Applicazione della metodica di Ilizarov nella ricostruzione dell\u2019arto inferiore dopo rimozione di protesi cementata sostitutiva di ginocchio in esiti di osteosarcoma

La sopravvivenza da osteosarcoma \ue8 notevolmente aumentata nelle ultime decadi, con interventi conservativi di salvataggio dell\u2019arto nella maggior parte dei casi. L\u2019inerente svantaggio \ue8 per\uf2 che a lungo termine le endoprotesi sostitutive vanno incontro a usura, infezione, rottura, causando talvolta metallosi o fenomeni di intolleranza. I pazienti sopravvissuti a lungo termine vanno spesso incontro a numerosi reinterventi chirurgici di revisione protesica e riprotesizzazione. Gli autori descrivono l\u2019esperienza nell\u2019applicazione della metodica di Ilizarov per ricostruzione di arto inferiore in una paziente di 32 anni (G.O.), 20 anni dopo la diagnosi di osteosarcoma teleangiectasico esteso al terzo medio e distale del femore sinistro. La paziente era stata trattata con Cisplatino intra-arterioso, Adriamicina e Metotrexate ad alte dosi, rimozione di 18 cm di femore e 2 cm di tibia con applicazione di protesi sostitutiva cementata di tipo Guepard e ancora trattamento chemioterapico. A 17 anni dall\u2019impianto della protesi, la paziente, presentando infezione periprotesica ed estesa metallosi, nonch\ue9 deficit dell\u2019apparato estensore del ginocchio, veniva sottoposta a rimozione della protesi e dell\u2019abbondante cemento periprotesico con metodica SEG-CES. Le veniva applicato un fissatore esterno trifocale di tipo Ilizarov, praticando due osteotomie della tibia e applicazione di perle antibiotate. La paziente \ue8 stata successivamente sottoposta a interventi per rimozione delle perle di antibiotico, osteotomia del perone, montaggi del piede, allungamento del tendine di Achille, innesti da cresta iliaca per scarso rigenerato tibiale. Dopo trasporto di circa 18 cm di tibia, \ue8 stata praticata fusione del moncone femorale con la tibia, supportata con successo da innesti da cresta iliaca e idrossiapatite porosa. Dopo 32 mesi di trattamento, \ue8 stato rimosso il fissatore e confezionato un gesso poi sostituito da tutore su misura. Il presente caso rappresenta la prima esperienza di ricostruzione dell\u2019arto inferiore con allungamento di 18 cm di tibia e fusione tibiofemorale in esiti di tumore osseo

Recursive calculation of matrix elements for the generalized seniority shell model

A recursive calculational scheme is developed for matrix elements in the generalized seniority scheme for the nuclear shell model. Recurrence relations are derived which permit straightforward and efficient computation of matrix elements of one-body and two-body operators and basis state overlaps.Comment: 19 pages, 1 figure; published in Nucl. Phys.

2023 EULAR recommendations on imaging in diagnosis and management of crystal-induced arthropathies in clinical practice.

To formulate evidence-based recommendations and overarching principles on the use of imaging in the clinical management of crystal-induced arthropathies (CiAs). An international task force of 25 rheumatologists, radiologists, methodologists, healthcare professionals and patient research partners from 11 countries was formed according to the EULAR standard operating procedures. Fourteen key questions on the role of imaging in the most common forms of CiA were generated. The CiA assessed included gout, calcium pyrophosphate deposition disease and basic calcium phosphate deposition disease. Imaging modalities included conventional radiography, ultrasound, CT and MRI. Experts applied research evidence obtained from four systematic literature reviews using MEDLINE, EMBASE and CENTRAL. Task force members provided level of agreement (LoA) anonymously by using a Numerical Rating Scale from 0 to 10. Five overarching principles and 10 recommendations were developed encompassing the role of imaging in various aspects of patient management: making a diagnosis of CiA, monitoring inflammation and damage, predicting outcome, response to treatment, guided interventions and patient education. Overall, the LoA for the recommendations was high (8.46-9.92). These are the first recommendations that encompass the major forms of CiA and guide the use of common imaging modalities in this disease group in clinical practice

General upper bound for distributing conferencing keys in arbitrary quantum networks

Secure quantum conferencing refers to a protocol where a number of trusted users generate exactly the same secret key to confidentially broadcast private messages. By a modification of the techniques first introduced in [Pirandola, arXiv:1601.00966], we derive a single-letter upper bound for the maximal rates of secure conferencing in a quantum network with arbitrary topology, where the users are allowed to perform the most powerful local operations assisted by two-way classical communications, and the quantum systems are routed according to the most efficient multipath flooding strategies. More precisely, our analysis allows us to bound the ultimate rates that are achievable by single-message multiple-multicast protocols, where N senders distribute N independent secret keys, and each key is to be shared with an ensemble of M receivers

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

Treatment strategies for complex fractures of the tibial plateau with external circular fixation and limited internal fixation

BACKGROUND: We intended to evaluate the technique of treatment of complex fractures of the tibial plateau using external circular fixation combined with limited internal fixation, and to evaluate the treatment outcomes. METHODS: From 1992 to 2002, we treated 59 patients (40 men, 19 women) ranging in age from 23 to 63 years with the external circular fixation. All the cases were classified preoperatively as Schatzker types V, VI/Orthopedic Trauma Association 41-C1.3, C2.3, C3.1, C3.3. Five fractures were open. Three different strategies of treatment were used: (1) the frame is confined to the tibia when the external fixation is stable enough to allow knee bending; (2) the frame is extended onto the distal femur, with the proximal tibial ring located at the level of the tibial plateau when the joint surface is severely unstable; and (3) the frame is extended onto the distal femur, with the proximal tibial ring located more distally, bypassing the fracture, when the skin and soft tissue are compromised and within the fracture there is no bone suitable to place wires and pins for the external fixation construct. RESULTS: The results were evaluated as excellent in 30 patients (50.85%), good in 27 patients (45.76%), fair in 1 patient (1.695%), and poor in another 1 (1.695%). The patients' satisfaction was significantly related with the functional results. CONCLUSIONS: Our hybrid Ilizarov method combined with minimal internal fixation enables excellent to good results in most cases of complex tibial plateau fractures

Massive metallosis due to metal-on-metal impingement in substitutive long-stemmed knee prosthesis

Metallosis is a combined chemical and toxic reaction which, if the contact surface of a metal implant is large, may cause extensive damage to the surrounding tissue.1 The importance and the effects of particles generated by wear and corrosion of joint replacement prostheses have been seldom described. This case is of interest because of: (1) prosthetic loosening with massive metallosis; (2) the length of bone loss replaced by the prosthesis (180 mm); (3) a modified Guepar-type prosthesis abundantly cemented; and (4) the history of the patient. A 30-year-old white female patient presented with a 2-year history of localized swelling in the medial aspect of the proximal tibia, and knee discomfort exacerbated by walking. The patient had had a left total 180-mm femur and knee replacement 15 years earlier. A needle biopsy of a subcutaneous mass at the level of the proximal tibia eroding the underlying bone showed metallic debris granuloma with metallosis. The condition was treated by multiple revisions of the prosthesis, consisting of debridement and prosthesis axle replacement in the attempt to block the hinge. Severe black staining due to metallic wear debris and extensive corrosion and metallosis of the surrounding tissues and periprosthetic residual bone were noted