421 results on '"Zanna, L."'
Search Results
152. On the divergence-free condition in Godunov-type schemes for ideal magnetohydrodynamics: the upwind constrained transport method
- Author
-
Londrillo, P, primary and Del Zanna, L, additional
- Published
- 2004
- Full Text
- View/download PDF
153. Spherically symmetric relativistic MHD simulations of pulsar wind nebulae in supernova remnants
- Author
-
Bucciantini, N., primary, Blondin, J. M., additional, Del Zanna, L., additional, and Amato, E., additional
- Published
- 2003
- Full Text
- View/download PDF
154. An efficient shock-capturing central-type scheme for multidimensional relativistic flows
- Author
-
Del Zanna, L., primary, Bucciantini, N., additional, and Londrillo, P., additional
- Published
- 2003
- Full Text
- View/download PDF
155. An efficient shock-capturing central-type scheme for multidimensional relativistic flows
- Author
-
Del Zanna, L., primary and Bucciantini, N., additional
- Published
- 2002
- Full Text
- View/download PDF
156. Parametric decay of circularly polarized Alfvén waves: Multidimensional simulations in periodic and open domains
- Author
-
Del Zanna, L., primary, Velli, M., additional, and Londrillo, P., additional
- Published
- 2001
- Full Text
- View/download PDF
157. High‐Order Upwind Schemes for Multidimensional Magnetohydrodynamics
- Author
-
Londrillo, P., primary and Del Zanna, L., additional
- Published
- 2000
- Full Text
- View/download PDF
158. A fully covariant mean-field dynamo closure for numerical 3 + 1 resistive GRMHD.
- Author
-
Bucciantini, N. and Del Zanna, L.
- Subjects
- *
COVARIANT field theories , *NUMERICAL analysis , *MAGNETOHYDRODYNAMICS , *FINITE differences , *TURBULENCE , *ASTROPHYSICS - Abstract
The powerful high-energy phenomena typically encountered in astrophysics invariably involve physical engines, like neutron stars and black hole accretion discs, characterized by a combination of highly magnetized plasmas, strong gravitational fields and relativistic motions. In recent years, numerical schemes for general relativistic magnetohydrodynamics (GRMHD) have been developed to model the multidimensional dynamics of such systems, including the possibility of evolving space-time. Such schemes have been also extended beyond the ideal limit including the effects of resistivity, in an attempt to model dissipative physical processes acting on small scales (subgrid effects) over the global dynamics. Along the same lines, the magnetic field could be amplified by the presence of turbulent dynamo processes, as often invoked to explain the high values of magnetization required in accretion discs and neutron stars. Here we present, for the first time, a further extension to include the possibility of a mean-field dynamo action within the framework of numerical 3 + 1 (resistive) GRMHD. A fully covariant dynamo closure is proposed, in analogy with the classical theory, assuming a simple β-effect in the comoving frame. Its implementation into a finite-difference scheme for GRMHD in dynamical space-times (the X-ECHO code by Bucciantini & Del Zanna) is described, and a set of numerical test is presented and compared with analytical solutions wherever possible. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
159. Upper-ocean singular vectors of the North Atlantic climate with implications for linear predictability and variability.
- Author
-
Zanna, L., Heimbach, P., Moore, A. M., and Tziperman, E.
- Published
- 2012
- Full Text
- View/download PDF
160. Lagrangian ocean analysis: Fundamentals and practices
- Author
-
van Sebille, E, Griffies, SM, Abernathey, R, Adams, TP, Berloff, P, Biastoch, A, Blanke, B, Chassignet, EP, Cheng, Y, Cotter, CJ, Deleersnijder, E, Doos, K, Drake, HF, Drijfhout, S, Gary, SF, Heemink, AW, Kjellsson, J, Koszalka, IM, Lange, M, Lique, C, MacGilchrist, GA, Marsh, R, Adame, CGM, McAdam, R, Nencioli, F, Paris, CB, Piggott, MD, Polton, JA, Ruehs, S, Shah, SHAM, Thomas, MD, Wang, J, Wolfram, PJ, Zanna, L, Zika, JD, Grantham Institute for Climate Change and the Environment, Imperial College London, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Center for Ocean-Atmospheric Prediction Studies (COAPS), Florida State University [Tallahassee] (FSU), Department of Mathematics [Imperial College London], Institute of Mechanics, Department of Meteorology [Stockholm] (MISU), Stockholm University, Royal Netherlands Meteorological Institute (KNMI), Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington [Seattle], Ocean and Earth Science [Southampton], University of Southampton-National Oceanography Centre (NOC), Plymouth Marine Laboratory (PML), Plymouth Marine Laboratory, Marine and Atmospheric Research, Sub Physical Oceanography, Dep Natuurkunde, Natural Environment Research Council (NERC), Engineering & Physical Science Research Council (E, European Research Council, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), and UCL - SST/IMMC/MEMA - Applied mechanics and mathematics
- Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Atmospheric Science ,Connectivity ,Particle tracking ,Oceanography ,Geotechnical Engineering and Engineering Geology ,Ocean circulation ,Future modelling ,Lagrangian analysis ,Computer Science (miscellaneous) ,0405 Oceanography ,Physics::Atmospheric and Oceanic Physics ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
Highlights: • Lagrangian ocean analysis is a powerful way to analyse the output of ocean circulation models • We present a review of the Kinematic framework, available tools, and applications of Lagrangian ocean analysis • While there are unresolved questions, the framework is robust enough to be used widely in ocean modelling Abstract: Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. The overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.
- Full Text
- View/download PDF
161. Systematic construction of upwind constrained transport schemes for MHD.
- Author
-
Mignone, A. and Del Zanna, L.
- Subjects
- *
MAGNETIC fields , *ART techniques , *MAGNETOHYDRODYNAMICS , *CELL anatomy , *ELECTRIC fields , *CONSTRUCTION - Abstract
• With this work we assess the validity of novel UCT schemes for the solution of the MHD equations in multiple dimensions. • The proposed schemes improve on the original formulation of Londrillo & Del Zanna (2004) [22] by providing more general guidelines allowing different Riemann solvers to be incorporated. • This approach offers enhanced flexibility allowing new upwind techniques to be incorporated in CT-MHD schemes at the modest cost of storing transverse velocity, weight coefficients for the fluxes and diffusion terms for the magnetic field. The constrained transport (CT) method reflects the state of the art numerical technique for preserving the divergence-free condition of magnetic field to machine accuracy in multi-dimensional MHD simulations performed with Godunov-type, or upwind, conservative codes. The evolution of the different magnetic field components, located at zone interfaces using a staggered representation, is achieved by calculating the electric field components at cell edges, in a way that has to be consistent with the Riemann solver used for the update of cell-centered fluid quantities at interfaces. Albeit several approaches have been undertaken, the purpose of this work is, on the one hand, to compare existing methods in terms of robustness and accuracy and, on the other, to extend the upwind constrained transport (UCT) method by Londrillo & Del Zanna (2004) [22] and Del Zanna et al. (2007) [23] for the systematic construction of new averaging schemes. In particular, we propose a general formula for the upwind fluxes of the induction equation which simply involves the information available from the base Riemann solver employed for the fluid part, provided it does not require full spectral decomposition, and 1D reconstructions of velocity and magnetic field components from nearby intercell faces to cell edges. Our results are presented here in the context of second-order schemes for classical MHD, but they can be easily generalized to higher than second order schemes, either based on finite volumes or finite differences, and to other physical systems retaining the same structure of the equations, such as that of relativistic or general relativistic MHD. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
162. The expansion of coronal plumes in the fast solar wind
- Author
-
Del Zanna, L., Rudolf von Steiger, and Velli, M.
163. The tearing instability in relativistic magnetohydrodynamics
- Author
-
Del Zanna, L., Papini, E., Simone Landi, Bugli, M., and Bucciantini, N.
164. Constraints on particle acceleration sites in the Crab Nebula from relativistic MHD simulations
- Author
-
Olmi, B., Zanna, L. D., Amato, E., and Niccolo' Bucciantini
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Physics::Accelerator Physics ,FOS: Physical sciences ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
The Crab Nebula is one of the most efficient accelerators in the Galaxy and the only galactic source showing direct evidence of PeV particles. In spite of this, the physical process behind such effective acceleration is still a deep mystery. While particle acceleration, at least at the highest energies, is commonly thought to occur at the pulsar wind termination shock, the properties of the upstream flow are thought to be non-uniform along the shock surface, and important constraints on the mechanism at work come from exact knowledge of where along this surface particles are being accelerated. Here we use axisymmetric relativistic MHD simulations to obtain constraints on the acceleration site(s) of particles of different energies in the Crab Nebula. Various scenarios are considered for the injection of particles responsible for synchrotron radiation in the different frequency bands, radio, optical and X-rays. The resulting emission properties are compared with available data on the multi wavelength time variability of the inner nebula. Our main result is that the X-ray emitting particles are accelerated in the equatorial region of the pulsar wind. Possible implications on the nature of the acceleration mechanism are discussed., Comment: 12 pages, 7 figures, 2 tables
165. Atypical fractures of the femur: An updated overview from the laboratory to the operating room
- Author
-
christian carulli, Zanna, L., Lus, L., Lepri, A. C., Villano, M., Civinini, R., and Innocenti, M.
166. Discovering causal relations and equations from data
- Author
-
Camps-Valls, G., Gerhardus, A., Ninad, U., Varando, G., Martius, G., Balaguer-Ballester, Emili, Vinuesa, R., Diaz, E., Zanna, L., Runge, J., Camps-Valls, G., Gerhardus, A., Ninad, U., Varando, G., Martius, G., Balaguer-Ballester, Emili, Vinuesa, R., Diaz, E., Zanna, L., and Runge, J.
- Abstract
Physics is a field of science that has traditionally used the scientific method to answer questions about why natural phenomena occur and to make testable models that explain the phenomena. Discovering equations, laws, and principles that are invariant, robust, and causal has been fundamental in physical sciences throughout the centuries. Discoveries emerge from observing the world and, when possible, performing interventions on the system under study. With the advent of big data and data-driven methods, the fields of causal and equation discovery have developed and accelerated progress in computer science, physics, statistics, philosophy, and many applied fields. This paper reviews the concepts, methods, and relevant works on causal and equation discovery in the broad field of physics and outlines the most important challenges and promising future lines of research. We also provide a taxonomy for data-driven causal and equation discovery, point out connections, and showcase comprehensive case studies in Earth and climate sciences, fluid dynamics and mechanics, and the neurosciences. This review demonstrates that discovering fundamental laws and causal relations by observing natural phenomena is revolutionised with the efficient exploitation of observational data and simulations, modern machine learning algorithms and the combination with domain knowledge. Exciting times are ahead with many challenges and opportunities to improve our understanding of complex systems.
167. A fourth-order accurate finite volume scheme for resistive relativistic MHD.
- Author
-
Mignone, A, Berta, V, Rossazza, M, Bugli, M, Mattia, G, Del Zanna, L, and Pareschi, L
- Subjects
- *
MAGNETIC reconnection , *RIEMANN-Hilbert problems , *RELATIVISTIC plasmas , *MAGNETIC fields , *COMPUTER software development - Abstract
We present a finite-volume, genuinely fourth-order accurate numerical method for solving the equations of resistive relativistic magnetohydrodynamics in Cartesian coordinates. In our formulation, the magnetic field is evolved in time in terms of face-average values via the constrained-transport method, while the remaining variables (density, momentum, energy, and electric fields) are advanced as cell volume averages. Spatial accuracy employs fifth-order accurate WENO-Z reconstruction from point values (as described in a companion paper) to obtain left and right states at zone interfaces. Explicit flux evaluation is carried out by solving a Riemann problem at cell interfaces, using the Maxwell–Harten–Lax–van Leer with contact wave resolution. Time-stepping is based on the implicit–explicit Runge–Kutta (RK) methods, of which we consider both the third-order strong stability preserving SSP3(4,3,3) and a recent fourth-order additive RK scheme, to cope with the stiffness introduced by the source term in Ampere's law. Numerical benchmarks are presented in order to assess the accuracy and robustness of our implementation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
168. Parametric decay of parallel and oblique Alfvén waves in the expanding solar wind.
- Author
-
Del Zanna, L., Matteini, L., Landi, S., Verdini, A., and Velli, M.
- Subjects
- *
PLASMA Alfven waves , *SOLAR wind , *MAGNETOHYDRODYNAMICS , *THEORY of wave motion , *COMPUTER simulation - Abstract
The long-term evolution of large-amplitude Alfvén waves propagating in the solar wind is investigated by performing two-dimensional MHD simulations within the expanding box model. The linear and nonlinear phases of the parametric decay instability are studied for both circularly polarized waves in parallel propagation and for arc-polarized waves in oblique propagation. The non-monochromatic case is also considered. In the oblique case, the direct excitation of daughter modes transverse to the local background field is found for the first time in an expanding environment, and this transverse cascade seems to be favored for monochromatic mother waves. The expansion effect reduces the instability growth rate, and it can even suppress its onset for the lowest frequency modes considered here, possibly explaining the persistence of these outgoing waves in the solar wind. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
169. Ocean heat uptake: drivers, variability and impacts
- Author
-
Aengenheyster, M, Read, P, Sutton, R, Allen, M, and Zanna, L
- Subjects
Ocean dynamics ,Physics ,Atmospheric physics ,Climate physics ,Oceanography - Abstract
Attributions of causes in the fully coupled atmosphere-ocean system are difficult due to a wide range of interactions in the climate system. One way to address this is to break down the fully coupled closed system into two open systems. Such studies often depend on the specification of sea surface temperature to link ocean and atmosphere. Instead, in this thesis we focus on understanding the impacts of perturbations to surface heat fluxes as this gives a better handle on imposing changing processes and improves the realism of air-sea interactions. We identify (Chapter 2) the local and non-local response of ocean heat content to idealised surface heat flux perturbation patterns, demonstrating the importance of circulation change in communicating the non-local response. The global heat content response pattern is shown to be a linear combination of the responses to flux perturbations in individual ocean basins, primarily the North Atlantic and the Southern Ocean. We further investigate (Chapter 3) processes and forcings that regulate the ocean heat content change in the South Pacific Gyre, finding an important cooling contribution from a weakening of the ocean circulation as a response to high-latitude Southern Ocean heat flux forcing. This mechanism is not robust in CMIP5 but is identified in the MPI-GE fully-coupled large ensemble. In order to investigate the impact of changing ocean circulation on atmospheric extreme events, we introduce, develop and validate (Chapter 4) the novel HadSM4 slab ocean-atmosphere model configuration. Using large ensembles of HadSM4, we quantify the impact of the ocean heat convergence anomaly that occurred in the North Atlantic in the 2013-14 winter season. Our results indicate that the 2013-14 anomaly induced a warming of around 1 K in the North Atlantic, 0.5 K in Western Europe, and an increase in winter precipitation that up to halves the return times of extremely wet winters over parts of Europe. To isolate the impact of air-sea feedbacks on mean state, variability and extreme events, sea surface temperature realisations from this slab ensemble are used to force an atmosphere-only sister ensemble (Chapter 5). Disabling the feedback of heat fluxes onto SST strongly increases the ensemble spread of seasonal mean air-sea heat flux components, as the first-order impact of coupling is a negative feedback. Regionally important changes in extreme events indicate the importance of representing atmosphere-ocean coupling for studies exploring the impact of external forcing on weather extremes. This work improves our understanding on how ocean and atmosphere force each other’s dynamics and variability through surface energy exchange, by the way of the centennial impact of atmospheric forcing on ocean dynamics, the seasonal impact of ocean forcing on atmospheric dynamics, and the atmospheric impact of mixed-layer coupling.
- Published
- 2023
170. A data-driven investigation into the behaviour and parameterisation of mesoscale eddies
- Author
-
Bolton, T and Zanna, L
- Subjects
Turbulence ,Ocean ,Physics ,Machine learning ,Oceanography - Abstract
Mesoscale eddies, turbulent oceanic features of length-scales 10-100km, are an important component of the climate system. They impact the large-scale circulation of both the ocean and atmosphere, as well as the transport of tracers such as heat and carbon. Due to the computational costs of running ocean models at high-resolution, climate models generally do not fully resolve mesoscale eddies, and will not be able to for the foreseeable future. We, therefore, need to parameterise the effects of mesoscale eddies on the large-scale flow. Eddy parameterisations are typically derived from physical theories and mechanisms; this approach can sometimes over-simplify the underlying dynamical process. The primary aim of this thesis is to uncover new ways of capturing the complex non-linear behaviour of mesoscale eddies. Using a hierarchy of numerical models, we take a data-driven approach to studying and parameterising mesoscale eddies. Using an observation-driven experiment, we investigate how the spatio-temporal variability of real mesoscale eddies affect tracer fluxes in the North Atlantic. In an idealised model, we demonstrate that modern machine learning algorithms, namely convolutional neural networks, can accurately represent eddy momentum fluxes. We also demonstrate that machine learning can construct expressions for eddy momentum and temperature fluxes while retaining interpretability. We find that, when implemented, data-driven parameterisations can emulate the scale-interaction between mesoscale eddies and the resolved flow, increasing the kinetic energy and improving the higher-order statistics of the velocity field. Our results show that data-driven algorithms, while respecting physical principles, can be used to parameterise the effects of mesoscale eddies, with implementation in more realistic models now a possibility. The predictive skill of data-driven algorithms is not the only advantage: our use of interpretable machine learning opens up the door for more knowledge discovery studies about eddies and turbulence in general.
- Published
- 2021
171. A turbulent story: role of diapycnal mixing in the ocean overturning circulation and tracer distribution
- Author
-
Cimoli, L, Heywood, KJ, Zanna, L, Marshall, DP, and Johnson, HL
- Subjects
Climate ,Oceanography - Abstract
Natural and anthropogenic heat and carbon, as well as other climatically and biologically important tracers, enter the deep global overturning circulation mainly during the formation of dense waters at the high latitudes around Antarctica and in the North Atlantic. Through the transport, sequestration and upwelling of tracers, the global overturning circulation contributes to the regulation and variability of our climate system. This thesis investigates the role of diapycnal (cross-density) mixing in regulating the deep ocean overturning circulation and the distribution of tracers carried within it. Diapycnal mixing is here quantified through a combination of pre-existing estimates inferred from different observational sources, namely Argo floats, CTD casts combined with microstructure profiles, bulk estimates from an inverse model and observation-based theoretical estimates of the mixing generated by internal tides and lee waves. Firstly, it is shown that the upwelling of abyssal waters is the residual of large near-boundary upwelling and interior downwelling, the patterns of which are highly sensitive to the specifics of the energy pathways from tides and geostrophic motions to internal waves and thereafter to mixing and dissipation. Secondly, we focus on the Atlantic Ocean, where we investigate the role of mixing in the closure of the Atlantic meridional overturning circulation. Diapycnal mixing is shown to contribute only marginally to the conversion of the dense waters formed in the North Atlantic into lighter northward-flowing waters within the Atlantic basin, but it plays a crucial role in the distribution of tracers carried from the North Atlantic to the Southern Ocean. The impact of mixing on tracer distributions is analysed both from observational mixing estimates and from pre-existing numerical simulations of a tracer release experiment in a quasi-realistic Atlantic sector model. As a tracer is carried southward by the Atlantic overturning circulation, we quantify its exchange between different water masses. The tracer transport and exchange rates are key in determining in which density classes tracers are going to upwell in the Southern Ocean, therefore determining which pathway they will follow in the global overturning circulation.
- Published
- 2021
172. Statistical physics interpretation of southern ocean mesoscale turbulence
- Author
-
David, T, Zanna, L, and Marshall, D
- Abstract
Ocean mesoscale (10-100km) turbulence is integral to the complex and interconnected climate system. Many of the assumptions made in classical turbulence theory are inappropriate for describing the characteristic features of geophysical flows. In particular, when the fluid flow is both forced and dissipative. With increased interest in stochastic parameterization of ocean eddies, it becomes pertinent to consider what the statistics of ocean turbulence should look like as well as consider what statistical physics concepts can be used to further the theoretical understanding of the ocean mesoscale. In this thesis, we examine mesoscale turbulence from both a theoretical and empirical perspective employing both idealized models and realistic ocean model data. The statistical nature of a turbulent barotropic jet is explored empirically in the context of an idealized model as well as for realistic ocean model data. Additionally, an entropic and statistical mechanics framework is investigated in the context of force-dissipative flow. It is shown that: ocean jets which exhibit strong mixing barriers have a profound effect on the statistics, leading to multi-modal probability distributions and pointing to the importance asymmetry and extreme values in the statistics; an eddy-mixing entropy, which quantifies turbulent disorder, is a useful metric in describing turbulent motions and evidence is found for the maximization of this entropy in a forced-dissipative fluid flow. Further, across the separate studies presented in this thesis, it is shown that Lagrangian information is useful in distinguishing large-scale coherent structures from the more stochastic small-scale turbulence; and high-order Casimir invariants of motion are important for describing forced-dissipative geophysical flows in a statistical mechanics framework.
- Published
- 2019
173. Climate-carbon feedback of the high latitude ocean
- Author
-
Bronselaer, B, Zanna, L, and Lowe, J
- Abstract
The warming induced by anthropogenic carbon emissions affects the climate system through a multitude of physical mechanisms. Changes in the dynamics, thermodynamics and biogeochemistry of the ocean alter the different ocean carbon reservoirs, potentially resulting in further carbon emissions and a climate- carbon feedback. Surface wind stress and surface warming are two of the most influential forcings acting on the ocean carbon system in past, present and future climates due to their influence on the mixed layer dynamics and the large scale ocean circulation. This thesis quantifies the climate-carbon feedback of wind stress and surface warming, with a particular focus on the mechanisms driving the feedbacks and the role of the Southern Ocean and the North Atlantic. To study the feedbacks, a set of theoretical scalings and a hierarchy of numerical simulations are used. Of the climate feedbacks examined, increased surface warming is likely to result in large atmospheric CO2 anomalies while the effects of North Atlantic wind stress are likely to be negligible. The atmospheric feedback of surface warming is constrained by compensating changes in separate ocean carbon reservoirs as a result of warming-induced circulation changes. Southern Ocean winds affect atmospheric CO2 through both local upwelling of carbon as well as the remote modification of Equatorial and North Atlantic chemistry. As a result, the net Southern Ocean wind stress feedback could be significant and even comparable to the temperature feedback. This thesis provides a quantification of regional and global climate-carbon feedbacks due to ocean dynamics. The estimates of carbon-climate feedbacks are useful tools for understanding past, present and future climates.
- Published
- 2016
174. The Role of Intraoperative Positive Tissue Sample Location in Predicting Septic Failure After One-Stage Septic Revision Total Hip Arthroplasty.
- Author
-
Karlidag T, Zanna L, Lee M, Gehrke T, and Citak M
- Abstract
Background: The practice of collecting various intraoperative tissue samples from diverse periarticular sites is essential for accurately identifying the responsible microorganism, making it the gold standard in the procedure for managing periprosthetic joint infection (PJI). We hypothesized that the location of positive intraoperative cultures differs significantly between patients who underwent septic revision following a one-stage exchange for hip PJI and those who did not., Methods: We conducted a retrospective case-control study at our tertiary arthroplasty center, analyzing data from January 2009 to September 2017. Our search identified 56 patients who experienced septic failure following one-stage hip revision arthroplasty for PJI. These patients were matched 1:1 by age, sex, and surgery date with a control group who had successful one-stage revision total hip arthroplasty (THA) without septic failure. Positive intraoperative tissue samples were categorized into three locations: soft-tissue, bone-prosthesis interface (superficial bone), and deep bone (intramedullary)., Results: The septic failure cohort demonstrated a statistically significant increase in both the Charlson Comorbidity Index (CCI) and Body Mass Index (BMI) compared to the control group (P < 0.001 and P = 0.01, respectively). Furthermore, a significantly greater number of positive superficial and deep bone culture samples were identified within the septic failure group (P < 0.001 and P < 0.001, respectively). Additionally, regression analysis indicated that a positive deep bone culture is associated with nearly a three-fold increase in the odds of re-infection, with an odds ratio of 2.8 (95% confidence interval: 1.1 to 7.3, P = 0.031)., Conclusion: A positive deep bone culture sample is significantly correlated with septic failure following a one-stage exchange for PJI of the hip. Patients exhibiting positive deep bone cultures may derive benefit from extended postoperative antibiotic therapy for the treatment of infection, as well as rigorous monitoring and evaluation of inflammatory markers during the follow-up phases subsequent to one-stage exchange arthroplasty., (Copyright © 2025 Elsevier Inc. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
175. Assessing the reliability of automated cell count analysis of synovial fluid in the setting of revision total knee arthroplasty.
- Author
-
Karlidag T, Zanna L, Traverso G, Lee MJ, Gehrke T, and Citak M
- Subjects
- Humans, Retrospective Studies, Female, Male, Aged, Middle Aged, Reproducibility of Results, Leukocyte Count, Aged, 80 and over, Prosthesis Failure, Knee Prosthesis adverse effects, Arthroplasty, Replacement, Knee adverse effects, Synovial Fluid chemistry, Synovial Fluid cytology, Reoperation, Prosthesis-Related Infections diagnosis
- Abstract
Purpose: The diagnostic challenges of periprosthetic joint infection (PJI) for orthopedic surgeons are significant. Prior research has indicated that patients with adverse reactions, dislocations, and aseptic loosening exhibit a heightened count of white blood cells (WBC) in their synovial fluid, along with an increased polymorphonuclear cell percentage (PMN%). The prevalence of false-positive results raises concerns about the reliability of these tools in distinguishing aseptic failure from PJI., Methods: We have performed a retrospective inquiry of the medical records of all patients who have undergone aseptic revision total knee arthroplasty (TKA) at our tertiary referral arthroplasty center. We conducted an assessment on 552 knees by applying the guidelines set forth by the 2018 International Consensus Meeting. Recorded preoperative parameters: aspiration results (WBC, PMN%, and AD immunoassay), preoperative and intraoperative diagnoses, microbiologic and histopathologic findings from periprosthetic tissue samples, and prosthetic details., Results: Among the causes of aseptic revision investigated, patients with polyethylene wear exhibited the highest median WBC count (median 1091 cells/µL, range 83.5-1715.5 cells/µL; p = 0.010). Concerning periprosthetic conditions, patients with wear-induced synovitis exhibited a significantly higher synovial fluid WBC count (median 1093 cells/µL, range 587-1683 cells/µL; p < 0.001). Among all the reasons for failure, periprosthetic fractures had the greatest percentage of WBC counts surpassing 3000 cells/µL (18.1% [2 of 11]; p = 0.006)., Conclusion: Our study has uncovered significant variations in WBC count during aseptic revision TKA when utilizing automated cell counting. Therefore, to optimize diagnostic accuracy in synovial aspiration during aseptic revision TKA, it is advisable to employ a combination of WBC count and PMN%, along with manual counting techniques or AD, depending on the specific clinical scenario., Level of Evidence: III., Competing Interests: Declarations. Conflict of interest: T.G. is a paid consultant for Waldemar Link and Zimmer Biomet. M.C. is a paid consultant for Waldemar Link. Ethical approval: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the ‘Ethikkommission der Ärztekammer Hamburg’ (2023-300352-WF). Consent to participate: Informed consent was obtained from all individual participants included in the study. Consent to publish: A statement confirming that consent to publish has been received from all participants., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2024
- Full Text
- View/download PDF
176. The Traditional Intramedullary Axis Underestimates the Medial Tibial Slope Compared to Transmalleolar Sagittal Axis in Image-based Robotic-Assisted Unicompartimental Knee Arthroplasty.
- Author
-
Chirico M, Zanna L, Akkaya M, Carulli C, Civinini R, and Innocenti M
- Subjects
- Humans, Retrospective Studies, Female, Male, Aged, Middle Aged, Knee Joint diagnostic imaging, Knee Joint surgery, Knee Joint physiopathology, Aged, 80 and over, Arthroplasty, Replacement, Knee, Tibia surgery, Tibia diagnostic imaging, Robotic Surgical Procedures, Osteoarthritis, Knee surgery, Osteoarthritis, Knee diagnostic imaging, Tomography, X-Ray Computed
- Abstract
The medial unicompartmental knee arthroplasty (mUKA) has been recognized as an excellent treatment for medial knee osteoarthritis. The posterior tibial slope (PTS) is measured radiographically with the intramedullary axis (IMA) to the tibial baseplate on the sagittal plane radiograph. However, in most computer-navigated or robotic mUKAs, the PTS is set from a transmalleolar axis (TMA).The PTS difference was evaluatedbetween the sagittal TMA and the sagittal IMA of patients undergoing a CT-based primary robotic-assisted mUKA.We retrospectively reviewed the preoperative computed tomography (CT) scans taken according to the MAKO system protocol (Stryker) of 67 patients undergoing mUKAs. We measured the angular difference between the IMA and the TMA in the sagittal plane.Using the TMA to set the PTS the estimation of the slope of the medial tibial plateau would increase by an average of 1.9 ± 3.2 degreescompared to the IMA. Furthermore, in nineknees, PTS was decreased.Tibial components implanted with the help of a CT scan-based preoperative planning MAKO will show an average of 1.9 degrees more than those measured on sagittal radiographs potentially of concern for knee kinematics. A universal language is needed to standardize the slope calculation and the respective reference axis used., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
177. The role of acetabular cement augmentation in 2-stage revision arthroplasty for prosthetic joint infection of the hip.
- Author
-
Raspanti F, Zanna L, Sangaletti R, Innocenti M, Benazzo F, Civinini R, and Mugnaini M
- Subjects
- Humans, Female, Male, Retrospective Studies, Middle Aged, Aged, Aged, 80 and over, Reoperation methods, Reoperation statistics & numerical data, Arthroplasty, Replacement, Hip methods, Arthroplasty, Replacement, Hip adverse effects, Prosthesis-Related Infections surgery, Prosthesis-Related Infections etiology, Bone Cements, Acetabulum surgery, Hip Prosthesis adverse effects
- Abstract
Introduction: In the treatment of chronic prosthetic joint infection (PJI) of the hip, two-stage exchange arthroplasty is commonly employed. Various spacer designs, including Hemi-Spacers and Articulating Spacers, are utilized during this process. However, these spacers are associated with a high rate of mechanical complications and pose a risk of progressive bone loss. This study aims to compare these two types of spacers in terms of mechanical complications, center of rotation (COR) restoration, and preservation of acetabular bone stock., Materials and Methods: From 2019 to 2022, patients who underwent two-stage exchange arthroplasty for hip PJI across three hospitals were retrospectively reviewed. Data including demographic, clinical, and microbiological information were collected. Radiographic imaging was analyzed to measure acetabular bone erosion, COR, and periacetabular bone resected. Additionally, the average surgical time in the first and second stages, mechanical complications, and the mean duration of the inter-stage period were recorded., Results: Forty patients were divided into two groups: Group A (Articulating Spacer, n = 23) received a preformed femur spacer with acetabular cement augmentation, while Group B (Hemi-Spacer, n = 17) received a preformed femur spacer alone. Acetabular cement augmentation slightly prolonged the first stage but facilitated a faster second stage during subsequent reimplantation. Spacer dislocation rates were 8.7% in Group A and 17.6% in Group B during the interstage period. Radiographic analysis revealed a statistically significant greater degree of acetabular erosion in Group B. A significant difference in Vertical-COR differential was observed, with a more proximalized revision cup compared to the primary cup in Group B, and Horizontal-COR values closer to the native hip in Group A., Conclusions: Dynamic spacers with acetabular cement augmentation help preserve peri-acetabular bone stock and prevent progression of acetabular bone erosion during the inter-stage period. Additionally, these spacers reduce the dislocation rates, making reimplantation easier and leading to better restoration of hip biomechanics during the second procedure., Competing Interests: Declarations. Ethical approval: The authors certify that the institution approved the human protocol for this investigation; all investigations were conducted in conformity with ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments. All patients have given their informed consent for participation and there is no financial interest to report. Consent for publication: Obtained. Conflict of interest: All authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Therefore, no benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2024
- Full Text
- View/download PDF
178. A Novel Radiological Classification System of the Proximal Humerus.
- Author
-
Sangaletti R, Abuljadail S, Akkaya M, Zanna L, Gehrke T, and Citak M
- Subjects
- Humans, Male, Female, Reproducibility of Results, Aged, Middle Aged, Radiography, Sensitivity and Specificity, Adult, Aged, 80 and over, Observer Variation, Humerus diagnostic imaging
- Abstract
Different anatomical variants have been reported for the proximal and distal femur. Given this context, the goal of our study was to answer the following question: Can we also identify different anatomical variants of the proximal humerus?Two hundred anteroposterior (AP) radiographs of the proximal humerus with an equal gender distribution and equal laterality per gender were reviewed. The metaphyseal diameter of the proximal humerus at the level of the anatomical neck (X) and the intramedullary diameter at 10 cm from the apex of the greater tuberosity (Y) were measured. A new ratio was established, based on both measurements (Y/X). Radiographs showed different anatomical variants: type A: Y/X < 0.3, type B: Y/X = 0.3-0.4, type C: Y/X > 0.4. Two observers reviewed the AP radiographs independently and blindly in 2 different sessions.Three different anatomical groups (A, B and C) were identified based on the 25th and 75th percentiles. A higher percentage of type C was observed among females and a higher percentage of type A among males. A high inter-observer reliability was noted, with a Cronbach's alpha of 0.97 (ICC 0.96-0.98). The intra-observer reliability for observer 1 had a Cronbach's alpha of 0.98.A novel radiological classification of the proximal humerus has been established based on 3 different anatomical types (A, B and C). Further studies are needed to establish whether the novel classification system can be used as an indicator for aseptic loosening of cemented or cementless total shoulder arthroplasty., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
179. Impact of size and fragmentation of the anteroinferior glenoid rim on clinical and functional outcomes of non-operatively treated Bony Bankart lesions in middle-aged population.
- Author
-
Secci G, Lazzarini F, Distefano M, Porciatti T, Tonelli F, Mugnaini M, and Zanna L
- Subjects
- Humans, Middle Aged, Female, Male, Prospective Studies, Shoulder Fractures therapy, Shoulder Fractures surgery, Aged, Treatment Outcome, Bankart Lesions therapy, Bankart Lesions surgery, Shoulder Dislocation therapy, Shoulder Dislocation surgery, Shoulder Joint physiopathology, Shoulder Joint surgery, Recurrence, Range of Motion, Articular
- Abstract
Introduction: The optimal treatment approach for Bony Bankart remains a subject of considerable debate among shoulder surgeons. Existing literature highlights low recurrence rates and high patient satisfaction with nonoperative treatment, particularly in the middle-aged population. This study aimed to evaluate the recurrence rate of dislocation, as well as the clinical and functional outcomes in middle-aged individuals treated nonoperatively following an acute bony Bankart fracture. Additionally, the impact of glenoid rim size and fragmentation on the treatment outcome was investigated., Material and Methods: A prospective analysis was conducted on 20 patients aged over 50 with nonoperatively treated bony Bankart fractures, ensuring a minimum follow-up of 24 months. The study population was categorized based on fragment size (small and medium) according to Kim classification and glenoid rim fragmentation (type 1b and 1c) according to Scheibel classification. Data including UCLA score, Rowe score, recurrence rate, clinical instability, and range of motion (ROM) were collected and analyzed., Results: The average UCLA and Rowe scores were 32.15 ± 2.85 and 93.85 ± 2.19, respectively, with no instances of dislocation recurrence. The affected shoulder exhibited no significant reductions in ROM compared to the contralateral side, except for a loss of external rotation (ER) (13.08° ± 7.51; p = 0.005). No differences were observed based on fragment size, although patients with multifragmented glenoid rims showed a greater loss of ER compared to those with a solitary fragment, albeit not reaching statistical significance., Conclusion: Nonoperative treatment appears to be a viable and effective option for middle-aged individuals with bony Bankart fractures, resulting in favorable functional outcomes and a low risk of recurrence. Additionally, a notable loss of external rotation was observed in fractures with glenoid rim fragmentation., Level of Evidence: IV., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
180. Intramedullary Positive Tissue Culture Increases the Risk of Reinfection Following One-Stage Septic Revision Total Knee Arthroplasty.
- Author
-
Zanna L, Lee M, Karlidag T, Luo TD, Gehrke T, and Citak M
- Subjects
- Humans, Male, Female, Aged, Middle Aged, Retrospective Studies, Reinfection, Risk Factors, Aged, 80 and over, Arthroplasty, Replacement, Knee adverse effects, Prosthesis-Related Infections etiology, Prosthesis-Related Infections surgery, Reoperation, Knee Prosthesis adverse effects
- Abstract
Background: Intraoperative acquisition of representative tissue samples is essential during revision arthroplasty of the infected total knee arthroplasty (TKA). While the number of intraoperative tissue samples needed to identify the organism is well described in the literature, there is still a paucity of evidence regarding the location of positive intraoperative samples and their correlation to postoperative outcomes., Methods: There were forty-two patients who had septic failure following one-stage revision TKA for periprosthetic joint infection who were identified between January 2009 and December 2017. They were matched to a control group of patients who had successful one-stage revision TKA without septic failure. The location of positive intraoperative tissue samples was categorized as: 1) soft tissue; 2) interface between bone and prosthesis; and 3) intramedullary (IM). Chi-square, Student's t-, and Wilcoxon Mann-Whitney U-tests were used as appropriate. Univariate and multivariate logistic regression analyses were performed to evaluate predictors of septic failure., Results: Weight > 100 kilograms (P = .033), higher Charlson Comorbidity Index (P < .001), and positive IM cultures (P < .001) were associated with a higher risk of reinfection after one-stage revision TKA. A positive IM sample carried a nearly five-fold increase in odds of reinfection (odds ratio 4.86, 95% confidence interval 1.85 to 12.78, P = .001)., Conclusions: A positive IM culture sample is significantly associated with septic failure after one-stage exchange for periprosthetic joint infection of the knee. Patients who had positive IM cultures may benefit from longer postoperative antibiotic therapy for the treatment of one-stage exchange arthroplasty to minimize the risk of reinfection., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
181. Following the Anatomy of the Proximal Tibia With a Standard Anatomic Technique and the Use of an Asymmetrical Tibial Base Plate can Lead to a Mismatched Internal Components' Rotation in Mechanically Aligned Total Knee Arthroplasty.
- Author
-
Innocenti M, Secci G, Zanna L, Sani G, Stimolo D, Matassi F, Carulli C, and Civinini R
- Abstract
Background: Tibiofemoral components rotational congruency affects the total knee arthroplasty (TKA) success. The smart insert sensor (I-S) helps to establish tibial component rotation reciprocally to a fixed femoral rotation. We aimed (1) to validate the use of I-S as a possible tool to reach reproducible reciprocal femorotibial rotation (RftR) in TKA independently from anatomic landmarks, reducing outliers in combined and mismatched femorotibial rotation (CftR and MMftR, respectively) positioning and (2) to validate the "curve-on-curve" method for a specific type of asymmetrical tibial component., Methods: From February 2018, we conducted a prospective case-control study including 106 patients undergoing TKA. Patients were divided into 2 groups based on the method used to establish tibial component rotation: with the I-S use (group A, n = 53) and with the standard "curve-on-curve" technique (group B, n = 53). Rotational alignment was calculated using the Berger protocol with postoperative computed tomography scanning. Alignment parameters measured were tibial and femoral component rotations (tR, fR), the CftR, the MMftR, and the RftR., Results: Intraoperative rotation measured by I-S correlated the best with RftR (r = 0.84; P < .001) at the post-operative CT scanning. No significant differences were found between groups A and B regarding all types of rotation (fR: P = .774; tR: P = .467; CftR: P = .847) except for MMftR ( P = .036) and RftR ( P = .023). There were no outliers in group A but 27 and 12 outliers in group B for MMftR and CftR respectively ( P < .001; P = .032)., Conclusions: The TKA components' rotation established using a smart I-S intraoperatively is ascribable to the RftR at postoperative computed tomography scan. The I-S helps reduce outliers in the CftR and MMftR. An asymmetrical tibial base plate implanted using the curve-on-curve technique does not create a neutral reciprocal femorotibial rotation significantly increasing the number of cases with mismatched femorotibial internal rotation., (© 2024 The Authors.)
- Published
- 2024
- Full Text
- View/download PDF
182. Data-driven dimensionality reduction and causal inference for spatiotemporal climate fields.
- Author
-
Falasca F, Perezhogin P, and Zanna L
- Abstract
We propose a data-driven framework to describe spatiotemporal climate variability in terms of a few entities and their causal linkages. Given a high-dimensional climate field, the methodology first reduces its dimensionality into a set of regionally constrained patterns. Causal relations among such patterns are then inferred in the interventional sense through the fluctuation-response formalism. To distinguish between true and spurious responses, we propose an analytical null model for the fluctuation-dissipation relation, therefore allowing us for uncertainty estimation at a given confidence level. We showcase the methodology on the sea surface temperature field from a state-of-the-art climate model. The usefulness of the proposed framework for spatiotemporal climate data is demonstrated in several ways. First, we focus on the correct identification of known causal relations across tropical basins. Second, we show how the methodology allows us to visualize the cumulative response of the whole system to climate variability in a few selected regions. Finally, each pattern is ranked in terms of its causal strength, quantifying its relative ability to influence the system's dynamics. We argue that the methodology allows us to explore and characterize causal relations in spatiotemporal fields in a rigorous and interpretable way.
- Published
- 2024
- Full Text
- View/download PDF
183. The impact of sustentaculum tali fracture on clinical outcome in patients affected by isolated calcaneal fractures.
- Author
-
Sani G, Giabbani N, Zanna L, Buzzi R, Pio AS, Rastrelli V, and Nardi C
- Subjects
- Humans, Fracture Fixation, Internal adverse effects, Fracture Fixation, Internal methods, Bone Screws, Foot, Treatment Outcome, Calcaneus diagnostic imaging, Calcaneus surgery, Calcaneus injuries, Fractures, Bone complications, Fractures, Bone diagnostic imaging, Fractures, Bone surgery, Ankle Injuries
- Abstract
Introduction: The sustentaculum tali is displaced in almost half of calcaneal fractures and during surgical fixation represents one of the main reference points upon which the other bone has to be reduced. The purpose of this study was to investigate which subtalar joint fracture pattern is more frequently associated with sustentaculum tali involvement. Furthermore, correlation between postoperative clinical outcome and sustentaculum tali integrity was performed., Material and Methods: Patients with isolated calcaneal fractures were analyzed. Sanders-type fracture and involvement of both sustentaculum tali and calcaneocuboid joint were detected on computed tomography imaging; postoperative AOFAS scores were analyzed according to sustentacular involvement., Results: Fifty calcaneus fractures in 47 patients were included in the final analysis. The sustentaculum tali was fractured in 18 cases (36.0%), thus contradicting its supposed constant position. Sanders type 3 and 4 fractures were more frequently associated with fractured sustentaculum than type 2 (p = 0.012). Sanders type 4 fractures were associated with displaced sustentacular fragment significantly more than type 2 and 3 (p = 0.043). Patients with intact sustentaculum tali reported significantly higher (p < 0.001) mean AOFAS scores than the uninjured group (84.4 ± 9.1 and 74.3 ± 9.5, respectively)., Conclusion: Sanders type 3 and 4 fractures were more frequently associated with sustentaculum tali and/or calcaneocuboid joint involvement than simpler fractures. Injury of sustentaculum tali was related to significant worse postoperative clinical outcomes, underlying the relevance of this fragment on clinical course., (© 2023. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
184. A new conceptual model of global ocean heat uptake.
- Author
-
Gregory JM, Bloch-Johnson J, Couldrey MP, Exarchou E, Griffies SM, Kuhlbrodt T, Newsom E, Saenko OA, Suzuki T, Wu Q, Urakawa S, and Zanna L
- Abstract
We formulate a new conceptual model, named " MT 2", to describe global ocean heat uptake, as simulated by atmosphere-ocean general circulation models (AOGCMs) forced by increasing atmospheric CO
2 , as a function of global-mean surface temperature change T and the strength of the Atlantic meridional overturning circulation (AMOC, M ). MT 2 has two routes whereby heat reaches the deep ocean. On the basis of circumstantial evidence, we hypothetically identify these routes as low- and high-latitude. In low latitudes, which dominate the global-mean energy balance, heat uptake is temperature-driven and described by the two-layer model, with global-mean T as the temperature change of the upper layer. In high latitudes, a proportion p (about 14%) of the forcing is taken up along isopycnals, mostly in the Southern Ocean, nearly like a passive tracer, and unrelated to T . Because the proportion p depends linearly on the AMOC strength in the unperturbed climate, we hypothesise that high-latitude heat uptake and the AMOC are both affected by some characteristic of the unperturbed global ocean state, possibly related to stratification. MT 2 can explain several relationships among AOGCM projections, some found in this work, others previously reported: ∙ Ocean heat uptake efficiency correlates strongly with the AMOC. ∙ Global ocean heat uptake is not correlated with the AMOC. ∙ Transient climate response (TCR) is anticorrelated with the AMOC. ∙ T projected for the late twenty-first century under high-forcing scenarios correlates more strongly with the effective climate sensitivity than with the TCR., Competing Interests: Conflict of interestNone., (© The Author(s) 2023.)- Published
- 2024
- Full Text
- View/download PDF
185. Accuracy of radiographic projections to guide cephalic screw position in pertrochanteric fracture: a cadaveric study.
- Author
-
Lazzarini F, Paoli T, Cozzi Lepri A, Secci G, Zanna L, Innocenti M, Matassi F, Carulli C, and Civinini R
- Subjects
- Humans, Bone Screws, Femur surgery, Lower Extremity, Cadaver, Fracture Fixation, Internal, Femoral Fractures surgery
- Abstract
Purpose: The aim of this study was to evaluate the relationship between the Löwenstein Lateral view and the True Lateral view for the positioning of the cephalic hip screw, through a cadaveric study., Materials and Methods: We placed two Kirschner wires in eight femur specimens using an Antero-Posterior view, Löwenstein Lateral view and True Lateral view. The distances between the Kirschner wires and the anterior, posterior, superior and inferior cortex were measured in all projections. The head of the femur was then sectioned, and the same macroscopic distances were measured. Finally, we could calculate the accuracy of the two radiographic lateral projections., Results: When the Kirschner wire was placed in the center of the head using the Antero-Posterior and the True Lateral view, the accuracy of Antero-Posterior view was 0.9705 while the accuracy of True Lateral view and Löwenstein Lateral view was 1.1479 and 1.1584, respectively. When the Kirschner wire was placed superior on the Antero-Posterior and centrally on the True Lateral view, the accuracy of Antero-Posterior view was 0.9930 while the accuracy of True Lateral view and Löwenstein Lateral view was 1.1159 and 0.7224, respectively., Conclusion: When the Kirschner wire was positioned proximal in Antero-Posterior view and central in True Lateral view, only the True Lateral view showed high accuracy., (© 2023. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
186. Anatomic Reduction of Greater Tuberosity Fragment for Shoulder Hemiarthroplasty: a Predictor of Good Clinical Outcome.
- Author
-
Lazzarini F, Distefano M, Shen T, Secci G, Cresci M, Tucci R, and Zanna L
- Abstract
Objectives: Proximal humerus fractures account for four-five % of all fractures. Shoulder hemiarthroplasty is indicated for complex fractures with high complication rates when treated with ORIF. This study aims to evaluate the correlation between the proper intraoperative tuberosity reduction, and the mid-to-long-term clinical outcome in a series of patients treated with hemiarthroplasty after proximal humerus fracture., Methods: Forty-one patients with proximal humerus fractures who underwent hemiarthroplasty surgery between July 2009 and December 2019 were retrospectively reviewed. Quantitative analysis of the reduction of the tuberosities was performed on postoperative X-rays focusing on the distance between reconstructed greater tuberosity and the apex of the head of the prosthesis, (head-tuberosity distance), and contact between tuberosity and humerus diaphysis. The University of California Los Angeles Score (UCLA) was calculated for each patient., Results: The mean time to surgery was 6.29 ± 2.8 days (range 2-18 days). Nine patients out of 41 (22%) had non anatomic tuberosity, and 32 (78%) were anatomic reduced. The UCLA score at the final follow-up was good and excellent (≥27) in 27 patients (66%), and poor (<27) in 14 (34%). A significant correlation was observed between proper tuberosity reduction and good/excellent UCLA scores (P<0.001)., Conclusion: Hemiarthroplasty is a valid and reliable technique for the treatment of proximal humerus fracture not eligible for internal fixation, with high risk of failure. The proper tuberosity reconstruction, paying special attention to the HTD and the contact between the cortical of the humeral diaphysis and the reconstructed tuberosity, is essential to reach a good clinical outcome., Competing Interests: None, (2024 © BY THE ARCHIVES OF BONE AND JOINT SURGERY.)
- Published
- 2024
- Full Text
- View/download PDF
187. What Is the Most Reliable Concordance Rate of Preoperative Synovial Fluid Aspiration and Intraoperative Biopsy to Detect Periprosthetic Joint Infection in Knee, Hip and Shoulder Arthroplasty?
- Author
-
Akkaya M, Zanna L, Sangaletti R, Bokhari A, Gehrke T, and Citak M
- Abstract
The accuracy of preoperative synovial fluid microbe detection in periprosthetic joint infection (PJI) is widely reported. However, the reliability of this diagnostic modality amongst the different joints is not yet described. We aimed to compare the concordance rate between preoperative synovial fluid and intraoperative tissue cultures in shoulder, knee and hip PJIs. A total of 150 patients who met the 2018 International Consensus Meeting criteria for shoulder, hip and knee PJI were retrospectively reviewed. This cohort was divided into three groups based on the involved joint (should, hip or knee), with 50 patients in each group. Cultures were collected and held for culture for 14 days. The overall concordance rate was 56.7%. Concordance rates between preoperative and intraoperative cultures were 60%, 56% and 54% for the knee, shoulder and hip joints, respectively. The analysis of high- or low-virulence and difficult- or not-difficult-to-treat germs did not reveal any significant differences between preoperative and intraoperative cultures in any of the groups. However, even considering the higher concordance in knee PJI, the overall discordance between preoperative and intraoperative cultures should prompt surgeons not to rely solely on preoperative synovial fluid culture data in determining appropriate treatment and antibiotics.
- Published
- 2023
- Full Text
- View/download PDF
188. Acetabular Morphology Predicts the Risk of Dislocation Following Hemiarthroplasty for Femoral Neck Fractures in the Elderly.
- Author
-
Zanna L, Innocenti M, Secci G, Cipolleschi L, Carulli C, and Civinini R
- Subjects
- Humans, Aged, Retrospective Studies, Acetabulum surgery, Hemiarthroplasty adverse effects, Joint Dislocations epidemiology, Joint Dislocations etiology, Joint Dislocations surgery, Femoral Neck Fractures surgery, Femoral Neck Fractures complications, Hip Dislocation epidemiology, Hip Dislocation etiology, Hip Dislocation surgery, Arthroplasty, Replacement, Hip adverse effects
- Abstract
Background: Hip hemiarthroplasty dislocation is a devastating complication. Among other preoperative risk factors, acetabular morphology has been rarely studied. The purpose of the study was to evaluate the influence of preoperative native acetabular morphology on hemiarthroplasty dislocation., Methods: We retrospectively reviewed 867 patients who underwent hip hemiarthroplasty for femoral neck fracture between January 1, 2014 and January 1, 2019. The 380 included patients were treated with an anterior-based muscle-sparing approach. The central-edge angle (CEA) and acetabular depth-to-width ratio (ADWR) of the fractured hip were measured preoperatively on the anteroposterior pelvic view. Receiver operating characteristic curves were performed to analyze the optimal cutoff for CEA and ADWR. Hemiarthroplasty dislocation occurred in 18 patients (4.7%), and the remaining 362 patients were used as the control group., Results: No significant differences in terms of sex, age, dementia, neuromuscular disease, and body mass index were found between the 2 groups. The 18 patients who had a hip dislocation had significantly smaller mean CEA than the control group (P = .0001) (mean 36.1 ± 7.5° and 43.2 ± 5.6°, respectively) as well as ADWR (mean 34 ± 6 versus 37 ± 4, respectively) (P = .001). Using the receiver operating characteristic analysis, we report significant cutoffs of 38.5° for CEA (P = .0001) and 34.5 for the ADWR (P = .017)., Conclusion: Higher rates of hemiarthroplasty dislocation were observed in patients who had a preoperative CEA of less than 38.5° and an ADWR of less than 34.5. Patients who have preoperative acetabular morphological risk factors for dislocation might be better candidates for a total hip arthroplasty., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
189. What is the Safe Distance Between Hip and Knee Implants to Reduce the Risk of Ipsilateral Metachronous Periprosthetic Joint Infection?
- Author
-
Akkaya M, Vles G, Sangaletti R, Zanna L, Gehrke T, and Citak M
- Subjects
- Humans, Retrospective Studies, Knee Joint surgery, Reoperation adverse effects, Prosthesis-Related Infections surgery, Prosthesis-Related Infections microbiology, Arthroplasty, Replacement, Knee adverse effects, Arthroplasty, Replacement adverse effects, Arthroplasty, Replacement, Hip adverse effects
- Abstract
Background: Periprosthetic joint infection (PJI), the most common cause of revision after TKA and THA, is a devastating complication for patients that is difficult to diagnose and treat. An increase in the number of patients with multiple joint arthroplasties in the same extremity will result in an increased risk of ipsilateral PJI. However, there is no definition of risk factors, micro-organism patterns, and safe distance between knee and hip implants for this patient group., Questions/purposes: (1) In patients with hip and knee arthroplasties on the same side who experience a PJI of one implant, are there factors associated with the development of subsequent PJI of the other implant? (2) In this patient group, how often is the same organism responsible for both PJIs? (3) Is a shorter distance from an infected prosthetic joint to an ipsilateral prosthetic joint associated with greater odds of subsequent infection of the second joint?, Methods: We designed a retrospective study of a longitudinally maintained institutional database that identified all one-stage and two-stage procedures performed for chronic PJI of the hip and knee at our tertiary referral arthroplasty center between January 2010 and December 2018 (n = 2352). Of these patients, 6.8% (161 of 2352) had an ipsilateral hip or knee implant in situ at the time of receiving surgical treatment for a PJI of the hip or knee. The following criteria led to the exclusion of 39% (63 of 161) of these patients: 4.3% (seven of 161) for incomplete documentation, 30% (48 of 161) for unavailability of full-leg radiographs, and 5% (eight of 161) for synchronous infection. With regard to the latter, per internal protocol, all artificial joints were aspirated before septic surgery, allowing us to differentiate between synchronous and metachronous infection. The remaining 98 patients were included in the final analysis. Twenty patients experienced ipsilateral metachronous PJI during the study period (Group 1) and 78 patients did not experience a same-side PJI (Group 2). We analyzed the microbiological characteristics of bacteria during the first PJI and ipsilateral metachronous PJI. Calibrated, full-length plain radiographs were evaluated. Receiver operating characteristic curves were analyzed to determine the optimal cutoff for the stem-to-stem and empty native bone distance. The mean time between the initial PJI and ipsilateral metachronous PJI was 8 ± 14 months. Patients were followed for a minimum of 24 months for any complications., Results: The risk of ipsilateral metachronous PJI in the other joint secondary to a joint implant in which PJI develops can increase up to 20% in the first 2 years after the procedure. There was no difference between the two groups in age, sex, initial joint replacement (knee or hip), and BMI. However, patients in the ipsilateral metachronous PJI group were shorter and had a lower weight (1.6 ± 0.1 m and 76 ± 16 kg). An analysis of the microbiological characteristics of bacteria at the time of the initial PJI showed no differences in the proportions of difficult-to-treat, high virulence, and polymicrobial infections between the two groups (20% [20 of 98] versus 80% [78 of 98]). Our findings showed that the ipsilateral metachronous PJI group had a shorter stem-to-stem distance, shorter empty native bone distance, and a higher risk of cement restrictor failure (p < 0.01) than the 78 patients who did not experience ipsilateral metachronous PJI during the study period. An analysis of the receiver operating characteristic curve showed a cutoff of 7 cm for the empty native bone distance (p < 0.01), with a sensitivity of 72% and a specificity of 75%., Conclusion: The risk of ipsilateral metachronous PJI in patients with multiple joint arthroplasties is associated with shorter stature and stem-to-stem distance. Appropriate position of the cement restrictor and native bone distance are important in reducing the risk of ipsilateral metachronous PJI in these patients. Future studies might evaluate the risk of ipsilateral metachronous PJI owing to bone adjacency., Level of Evidence: Level III, therapeutic study., Competing Interests: All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research ® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2023 by the Association of Bone and Joint Surgeons.)
- Published
- 2023
- Full Text
- View/download PDF
190. Outcome of surgically treated acetabular fractures: risk factors for postoperative complications and for early conversion to total hip arthroplasty.
- Author
-
Zanna L, Ceri L, Scalici G, Boncinelli D, Burchette DT, Buzzi R, and De Biase P
- Subjects
- Humans, Retrospective Studies, Acetabulum diagnostic imaging, Acetabulum surgery, Acetabulum injuries, Treatment Outcome, Postoperative Complications epidemiology, Postoperative Complications etiology, Postoperative Complications surgery, Fracture Fixation, Internal adverse effects, Risk Factors, Arthroplasty, Replacement, Hip adverse effects, Hip Fractures surgery, Fractures, Bone surgery, Fractures, Bone etiology, Spinal Fractures surgery
- Abstract
Introduction: The gold standard of Acetabular fractures treatment is open reduction and internal fixation (ORIF). Our purpose is to assess the short- to medium-term outcomes and complications of surgically treated acetabular fractures. We analysed factors influencing clinical outcomes, incidence of complications and predictors of conversion in total hip arthroplasty (THA)., Materials and Methods: We retrospectively analysed 102 patients with acetabular fracture surgically treated between December 2017 and September 2020. We evaluated the quality of reduction with x-ray measuring residual displacement, classified into 3 groups (Matta Radiological Score). At the final follow-up, radiographs were graded according to Matta's Radiological Outcome Grading, and the clinical outcomes were graded using Oxford Hip Score (OHS)., Results: 62 patients were enrolled. OHS was influenced by quality of reduction (p = 0.031), injury severity score (ISS) (p = 0.003) and BMI > 30 (p < 0.0001). The late sequelae were heterotopic ossification (HO) in 13 patients, osteoarthritis (OA) in 22 and avascular necrosis (AVN) in 4. HO was significantly affected by posterior approach and ISS > 15. The analysis showed a correlation between AVN and posterior hip dislocation. OA had a correlation with postoperative quality of reduction (p = 0.014). Eight patients required THA with a significant correlation between THA and posterior dislocation, isolated posterior wall fracture and ISS > 15., Conclusion: A high rate of patients with acetabular fractures still develop complications and require THA. Identification of predictors for poor outcome may help to inform surgical decision-making regarding options of plate osteosynthesis or 'Fix and Replace', to avoid poor outcomes and early revision surgery., (© 2022. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)
- Published
- 2023
- Full Text
- View/download PDF
191. Clinical outcomes and return to sport after single-stage revision anterior cruciate ligament reconstruction by bone-patellar tendon autograft combined with lateral extra-articular tenodesis.
- Author
-
Zanna L, Niccolò G, Matteo I, Malone J, Roberto C, and Fabrizio M
- Subjects
- Humans, Retrospective Studies, Autografts, Return to Sport, Knee Joint surgery, Tenodesis methods, Patellar Ligament surgery, Anterior Cruciate Ligament Injuries complications, Anterior Cruciate Ligament Injuries surgery, Anterior Cruciate Ligament Reconstruction adverse effects, Anterior Cruciate Ligament Reconstruction methods, Joint Instability etiology, Joint Instability surgery
- Abstract
Purpose: The anterior cruciate ligament reconstruction (ACLR) failure rate continues to increase. Involvement of a young population with a desire to return to sport, explains the increased need for ACLR (revACLR) revision. The aim of this study was to evaluate clinical outcome, complications, failure rate and return to sport of a single-stage revACLR using bone patellar tendon-bone (BTBT) combined with lateral extra-articular tenodesis (LET)., Material and Methods: A retrospective analysis was performed on 36 patients who underwent revACLR. Knee stability was assessed by Lachman and Pivot shift test. Objective anterior laxity was determined by KT-2000 arthrometer. The IKDC subjective, Lysholm, ACL-RSI Scores, level of sport activity and Forgotten Joint Score-12 were recorded., Results: Of 36 patients, we collected data from 17 who underwent single-stage revACLR with autologous BTBT combined with LET, performed using an extra-articular MacIntosh procedure as modified by Arnold-Coker. The side-to-side difference in Lachman test and Pivot shift test significantly improved postoperatively. The subjective IKDC, Lysholm and ACL-RSI significantly improved from 71.4 ± 9.03 to 92 ± 6.9, from 58.3 ± 19.3 to 66.8 ± 27.7 and from 50.4 ± 12.2 to 68.6 ± 24.5, respectively during the post-operative follow-up. Ten patients (58.8%) returned to their desired level of sport. One patient was considered a failure because of the postoperative laxity., Conclusion: Single-stage revACLR with BPTB combined with LET is a safe procedure that shows good objective and subjective outcomes, and a high rate of return to the same level of sport. Reducing rotational instability and strain on intra-articular reconstructed structures results in a low rate of complications and failure., (© 2022. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
192. Unexpected Positive Cultures in Patients Who Have a History of Septic Revision in the Same Joint.
- Author
-
Ribau A, Ekhtiari S, Budin M, Zanna L, Dasci MF, Gehrke T, and Citak M
- Subjects
- Aged, Humans, Arthroplasty, Replacement, Hip adverse effects, Arthroplasty, Replacement, Hip methods, Arthroplasty, Replacement, Knee adverse effects, Knee Joint surgery, Reoperation adverse effects, Retrospective Studies, Prosthesis-Related Infections epidemiology, Prosthesis-Related Infections etiology, Prosthesis-Related Infections surgery
- Abstract
Background: The prevalence of unexpected positive cultures (UPC) in an aseptic revision surgery of the joint with a prior septic revision in the same joint remains unknown. The purpose of this study was to determine the prevalence of UPC in that specific group. As secondary outcomes, we explored risk factors for UPC., Methods: This retrospective study includes patients who had an aseptic revision total hip/knee arthroplasty procedure with a prior septic revision in the same joint. Patients who had less than 3 microbiology samples, without joint aspiration or with aseptic revision surgery performed <3 weeks after a septic revision were excluded. The UPC was defined as a single positive culture in a revision that the surgeon had classified as aseptic according to the 2018 International Consensus Meeting. After excluding 47, a total of 92 patients were analyzed, who had a mean age of 70 years (range, 38 to 87). There were 66 (71.7%) hips and 26 (28.3%) knees. The mean time between revisions was 83 months (range, 31 to 212)., Results: We identified 11 (12%) UPC and in 3 cases there was a concordance of the bacteria compared to the previous septic surgery. There were no differences for UPC between hips/knees (P = .282), diabetes (P = .701), immunosuppression (P = .252), previous 1-stage or 2-stages (P = .316), causes for the aseptic revision (P = .429) and time after the septic revision (P = .773)., Conclusion: The prevalence of UPC in this specific group was similar to those reported in the literature for aseptic revisions. More studies are needed to better interpret the results., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
193. Setting the Tibial Component Rotation Based on Femoral Landmarks Allows Congruent Knee Kinematics in Robotic-Assisted Medial Unicompartmental Knee Replacement.
- Author
-
Innocenti M, Zanna L, Akkaya M, Huber K, Christen B, and Calliess T
- Abstract
The accurate positioning of the prosthetic components is essential for achieving successful results in medial unicompartmental knee arthroplasty (mUKA). The tibial component rotation in image-based robotic-assisted UKA is usually based on tibial bony landmarks matched to the pre-operative CT model. The study aimed to evaluate whether setting the tibial rotation on femoral CT-based landmarks allows congruent knee kinematics. We retrospectively analyzed data from 210 consecutive image-based robotic-assisted mUKA cases. In every case, we set the tibia rotation landmark parallel to the posterior condylar axis and centered it on the trochlea groove defined on the preoperative CT scan. The implant positioning was primarily set parallel to this rotation landmark and then adjusted based on tibial sizes avoiding component over- or under-hang. During surgery, we recorded the knee kinematics under valgus stress to reduce the arthritic deformity. A femoral-tibial contact point was recorded over the entire range of motion and displayed as a tracking profile on the tibia implant. The femoro-tibial tracking angle (FTTA) was then calculated based on a tangent line to the femoro-tibial tracking-points and the difference to the femur-based rotation landmark. In 48% of the cases, we could position the tibia component exactly to the femoral rotation landmark, whereas in 52% of cases, minimal adjustments were made to avoid component's under- or over-hang. The mean tibia component rotation (TRA) with reference to our femur-based landmark was +0.24° (SD ± 2.9°). The femur-based tibia rotation landmark showed a high correspondence to the FTTA with 60% of the cases having less than 1° of deviation. Mean FTTA was +0.7° (SD ± 2.2°). The mean difference between the absolute value of the TRA and the FTTA (|TRA| - |FTTA|) was -0.18° (SD ± 2°). Setting the tibial component rotation based on CT scan femoral landmarks and not on tibial anatomical landmarks is a reliable method to obtain congruent knee kinematics during image-based robotic-assisted medial UKA with less the 2° deviations on average.
- Published
- 2023
- Full Text
- View/download PDF
194. Periprosthetic joint infection in patients with multiple arthroplasties.
- Author
-
Sangaletti R, Zanna L, Akkaya M, Sandiford N, Ekhtiari S, Gehrke T, and Citak M
- Subjects
- Humans, Female, Arthroplasty, Lower Extremity, Prosthesis-Related Infections epidemiology, Prosthesis-Related Infections etiology, Arthritis, Infectious, Joint Prosthesis
- Abstract
Despite numerous studies focusing on periprosthetic joint infections (PJIs), there are no robust data on the risk factors and timing of metachronous infections. Metachronous PJIs are PJIs that can arise in the same or other artificial joints after a period of time, in patients who have previously had PJI. Between January 2010 and December 2018, 661 patients with multiple joint prostheses in situ were treated for PJI at our institution. Of these, 73 patients (11%) developed a metachronous PJI (periprosthetic infection in patients who have previously had PJI in another joint, after a lag period) after a mean time interval of 49.5 months (SD 30.24; 7 to 82.9). To identify patient-related risk factors for a metachronous PJI, the following parameters were analyzed: sex; age; BMI; and pre-existing comorbidity. Metachronous infections were divided into three groups: Group 1, metachronous infections in ipsilateral joints; Group 2, metachronous infections of the contralateral lower limb; and Group 3, metachronous infections of the lower and upper limb. We identified a total of 73 metachronous PJIs: 32 PJIs in Group 1, 38 in Group 2, and one in Group 3. The rate of metachronous infection was 11% (73 out 661 cases) at a mean of four years following first infection. Diabetes mellitus incidence was found significantly more frequently in the metachronous infection group than in non-metachronous infection group. The rate of infection in Group 1 (21.1%) was significantly higher (p = 0.049) compared to Groups 2 (6.2%) and 3 (3%). The time interval of metachronous infection development was shorter in adjacent joint infections. Concordance between the bacterium of the first PJI and that of the metachronous PJI in Group 1 (21/34) was significantly higher than Group 2 (13/38; p = 0.001). The findings of this study suggest that metachronous PJI occurs in more than one in ten patients with an index PJI. Female patients, diabetic patients, and patients with a polymicrobial index PJI are at significantly higher risk for developing a metachronous PJI. Furthermore, metachronous PJIs are significantly more likely to occur in an adjacent joint (e.g. ipsilateral hip and knee) as opposed to a more remote site (i.e. contralateral or upper vs lower limb). Additionally, adjacent joint PJIs occur significantly earlier and are more likely to be caused by the same bacteria as the index PJI., Competing Interests: M. Citak reports speaker payments from Waldemar-Link, unrelated to this study. S. Ekhtiari reports fellowship support from the ME Müller Foundation/Hip Society European Fellowship, and research grants from the PSI Foundation, the Michael G. DeGroote Foundation, and the Research Institute of St Joe's Hamilton, all of which are unrelated to this study. T. Gehrke reports speaker payments from Zimmer-Biomet, Waldemar-Link, 3M, and Ceramic, unrelated to this study., (© 2023 The British Editorial Society of Bone & Joint Surgery.)
- Published
- 2023
- Full Text
- View/download PDF
195. Successful eradication rate following one-stage septic knee and hip exchange in selected pre-operative culture-negative periprosthetic joint infections.
- Author
-
Zanna L, Sangaletti R, Lausmann C, Gehrke T, and Citak M
- Subjects
- Humans, Middle Aged, Aged, Aged, 80 and over, Retrospective Studies, Knee Joint surgery, Reoperation adverse effects, Arthroplasty, Replacement, Knee adverse effects, Prosthesis-Related Infections diagnosis, Prosthesis-Related Infections epidemiology, Prosthesis-Related Infections surgery, Arthritis, Infectious diagnosis, Arthritis, Infectious surgery, Arthritis, Infectious etiology, Arthroplasty, Replacement, Hip adverse effects
- Abstract
Purpose: The main requirement for performing the one-stage septic exchange is the pre-operative identification of the pathogen and its susceptibility. The purpose of this study is to evaluate the success rate with special focus on reinfection in a cohort of patients who underwent one-stage septic knee or hip revision for pre-operative culture-negative PJI., Methods: We retrospectively analyzed 640 patients treated by one-stage revision for chronic knee or hip PJI between January 1, 2016, and December 31, 2018. Only cases with pre-operative culture-negative PJI, with culture-negative synovial aspirations and one negative open biopsy, were analyzed. We evaluated the septic and aseptic complication and the rate of complication-free survival defined as the time from the date of first operation and the date of complication events., Results: A total of 22 patients fulfilled the inclusion and were enrolled. The mean age of the group was 73.2 ± 9.8 years, with a median ASA score of 3 (range 3-4). After mean follow-up of 3.6 ± 2.6 years, 86.4% (19 out of 22) of patients reported no complications. Two patients (9.1%) after one-stage hip required revision arthroplasty due to septic failure, while one patient (4.5%) with one-stage knee had revision for femoral component aseptic loosening., Conclusion: Our analysis suggests that the absence of pre-operative pathogen detection may not be contraindication to the one-stage revision in selected patients. The one-stage exchange might be considered in patients with pre-operative negative cultures in presence of ASA > 3 and multiple comorbidities that are not able to tolerate multiple surgeries., (© 2022. The Author(s) under exclusive licence to SICOT aisbl.)
- Published
- 2023
- Full Text
- View/download PDF
196. What is the concordance rate of preoperative synovial fluid aspiration and intraoperative biopsy in detecting periprosthetic joint infection of the shoulder?
- Author
-
Zanna L, Sangaletti R, Akkaya M, Shen T, Abuljadail S, Gehrke T, and Citak M
- Subjects
- Humans, Synovial Fluid, Shoulder, Sensitivity and Specificity, Retrospective Studies, Staphylococcus aureus, Biopsy, Prosthesis-Related Infections diagnosis, Prosthesis-Related Infections microbiology, Arthritis, Infectious
- Abstract
Background: The accuracy of preoperative synovial fluid culture for microbe detection in shoulder periprosthetic joint infection (PJI) is poorly described. To evaluate the utility of preoperative culture data for early pathogen identification for shoulder PJI, we determined the concordance between preoperative synovial fluid culture results and intraoperative tissue culture results., Methods: Fifty patients who met the 2014 Musculoskeletal Infection Society criteria for shoulder PJI between January 2016 and December 2019 were retrospectively reviewed for clinical and demographic data. This cohort of patients was divided into 2 groups based on the concordance between preoperative and intraoperative culture results. The pathogens identified on preoperative and intraoperative cultures were classified as high-virulence or low-virulence. Student's t tests and Mann-Whitney U tests were used as appropriate for continuous variables, and χ
2 and Fisher's exact tests were used as appropriate for categorical variables., Results: Concordance between preoperative aspiration and intraoperative tissue culture was identified in 28 of 50 patients (56%). Preoperative cultures positive for Gram-positive species were more likely to be concordant than discordant (P = .015). Preoperative cultures positive for Cutibacterium acnes were more likely to be concordant with intraoperative cultures (P = .022). There were more patients with polymicrobial infection in the discordant group compared with the concordant group (P < .001). No statistically significant correlation between the preoperative serum C-reactive protein level and the intraoperative category of bacteria was reported. Staphylococcus aureus and coagulase-negative Staphylococci were associated with high specificity and negative predictive value. Preoperative cultures positive for C. acnes demonstrated sensitivity, specificity, positive predictive value, and negative predictive value lower than 0.8. Gram-negative pathogens demonstrated the highest sensitivity (1) and specificity (1), whereas polymicrobial infections exhibited the lowest sensitivity and positive predictive value., Conclusion: Preoperative synovial fluid aspiration for shoulder PJI poorly predicts intraoperative culture results, with a discordance of 44%. More favorable concordance was observed for monomicrobial preoperative cultures, particularly for Gram-negative organisms and methicillin-sensitive S. aureus. The overall high rate of discordance between preoperative and intraoperative culture may prompt surgeons to base medical and surgical management on patient history and other factors and avoid relying solely on preoperative synovial fluid culture data., (Copyright © 2022 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
197. Time to Positivity of Cultures Obtained for Periprosthetic Joint Infection.
- Author
-
Tarabichi S, Goh GS, Zanna L, Qadiri QS, Baker CM, Gehrke T, Citak M, and Parvizi J
- Subjects
- Humans, Retrospective Studies, Methicillin-Resistant Staphylococcus aureus, Prosthesis-Related Infections etiology, Arthroplasty, Replacement, Knee adverse effects, Arthritis, Infectious diagnosis, Arthroplasty, Replacement, Hip adverse effects
- Abstract
Background: Despite its well-established limitations, culture remains the gold standard for microbial identification in periprosthetic joint infection (PJI). However, there are no benchmarks for the time to positivity (TTP) on culture for specific microorganisms. This study aimed to determine the TTP for pathogens commonly encountered in PJI., Methods: This retrospective, multicenter study reviewed prospectively maintained institutional PJI databases to identify patients who underwent hip or knee revision arthroplasty from 2017 to 2021 at 2 tertiary centers in the United States and Germany. Only patients who met the 2018 International Consensus Meeting (ICM) criteria for PJI and had a positive intraoperative culture were included. TTP on culture media was recorded for each sample taken intraoperatively. The median TTP was compared among different microbial species and different specimen types. Data are presented either as the mean and the standard deviation or as the median and the interquartile range (IQR)., Results: A total of 536 ICM-positive patients with positive cultures were included. The mean number of positive cultures per patient was 3.9 ± 2.6. The median TTP, in days, for all positive cultures was 3.3 (IQR, 1.9 to 5.4). Overall, gram-negative organisms (TTP, 1.99 [1.1 to 4.1]; n = 225) grew significantly faster on culture compared with gram-positive organisms (TTP, 3.33 [1.9 to 5.8]; n = 1,774). Methicillin-resistant Staphylococcus aureus (TTP, 1.42 [1.0 to 2.8]; n = 85) had the fastest TTP, followed by gram-negative rods (TTP, 1.92 [1.0 to 3.9]; n = 163), methicillin-sensitive Staphylococcus aureus (TTP, 1.95 [1.1 to 3.3] n = 393), Streptococcus species (TTP, 2.92 [1.2 to 4.3]; n = 230), Staphylococcus epidermidis (TTP, 4.20 [2.4 to 5.5]; n = 555), Candida species (TTP, 5.30 [3.1 to 10]; n = 63), and Cutibacterium acnes (TTP, 6.97 [5.9 to 8.2]; n = 197). When evaluating the median TTP according to specimen type, synovial fluid (TTP, 1.97 [1.1 to 3.1]; n = 112) exhibited the shortest TTP, followed by soft tissue (TTP, 3.17 [1.4 to 5.3]; n = 1,199) and bone (TTP, 4.16 [2.3 to 5.9]; n = 782)., Conclusions: To our knowledge, this is the first study to examine the TTP of common microorganisms that are known to cause PJI. Increased awareness of these data may help to guide the selection of appropriate antimicrobial therapy and to predict treatment outcomes in the future. Nonetheless, additional studies with larger cohorts are needed to validate these benchmarks., Level of Evidence: Diagnostic Level IV . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H337 )., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)
- Published
- 2023
- Full Text
- View/download PDF
198. The use of posteromedial portal for arthroscopic treatment of synovial chondromatosis of the knee: a case report.
- Author
-
Zanna L, Secci G, Innocenti M, Giabbani N, Civinini R, and Matassi F
- Subjects
- Humans, Male, Adult, Activities of Daily Living, Knee Joint diagnostic imaging, Knee Joint surgery, Synovectomy, Arthroscopy methods, Chondromatosis, Synovial diagnostic imaging, Chondromatosis, Synovial surgery, Joint Loose Bodies diagnostic imaging, Joint Loose Bodies surgery
- Abstract
Background: The synovial chondromatosis is an uncommon proliferative metaplastic process of the synovial cells that can develop in any synovial joint. An isolated primary chondromatosis of the posterior compartment of the knee is uncommon and few cases are reported in literature. Our purpose is to describe a rare case of primary chondromatosis of the knee posterior compartment and report the arthroscopic loose bodies excision through a difficult posteromedial portal, avoiding the use of the accessory posterior portal, most commonly reported for approaching this disease., Case Presentation: We report a rare case of a 35-year-old Caucasian male patient with diagnosis of chondromatosis of the posterior knee compartment. The radiographs showed multiple loose bodies of the posterior compartment. The MRI revealed minimal synovial hypertrophy areas, multiple osteophytes in the intercondylar notch, and loose bodies in the posteromedial compartment. The CT allowed us to assess the bony structures, the morphology of the intercondylar notch, and the presence osteophytes of the medial and lateral femoral condyles. The CT images were crucial to plan how to reach the posterior compartments of the knee through a trans-notch passage. The patient underwent arthroscopic surgery using anteromedial, anterolateral, and posteromedial portals. The tunneling through the intercondylar osteophytes was performed to allow the arthroscope to pass trans-notch. To avoid additional accessory posterior portals, we used a 70° arthroscope to better explore the posterior knee compartment. The cartilage-like bodies were removed and synovectomy of the inflamed areas was performed. The clinical and radiological follow-up was 12 months and the patient showed excellent clinical outcomes, returning to his activities of daily living and sport activity., Conclusion: Our case report highlights the importance of the arthroscopic approach to treat synovial chondromatosis, despite the involvement of the posterior compartment of the knee. An optimal preoperative imaging allows to plan for the proper surgical procedure even in patients with severe osteoarthritis. Moreover, the adoption of an intercondylar notch tunneling and a 70° arthroscope can help surgeons to better explore the posterior knee compartment, avoiding an accessory posterior trans-septal portal. Therefore, a synovectomy of the inflamed foci may be useful to prevent recurrence., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
199. Acute distal biceps tendon rupture: retrospective analysis of two different approaches and fixation techniques.
- Author
-
Di Stefano M, Sensi L, di Bella L, Tucci R, Bazzucchi E, and Zanna L
- Subjects
- Humans, Elbow, Retrospective Studies, Range of Motion, Articular, Treatment Outcome, Rupture etiology, Tendons surgery, Orthopedic Procedures methods, Tendon Injuries surgery, Arm Injuries etiology, Arm Injuries surgery, Surgical Wound surgery
- Abstract
Purpose: The aim of our study is to compare the modified double incision (DI) with bone tunnel reinsertion with the single-incision (SI) double tension slide technique in terms of clinical and functional outcomes and complication rates., Methods: A retrospective comparative analysis was performed on 65 patients treated for total distal biceps tendon rupture. The surgical technique adopted for each patient was based on the preference of two experienced elbow surgeons. The DASH and MAYO questionnaires, functional outcome and ROM were recorded in all subjects., Results: Of 65 patients, we collected data of a cohort of 54 distal biceps tendon ruptures that satisfied inclusion criteria. Twenty-five were treated by modified DI and 29 SI techniques. The recovery of the complete ROM in terms of flexion/extension and prono-supination occurred in the 79.6% of the patients, without statistical significant difference between the adopted technique. We reported a complication rate of 12% and 20.7% for DI and SI techniques, respectively, without statistical correlation (P = 0.84). The average DASH score was similar for DI and SI techniques without significant differences (P = 0,848). The Mayo score results were excellent in the majority of the patients. No significant difference in MAYO results was reported comparing the surgical techniques (P = 1)., Conclusion: Both techniques provide a reliable and strong repair with an optimal recovery of ROM returning to preinjury activity with substantially overlapping timelines., (© 2021. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
200. Correction to: Acute distal biceps tendon rupture: retrospective analysis of two different approaches and fixation techniques.
- Author
-
Distefano M, Sensi L, di Bella L, Tucci R, Bazzucchi E, and Zanna L
- Published
- 2022
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.