Total Knee Arthroplasty for Post-Traumatic Proximal Tibial Bone Defect: Three Cases Report

Bone stock deficiency in primary as well as in revision total knee arthroplasty (TKA) represents a difficult problem to surgeon with regard to maintaining proper alignment of the implant components and in establishing a stable bone-implant interface. Different surgical procedures are available in these situations, for instances the use of bone cement, prosthetic augments, custom implant, and wire mesh with morsellized bone grafting and structural bone allograft. Structural allograft offers a numerous advantages as easy remodeling and felling cavitary or segmental defects, excellent biocompatibility, bone stock restoration and potential for ligamentous reattachment. In this article we report a short term result of three cases affected by severe segmental medial post/traumatic tibial plateau defect in arthritic knee, for which massive structural allograft reconstruction and primary total knee replacement were carried. The heights of the bone defect were between 27-33 mm and with moderate medio-lateral knee instability. Pre-operative AKS score in three cases was 30, 34 and 51 points consecutively and improved at the last follow-up to 83, 78 and 85 consecutively. No acute or chronic complication was observed. Last radiological exam referred no signs of prosthetic loosening, no secondary resorption of bone graft and well integrated graft to host bone. These results achieved in our similar three cases have confirmed that the structural bone allograft is a successful biological material to restore hemi-condylar segmental tibial bone defect when total knee replacement is indicated

Rapid communications Ongoing outbreak of visceral leishmaniasis in Bologna

(VL) cases has recently been reported in Bologna Province in northern Italy. Over six months from November 2012 to May 2013, 14 cases occurred, whereas the average number of cases per year was 2.6 (range: 0–8) in 2008 to 2012. VL was diagnosed in a median of 40 days (range: 15–120) from disease onset. This delay in diagnosis shows the need for heightened awareness of clinicians for autochthonous VL in Europe. From November 2012 to May 2013, public health authorities, microbiologists and clinicians in Bologna Province, northern Italy, noted an upsurge in human cases of visceral leishmaniasis. During these six months, 14 cases were notified, an over five-fold increase compared with the annual average of 2.

“Different Strokes”: A management dilemma

Stroke is a common medical emergency resulting from numerous pathophysiological mechanisms and with varied clinical manifestations; as such, the diagnosis of stroke requires diligent clinical assessment. When different stroke syndromes occur in the same patient, it may cause a dilemma in terms of diagnosis and management. This continuing medical education article describes an interesting patient with recurrent neurological events, highlighting the complex pathophysiological processes associated with cerebrovascular syndromes. It offers readers the opportunity to apply their own basic neuroscience knowledge and clinical skills to solve the challenges encountered during the course of diagnosing and treating this patient. Specifically, the article aims to familiarise readers with an approach to diagnosing brainstem strokes and the diverse manifestations of a common stroke syndrome. Keywords: Stroke; Lacunar Stroke; Cerebral Hemorrhage; Cerebral Small Vessel Disease; Continuing Medical Education

Ongoing outbreak of visceral leishmaniasis in Bologna Province, Italy, November 2012 to May 2013

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Spectrum of Cerebral Venous Thrombosis in Oman

Objectives: Cerebral venous thrombosis (CVT) can have varied and life-threatening manifestations. This study aimed to examine the spectrum of its clinical presentations and outcomes in a tertiary hospital in Oman. Methods: This retrospective study was conducted at the Sultan Qaboos University Hospital, Muscat, Oman, between January 2009 and December 2017. The medical records of all patients with CVT were reviewed to determine demographic characteristics, clinical features and patient outcomes. Results: A total of 30 patients had CVT. The mean age was 36.8 ± 11 years and the male-to-female ratio was 2:3. Common manifestations included headache (83%), altered sensorium (50%), seizures (43%) and hemiparesis (33%). Underlying risk factors were present in 16 patients (53%). Computed tomography or magnetic resonance imaging of the brain was abnormal in all patients, with indications of infarcts (40%) and major sinus thrombosis (100%). There were five cases (20%) of deep CVT. The patients were treated with low-molecular-weight heparin, mannitol and anticonvulsants. The majority (77%) had no residual neurological deficits at follow-up. Conclusion: These findings indicate that CVT is a relatively uncommon yet treatable disorder in Oman. A high index of suspicion, early diagnosis, prompt anticoagulation treatment and critical care may enhance favourable patient outcomes. Keywords: Venous Thrombosis; Cerebral Thrombosis; Cranial Venous Sinuses; Neurological Manifestations; Patient Outcome Assessment; Oman

A large topographic feature on the surface of the trans-Neptunian object (307261) 2002 MS4_4 measured from stellar occultations

This work aims at constraining the size, shape, and geometric albedo of the dwarf planet candidate 2002 MS4 through the analysis of nine stellar occultation events. Using multichord detection, we also studied the object's topography by analyzing the obtained limb and the residuals between observed chords and the best-fitted ellipse. We predicted and organized the observational campaigns of nine stellar occultations by 2002 MS4 between 2019 and 2022, resulting in two single-chord events, four double-chord detections, and three events with three to up to sixty-one positive chords. Using 13 selected chords from the 8 August 2020 event, we determined the global elliptical limb of 2002 MS4. The best-fitted ellipse, combined with the object's rotational information from the literature, constrains the object's size, shape, and albedo. Additionally, we developed a new method to characterize topography features on the object's limb. The global limb has a semi-major axis of 412 $\pm$ 10 km, a semi-minor axis of 385 $\pm$ 17 km, and the position angle of the minor axis is 121 $^\circ$ $\pm$ 16$^\circ$. From this instantaneous limb, we obtained 2002 MS4's geometric albedo and the projected area-equivalent diameter. Significant deviations from the fitted ellipse in the northernmost limb are detected from multiple sites highlighting three distinct topographic features: one 11 km depth depression followed by a 25$^{+4}_{-5}$ km height elevation next to a crater-like depression with an extension of 322 $\pm$ 39 km and 45.1 $\pm$ 1.5 km deep. Our results present an object that is $\approx$138 km smaller in diameter than derived from thermal data, possibly indicating the presence of a so-far unknown satellite. However, within the error bars, the geometric albedo in the V-band agrees with the results published in the literature, even with the radiometric-derived albedo

Pluto's lower atmosphere and pressure evolution from ground-based stellar occultations, 1988-2016

Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft. Aims. The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015. Methods. Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ~5 and ~380 km (i.e. pressures from ~ 10 μbar to 10 nbar). Results. (i) Pressure has suffered a monotonic increase from 1988 to 2016, that is compared to a seasonal volatile transport model, from which tight constraints on a combination of albedo and emissivity of N2 ice are derived. (ii) A central flash observed on 2015 June 29 is consistent with New Horizons REX profiles, provided that (a) large diurnal temperature variations (not expected by current models) occur over Sputnik Planitia; and/or (b) hazes with tangential optical depth of ~0.3 are present at 4–7 km altitude levels; and/or (c) the nominal REX density values are overestimated by an implausibly large factor of ~20%; and/or (d) higher terrains block part of the flash in the Charon facing hemisphere

Tricalcium phosphate and hydroxyapatite ceramics in the surgery of bone tumors: preliminary results.

The authors report their preliminary experience in the use of substitutive bone compounds in order to fill the bone cavity after curettage. The material used is constituted by a biphasic compound, made up of tricalcium phosphate and hydroxyapatite. Twenty-one patients were submitted to surgery because of the presence of a benign or low-grade malignant tumor. After removing the neoplastic tissue the residual cavity was filled with: tricalcium phosphate/hydroxyapatite (5 cases); tricalcium phosphate/hydroxyapatite plus autogenous bone (8 cases); tricalcium phosphate/hydroxyapatite plus bone allografts (8 cases). A radiological evaluation obtained 12 months after treatment showed that the incorporation of the compound in granular form was nearly complete in most of the cases, while the blocks revealed partial remodelling which was more evident in the angles. Finally, bone resorption in the site of the compounds used was not observed