different outcome scores. The average age was 35 years old and 86% of the patients were male. Thirty-one percent were Gustilo I, 28% Gustilo II, 19% Gustilo IIIA, 17% Gustilo IIIB and 5% Gustilo IIIC. The most common complications reported were 18% infection, 15% non-union and 15% amputation. Economic impact was reported in only one study with 100% patients working pre-injury and 20% post-injury at 12 months. Mean follow-up duration for outcome scores was 19.8 months. There was heterogeneity between the studies in terms of subject of the studies, outcome criteria, fracture type, surgical technique and length of follow-up. Therefore, no meta-analysis could be performed. CONCLUSION: The clinical history of open tibia fractures in low or middle income countries remains largely unknown in terms of patient reported outcomes. Further studies are required to define these outcomes in open tibia fractures before best treatments can be assessed.


Asunto(s)
Fracturas Abiertas/complicaciones , Fracturas Abiertas/cirugía , Fracturas de la Tibia/epidemiología , Adulto , Cuidados Posteriores , Amputación Quirúrgica/estadística & datos numéricos , Países en Desarrollo/estadística & datos numéricos , Femenino , Fracturas Abiertas/diagnóstico , Fracturas no Consolidadas/epidemiología , Humanos , Infecciones/epidemiología , Masculino , Medición de Resultados Informados por el Paciente , Fracturas de la Tibia/clasificación , Fracturas de la Tibia/mortalidad
20.
SICOT J ; 5: 41, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31769752

RESUMEN

BACKGROUND: To perform a bibliometric analysis and quantify the amount of orthopaedic and trauma literature published from low-income countries (LICs). METHODS AND METHODS: The Web of Science database was utilised to identify all indexed orthopaedic journals. All articles published in the 76 orthopaedics journals over the last 10 years were reviewed, to determine their geographic origin. RESULTS: A total of 131 454 articles were published across 76 orthopaedic journals over the last 10 years. Of these, 132 (0.1%) were published from LICs and 3515 (2.7%) were published from lower middle-income countries (LMICs); 85.7% (n = 112 716) of published orthopaedic research was undertaken in a high-income setting. The majority of the studies (n = 90, 74.4%) presented level IV evidence. Only 7.4% (n = 9) were high-quality evidence (level I or II). Additionally, the majority of research (74 articles, 56%) was published in partnership with high-income countries (HICs). CONCLUSIONS: There is a stark mismatch between the publication of scientific reports on orthopaedic research and the geographical areas of greatest clinical need. We believe there is an urgent need for orthopaedic research to be carried out in low-income settings to guide treatment and improve outcomes, rather than assuming that evidence from high-income settings will translate into this environment. LEVEL OF EVIDENCE: IV.

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