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1.
J Pediatr Orthop ; 44(5): e381-e388, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38441619

RESUMO

BACKGROUND: The management of congenital scoliosis poses a significant challenge for treating surgeons. The aim of our study was to provide insight into the long-term clinical results of spinal fusion in congenital scoliosis. METHODS: We performed a retrospective review of the scoliosis database in our institution for the period 1976 until 2002 identifying 43 patients with congenital scoliosis who underwent spinal fusion. Patient demographics, diagnosis, levels fused, and radiographs were evaluated. Patients were evaluated for unplanned return to the operating room (UPROR) via SRS 22, EQ5D-5L, and Oswestry Disability Index (ODI). RESULTS: Of the 43 patients who fulfilled the inclusion criteria, 22 patients agreed to participate, 3 patients were known to be deceased and 18 patients were lost to follow-up or declined to participate and were excluded. The mean age of the respondents was 40.7 years (range, 30 to 47 y) with a mean follow-up from index surgery of 35 years (range, 20 to 44 y). At most recent follow-up, 12 patients (54%) underwent UPROR. The mean age at diagnosis was 3.4 years (range, birth to 11.5 y), and the mean age for first surgery was 5.8 years (range, 1 to 13 y). As regards radiologic follow-up; the mean number of levels fused was 5.2 (range, 2 to 12). Thoracic fusion was performed in 17 patients (77%). The mean T1 to T12 height at index surgery and maturity was 166 mm (range, 130 to 240 mm) and 202 mm (range, 125 to 270 mm), respectively. The mean functional scores at follow-up were SRS 22: 4.5 (range, 2.4 to 5), cumulative EQ5D-5L score 7.2 (range, 5 to 15), and ODI: 8% (range, 2 to 30%). All respondents completed high school, 10 patients (45%) completed university, and 2 patients were awarded doctorates. Currently, 17 patients (77%) are in paid employment. CONCLUSIONS: This report constitutes the largest series of patients treated by spinal arthrodesis for congenital scoliosis followed into maturity. We demonstrate the thorax continues to grow after index fusion, patient-reported outcomes were satisfactory with superior educational and employment rates and unplanned return to theatre is rare in adult life. LEVEL OF EVIDENCE: Therapeutic Level IV.


Assuntos
Escoliose , Fusão Vertebral , Adulto , Humanos , Pessoa de Meia-Idade , Criança , Lactente , Pré-Escolar , Adolescente , Escoliose/diagnóstico por imagem , Escoliose/cirurgia , Seguimentos , Resultado do Tratamento , Estudos Retrospectivos , Fusão Vertebral/métodos
2.
J Pediatr Orthop ; 42(10): 552-557, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35993600

RESUMO

BACKGROUND: A fundamental tenent of treating developmental dysplasia of the hip is to identify patients with dislocated hips early so as to avoid the long-term sequelae of late diagnosis. The aim of this study was to develop a readily useable triage tool for patients with suspected hip dislocation, based on the clinical history and examination findings of the referring practitioner. METHODS: All primary care referrals (n=934) over a 3-year period for suspected developmental dysplasia of the hip to a tertiary pediatric center were evaluated. Defined parameters with respect to history and clinical examination were evaluated. Multivariable logistic regression was used to establish predictors of hip dislocation, and from this a predictive model was derived which incorporated significant predictors of dislocation. An illustrative nomogram translated this predictive model into a usable numerical scoring system called the Children's Hip Prediction score, which estimates probability of hip dislocation. RESULTS: There were 97 dislocated hips in 85 patients. The final predictive model included age, sex, family history, breech, gait concerns, decreased abduction, leg length discrepancy, and medical/neurological syndrome. The area under receiver operating curve for the model is 0.761. A Children's Hip Prediction score of≥5 corresponds to a sensitivity of 76.3% and a score of≥15 has a specificity of 97.8%, corresponding to an odds ratio of 27.3 for increased risk of dislocation. CONCLUSION: We found that a novel clinical prediction score, based on readily available history and examination parameters strongly predicted risk of dislocations in hip dysplasia referral. It is hoped that this tool could be utilized to optimize resource allocation and may be of particular benefit in less well-resourced health care systems. LEVEL OF EVIDENCE: Level II.


Assuntos
Displasia do Desenvolvimento do Quadril , Luxação Congênita de Quadril , Luxação do Quadril , Luxações Articulares , Criança , Luxação do Quadril/diagnóstico , Luxação Congênita de Quadril/diagnóstico , Luxação Congênita de Quadril/terapia , Humanos , Encaminhamento e Consulta , Estudos Retrospectivos , Fatores de Risco , Triagem
3.
Ir J Med Sci ; 191(2): 589-595, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33743160

RESUMO

BACKGROUND: The SARS-CoV-2 pandemic and government-enforced restrictions have impacted medical practices. AIMS: The aim of our study was to investigate the impact SARS-CoV-2 and public health restrictions had on trauma presentations to a regional paediatric emergency service. METHODS: We carried out a multisite retrospective longitudinal study of all paediatric ED attendances from 2018 including 13 March to 7 June 2020. This aligned with the initial government-enforced public health phases: delay phase, mitigation phase and reopening phase 1. RESULTS: There were 7975 total regional attendances during government-enforced restrictions. This represents 17.5% and 15.6% reductions in site attendances when compared with the two previous years. Regional attendances reduced by 52.5% in 2020 compared with 2018 and 50.9% compared with 2019. Following an initial reduction in injury attendances at the beginning of the 'lockdown' (p = 0.076), the number of injuries consistently grew as weeks progressed (p < 0.05), reaching a peak of 44.6% of all attendances. As restrictions eased, the most common location where injuries occurred moved to areas outside the home (p < 0.000). There was a significant change in injury type, final disposition and device-associated injury (p < 0.05). Wheeled recreational devices were associated with over 20% of all injuries by reopening phase 1. CONCLUSIONS: This study reveals that total attendances and total injuries reduced during initial phases of the lockdown. This was followed by a significant increase in injury presentations, which reached a peak of 44.6% of all attendances. We identified potential modifiable characteristics of paediatric trauma which can be addressed by future public health strategies.


Assuntos
COVID-19 , Saúde Pública , COVID-19/epidemiologia , Criança , Controle de Doenças Transmissíveis , Serviço Hospitalar de Emergência , Humanos , Irlanda/epidemiologia , Estudos Longitudinais , Estudos Retrospectivos , SARS-CoV-2
4.
J Child Orthop ; 15(3): 186-193, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34211594

RESUMO

PURPOSE: The aim of this paper is to describe our experience with a virtual fracture management pathway in the setting of a paediatric trauma service. METHODS: All patients referred to the virtual fracture clinic service from the Paediatric Emergency Department (PED) were prospectively collected. Outcome data of interest (patients discharged, referred for urgent operative treatment, referred back to emergency department for further evaluation, referred for face-to-face clinical assessment and all patients who re-presented on an unplanned basis for further management of the index injury) were compiled and collated. Cost analysis was performed using established costing for a virtual fracture clinic within the Irish Healthcare System. RESULTS: There were a total of 3961 patients referred to the virtual fracture clinic from the PED. Of these, 70% (n = 2776) were discharged. In all, 26% (n = 1033) were referred to a face-to-face appointment. Of discharged patients, 7.5% (n = 207) required an unplanned face-to-face evaluation. A total of 0.1% (n = 3) subsequently required operative treatment relating to their index injury. Implementation of the virtual fracture clinic model generated calculated savings of €254 120. CONCLUSION: This prospective evaluation has demonstrated that a virtual fracture clinic pathway for minor paediatric trauma is safe, effective and brings significant cost savings. LEVEL OF EVIDENCE: II.

5.
Injury ; 52(8): 2233-2243, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34083024

RESUMO

BACKGROUND: The construction of a new tertiary children's hospital and reconfiguration of its two satellite centres will become the Irish epicentre for all paediatric care including paediatric trauma. Ireland is also currently establishing a national trauma network although further planning of how to manage paediatric trauma in the context of this system is required. This research defines the unknown epidemiology of paediatric major trauma in Ireland to assist strategic planning of a future paediatric major trauma network. METHODS: Data from 1068 paediatric trauma cases was extracted from a longitudinal series of annual cross-sectional studies collected by the Trauma Audit and Research Network (TARN). All paediatric patients between the ages of 0-16 suffering AIS ≥2 injuries in Ireland between 2014-2018 were included. Demographics, injury patterns, hospital care processes and outcomes were analysed. RESULTS: Children were most commonly injured at home (45.1%) or in public places/roads (40.1%). The most frequent mechanisms of trauma were falls <2 m (36.8%) followed by RTAs (24.3%). Limb injuries followed by head injuries were the most often injured body parts. The proportion of head injuries in those aged <1 year is double that of any other age group. Only 21% of patients present directly to a children's hospital and 46% require transfer. Consultant-led emergency care is currently delivered to 41.5% of paediatric major trauma patients, there were 555 (48.2%) patients who required operative intervention and 22.8% who required critical care admission. A significant number of children in Ireland aged 1-5 years die from asphyxia/drowning. The overall mortality rate was 3.8% and was significantly associated with the presence of head injuries (p < 0.001). CONCLUSION: Paediatric Trauma represents a significant childhood burden of mortality and morbidity in Ireland. There are currently several sub-optimal elements of paediatric trauma service delivery that will benefit from the establishment of a trauma network. This research will help guide prevention strategy, policy-making and workforce planning during the establishment of an Irish paediatric trauma network and will act as a benchmark for future comparison studies after the network is implemented.


Assuntos
Traumatismos Craniocerebrais , Serviços Médicos de Emergência , Ferimentos e Lesões , Acidentes por Quedas , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Hospitalização , Humanos , Lactente , Recém-Nascido , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/terapia
6.
J Pediatr Orthop ; 41(4): 209-215, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33492040

RESUMO

BACKGROUND: The aim was to describe the introduction and operation of a virtual developmental dysplasia of the hip (DDH) clinic. Our secondary objectives were to provide an overview of DDH referral reasons, treatment outcomes, and adverse events associated with it. METHODS: A prospective observational study involving all patients referred to the virtual DDH clinic was conducted. The clinic consultant delivered with 2 DDH clinical nurse specialists (CNS). The outcomes following virtual review include further virtual review, CNS review, consultant review or discharge. Treatment options include surveillance, brace therapy, or surgery. Efficiency and cost analysis were assessed. RESULTS: Over the 3.5-year study period, 1002 patients were reviewed, of which 743 (74.2%) were female. The median age at time of referral was 7 months, (interquartile range of 5 to 11) with a median time to treatment decision of 9 days. Median waiting times from referral to treatment decision was reduced by over 70%. There were 639 virtual reviews, 186 CNS reviews, and 144 consultant reviews. The direct discharge rate was 24%. One hundred one patients (10%) had dislocated or subluxed hips at initial visit while 26.3% had radiographically normal hips. Over the study period 704 face to face (F2F) visits were avoided. Cost reductions of €170 were achieved per patient, with €588,804 achieved in total. Eighteen parents (1.8%) opted for F2F instead of virtual review. There were no unscheduled rereferrals or recorded adverse events. CONCLUSION: We report the outcomes of the first prospective virtual DDH clinic. This clinic has demonstrated efficiency and cost-effectiveness, without reported adverse outcomes to date. It is an option to provide consultant delivered DDH care, while reducing F2F consults. LEVEL OF EVIDENCE: Level III.


Assuntos
Assistência Ambulatorial/métodos , Luxação Congênita de Quadril/diagnóstico por imagem , Luxação Congênita de Quadril/terapia , Telemedicina/estatística & dados numéricos , Assistência Ambulatorial/economia , Assistência Ambulatorial/organização & administração , Braquetes , Redução de Custos/estatística & dados numéricos , Feminino , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Lactente , Masculino , Enfermeiros Clínicos/organização & administração , Visita a Consultório Médico/economia , Visita a Consultório Médico/estatística & dados numéricos , Alta do Paciente/estatística & dados numéricos , Estudos Prospectivos , Encaminhamento e Consulta/estatística & dados numéricos , Telemedicina/economia , Telemedicina/organização & administração , Tempo para o Tratamento , Resultado do Tratamento , Conduta Expectante
7.
BMJ Case Rep ; 13(11)2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33257361

RESUMO

A 7-year-old boy presented with a 1-week history of a limp, low grade temperature and mildly elevated inflammatory markers. He sustained a fall 2 weeks ago but was relatively symptom free for a week. The inital physical exam demonstrated a knee effusion clinically, radiographs did not demonstrate any overt pathology and biochemical testing demonstrated an elevated C reactive protein of 8 mg/L. An arthroscopy was conducted, with a plan for synovial biopsies to investigate for infective versus inflammatory arthritis as a cause for the effusion. An isolated lateral meniscal tear was discovered. This was repaired using all inside technique with Smith and Nephew's FastFix 360 (R) suture anchors. It is quite uncommon to find isolated lateral meniscus tears in this population, but the learning point demonstrates it is important to arthroscopically examine the whole knee, even while performing synovial biopsies as there may be unexpected findings.


Assuntos
Artrite Infecciosa/diagnóstico , Lesões do Menisco Tibial/diagnóstico , Artroscopia , Criança , Diagnóstico Diferencial , Humanos , Masculino , Lesões do Menisco Tibial/cirurgia
8.
Cureus ; 12(3): e7416, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32337140

RESUMO

Triplane fractures of the distal femur in paediatric populations are extremely rare. Only three cases of paediatric triplane fractures of the distal femur are described in the literature. Our aim is to add to the scant literature on triplane fractures of the distal femur in the paediatric population. The majority of trauma and orthopaedic surgeons are not expected to come across this injury throughout their careers. A CT is recommended to plan surgery, and subsequent follow up is crucial to provide the child with the best possible outcome. In particular, follow up is important to monitor for any abnormal growth or deformities.

9.
Ir J Med Sci ; 189(1): 27-31, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31129868

RESUMO

BACKGROUND: We describe the first radiographic clinic in the literature for DDH and how this novel clinic can significantly improve the efficiency and cost-effectiveness of service in a tertiary referral centre. AIMS: A radiographic clinic for the management of developmental dysplasia of the hip was introduced in 2017 in our institution. We performed a detailed cost analysis to assess the economic savings made with the introduction of this new clinic. We assessed the efficiency of the service by identifying how many unnecessary outpatient visits were prevented. We also assessed the difference in times from referral to review between the two clinics. METHODS: Analysis of the clinic activity in 2017 was possible as all data was collected prospectively by the DDH CNS and stored in our database. Cost analysis was performed, and the savings made per patient along with the financial benefit to our institution was recorded. RESULTS: The new radiographic clinic reduced the cost of reviewing one patient by €162.51 per patient. There was a 73% discharge rate from the clinic which prevented 251 unnecessary patient visits to the outpatient department over the course of the year. There was a significant 11-day reduction in waiting times between referral and review when comparing the radiographic to the conventional clinic (p < 0.05). CONCLUSIONS: A radiographic clinic for the management of developmental dysplasia of the hip has a significant effect on the efficiency and overall cost-effectiveness of service provision in a tertiary referral centre.


Assuntos
Luxação Congênita de Quadril/radioterapia , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
10.
Front Biosci (Landmark Ed) ; 23(7): 1370-1379, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29293439

RESUMO

Parkinson's disease (PD) is primarily considered to be a progressive degenerative motor disease associated with the degeneration of striatal dopamine neurons. However, increasing evidence has suggested progressive cognitive and psychiatric changes as well. Forty-six patients with PD, ranging in severity from Hoehn and Yahr (H-Y) score of 1:4, were recruited from a clinic specializing in PD. Various cognitive and neuropsychological measures were used to discover if there were indeed differences due to the progression of PD. As H-Y stage significantly increased, so did age and levodopa equivalency dose of medications, both independent of one another. Years of education had a significant negative relationship with H-Y score. Measures of general cognition divulged a significant decrease as H-Y score increased. Finally, as H-Y score increased, magical ideation decreased, and religious group social support increased. Mechanistically, the significant cognitive decline occurring with H-Y staging may be linked to a reduced dopaminergic function. Significant cognitive and neuropsychological changes are associated with the progression of PD and its possible relationship to Reward Deficiency Syndrome (RDS).


Assuntos
Cognição/fisiologia , Testes Neuropsicológicos/estatística & dados numéricos , Doença de Parkinson/fisiopatologia , Doença de Parkinson/psicologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antiparkinsonianos/uso terapêutico , Progressão da Doença , Escolaridade , Feminino , Humanos , Levodopa/uso terapêutico , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico
11.
Soft Matter ; 13(39): 7141-7153, 2017 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-28872644

RESUMO

We investigate the fluid structure and self-assembly of a system of Janus dumbbells by means of aggregation-volume-bias Monte Carlo simulations and Simulated Annealing techniques. In our approach, Janus dumbbells model asymmetric colloidal particles constituted by two tangent (touching) spheres (labelled as h and s) of different sizes and interaction properties: specifically, the h spheres interact with all other spheres belonging to different dumbbells via hard-sphere potentials, whereas two s spheres interact via a square-well potential. By introducing a parameter α ∈ [0,2] that controls the size ratio between the h and s spheres, we are able to investigate the overall phase behaviour of Janus dumbbells as a function of α. In a previous paper (O'Toole et al., Soft Matter, 2017, 13, 803) we focused on the region where the s sphere is larger than the h sphere (α > 1), documenting the presence of a variety of phase behaviours. Here we investigate a different regime of size ratios, predominantly where the hard sphere is larger than (or comparable to) the attractive one. Under these conditions, we observe the onset of many different self-assembled super-structures. Depending on the specific value of α we document the presence of spherical clusters (micelles) progressively evolving into more exotic structures including platelets, filaments, networks and percolating fluids, sponge structures and lamellar phases. We find no evidence of a gas-liquid phase separation for α ≤ 1.1, since under these conditions it is pre-empted by the development of self-assembled phases.

12.
J Pediatr Orthop ; 37(5): e326-e328, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28346328

RESUMO

BACKGROUND: Tibial pseudoarthrosis is a source of considerable morbidity in children with neurofibromatosis. Preventing the progression of anterolateral bowing of the tibia (ALBT) to tibial pseudoarthrosis is difficult. The aim of this paper is to report the successful use of guided growth to prevent tibial pseudoarthrosis in a child with neurofibromatosis. METHODS: With local ethical approval, we reviewed the case notes and radiographs of a child with pronounced ALBT who was treated with guided growth to correct the deformity and prevent fracture. RESULTS: At 4-year follow-up guided growth has successfully corrected the deformity and prevented tibial pseudoarthrosis. CONCLUSIONS: This is the first report of the use of guided growth to prevent the progression of ALBT to pseudoarthrosis of the tibia in a child with neurofibromatosis. LEVEL OF EVIDENCE: Level IV.


Assuntos
Alongamento Ósseo/instrumentação , Genu Varum/cirurgia , Neurofibromatose 1/cirurgia , Pseudoartrose/prevenção & controle , Tíbia/anormalidades , Placas Ósseas , Pré-Escolar , Progressão da Doença , Feminino , Genu Varum/diagnóstico por imagem , Humanos , Neurofibromatose 1/diagnóstico por imagem , Aparelhos Ortopédicos , Radiografia , Tíbia/diagnóstico por imagem
13.
Brain Dev ; 39(6): 470-474, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28189272

RESUMO

Alice in Wonderland Syndrome was originally coined by Dr. John Todd in 1955. The syndrome is named after the sensations experienced by the character Alice in Lewis Carroll's novel Alice's Adventures in Wonderland. Alice in Wonderland Syndrome consists of metamorphopsia (seeing something in a distorted fashion), bizarre distortions of their body image, and bizarre perceptual distortions of form, size, movement or color. Additionally, patients with Alice in Wonderland Syndrome can experience auditory hallucinations and changes in their perception of time. Currently, there is no known specific cause of Alice in Wonderland Syndrome. However, theories point to infections such as the Epstein-Barr virus, medications such as topiramate and associated migraines. Neuroimaging studies have revealed brain regions involved with the manifestation of symptoms. These include the temporo-parietal junction within the temporal lobe and the visual pathway, specifically the occipital lobe. There are no current treatments for Alice in Wonderland Syndrome. Further research is needed to find better treatments for Alice in Wonderland Syndrome and to elucidate the exact cause or causes of Alice in Wonderland Syndrome.


Assuntos
Síndrome de Alice no País das Maravilhas/complicações , Síndrome de Alice no País das Maravilhas/diagnóstico , Alucinações/complicações , Medicina na Literatura , Transtornos de Enxaqueca/complicações , Síndrome de Alice no País das Maravilhas/história , História do Século XX , Humanos , Ilusões/fisiologia
14.
Brain Behav ; 7(1): e00590, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28127512

RESUMO

BACKGROUND: Parkinson's disease (PD) usually emerges with a unilateral side-of-onset (left-onset: LOPD; right-onset: ROPD; Marinus & van Hilten, 2015) due to an asymmetrical degeneration of striatal dopaminergic neurons (Donnemiller et al., Brain, 135, 2012, 3348). This has led to a body of research exploring the cognitive, neuropsychological, and clinical differences between LOPD and ROPD (e.g., Verreyt et al., Neuropsychology Review, 21, 2011, 405). METHODS: Thirty ROPD and 14 LOPD cases were drawn from a Boston clinic specializing in PD. Various cognitive and neuropsychological measures were used in an attempt to discover if there were indeed any differences between LOPD and ROPD in this cohort. RESULTS: For LOPD, duration of illness was found to be significantly greater than that of ROPD. However, further testing was able to confirm that despite this difference, it was not the cause of the other significant differences found. Furthermore, this increased duration was consistent with a previous study (Munhoz et al., Parkinsonism and Related Disorders, 19, 2013, 77). Performance on the Digit Span Backward (DSB) was found to be significantly poorer in LOPD than ROPD, suggesting compromised executive function in LOPD. Additionally, LOPD had significantly greater anxiety on the DASS Anxiety scales than ROPD. However, unlike Foster et al (Cognitive and Behavioral Neurology, 23, 2010, 4), this increased anxiety could not account for the poorer performance on the DSB for LOPD. Finally, ROPD had significantly greater magical ideation than LOPD, which can be explained by the theory put forth by Brugger and Graves (European Archives of Psychiatry, 247, 1997, 55). CONCLUSION: Clear and significant differences between LOPD and ROPD were found within our cohort. LOPD showed greater impairment of working memory, greater anxiety, and greater duration of illness-all independent of one another; whereas, those with ROPD had greater magical ideation, also independent of any other variables.


Assuntos
Ansiedade/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Função Executiva/fisiologia , Memória de Curto Prazo/fisiologia , Doença de Parkinson/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/etiologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/complicações
15.
Soft Matter ; 13(4): 803-813, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28058439

RESUMO

Using aggregation-volume-bias Monte Carlo simulations along with successive umbrella sampling and histogram re-weighting, we study the phase diagram of a system of dumbbells formed by two touching spheres having variable sizes, as well as different interaction properties. The first sphere (h) interacts with all other spheres belonging to different dumbbells with a hard-sphere potential. The second sphere (s) interacts via a square-well interaction with other s spheres belonging to different dumbbells and with a hard-sphere potential with all remaining h spheres. We focus on the region where the s sphere is larger than the h sphere, as measured by a parameter 1 ≤ α ≤ 2 controlling the relative size of the two spheres. As α → 2 a simple fluid of square-well spheres is recovered, whereas α → 1 corresponds to the Janus dumbbell limit, where the h and s spheres have equal sizes. Many phase diagrams falling into three classes are observed, depending on the value of α. The 1.8 ≤ α ≤ 2 is dominated by a gas-liquid phase separation very similar to that of a pure square-well fluid with varied critical temperature and density. When 1.3 ≤ α ≤ 1.8 we find a progressive destabilization of the gas-liquid phase diagram by the onset of self-assembled structures, that eventually lead to a metastability of the gas-liquid transition below α = 1.2.

16.
J Pediatr Orthop B ; 26(4): 362-369, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27832013

RESUMO

Intraoperative radiographic guidance has traditionally been utilized in orthopedic surgery through 2-D navigation with the C-arm and recently with 3-D navigation with the O-arm. The aim of this study was to describe the outcome of surgical treatment of spinal osteoblastoma and osteoid osteoma with the utilization of the O-arm and conventional C-arm guidance. This is a retrospective cohort study of patients with spinal osteoid osteoma and or osteoblastoma who were treated at our institution between 2002 and 2011. Seventeen patients were examined in this study including seven with spinal osteoblastoma and 10 with spinal osteoid osteoma. The mean age of the patients at surgery was 11.5±3.9 years. The O-arm was used in seven patients and the C-arm in 10 patients. The C-arm failed to identify the tumor in one case and needed transport to perform a computed tomographic-scan. The length of surgery was shorter when the O-arm was used, especially in the osteoblastoma group. Thirteen patients were pain free at the last follow-up visit and two patients developed recurrence. Radiographs at the last follow-up did not show signs of vertebral instability following tumor resection. Safe and effective localization of spine tumors and confirmation of tumor removal during surgery was achieved by intraoperative radiographic guidance specifically with the O-arm 3-D navigation system. LEVEL OF EVIDENCE: III.


Assuntos
Osteoblastoma/cirurgia , Osteoma Osteoide/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Cirurgia Assistida por Computador/instrumentação , Adolescente , Criança , Feminino , Humanos , Masculino , Osteoblastoma/diagnóstico por imagem , Osteoblastoma/patologia , Osteoma Osteoide/diagnóstico por imagem , Osteoma Osteoide/patologia , Radiografia , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/patologia , Cirurgia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X
17.
J Arthroplasty ; 31(1): 7-10, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26304510

RESUMO

Total joint arthroplasties (TJAs) are projected to increase, along with increased complications like periprosthetic joint infections (PJIs). However, no study has projected TJAs secondary to PJI and how these relate to comorbidities in these patients. The NIS database was assessed from 1993 to 2000 to evaluate primary and revision TJAs, and projections were made until 2028. ICD-9 codes were used to identify patients with obesity, diabetes, and PJI. Rates of diabetes and adult obesity are predicted to increase for both genders, and patients receiving revision surgery for PJI are predicted to increase over time; males had higher rates than females. With an exponential increase of PJI secondary to diabetes and obesity, it is imperative that orthopedists intervene in these patients prior to TJA to decrease PJI's burden.


Assuntos
Artroplastia de Substituição/estatística & dados numéricos , Complicações do Diabetes/complicações , Prótese Articular/efeitos adversos , Obesidade/complicações , Infecções Relacionadas à Prótese/epidemiologia , Artrite Infecciosa/etiologia , Artrite Infecciosa/cirurgia , Artroplastia de Substituição/efeitos adversos , Comorbidade , Diabetes Mellitus , Feminino , Previsões , Humanos , Masculino , Infecções Relacionadas à Prótese/etiologia , Reoperação/efeitos adversos , Estados Unidos/epidemiologia
19.
Arthrosc Tech ; 3(3): e335-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25126498

RESUMO

Pediatric and adolescent anterior cruciate ligament reconstruction is a commonly performed procedure that has been increasing in incidence. Multiple techniques for graft fixation have been described. Button-based femoral cortical suspension fixation of the anterior cruciate ligament graft allows for fast, secure fixation with strong load-to-failure biomechanical properties. The biomechanical properties of button-based femoral cortical suspension fixation are especially beneficial with soft-tissue grafts such as hamstring autografts. Confirmation of a successfully flipped button can be achieved with intraoperative fluoroscopy or indirect viewing; however, these techniques do not provide direct visualization of the flipped button. Our trans-iliotibial band endoscopic portal allows the surgeon to safely and directly visualize the flipped button on the lateral femoral cortex and ensure that there is no malpositioning in the form of an incompletely flipped button or from soft-tissue interposition between the button and the lateral femoral cortex. This portal therefore allows for direct visual confirmation that the button is fully flipped and resting flush against the femoral cortex, deep to the iliotibial band and vastus lateralis.

20.
Soft Matter ; 10(29): 5269-79, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24894703

RESUMO

We numerically investigate colloidal dimers with asymmetric interaction strengths to study how the interplay between molecular geometry, excluded volume effects and attractive forces determines the overall phase behavior of such systems. Specifically, our model is constituted by two rigidly-connected tangent hard spheres interacting with other particles in the first instance via identical square-well attractions. Then, one of the square-well interactions is progressively weakened, until only the corresponding bare hard-core repulsion survives, giving rise to a "Janus dumbbell" model. We investigate structure, thermodynamics and phase behavior of the model by means of successive umbrella sampling and Monte Carlo simulations. In most of the cases, the system behaves as a standard simple fluid, characterized by a gas-liquid phase separation, for sufficiently low temperatures. In these conditions we observe a remarkable linear scaling of the critical temperature as a function of the interaction strength. But, as the interaction potential approaches the Janus dumbbell limit, we observe the spontaneous formation of self-assembled lamellar structures, preempting the gas-liquid phase separation. Comparison with previous studies allows us to pinpoint the role of the interaction range in controlling the onset of ordered structures and the competition between the formation of these structures and gas-liquid condensation.

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