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PURPOSE: Ulnar variance (UV) is a radiographic measurement relating the articular surface heights of the distal radius and ulna. Abnormal UV increases the risk for wrist pathology; however, it only provides a static measurement of an inherently dynamic bony relationship that changes with wrist position and loading. The purpose of this study was to investigate how full-body weight-bearing affects UV using weight-bearing computed tomography (WBCT). METHODS: Ten gymnasts completed two 45-second scans inside a WBCT machine while performing a handstand on a flat platform (H) and parallettes (P). A non-weight-bearing CT scan was collected to match clinical practice (N). Differences in UV between weight-bearing conditions were evaluated separately for dominant and nondominant sides, and then, UV was compared between weight-bearing conditions on pooled dominant/nondominant data. RESULTS: Pooled analyses comparing weight-bearing conditions revealed a significant increase in UV for H versus N (0.58 mm) and P versus N (1.00 mm), but no significant change in UV for H versus P (0.43 mm). Significant differences in UV were detected for H versus N, P versus N, and H versus P for dominant and nondominant extremities. The change from N to H was significantly greater in the dominant versus nondominant side, but greater in the nondominant side from N to P. CONCLUSIONS: Ulnar variance changed with the application of load and position of the wrist. Differences in UV were found between dominant and nondominant extremities. CLINICAL RELEVANCE: Upper extremity loading patterns are affected by hand dominance as defined by a cartwheel and suggest skeletal consequences from repetitive load on a dominantly used wrist. Although statistically significant, subtle changes detected in this investigational study do not necessarily bear clinical significance. Future WBCT research can lead to improved diagnostic measures for wrist pathologies affected by active loading and rotational wrist behavior.
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To increase the repertoire of PCR based laboratory developed tests (LDTs) for the detection of SARS-CoV-2, we describe a new multiplex assay (SORP), targeting the SARS-CoV-2's, Spike and ORF8 genes. The widely used human RNaseP internal control was modified to specifically co-amplify the RNaseP mRNA. The SORP triplex assay was tested on a cohort (n = 372; POS = 144/NEG = 228) of nasopharyngeal flocked swab (NPFS) specimens, previously tested for the presence of SARS-CoV-2 using a PCR assay targeting E and RdRp genes. The overall sensitivity and specificity of the SORP assay was: 99.31% (95% CI: 96.22-99.98%), 100.0% (95% CI: 98.4-100%) respectively. The SORP assay could also detect a panel of variants of concern (VOC) from the B1.1.7 (UK) and B1.351 (SA) lineage. In summary, access to a repertoire of new SARS-CoV-2 LDT's would assist diagnostic laboratories in developing strategies to overcome some of the testing issues encountered during high-throughput SARS-CoV-2 testing.
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Teste para COVID-19/métodos , COVID-19/diagnóstico , Técnicas de Laboratório Clínico/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/genética , COVID-19/virologia , Primers do DNA/genética , Sondas de DNA/genética , Humanos , Técnicas de Diagnóstico Molecular/métodos , Reprodutibilidade dos Testes , Ribonuclease P/genética , SARS-CoV-2/fisiologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/genética , Proteínas Virais/genéticaRESUMO
The larval stage of invasive Dreissena spp. mussels (i.e., veligers) are understudied despite their seasonal numerical dominance among plankton. We report the spring and summer veliger densities and size structure across the main basin, North Channel, and Georgian Bay of Lake Huron, and seek to explain spatiotemporal variation. Monthly sampling was conducted at 9 transects and up to 3 sites per transect from spring through summer 2017. Veliger densities peaked in June and July, and we found comparable densities and biomasses of veligers between basins, despite differences in density of juvenile and adult mussels across these regions. Using a generalized additive model to explain variations in veliger density, we found that temperature, chlorophyll a, and nitrates/nitrites were most important. We generated an index of veliger attrition based on size distributions that revealed a higher rate of attrition in the North Channel than the rest of the lake. A logistic model indicated a threshold calcium concentration of around 22 mg/L was necessary for veligers to survive to larger sizes and recruit to their juvenile and benthic adult life stages. Improved understanding of factors that regulate the production and survival of Dreissena veligers will improve the ability of managers to assess future invasion threats as well as explore potential control options.
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There is some uncertainty about pathological grading of mucinous colorectal adenocarcinoma, defined as colorectal cancer demonstrating at least 50% mucinous differentiation. Under the WHO 2000 classification mucinous colorectal cancer was considered high grade. However under the current WHO 2010 classification microsatellite unstable/mismatch repair-deficient (MSI/MMRd) mucinous colorectal cancer is considered low grade, whereas microsatellite stable/mismatch repair proficient (MSS/MMRp) tumours are high grade. However there is little empirical evidence for this approach. We therefore compared the long term survival of patients with MSI/MMRd vs MSS/MMRp mucinous colorectal cancer in a large unselected cohort of patients undergoing surgery at our institution from 1998 to 2011. There were 2608 patients in the cohort, of which 264 (10.1%) were mucinous. 95 (36%) of the mucinous tumours were microsatellite unstable. The all-cause 5-year survival of mucinous MSI/MMRd colorectal cancer was similar to that of non-mucinous low-grade colorectal cancer (73 vs 67%, P=0.368), and significantly better than that of both non-mucinous high-grade (73 vs 53%, P<0.001) and mucinous MSS/MMRp colorectal cancer (73 vs 57%, P=0.023). The 5-year survival of mucinous MSS/MMRp colorectal cancer was slightly better than that of non-mucinous high-grade patients (57 vs 53%, P=0.027), but significantly worse than that of non-mucinous low-grade colorectal cancer (57 vs 67%, P=0.018). In multivariate Cox regression analysis, conventional histological grade based on glandular differentiation maintained prognostic significance (P=0.003) whereas MSI/MMRd status just failed to be statistically significant (P=0.062). Our findings support the WHO 2010 approach that as a group mucinous MSS/MMRp colorectal cancers are biologically aggressive. However, grading based exclusively on MSI/MMR status may be overly simplistic as conventional grading based on the degree of glandular differentiation still holds greater prognostic significance in multivariate analysis.
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Adenocarcinoma Mucinoso/patologia , Neoplasias Colorretais/patologia , Distúrbios no Reparo do DNA/mortalidade , Gradação de Tumores/métodos , Adenocarcinoma Mucinoso/classificação , Adenocarcinoma Mucinoso/mortalidade , Idoso , Neoplasias Colorretais/classificação , Neoplasias Colorretais/mortalidade , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Análise Serial de TecidosRESUMO
Although most mesotheliomas present with pleural effusions, it is controversial whether mesothelioma can be diagnosed with confidence in effusion cytology. Therefore, an ancillary marker of malignant mesothelial cells applicable in effusions would be clinically valuable. BRCA-1-associated protein (BAP1) is a tumor suppressor gene, which shows biallelic inactivation in approximately half of all mesotheliomas. We investigated whether loss of BAP1 expression by immunohistochemistry can be used to support a diagnosis of mesothelioma in effusion cytology. Immunohistochemistry for BAP1 was performed on cell blocks and interpreted blinded. 43 of 75 (57%) effusions associated with confirmed mesothelioma showed negative staining with positive internal controls. Of 57 effusions considered to have atypical mesothelial cells in the absence of a definitive diagnosis of mesothelioma, 8 cases demonstrated negative staining for BAP1. On follow-up six of these patients received a definitive diagnosis of mesothelioma in the subsequent 14 months (two were lost to follow-up immediately, and mesothelioma could not be excluded). Only 5 of 100 consecutive benign effusions were interpreted as BAP1 negative. One of these patients died soon after and mesothelioma could not be excluded. On unblinded review the four other patients with apparently negative BAP1 staining but no malignancy lacked convincing positive staining in non-neoplastic cells suggesting that BAP1 immunohistochemistry may have initially been misinterpreted. 47 effusions with adenocarcinoma were BAP1 positive. We conclude that loss of BAP1 expression, while not definitive, can be used to support the diagnosis of mesothelioma in effusion cytology. We caution that interpretation of BAP1 immunohistochemistry on cell block may be difficult and that convincing positive staining in non-neoplastic cells is required before atypical cells are considered negative. We also note that BAP1 loss is not a sensitive test as it occurs in only half of all mesotheliomas and cannot be used to exclude the diagnosis.
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Biomarcadores Tumorais/análise , Mesotelioma/diagnóstico , Derrame Pleural Maligno/etiologia , Neoplasias Pleurais/diagnóstico , Proteínas Supressoras de Tumor/biossíntese , Ubiquitina Tiolesterase/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Citodiagnóstico/métodos , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Derrame Pleural Maligno/diagnóstico , Proteínas Supressoras de Tumor/análise , Ubiquitina Tiolesterase/análise , Adulto JovemRESUMO
AIM: Medullary carcinoma is a recently described subtype of mismatch repair deficient (MMRd) colorectal carcinoma (CRC) which, despite being poorly differentiated by traditional morphological criteria, has been reported to have a good prognosis. We investigated the pathological and clinical features of medullary CRC in an unselected cohort of CRCs undergoing surgical resection. METHODS: All CRCs resected within a single health district database from 1998 to 2012 were categorized prospectively and underwent retrospective review to identify 91 medullary CRCs, with 11 additional cases from 2013 to 2014. Strict criteria were employed to diagnose medullary carcinoma requiring both MMRd and greater than 90 % of the tumor to demonstrate typical morphology, including solid growth. The demographic and pathological features, as well as all-cause survival, were compared with other CRCs, and specifically to other MMRd CRCs. RESULTS: From 1998 to 2012, 91 of 3,295 CRCs (2.8 %) were of the medullary type. Medullary CRC was more likely to arise in females than males (3.3:1; p < 0.0001), the elderly (mean age 77 vs. 71 years; p < 0.001), and the right colon (86 %; p < 0.0001). All medullary CRCs demonstrated MMR deficiency (considered an inclusion criteria) and 86 % were BRAFV600E-mutated (p < 0.0001). Thirty-day mortality after resection was higher in medullary CRC (4.6 vs. 1.7 %; p = 0.049). On univariate analysis, survival was not better than well-differentiated or other MMRd tumors. However, using a multivariate model, a medullary phenotype was protective (hazard ratio of death 0.54, 95 % CI 0.30-0.96; p = 0.037). CONCLUSIONS: Medullary CRC is more common than previously reported, frequently presents with locally advanced disease, and may be associated with higher mortality at 30 days after resection. Despite this, when strict criteria are used for diagnosis, the overall survival is favorable when compared with CRCs with equivalent demographic and pathological characteristics.
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Adenocarcinoma/patologia , Carcinoma Medular/patologia , Neoplasias Colorretais/patologia , Adenocarcinoma/mortalidade , Idoso , Idoso de 80 Anos ou mais , Carcinoma Medular/mortalidade , Neoplasias Colorretais/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Objective: Serious mental illness (SMI) remains a leading cause of disability worldwide. However, there is limited Australian evidence of community-based programs to enhance the psychosocial wellbeing of adults experiencing SMI. Foundations is a long-term community-based psychosocial outreach support program delivered in Tasmania, Australia. A longitudinal non-randomised controlled trial was conducted to examine the effectiveness of the Foundations program on adults' psychosocial functioning, clinical symptomology, and hospital readmissions, in comparison to standard care only. Method: Participants were adults aged 18-64 years experiencing SMI. Control participants received standard clinical care only. Intervention participants were engaged in the Foundations program in addition to standard care. Data were collected at program commencement, midpoint, closure, and six-months post-closure. Linear mixed modelling was used to examine differences between groups. Results: Intervention participants achieved better psychosocial functioning in comparison to the control group by program closure and at six-month follow-up. No significant differences were observed for clinical mental health symptomology or hospital readmission rates. Length of readmission stay was significantly shorter for intervention participants. Conclusions: The findings highlight the additional value of community-based, recovery-oriented, psychosocial outreach support alongside clinical mental health care to enhance the psychosocial wellbeing of adults experiencing SMI.
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Transtornos Mentais , Readmissão do Paciente , Humanos , Adulto , Masculino , Feminino , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Readmissão do Paciente/estatística & dados numéricos , Estudos Longitudinais , Tasmânia , Serviços Comunitários de Saúde Mental , Avaliação de Programas e Projetos de Saúde , Funcionamento PsicossocialRESUMO
Recreational sedentary screen time (rSST) is the most prevalent sedentary behavior for adults outside of work, school, and sleep, and is strongly linked to poor health. StandUPTV is a mHealth trial that uses the Multiphase Optimization Strategy (MOST) framework to develop and evaluate the efficacy of three theory-based strategies for reducing rSST among adults. This paper describes the preparation and optimization phases of StandUPTV within the MOST framework. We identified three candidate components based on previous literature: (a) rSST electronic lockout (LOCKOUT), which restricts rSST through electronic means; (b) adaptive prompts (TEXT), which provides adaptive prompts based on rSST behaviors; and (c) earning rSST through increased moderate-vigorous physical activity (MVPA) participation (EARN). We also describe the mHealth iterative design process and the selection of an optimization objective. Finally, we describe the protocol of the optimization randomized controlled trial using a 23 factorial experimental design. We will enroll 240 individuals aged 23-64 y who engage in >3 h/day of rSST. All participants will receive a target to reduce rSST by 50% and be randomized to one of 8 combinations representing all components and component levels: LOCKOUT (yes vs. no), TEXT (yes vs. no), and EARN (yes vs. no). Results will support the selection of the components for the intervention package that meet the optimization objective and are acceptable to participants. The optimized intervention will be tested in a future evaluation randomized trial to examine reductions in rSST on health outcomes among adults.
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Comportamento Sedentário , Telemedicina , Adulto , Humanos , Projetos de Pesquisa , Tempo de Tela , Adulto Jovem , Pessoa de Meia-IdadeRESUMO
The purpose of this study was to compare strength, bulk and time of repair of human cadaveric flexor digitorum profundus tendons repaired in situ versus ex situ. Ninety-six human cadaveric flexor digitorum profundus tendons were transected 5 mm distal to the A2-pulley and randomized to 2-strand, 4-strand or 6-strand repairs. We found no significant differences in repair strength between in situ and ex situ repairs, but repair strength increased with increasing number of strands. The cross-sectional area of the repair was not significantly related to the number of strands, but 4- and 6-strand in situ repairs were bulkier than ex situ repairs. In situ repair took longer, and repair time increased with increasing number of strands. We suggest that cadaveric studies of flexor tendon repair should be performed in situ in order to better mimic the clinical reality of tissue handling and repair bulkiness.
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Traumatismos dos Tendões , Humanos , Traumatismos dos Tendões/cirurgia , Técnicas de Sutura , Tendões/cirurgia , Mãos/cirurgia , Cadáver , Fenômenos Biomecânicos , Resistência à Tração , SuturasRESUMO
As part of the COVID-19 pandemic, clinical laboratories have been faced with massive increases in testing, resulting in sample collection systems, reagent, and staff shortages. We utilized self-collected saline gargle samples to optimize high throughput SARS-CoV-2 multiplex polymerase chain reaction (PCR) testing in order to minimize cost and technologist time. This was achieved through elimination of nucleic acid extraction and automation of sample handling on a widely available robotic liquid handler, Hamilton STARlet. A customized barcode scanning script for reading the sample ID by the Hamilton STARlet's software system was developed to allow primary tube sampling. Use of pre-frozen SARS-CoV-2 assay reaction mixtures reduced assay setup time. In both validation and live testing, the assay produced no false positive or false negative results. Of the 1060 samples tested during validation, 3.6% (39/1060) of samples required retesting as they were either single gene positive, had internal control failure or liquid aspiration error. Although the overall turnaround time was only slightly faster in the automated workflow (185 min vs 200 min), there was a 76% reduction in hands-on time, potentially reducing staff fatigue and burnout. This described process from sample self-collection to automated direct PCR testing significantly reduces the total burden on healthcare systems in terms of human resources and reagent requirements.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Pandemias , Teste para COVID-19 , Manejo de Espécimes , Reação em Cadeia da Polimerase Multiplex , Sensibilidade e Especificidade , RNA Viral/análiseRESUMO
Children of problem gamblers are at risk of harm, however, there are no population level estimates as to how many children are currently exposed to parental problem- and at-risk gambling. The current study analysed data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey, a nationally representative survey, to derive the first ever national estimates of the proportion of problem, moderate, and low risk gamblers (as measured by PGSI) in the Australian parent population. It also reports how many children under 15 years of age in Australia are exposed to parental gambling across the gambling risk categories. The results show that 13.7% of all Australian families with dependent children are currently exposed to some level of gambling risk due to parental gambling, and nearly 4% of families with children are exposed to parental moderate risk or problem gambling. This corresponds to almost 200,000 children each year. The results and approach of this study will guide future examination of child wellbeing in families where parents experience problems with gambling. The results are discussed in the context of public health approaches to familial gambling harm.
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Jogo de Azar , Austrália/epidemiologia , Criança , Jogo de Azar/epidemiologia , Humanos , Pais , Assunção de Riscos , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: Adjacent-segment disease (ASD) proximal to lumbosacral fusion is assumed to result from increased stress and motion that extends above or below the fusion construct. Sublaminar bands (SBs) have been shown to potentially mitigate stresses in deformity constructs. A similar application of SBs in lumbar fusions is not well described yet may potentially mitigate against ASD. METHODS: Eight fresh-frozen human cadaveric spine specimens were instrumented with transforaminal lumbar interbody fusion (TLIF) cages at L3-4 and L4-5, and pedicle screws from L3 to S1. Bilateral SBs were applied at L2 and tightened around the rods extending above the L3 pedicle screws. After being mounted on a testing frame, the spines were loaded at L1 to 6 Nm in all 3 planes, i.e., flexion/extension, right and left lateral bending, and right and left axial rotation. Motion and intradiscal pressures (IDPs) at L2-3 were measured for 5 conditions: intact, instrumentation (L3-S1), band tension (BT) 30%, BT 50%, and BT 100%. RESULTS: There was significant increase in motion at L2-3 with L3-S1 instrumentation compared with the intact spine in flexion/extension (median 8.78°, range 4.07°-10.81°, vs median 7.27°, range 1.63°-9.66°; p = 0.016). When compared with instrumentation, BT 100% reduced motion at L2-3 in flexion/extension (median 8.78°, range 4.07°-10.81°, vs median 3.61°, range 1.11°-9.39°; p < 0.001) and lateral bending (median 6.58°, range 3.67°-8.59°, vs median 5.62°, range 3.28°-6.74°; p = 0.001). BT 50% reduced motion at L2-3 only in flexion/extension when compared with instrumentation (median 8.78°, range 4.07°-10.81°, vs median 5.91°, range 2.54°-10.59°; p = 0.027). There was no significant increase of motion at L1-2 with banding when compared with instrumentation, although an increase was seen from the intact spine with BT 100% in flexion/extension (median 5.14°, range 2.47°-9.73°, vs median 7.34°, range 4.22°-9.89°; p = 0.005). BT 100% significantly reduced IDP at L2-3 from 25.07 psi (range 2.41-48.08 psi) before tensioning to 19.46 psi (range -2.35 to 29.55 psi) after tensioning (p = 0.016). CONCLUSIONS: In this model, the addition of L2 SBs reduced motion and IDP at L2-3 after the L3-S1 instrumentation. There was no significant increase in motion at L1-2 in response to band tensioning compared with instrumentation alone. The application of SBs may have a clinical application in reducing the incidence of ASD.
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Fusão Vertebral , Humanos , Fenômenos Biomecânicos , Cadáver , Vértebras Lombares/cirurgia , Vértebras Lombares/fisiologia , Amplitude de Movimento Articular/fisiologia , RotaçãoRESUMO
An important aspect of an indefinite life household panel study is to provide a sample of children who become new generations of respondents over time. The representativity of children and young adults in the Household, Income and Labour Dynamics in Australia (HILDA) Survey is assessed after 16 waves. Estimates from the HILDA Survey are compared to official data sources of the Australian Bureau of Statistics (ABS) and include demographic, education, employment, income and residential mobility variables. Both cross-section and longitudinal estimates are assessed. Overall, the HILDA Survey estimates are relatively close to the ABS estimates with the exception of the year of arrival of recent immigrants, having foreign-born parents, having a certificate level qualification, type of relationship in household, having zero income, the main source of income, and residential mobility. Most of these exceptions can be explained by differences in questionnaire design, respondent recall error, linkage error, and differences in the amount of missing data. The estimate of particular concern is the proportion of immigrants arriving in the last five years, which is underestimated in the HILDA Survey due to undercoverage of recent immigrants. This could be addressed by regular refreshment samples of recent immigrants.
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Emprego , Renda , Austrália , Criança , Características da Família , Humanos , Inquéritos e Questionários , Adulto JovemRESUMO
Background: While there is discussion of increasing rates of mental disorders, epidemiological research finds little evidence of change over time. This research generally compares cross-sectional surveys conducted at different times. Declining response rates to representative surveys may mask increases in mental disorders and psychological distress. Methods: Analysis of data from two large nationally representative surveys: repeated cross-sectional data from the Australian National Health Survey (NHS) series (2001-2017), and longitudinal data (2007-2017) from the Household, Income and Labor Dynamics in Australia (HILDA) Survey. Data from each source was used to generate weighted national estimates of the prevalence of very high psychological distress using the Kessler Psychological Distress scale (K10). Results: Estimates of the prevalence of very high psychological distress from the NHS were stable between 2001 and 2014, with a modest increase in 2017. In contrast, the HILDA Survey data demonstrated an increasing trend over time, with the prevalence of very high distress rising from 4.8% in 2007 to 7.4% in 2017. This increase was present for both men and women, and was evident for younger and middle aged adults but not those aged 65 years or older. Sensitivity analyses showed that this increase was notable in the upper end of the K10 distribution. Conclusions: Using household panel data breaks the nexus between declining survey participation rates and time, and suggests the prevalence of very high psychological distress is increasing. The study identifies potential challenges in estimating trends in population mental health using repeated cross-sectional survey data.
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Emprego , Renda , Humanos , Características da Família , Austrália/epidemiologia , Inquéritos e QuestionáriosRESUMO
Background: Calcium phosphate materials have been employed clinically as bone void fillers for several decades. These materials are most often provided in the form of small, porous granules that can be packed to fill the wide variety of size and shape of bony defects encountered. ReBOSSIS-85 (RB-85) is a synthetic bioresorbable bone void filler for the repair of bone defects with handling characteristics of glass wool-like (or cotton ball-like). The objective of this study is to evaluate the in vivo performance of RB-85 (test material), compared to a commercially available bone void filler, Mastergraft Putty (predicate material), when combined with bone marrow aspirate and iliac crest autograft, in an established posterolateral spine fusion rabbit model. Methods: One hundred fifty skeletally mature rabbits had a single level posterolateral fusion performed. Rabbits were implanted with iliac crest bone graft (ICBG), Mastergraft Putty™ plus ICBG, or one of 4 masses of ReBOSSIS-85 (0.2, 0.3, 0.45, or 0.6 g) plus ICBG. Plain films were taken weekly until euthanasia. Following euthanasia at 4, 8, and 12 weeks, the lumbar spine were tested by manual palpation. Spinal columns in the 12 week group were also subjected to non-destructive flexibility testing. MicroCT and histology were performed on a subset of each implant group at each euthanasia period. Results: Radiographic scoring of the fusion sites indicated a normal healing response in all test groups. Bilateral radiographic fusion rates for all test groups were 0% at 4 weeks; ICBG 43%, Mastergraft Putty 50%, RB-85-0.2g 0%, RB-85-0.3g 13%, RB-85-0.45g 38%, and RB-85-0.6g 63% at 8 weeks; and ICBG 50%, Mastergraft Putty 50%, RB-85-0.2g 0%, RB-85-0.3g 25%, RB-85-0.45g 36%, and RB-85-0.6g 50% at 12 weeks.Spine fusion was assessed by manual palpation of the treated motion segments. At 12 weeks, ICBG, MGP, and RB-85-0.6g were fused mechanically in at least 50% of the rabbits. All groups demonstrated significantly less range of motion in both flexion/extension, lateral bending, and axial rotation compared to normal unfused controls.Histopathology analysis of the fusion masses, in all test groups, indicated an expected normal response of mild inflammation with macrophage and multinucleated giant cell response to the graft material at 4 weeks and resolving by 12 weeks. Regardless of test article, new bone formation and graft resorption increased from 4 to 12 weeks post-op. Conclusions: This animal study has demonstrated the biocompatibility and normal healing features associated with the ReBOSSIS-85 bone graft (test material) when combined with autograft as an extender. ReBOSSIS-85 was more effective when a larger mass of test article was used in this study. Clinical Relevance: ReBOSSIS-85 can be used as an extender negating the need for large amounts of local or iliac crest bone in posterolateral fusions.
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Substitutos Ósseos/uso terapêutico , Transplante Ósseo , Fosfatos de Cálcio/uso terapêutico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/uso terapêutico , Fusão Vertebral/métodos , Animais , Fenômenos Biomecânicos , Carbonato de Cálcio/uso terapêutico , Ílio/transplante , Vértebras Lombares/cirurgia , Masculino , Modelos Animais , CoelhosRESUMO
BACKGROUND: The decompressive hemicraniectomy operation is highly effective in relieving refractory intracranial hypertension. However, one limitation of this treatment strategy is the requirement to perform a subsequent cranioplasty operation to reconstruct the skull defect-an expensive procedure with high complication rates. An implant that is capable of accommodated post-hemicraniectomy brain swelling, but also provides acceptable skull defect coverage after brain swelling abates, would theoretically eliminate the need for the cranioplasty operation. In an earlier report, the concept of using a thin, moveable plate implant for this purpose was introduced. METHODS: Measurements were obtained in a series of stroke patients to determine whether a plate offset from the skull by 5 mm would accommodate the observed post-hemicraniectomy brain swelling. The volume of brain swelling measured in all patients in the stroke series would be accommodated by a 5-mm offset plate. In the current report, we expanded our analysis to study brain swelling patterns in a different population of patients requiring a hemicraniectomy operation: those with traumatic brain injuries (TBI). RESULTS: We identified 56 patients with TBI and measured their postoperative brain herniation volumes. A moveable plate offset by 5 mm would create sufficient additional volume to accommodate the brain swelling measured in all but one patient. That patient had malignant intraoperative brain swelling and died the following day. CONCLUSIONS: These data suggest that a 5 mm offset plate will provide sufficient volume for brain expansion for almost all hemicraniectomy operations.
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Edema Encefálico/diagnóstico por imagem , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/cirurgia , Craniectomia Descompressiva/tendências , Hipertensão Intracraniana/diagnóstico por imagem , Retalhos Cirúrgicos/tendências , Adulto , Idoso , Idoso de 80 Anos ou mais , Edema Encefálico/etiologia , Craniectomia Descompressiva/efeitos adversos , Humanos , Hipertensão Intracraniana/etiologia , Pessoa de Meia-Idade , Tamanho do Órgão , Retalhos Cirúrgicos/estatística & dados numéricos , Adulto JovemRESUMO
OBJECTIVEProximal junctional kyphosis (PJK) and failure (PJF) are potentially catastrophic complications that result from abrupt changes in stress across rigid instrumented and mobile non-fused segments of the spine (transition zone) after adult spinal deformity surgery. Recently, data have indicated that extension (widening) of the transitional zone via use of proximal junctional (PJ) semi-rigid fixation can mitigate this complication. To assess the biomechanical effectiveness of 3 semi-rigid fixation constructs (compared to pedicle screw fixation alone), the authors performed cadaveric studies that measured the extent of PJ motion and intradiscal pressure changes (ΔIDP).METHODSTo measure flexibility and ΔIDP at the PJ segments, moments in flexion, extension, lateral bending (LB), and torsion were conducted in 13 fresh-frozen human cadaveric specimens. Five testing cycles were conducted, including intact (INT), T10-L2 pedicle screw-rod fixation alone (PSF), supplemental hybrid T9 Mersilene tape insertion (MT), hybrid T9 sublaminar band insertion (SLB1), and hybrid T8/T9 sublaminar band insertion (SLB2).RESULTSCompared to PSF, SLB1 significantly reduced flexibility at the level rostral to the upper-instrumented vertebral level (UIV+1) under moments in 3 directions (flexion, LB, and torsion, p ≤ 0.01). SLB2 significantly reduced motion in all directions at UIV+1 (flexion, extension, LB, torsion, p < 0.05) and at UIV+2 (LB, torsion, p ≤ 0.03). MT only reduced flexibility in extension at UIV+1 (p = 0.02). All 3 constructs revealed significant reductions in ΔIDP at UIV+1 in flexion (MT, SLB1, SLB2, p ≤ 0.02) and torsion (MT, SLB1, SLB2, p ≤ 0.05), while SLB1 and SLB2 significantly reduced ΔIDP in extension (SLB1, SLB2, p ≤ 0.02) and SLB2 reduced ΔIDP in LB (p = 0.05). At UIV+2, SLB2 similarly significantly reduced ΔIDP in extension, LB, and torsion (p ≤ 0.05).CONCLUSIONSCompared to MT, the SLB1 and SLB2 constructs significantly reduced flexibility and ΔIDP in various directions through the application of robust anteroposterior force vectors at UIV+1 and UIV+2. These findings indicate that semi-rigid sublaminar banding can most effectively expand the transition zone and mitigate stresses at the PJ levels of long-segment thoracolumbar constructs.
Assuntos
Cifose/cirurgia , Vértebras Lombares/cirurgia , Complicações Pós-Operatórias/cirurgia , Vértebras Torácicas/cirurgia , Adulto , Idoso , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Parafusos Pediculares , Amplitude de Movimento Articular/fisiologia , Fatores de Risco , Fusão Vertebral/métodosRESUMO
BACKGROUND: This study aims to provide biomechanical data on the effect of patella height in the setting of medial patellofemoral ligament (MPFL) reconstruction using finite element analysis. The study will also examine patellofemoral joint biomechanics using variable femoral insertion sites for MPFL reconstruction. METHODS: A previously validated finite element knee model was modified to study patella alta and baja by translating the patella a given distance to achieve each patella height ratio. Additionally, the models were modified to study various femoral insertion sites of the MPFL (anatomic, anterior, proximal, and distal) for each patella height model, resulting in 32 unique scenarios available for investigation. RESULTS: In the setting of patella alta, the patellofemoral contact area decreased, resulting in a subsequent increase in maximum patellofemoral contact pressures as compared to the scenarios with normal patellar height. Additionally, patella alta resulted in decreased lateral restraining forces in the native knee scenario as well as following MPFL reconstruction. Changing femoral insertion sites had a variable effect on patellofemoral contact pressures; however, distal and anterior femoral tunnel malpositioning in the setting of patella alta resulted in grossly elevated maximum patellofemoral contact pressures as compared to other scenarios. CONCLUSIONS: Patella alta after MPFL reconstruction results in decreased lateral restraining forces and patellofemoral contact area and increased maximum patellofemoral contact pressures. When the femoral MPFL tunnel is malpositioned anteriorly or distally on the femur, the maximum patellofemoral contact pressures increase with severity of patella alta. CLINICAL RELEVANCE: When evaluating patients with patellofemoral instability, it is important to recognize patella alta as a potential aggravating factor. Failure to address patella alta in the setting of MPFL femoral tunnel malposition may result in even further increases in patellofemoral contact pressures, making it essential to optimize intraoperative techniques to confirm anatomic MPFL femoral tunnel positioning.
Assuntos
Instabilidade Articular/fisiopatologia , Modelos Anatômicos , Patela/fisiopatologia , Articulação Patelofemoral/fisiopatologia , Fenômenos Biomecânicos/fisiologia , Análise de Elementos Finitos , Humanos , Instabilidade Articular/cirurgia , Patela/cirurgia , Articulação Patelofemoral/cirurgiaRESUMO
INTRODUCTION: Spinal fusion surgery is an effective but costly treatment for select spinal pathology. Historically iliac crest bone graft (ICBG) has remained the gold standard for achieving successful arthrodesis. Given well-established morbidity autograft harvest, multiple bone graft replacements, void fillers, and extenders have been developed. The objective of this study was to evaluate the in vivo efficacy and safety of two mineralized collagen bone void filler materials similar in composition. Both bone void fillers were composed of hydroxyapatite (HA), tricalcium phosphate (TCP) and bovine collagen. The first test article (Bi-Ostetic bioactive glass foam or "45S5") also contained 45S5 bioactive glass particles while the second test article (Formagraft or "FG") did not. 45S5 and FG were combined with bone marrow aspirate and iliac crest autograft and compared to ICBG in an established posterolateral spine fusion rabbit model. MATERIALS AND METHODS: Sixty-nine mature New Zealand White rabbits were divided into 3 test cohorts: ICBG, 45S5, and FG. A Posterolateral fusion model previous validated was utilized to assess fusion efficacy. The test groups were evaluated for spine fusion rate, new bone formation, graft resorption and inflammatory response using radiographic, µCT, biomechanical and histological endpoints at 4, 8 and 12 weeks following implantation. RESULTS: There were 4 clinical complications unrelated to the graft materials and were evenly split between groups (ICBG graft harvest complications; hind limb mobility, chronic pain) and were euthanized. These omissions did not affect the overall outcome of the study. Radiographic scoring of the fusion sites indicated a normal healing response in all test groups, with no adverse reactions and similar progressions of new bone formation observed over time. All groups demonstrated significantly less range of motion in both flexion/extension and lateral bending compared to normal not-fused controls, which supports fusion results observed in the other endpoints. Fusion occurred earlier in the 45S5 group: ICBG 0%, FG 0%, and 45S5 20% at 4 weeks; ICBG 43%, FG 38%, and 45S5 50% at 8 weeks; and ICBG 50%, FG 56%, and 45S5 56% at 12 weeks. Histopathology analysis of the fusion masses, from each test article and time point, indicated an expected normal response for resorbable calcium phosphate (HA/TCP) and collagen graft material. Mild inflammation with macrophage and multinucleated giant cell response to the graft material was evident in all test groups. DISCUSSION: This study has confirmed the biocompatibility, safety, efficacy and bone healing characteristics of the HA-TCP collagen (with or without 45S5 bioactive glass) composites. The results show that the 3 test groups had equivalent long-term fusion performance and outcome at 12 weeks. However, the presence of 45S5 bioactive glass seemed to accelerate the fusion process as evidenced by the higher fusion rates at 4 and 8 weeks for the HA-TCP-collagen composite containing bioactive glass particles. The results also demonstrate that the HA-TCP-45S5 bioactive glass-collagen composite used as an extender closely mirrors the healing characteristics (i.e. amount and quality of bone) of the 100% autograft group.