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1.
HIV Clin Trials ; 15(6): 246-60, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25433664

RESUMO

BACKGROUND: Convenient dosing, potency, and low toxicity support use of tenofovir disoproxil fumarate (TDF) as preferred nucleotide reverse transcriptase inhibitor (NRTI) for HIV-1 treatment. However, renal and metabolic safety of TDF compared to other NRTIs has not been well described in resource-limited settings. METHODS: This was a secondary analysis examining the occurrence of renal abnormalities (RAs) and renal and metabolic serious non-AIDS-defining events (SNADEs) through study follow-up between participants randomized to zidovudine (ZDV)/lamivudine/ efavirenz and TDF/emtricitabine/efavirenz treatment arms within A5175/PEARLS trial. Exact logistic regression explored associations between baseline covariates and RAs. Response profile longitudinal analysis compared creatinine clearance (CrCl) over time between NRTI groups. RESULTS: Twenty-one of 1,045 participants developed RAs through 192 weeks follow-up; there were 15 out of 21 in the TDF arm (P = .08). Age 41 years or older (odds ratio [OR], 3.35; 95% CI, 1.1-13.1), his- tory of diabetes (OR, 10.7; 95% CI, 2.1-55), and lower baseline CrCl (OR, 3.1 per 25 mL/min decline; 95% CI, 1.7-5.8) were associated with development of RAs. Renal SNADEs occurred in 42 participants; 33 were urinary tract infections and 4 were renal failure/insufficiency; one event was attributed to TDF. Significantly lower CrCl values were maintained among patients receiving TDF compared to ZDV (repeated measures analysis, P = .05), however worsening CrCl from baseline was not observed with TDF exposure over time. Metabolic SNADEs were rare, but were higher in the ZDV arm (20 vs 3; P < .001). CONCLUSIONS: TDF is associated with lower serious metabolic toxicities but not higher risk of RAs, serious renal events, or worsening CrCl over time compared to ZDV in this randomized multinational study.


Assuntos
Fármacos Anti-HIV/efeitos adversos , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1 , Nefropatias/induzido quimicamente , Doenças Metabólicas/induzido quimicamente , Adulto , Fármacos Anti-HIV/administração & dosagem , Quimioterapia Combinada , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade
2.
Lett Appl Microbiol ; 59(4): 412-21, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24888993

RESUMO

The antimicrobial activities of 44 methanolic extracts from different parts of Iranian indigenous plant species used in traditional medicines of Iran were tested against a panel of 35 pathogenic and multiresistant bacteria and 1 yeast. The antimicrobial efficacy was determined using Müller-Hinton agar in Petri dishes seeded by a multiple inoculator and minimal inhibition concentration (MIC) method. The 21 most active extracts (MIC < 0·3 mg ml(-1) for one or several micro-organisms) were submitted to a more refined measurement. The best antibacterial activity was obtained by 10 plants. Microdilution assays allowed to determinate the MIC and MBC of the 21 most active extracts. The lowest achieved MIC value was 78 µg ml(-1), with 4 extracts. This work confirms the antimicrobial activity of assayed plants and suggests further examination to identify the chemical structure of their antimicrobial compounds. Significance and impact of the study: This study describes the antimicrobial screening of Iranian plant extracts chosen according to traditional practice against 36 microbial strains, from reference culture collections or recent clinical isolates, and enables to select 4 candidates for further chemical characterization and biological assessment: Dorema ammoniacum, Ferula assa-foetida, Ferulago contracta (seeds) and Perovskia abrotanoides (aerial parts). This may be useful in the development of potential antimicrobial agents, from easily harvested and highly sustainable plant parts. Moreover, the weak extent of cross-resistance between plant extracts and antibiotics warrants further research and may promote a strategy based on less potent but time-trained products.


Assuntos
Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Anti-Infecciosos/química , Irã (Geográfico) , Testes de Sensibilidade Microbiana , Extratos Vegetais/química
3.
Nat Commun ; 14(1): 796, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36781863

RESUMO

Self-organization of cells is central to a variety of biological systems and physical concepts of condensed matter have proven instrumental in deciphering some of their properties. Here we show that microphase separation, long studied in polymeric materials and other inert systems, has a natural counterpart in living cells. When placed below a millimetric film of liquid nutritive medium, a quasi two-dimensional, high-density population of Dictyostelium discoideum cells spontaneously assembles into compact domains. Their typical size of 100 µm is governed by a balance between competing interactions: an adhesion acting as a short-range attraction and promoting aggregation, and an effective long-range repulsion stemming from aerotaxis in near anoxic condition. Experimental data, a simple model and cell-based simulations all support this scenario. Our findings establish a generic mechanism for self-organization of living cells and highlight oxygen regulation as an emergent organizing principle for biological matter.


Assuntos
Dictyostelium , Dictyostelium/fisiologia , Quimiotaxia/fisiologia
4.
Front Digit Health ; 5: 1104700, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37228301

RESUMO

Research aim and purpose: The benefits of Electronic Patient -Reported Outcomes (e-PRO) for telemonitoring are well established, allowing early detection of illnesses and continuous monitoring of patients. The primary objective of the PROTECTY study was to assess the compliance with patient use of the telemonitoring platform Cureety. An exploratory objective was to assess if the first-month health status is a prognostic factor of progression free-survival (PFS) and overall survival (OS) for prostate cancer patient. Methods: This prospective study was conducted at the Military Hospital Bégin on prostate cancer patients. Patients were allowed to respond to a symptomatology questionnaire based on CTCAE v.5.0, personalized to their pathology and treatment. An algorithm evaluates the health status of the patient based on the reported adverse events, with a classification into 2 different states: Good Health Status (GHS) and Poor Health status (PHS). Results: Sixty-one patients were enrolled between July 1st, 2020 and September 30th, 2021. The median age was 74.0 (range 58.0-94.0). 78% presented a metastatic stage, and the most represented cancer was mHSPC. Overall, 2,457 questionnaires were completed by the patients, 4.0% resulted in a health classification in to monitor or critical state. 87% of patients were classified in the GHS group. The compliance was 72% in the overall population during the first month, 71% in GHS group and 75% in PHS group. The median follow-up was 8 months. PFS at 6 months was 84% in GHS group vs. 57% in PHS group, p = 0.19. OS at 6 months was 98% in GHS group vs. 83% in PHS group, p = 0.31. Conclusions: Our study showed that compliance was satisfactory. The feasibility of remote monitoring for prostate cancer patients means that they should benefit from its implementation. Our study is also the first to assess the correlation between treatment tolerance and survival. The initial results suggest that e-PRO assessment could help identify in the early stages the patients that require further health assessment and potential therapeutic changes. While further follow-up of more patients will be required, our study highlights the importance of e-PRO in cancer patient care.

5.
IEEE Sens J ; 12(5): 1207-1208, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-23087597

RESUMO

Gyroscope-free inertial measurement units have been gaining popularity in applications such as motion sensing of hand-held microsurgical instruments. Various accelerometer placement configurations have been proposed in the past. However, the effect of non-identical transfer functions of accelerometers on the accuracy of angular motion sensing has been underestimated and never been taken into consideration. In this paper, significant effect of different phases at different accelerometer outputs due to non-identical transfer functions on the accuracy is highlighted, and a method is proposed to make the transfer functions of all the accelerometers identical. Effectiveness of the method is confirmed with an experiment using ADXL-203 accelerometers.

6.
Sens Actuators A Phys ; 167(2): 304-316, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22423176

RESUMO

High sensing resolution is required in sensing of surgical instrument motion in micromanipulation tasks. Accelerometers can be employed to sense physiological motion of the instrument during micromanipulation. Various configurations of accelerometer placement had been introduced in the past to sense motion of a rigid-body such as a surgical instrument. Placement (location and orientation) of accelerometers fixed in the instrument plays a significant role in achieving high sensing resolution. However, there is no literature or work on the effect of placement of accelerometers on sensing resolution. In this paper, an approach of placement of accelerometers within an available space to obtain highest possible sensing resolution in sensing of rigid-body motion in micromanipulation tasks is proposed. Superiority of the proposed placement approach is shown in sensing of a microsurgical instrument angular motion by comparing sensing resolutions achieved as a result of employing the configuration following the proposed approach and the existing configurations. Apart from achieving high sensing resolution, and design simplicity, the proposed placement approach also provides flexibility in placing accelerometers; hence it is especially useful in applications with limited available space to mount accelerometers.

7.
Lab Chip ; 20(21): 4016-4030, 2020 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-32975276

RESUMO

Emerging evidence suggests the importance of mechanical stimuli in normal and pathological situations for the control of many critical cellular functions. While the effect of matrix stiffness has been and is still extensively studied, few studies have focused on the role of mechanical stresses. The main limitation of such analyses is the lack of standard in vitro assays enabling extended mechanical stimulation compatible with dynamic biological and biophysical cell characterization. We have developed an agarose-based microsystem, the soft cell confiner, which enables the precise control of confinement for single or mixed cell populations. The rigidity of the confiner matches physiological conditions and its porosity enables passive medium renewal. It is compatible with time-lapse microscopy, in situ immunostaining, and standard molecular analyses, and can be used with both adherent and non-adherent cell lines. Cell proliferation of various cell lines (hematopoietic cells, MCF10A epithelial breast cells and HS27A stromal cells) was followed for several days up to confluence using video-microscopy and further documented by Western blot and immunostaining. Interestingly, even though the nuclear projected area was much larger upon confinement, with many highly deformed nuclei (non-circular shape), cell viability, assessed by live and dead cell staining, was unaffected for up to 8 days in the confiner. However, there was a decrease in cell proliferation upon confinement for all cell lines tested. The soft cell confiner is thus a valuable tool to decipher the effects of long-term confinement and deformation on the biology of cell populations. This tool will be instrumental in deciphering the impact of nuclear and cytoskeletal mechanosensitivity in normal and pathological conditions involving highly confined situations, such as those reported upon aging with fibrosis or during cancer.


Assuntos
Núcleo Celular , Citoesqueleto , Proliferação de Células , Matriz Extracelular , Sefarose
8.
J Nanosci Nanotechnol ; 9(10): 5717-25, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19908443

RESUMO

This manuscript analyses the use of newly developed hybrid gadolinium oxide nanoparticles as cell-labeling tracers. The nanoparticles are core-shell particles composed of a core of gadolinium oxide of [2-4] nm and a protecting shell of polysiloxane [1-3 nm] where different organic dyes (fluoresceine isothiocyanate (FITC) or rhodamine B isothiocyanate (RBITC)) are embedded. They are functionalized with poly(ethylene glycol)bis(carboxymethyl) to ensure their colloidal stability in biological buffers. These particles are potential multi-labeling tracers (magnetic and optical). In this paper, we show by optical imaging that they can be efficiently internalized in cells without cell alteration. The in-vitro uptake of the nanoparticles was followed in two cell lines (human fibroblasts and a human adenocarnima cell lines MCF7 cells). Nanoparticles distribution within cells was analysed by confocal analysis, and gadolinium concentration within cells was quantified by mass spectrometry (ICP-MS analysis). Nanoparticles uptake is found to be fast and efficient for both cell lines, with fluorescent labeling visible after 10 min of incubation whatever the nature of the fluorophore. The fluorescent intensity is mainly found as concentrated dots in the perinuclear region of the cells and decreases with the number of days in culture, but is still easily detectable after 3 days in culture. No significant effect on cell growth was detected. Finally, we show in this study the protective effect of the polysiloxane layer: encapsulation of RBITC within the polysiloxane shell, leads to a better photostability of this low cost dye than Cy3 and even reach a level comparable to Alexa 595. With their high photostability and long-lasting contrast properties, these hybrid luminescent nanoparticles appears thus as a versatile solution to assess multiple cell fate both in in-vitro cell model as well as in-vivo.


Assuntos
Gadolínio/química , Nanopartículas Metálicas , Divisão Celular , Linhagem Celular Tumoral , Humanos , Espectrometria de Massas , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Tamanho da Partícula
9.
Vet Comp Orthop Traumatol ; 21(4): 358-64, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18704243

RESUMO

Distal limb lacerations are common injuries in horses, with a better prognosis reported for extensor tendons lacerations compared to flexor tendons lacerations. The objective of the present study was to determine the influence of type and location of injury, modalities of treatment and post surgical complications on the outcome of extensor tendon lacerations. The medical records of 156 horses surgically treated for extensor tendon lacerations over a 10-year period were analysed retrospectively. Information was obtained for 124 horses with a minimum of 18 months follow-up. Statistical analysis was performed on 129 horses (five horses were euthanatized during hospitalization) in order to determine factors affecting outcome. Seventy-four percent of the horses returned to soundness, 17% had moderate gait impairment and 9% remained lame. Approximately 60% of the sports horses returned to an equal or higher level of performance, and 17.5% returned to a lower level. In the multivariate statistical analysis, the only significant factor that favourably influenced outcome was complete suture of the wound. A significant association could not be detected between outcome and absence of a functional extensor tendon, The most important post-surgical complication was extensive scarring of the wound. The present results report outcome of extensor tendon lacerations in a large number of horses and outline the importance of primary wound healing in order to avoid major scarring with potential functional consequences.


Assuntos
Cavalos/lesões , Cavalos/cirurgia , Complicações Pós-Operatórias/veterinária , Traumatismos dos Tendões/veterinária , Cicatrização/fisiologia , Animais , Cicatriz/complicações , Cicatriz/veterinária , Feminino , Seguimentos , Membro Anterior , Membro Posterior , Incidência , Masculino , Análise Multivariada , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Retrospectivos , Suturas/veterinária , Traumatismos dos Tendões/cirurgia , Resultado do Tratamento
10.
Orthop Traumatol Surg Res ; 104(2): 165-170, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29223778

RESUMO

INTRODUCTION: Kinematic (KA) and mechanical (MA) alignment techniques are two different philosophies of implant positioning that use the same TKA implants. This might generate differences in the resulting prosthetic trochleae parameters between the two techniques of alignment. Our study aim was to test the following hypotheses : (1) mechanically or kinematically aligned femoral implant understuffs the native trochlear articular surface and poorly restores the native groove orientation, and (2) the orientation of the prosthetic trochlear groove and trochlear fill are different between MA and KA. METHODS: Three-dimensional models of the femur were made from segmentation of preoperative Magnetic Resonance Imaging scans (MRIs) of ten subjects with isolated medial tibiofemoral osteoarthritis. In-house planning and analysis software kinematically and mechanically aligned a modern cruciate retaining femoral component and determined differences in parameters of the trochlear fit between native and prosthetic trochleae, and between KA and MA prosthetic trochleae. RESULTS: The MA prosthetic trochleae did not fill (understuffed) the entire length of the native medial facet and the proximal 70% of the native groove and lateral facet, and oriented the trochleae groove 8° more valgus than native. The KA prosthetic trochleae understuffed the proximal 70% of the native trochleae, and had a groove 6° more valgus than native. The KA trochleae understuffed the medial facet distally and oriented the groove 2° less valgus and 3° more internally rotated than the MA trochleae. CONCLUSION: MA and KA prosthetic trochleae substantially understuff and create a prosthetic groove more valgus compared to native trochlear anatomy, and they also differed between each other regarding trochleae stuffing and groove alignment. Although randomized trials have not shown differences in patellofemoral complications between KA and MA, a femoral component designed specifically for KA that more closely restores the native trochlear anatomy might improve patient reported satisfaction and function. LEVEL OF EVIDENCE: Level 2 controlled laboratory study.


Assuntos
Artroplastia do Joelho , Articulação do Joelho/fisiopatologia , Prótese do Joelho , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/cirurgia , Artroplastia do Joelho/métodos , Fenômenos Biomecânicos , Feminino , Fêmur , Humanos , Imageamento Tridimensional , Articulação do Joelho/cirurgia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade
12.
Equine Vet J ; 50(4): 457-464, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29193393

RESUMO

BACKGROUND: In horses, the only established method for reinnervation of the larynx is the nerve-muscle pedicle implantation, whereas in human medicine, direct nerve implantation is a standard surgical technique for selective laryngeal reinnervation in human patients suffering from bilateral vocal fold paralysis. OBJECTIVES: (1) To describe a modified first or second cervical nerve transplantation technique for the treatment of recurrent laryngeal neuropathy (RLN) in horses and (2) evaluate the outcomes of reinnervation using direct nerve needle-stimulation of the first cervical nerve and exercising endoscopy before and after surgery. STUDY DESIGN: Case series. METHODS: Nerve transplantation surgery, in which the first or second cervical nerve is tunnelled through the atrophied left cricoarytenoideus dorsalis muscle, was performed in combination with ipsilateral laser ventriculocordectomy. Ultrasound-guided stimulation of the first cervical nerve at the level of the alar foramen was used to confirm successful reinnervation post-operatively. Exercising endoscopy was performed before and after surgery. The exercising RLN grade of the left arytenoid was blindly determined at the highest stride frequency for each examination. RESULTS: Surgery was performed in 17 client-owned animals with RLN. Reinnervation was confirmed by nerve stimulation and subsequent arytenoid abduction observed in 11 out of 12 cases between 4 and 12 months post-operatively. Fourteen horses had exercising endoscopy before and after surgery. Nine horses had an improved exercising RLN grade, four horses had the same exercising grade and one horse had a worse exercising grade after surgery. MAIN LIMITATIONS: A sham-operated control group was not included and follow-up beyond 12 months and objective performance data were not obtained. CONCLUSIONS: The modified first or second cervical nerve transplantation technique, using tunnelling and direct implantation of the donor nerve into the cricoarytenoideus dorsalis muscle, resulted in reinnervation in 11 out of 12 cases and improved exercising grade in 9 out of 14 horses within 12 months after surgery.


Assuntos
Doenças dos Cavalos/cirurgia , Paralisia das Pregas Vocais/veterinária , Animais , Feminino , Cavalos , Músculos Laríngeos/inervação , Masculino , Regeneração Nervosa , Paralisia das Pregas Vocais/cirurgia
13.
J Biomech ; 40(1): 64-77, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16406381

RESUMO

In micro-organisms, as well as in metazoan cells, cellular polarization and directed migration are finely regulated by external stimuli, including mechanical stresses. The mechanisms sustaining the transduction of such external stresses into intracellular biochemical signals remain mainly unknown. Using an external magnetic tip, we generated a magnetic field gradient that allows migration analysis of cells submitted to local low-intensity magnetic forces (50 pN). We applied our system to the amoeba Entamoeba histolytica. Indeed, motility and chemotaxis are key activities that allow this parasite to invade and destroy the human tissues during amoebiasis. The magnetic force was applied either inside the cytoplasm or externally at the rear pole of the amoeba. We observed that the application of an intracellular force did not affect cell polarization and migration, whereas the application of the force at the rear pole of the cell induced a persistent polarization and strongly directional motion, almost directly opposed to the magnetic force. This phenomenon was completely abolished when phosphatidylinositol 3-kinase activity was inhibited by wortmanin. This result demonstrated that the applied mechanical stimulus was transduced and amplified into an intracellular biochemical signal, a process that allows such low-intensity force to strongly modify the migration behavior of the cell.


Assuntos
Entamoeba histolytica/enzimologia , Entamoeba histolytica/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Fenômenos Biomecânicos , Polaridade Celular , Magnetismo , Mecanotransdução Celular , Movimento
14.
Phys Rev E Stat Nonlin Soft Matter Phys ; 75(4 Pt 1): 041906, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17500920

RESUMO

We report the control of cell migration by external magnetic forces during the early stage of Dictysostelium discoideum morphogenesis. Magnetically labeled aggregating cells respond to the presence of a magnetic field created by a thin magnetic tip: forces as low as 30 pN are sufficient to elicit the aggregation of the cells at the extremity of the tip. This induced magnetotaxis is competitive to classical chemotaxis. We therefore underline the interplay between external mechanical forces and morphogenesis. This magnetic assay will open new possibilities in the study of morphogenesis in Dictyostelium.


Assuntos
Dictyostelium/metabolismo , Animais , Biofísica/métodos , Calibragem , Adesão Celular , Movimento Celular , Quimiotaxia , AMP Cíclico/metabolismo , Corantes Fluorescentes/química , Processamento de Imagem Assistida por Computador , Magnetismo , Modelos Biológicos , Fatores de Tempo
15.
Orthop Traumatol Surg Res ; 103(7): 1047-1056, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28864235

RESUMO

In spite of improvements in implant designs and surgical precision, functional outcomes of mechanically aligned total knee arthroplasty (MA TKA) have plateaued. This suggests probable technical intrinsic limitations that few alternate more anatomical recently promoted surgical techniques are trying to solve. This review aims at (1) classifying the different options to frontally align TKA implants, (2) at comparing their safety and efficacy with the one from MA TKAs, therefore answering the following questions: does alternative techniques to position TKA improve functional outcomes of TKA (question 1)? Is there any pathoanatomy not suitable for kinematic implantation of a TKA (question 2)? A systematic review of the existing literature utilizing PubMed and Google Scholar search engines was performed in February 2017. Only studies published in peer-reviewed journals over the last ten years in either English or French were reviewed. We identified 569 reports, of which 13 met our eligibility criteria. Four alternative techniques to position a TKA are challenging the traditional MA technique: anatomic (AA), adjusted mechanical (aMA), kinematic (KA), and restricted kinematic (rKA) alignment techniques. Regarding osteoarthritic patients with slight to mid constitutional knee frontal deformity, the KA technique enables a faster recovery and generally generates higher functional TKA outcomes than the MA technique. Kinematic alignment for TKA is a new attractive technique for TKA at early to mid-term, but need longer follow-up in order to assess its true value. It is probable that some forms of pathoanatomy might affect longer-term clinical outcomes of KA TKA and make the rKA technique or additional surgical corrections (realignment osteotomy, retinacular ligament reconstruction etc.) relevant for this sub-group of patients. Longer follow-up is needed to define the best indication of each alternative surgical technique for TKA. Level I for question 1 (systematic review of Level I studies), level 4 for question 2.


Assuntos
Artroplastia do Joelho/métodos , Artroplastia do Joelho/instrumentação , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/anatomia & histologia , Articulação do Joelho/fisiologia , Articulação do Joelho/cirurgia , Prótese do Joelho
16.
Orthop Traumatol Surg Res ; 103(7): 1069-1073, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28870873

RESUMO

INTRODUCTION: Kinematic alignment (KA) technique is an alternative technique for positioning a TKA, which aims a patient-specific implant positioning in order to reproduce the pre-arthritic knee anatomy. Because reliability in implant positioning is of interest to obtain reproducible good functional results, our study tests the hypothesis that the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically aligned femoral component are similar. METHODS: Preoperative knee magnetic resonance imaging (MRI) and postoperative knee computed tomography (CT) of 13 patients implanted with a KA Persona® TKA (Zimmer, Warsaw, USA) using manual instrumentation (kinematically-aligned TKA procedure pack®, Zimmer Biomet, Warsaw, USA) were segmented to create 3D femoral models. The kinematic alignment position of the femoral component was planned on the 3D model created from the preoperative MRI. Differences in the positions of the planned and surgically implanted kinematically-aligned femoral component were determined with in-house analysis software. RESULTS: The average differences between the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically-aligned femoral component were inferior to 1mm and no statistically significant. In terms of variability, 62% (8/13) of performed implants matched all four positions within 1.5mm, and the maximum difference was 3mm. CONCLUSION: In this small series, intraoperative kinematic positioning of the femoral component with the specific manual instrumentation closely matched the planned position, which suggests that this technique reliably aligned the flexion-extension axis of the femoral component to the cylindrical axis. LEVEL OF EVIDENCE: Level 3.


Assuntos
Artroplastia do Joelho/métodos , Osteoartrite do Joelho/cirurgia , Cirurgia Assistida por Computador/métodos , Artroplastia do Joelho/instrumentação , Fenômenos Biomecânicos , Feminino , Humanos , Imageamento Tridimensional , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Prótese do Joelho , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Osteoartrite do Joelho/diagnóstico por imagem , Reprodutibilidade dos Testes , Software , Cirurgia Assistida por Computador/instrumentação , Tomografia Computadorizada por Raios X
17.
Orthop Traumatol Surg Res ; 103(7): 1057-1067, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28888523

RESUMO

BACKGROUND: Mechanically aligned (MA) total knee arthroplasty (TKA) is affected by disappointing functional outcomes in spite of the recent improvements in surgical precision and implant designs. This might suggest the existence of intrinsic technical limitations. Our study aims to compare the prosthetic and native trochlear articular surfaces and to estimate the extent of collateral ligament imbalance, which is technically uncorrectable by collateral ligament release when TKA implants are mechanically aligned. STUDY HYPOTHESIS: Conventional MA technique generates a high rate of prosthetic overstuffing of the distal groove, distal lateral trochlear facet and distal lateral femoral condyle (Hypothesis 1), and technically uncorrectable collateral ligament imbalance (hypothesis 2)? Disregarding the distal femoral joint line obliquity (DFJLO) when performing femoral cuts explains distal lateral femoral prosthetic stuffing and uncorrectable imbalance (hypothesis 3)? METHODS: Twenty patients underwent a conventional MA TKA. Pre-operative MRI-based 3D knee models were generated and MA TKA was simulated. Native and prosthetic trochlear articular surfaces were compared using in-house analysis software. Following the automatic determination by the planning software of the size of the extension and flexion gaps, an algorithm was applied to balance the gaps and the frequency and amplitude of technically uncorrectable knee imbalance were estimated. RESULTS: The conventional MA technique generates a significant slight distal lateral femoral prosthetic overstuffing (mean 0.6mm, 0.8mm, 1.25mm for the most distal lateral facet point, groove, and at the most distal point of lateral femoral condyle, respectively) and a high rate of type 1 and 2 uncorrectable knee imbalance (30% and 40%, respectively). The incidence of distal lateral prosthetic overstuffing (trochlea and condyle) and uncorrectable knee imbalance were strongly to very strongly correlated with the DFJLO (r=0.53 to 0.89). CONCLUSION: Conventional MA technique for TKA generates frequent lateral distal femoral prosthetic overstuffing and technically uncorrectable knee imbalance secondary to disregarding the DFJLO when adjusting the femoral component frontal and axial rotations, respectively. LEVEL OF EVIDENCE: level 4.


Assuntos
Artroplastia do Joelho/métodos , Osteoartrite do Joelho/cirurgia , Cirurgia Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Artroplastia do Joelho/instrumentação , Feminino , Humanos , Imageamento Tridimensional , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Prótese do Joelho , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Osteoartrite do Joelho/diagnóstico por imagem , Software , Cirurgia Assistida por Computador/instrumentação
18.
Orthop Traumatol Surg Res ; 103(4): 559-568, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28373138

RESUMO

Sagittal pelvic kinematics along with spino-pelvic angular parameters have recently been studied by numerous investigators for their effect on total hip replacement (THR) clinical outcomes, but many issue of spine-hip relations (SHR) are currently unexplored. Therefore, our review aims at clarifying the following questions: is there any evidence of a relationship between articular impingement/dislocation risk in primary THR and (1) certain sagittal pelvic kinematics patterns, (2) pelvic incidence, and (3) types of SHRs? A systematic review of the existing literature utilising PubMed and Google search engines was performed in January 2017. Only clinical or computational studies published in peer-reviewed journals over the last five years in either English or French were reviewed. We identified 769 reports, of which 12 met our eligibility criteria. A review of literature shows that sagittal pelvic kinematics, but not the pelvic incidence, influences the risk of prosthetic impingement/dislocation. We found no study having assessed the relationship between this risk and the types of SHRs. Sagittal pelvic kinematics is highly variable among individuals and certain kinematic patterns substantially influences the risk of prosthetic impingement/dislocation. Recommendations for cup positioning are therefore switching from a systematic to a patient-specific approach, with the standing cup orientation Lewinneck safe zone progressively giving way to a new parameter of interest: the functional orientation of the cup. Based on a recently published classification for SHRs, We propose a new concept of "kinematically aligned THR" for the purposes of THR planning. Further studies are needed to investigate the relevance of such a classification towards the assumptions and hypothesis we have made. Level of evidence,- Level IV, systematic review of level III and IV studies.


Assuntos
Artroplastia de Quadril/métodos , Impacto Femoroacetabular/cirurgia , Articulação do Quadril/fisiopatologia , Coluna Vertebral/fisiopatologia , Humanos , Postura
19.
Orthop Traumatol Surg Res ; 103(4): 549-557, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28373141

RESUMO

Relationship between hip pathoanatomy and symptomatic FAI has been reported to be weak. This is explained by the reciprocal interaction between proximal femur and acetabular anatomies, but potentially also by the individual spine-hip relations (SHR). The key-answer for a complete understanding of the pathophysiology of FAI might lie in the comprehension of the SHRs, which have not yet been fully addressed. Therefore we conducted a systematic review to answer the subsequent questions: Is there any evidence of a relationship between FAI and (1) sagittal pelvic kinematics, (2) pelvic incidence, and (3) types of SHRs? A systematic review of the existing literature utilizing PubMed and Google search engines was performed in December 2016. Only studies published in peer-reviewed journals over the last ten years in either English or French were reviewed. We identified 90 reports, of which 9 met our eligibility criteria. Review of literature shows Caucasian FAI patients have a pelvis with higher anterior tilt, lesser sagittal mobility, and lower pelvic incidence compared to healthy patients. We found no study having assessed the relationship between SHR and FAI. In order to help further investigations at answering questions 3 and 4, we have developed a classification for SHRs. The classification according spino-pelvic parameters allows identifying patient at risk regarding FAI occurrence. Higher anterior pelvic tilt in standing, sitting and squatting positions and lower pelvic incidence have been found to correlate with symptomatic FAI. Because defining the individual SHR might increase the understanding of the pathophysiology of hip impingement, we have developed a classification for SHRs. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.


Assuntos
Impacto Femoroacetabular/fisiopatologia , Articulação do Quadril/fisiopatologia , Coluna Vertebral/fisiopatologia , Humanos , Amplitude de Movimento Articular
20.
Accid Anal Prev ; 38(2): 248-59, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16257384

RESUMO

To reduce the number and the gravity of accidents, it is necessary to analyse and reconstruct them. Accident modelling requires the modelling of the impact which in turn requires the estimation of the deformation energy. There are several tools available to evaluate the deformation energy absorbed by a vehicle during an impact. However, there is a growing demand for more precise and more powerful tools. In this work, we express the deformation energy absorbed by a vehicle during a crash as a function of the Energy Equivalent Speed (EES). The latter is a difficult parameter to estimate because the structural response of the vehicle during an impact depends on parameters concerning the vehicle, but also parameters concerning the impact. The objective of our work is to design a model to estimate the EES by using an original approach combining Bayesian and Neural Network approaches. Both of these tools are complementary and offer significant advantages, such as the guarantee of finding the optimal model and the implementation of error bars on the computed output. In this paper, we present the procedure for implementing this Bayesian Neural Network approach and the results obtained for the modelling of the EES: our model is able to estimate the EES of the car with a mean error of 1.34 m s(-1). Furthermore, we built a sensitivity analysis to study the relevance of model's inputs.


Assuntos
Acidentes de Trânsito , Teorema de Bayes , Modelos Teóricos , Redes Neurais de Computação , Física , Movimento (Física) , Fenômenos Físicos
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