Epidemiological evaluation of meniscal ramp lesions in 3214 anterior cruciate ligament–injured knees from the SANTI study group database: a risk factor analysis and study of secondary meniscectomy rates following 769 ramp repairs

Background: Ramp lesions are characterized by disruption of the peripheral meniscocapsular attachments of the posterior horn of the medial meniscus. Ramp repair performed at the time of ACL reconstruction has been shown to improve knee biomechanics. Hypothesis/Purpose: Primary objectives of this study were to evaluate the incidence and risk factors for ramp lesions in a large series of patients undergoing ACL reconstruction, Secondary objectives were to determine the re-operation rate for failure of ramp repair, defined by subsequent re-operations for partial medial meniscectomy Study Design: Case series Methods: All patients underwent trans-notch posteromedial compartment evaluation of the knee during ACL reconstruction. Ramp repair was performed if a lesion was detected. Potentially important risk factors were analyzed for their association with ramp lesions. A secondary analysis of all patients who underwent ramp repair and had a minimum follow-up of two years was undertaken in order to determine the secondary partial meniscectomy rate for failed ramp repair. Results: The overall incidence of ramp lesions in the study population was 23.9% (769 ramp lesions in 3214 patients). Multivariate analysis demonstrated that the presence of ramp lesions was significantly associated with the following risk factors: male gender, patients aged under 30 years, revision ACLR, chronic injuries, pre-operative side-to-side laxity >6 mm and the presence of concomitant lateral meniscus tears. The secondary meniscectomy rate was 10.8% at a mean follow up of 45.6 months (24.2-66.2). Patients who underwent ACLR + ALLR had a greater than 2-fold reduction in the risk of reoperation for failure of ramp repair as compared with patients who underwent isolated ACLR (hazard ratio, 0.457; 95%CI, 0.226-0.864; P = .021). Conclusion: There is a high incidence of ramp lesions in patients undergoing ACLR. The identification of important risk factors for ramp lesions in this study in an individual patient should help raise an appropriate index of suspicion and prompt posteromedial compartment evaluation. The overall secondary partial meniscectomy rate after ramp repair is 10.8%. Anterolateral ligament reconstruction appears to confer a protective effect on the ramp repair performed at the time of ACLR and results in a significant reduction in secondary meniscectomy rates

Combined Anterior Cruciate Ligament Repair and Anterolateral Ligament Reconstruction.

There has been a renewed interest in anterior cruciate ligament (ACL) repairs over the last decade with some early promising results in the right patient population. Additionally, the anterolateral ligament has been extensively studied and has recently been shown to have a protective effect on standard ACL reconstructions in a clinical trial. Given its protective effect on ACL reconstructions, we believe this phenomenon is also relevant to ACL repairs and can decrease rerupture rates. In this publication, we demonstrate a surgical technique for ACL repair using an internal brace combined with an anterolateral ligament reconstruction using a gracilis autograft

Superhydrophobic capillary coatings: Elaboration, characterization and application to electrophoretic separations

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Size-based characterization of nanoparticle mixtures by the inline coupling of capillary electrophoresis to Taylor dispersion analysis

International audienceSeparation of closely related nanoparticles is still a challenging issue for the characterization of complex mixtures for industrial/research applications or regulatory purposes. In this work, the remarkable separating performances of CE were complemented with the absolute size-based determination provided by Taylor dispersion analysis (TDA) for the characterization of nanoparticle mixtures. The inline hyphenation of CE to TDA was successfully implemented for the baseline separation followed by a size-based characterization of a bimodal mixture containing two closely size-related nanolatexes (70nm and 56nm radii). A pixel sensor UV area imager providing three detection points along the capillary was used for a differential measurement of the peak broadening during the Taylor dispersion step. Comparison of this new technique with dynamic light scattering and hydrodynamic chromatography is also discussed

Hydrodynamic size characterization of a self-emulsifying lipid pharmaceutical excipient by Taylor dispersion analysis with fluorescent detection

International audienceIn this work, the sizing of microemulsion droplets of a lipid-based pharmaceutical excipient (Labrasol® ALF) is performed by Taylor dispersion analysis (TDA) using fluorescent detection. An hydrophobic fluorescent marker is used to tag the microemulsion droplet and to increase the sensitivity of detection (compared to UV detection). Combined with the frontal TDA mode, fluorescent detection was mandatory for an accurate sizing of microemulsions containing large coacervates. Microemulsion sizing of Labrasol was performed at various concentrations from 1 to 70g.L-1 and at two different temperature (25°C and 37°C). Results obtained by TDA are compared to those derived from DLS measurements. The combination of both techniques allows estimating the size and proportion of coacervates in the microemulsion, as well as the polydispersity in size of the sample

Size characterization of commercial micelles and microemulsions by Taylor dispersion analysis

International audienceIn this work, Taylor dispersion analysis was applied to the measurement of micelles (or microdroplets) molecular diffusion coefficient in micellar (or microemulsion) systems based on neutral/anionic/cationic or zwitterionic surfactants. The choice of the micellar marker and the influence the surfactant/marker concentrations on this determination are studied. Experimental results are compared to those derived from the literature using other experimental techniques. Taylor dispersion analysis, experienced in narrow capillaries, was found to be an efficient and suitable method for micelle (or microdroplet) size measurement due to: the low sample consumption, the absence of filtration requirement of the sample, the broad range of size determination (with no lower limit down to angstroms), the simplicity of the protocol, the possibility to measure the viscosity of surfactant solutions in given conditions and the determination of the weight-average micelle hydrodynamic radius. Application to the size-characterization of commercial microemulsions (Gelucire(®) 44/14), used as an excipient in the pharmaceutical formulation, is provided with a comparison to DLS measurements. It was found that the polydispersity in size of the micelle did not influence the Gaussian peak shape of the taylorgram due to rapid surfactant exchange compared to the time-scale of the experiments (a few minutes)

Study of interactions between antigens and polymeric adjuvants in vaccines by frontal analysis continuous capillary electrophoresis

International audienceVaccine adjuvants are used to enhance the immune response induced by antigens that have insufficient immunostimulatory capabilities. The present work aims at developing a frontal analysis continuous capillary electrophoresis (FACCE) methodology for the study of antigen–adjuvant interactions in vaccine products. After method optimization using three cationic model proteins, namely lysozyme, cytochrome c, and ribonuclease A, FACCE was successfully implemented to quantify the free antigen and thus to determine the interaction parameters (stoichiometry and binding constant) between an anionic polymeric adjuvant (polyacrylic acid, SPA09) and a cationic vaccine antigen in development for the treatment for Staphylococcus aureus. The influence of the ionic strength of the medium on the interactions was investigated. A strong dependence of the binding parameters with the ionic strength was observed. The concentration of the polymeric adjuvant was also found to significantly modify the ionic strength of the formulation, the extent of which could be estimated and corrected

Size characterization of lipid-based self-emulsifying pharmaceutical excipients during lipolysis using Taylor dispersion analysis with fluorescence detection

International audienceSelf-emulsifying drug delivery systems based on lipids have gained in interest in recent years due to their capacity to enhance the bioavailability of poorly water soluble drugs. Their oral intake suggests that they will be in contact with gastric and pancreatic enzymes during their passage through the gastrointestinal tract. The study of the evolution of such systems in the presence of enzymes is thus essential to develop better drug delivery vehicles. In this work, the lipolysis of two lipid based self-emulsifying drug delivery systems, Labrasol® and Gelucire® 44/14 by pancreatic enzymes and under conditions mimicking the gastrointestinal tract are presented. The following of the digestion is realized by Taylor dispersion analysis using fluorescent detection. A hydrophobic marker was used to tag the microdroplets. Results have shown that, Labrasol® droplets decrease exponentially in size with lipolysis time, from 11.8 nm to 3.5 nm in 20 min. On the contrary, Gelucire® 44/14 droplets increased sigmoïdally in size from 5.6 to 24.7 nm. Even after 120 min lipolysis, both systems maintained a solubilizing capacity of the hydrophobic marker