Blade-plate fixation for distal femoral fractures: A case-control study

AbstractBackgroundThe blade-plate is the earliest of the contemporary internal fixation devices introduced for distal femoral fractures. The recent development of dedicated, fixation devices has considerably limited its use. The objective of this study was to evaluate outcomes after blade-plate fixation and after fixation using other devices.HypothesisOutcomes after blade-plate fixation are similar to those after condylar screw-plate, distal femoral nail, or locking condylar plate fixation.Material and methodsWe reviewed outcomes after 62 patients managed with blade-plate fixation and included in a multicentre retrospective study (n=57) or a multicentre prospective study (n=5) and we compared them to outcomes after fixation using condylar screw-plates (n=82), distal femoral nail (n=219), or locking condylar plates (n=301). The four groups were comparable for age, gender distribution, occupational status, prevalence of skin wounds, patient-related factors, type of accident, and type of fracture. The evaluation relied on the clinical International Knee Society (IKS) score and on radiographs.ResultsNo significant differences existed across the four groups for operative time, blood transfusion use, complications, need for bone grafting, non-union rate, or IKS score values. The early surgical revision rate for removal of the fixation material was 4% with the blade-plate and 16% with the other three fixation devices (P=0.02). Post-operative fracture deformity was similar in the four groups with, however, a higher proportion of residual malalignment in the screw-fixation group. The final anatomic axis was 3.3±1.4° with the blade-plate versus 2.3±3.7° with the other three fixation devices. The blade-plate group had few patients with axial malalignment, and the degree of malalignment was limited to 3° of varus and 10° of valgus at the most, compared to 10° and 18° respectively, with the other three fixation devices.ConclusionDespite the now extremely limited use and teaching of blade-plate fixation, as well as the undeniable technical challenges raised by the implantation of this device, the blade-plate is a simple, strong, and inexpensive fixation method. It remains reliable for the fixation of distal femoral fractures. The disfavour into which the blade-plate is currently falling is not warranted.Level of evidenceIII, case-control study

Epidemiology of distal femur fractures in France in 2011–12

AbstractIntroductionEpidemiological study of femoral fractures has been dominated by proximal fractures. Distal fracture requires equal attention for correct management.Patients and methodsA prospective study in 12 French hospital centres between June 1st, 2011 and May 31st, 2012 recruited cases of non-pathologic distal femoral fracture in patients over 15 years of age without ipsilateral knee prosthesis.ResultsThere were 183 fractures in 177 patients. Mean age was 63.5 years. Female patients (60.5%) were significantly older than males (mean age, respectively 73 versus 48.4 years). Walking was unrestricted in only 83 patients (46.89%). On the AO/OTA (Orthopaedic Trauma Association) classification, there were 86 type A fractures (47%), 29 type B (15.8%) and 68 type C (37.2%). Fractures were open in 32 cases (17.5%), most frequently in male, young patients and type C fracture. Causal trauma was low-energy (fall from own height) in 108 cases, most frequently in female patients and type A fracture. Forty-five patients were proximal femoral implant bearers.ConclusionDistal femoral fracture shows highly variable epidemiology. AO/OTA type A fracture mainly involves elderly, relatively dependent female subjects. Outcome study requires radiographic data and assessment of functional capacity.Level of evidence IVProspective cohort study

Primary total knee arthroplasty in the management of epiphyseal fracture around the knee

SummaryIntroductionOver the past few years the use of arthroplasty was broadened to treating complex epiphyseal fractures at the shoulder and elbow joints. Similar trends to treat this type of fractures at the knee are less documented. Based on a multicenter retrospective series study, the aims of this work is to evaluate the short term clinical results of total knee prostheses in the management of comminuted epiphyseal fractures around the knee, to identify the technical issues and fine tune the indications.Material and methodsFollowing the initiative of the French Hip and Knee Society (SFHG) and the Traumatology Study Group (GETRAUM), 26 charts from eight different centers in France were included in this multicenter retrospective series. Inclusion criteria were: primary total knee arthroplasty (TKA) in the management of complex articular fractures involving the proximal end of the tibia or distal end of the femur. Surgical features were identified and complications were analyzed. The assessment protocol at last follow-up was standardized and included patient demographic data, analysis of the Parker and IKS scores.ResultsDuring the immediate postoperative period, six patients (23%) reported a general complication and four patients (15%) a local arthroplasty-related complication. At last follow-up (mean 16.2 months), the overall final Parker score was 6.3 (a mean decrease of 1.7) and the mean IKS knee score was 82 points for a mean function score of 54 points.DiscussionPrimary TKA is a suitable management option for complex fractures in autonomous elderly patients suffering from knee osteoarthritis. The key technical details of this procedure should be respected and meticulously planned to achieve optimal results and limit the risk of complications. This risk in these acute complex fractures remains higher than after conventional TKA but comparable to that observed after TKA for post-traumatic arthritis.Level of evidenceIV; retrospective cohort study

Searching for sub-stellar companion into the LkCa15 proto-planetary disk

Recent sub-millimetric observations at the Plateau de Bure interferometer evidenced a cavity at ~ 46 AU in radius into the proto-planetary disk around the T Tauri star LkCa15 (V1079 Tau), located in the Taurus molecular cloud. Additional Spitzer observations have corroborated this result possibly explained by the presence of a massive (>= 5 MJup) planetary mass, a brown dwarf or a low mass star companion at about 30 AU from the star. We used the most recent developments of high angular resolution and high contrast imaging to search directly for the existence of this putative companion, and to bring new constraints on its physical and orbital properties. The NACO adaptive optics instrument at VLT was used to observe LkCa15 using a four quadrant phase mask coronagraph to access small angular separations at relatively high contrast. A reference star at the same parallactic angle was carefully observed to optimize the quasi-static speckles subtraction (limiting our sensitivity at less than 1.0). Although we do not report any positive detection of a faint companion that would be responsible for the observed gap in LkCa15's disk (25-30 AU), our detection limits start constraining its probable mass, semi-major axis and eccentricity. Using evolutionary model predictions, Monte Carlo simulations exclude the presence of low eccentric companions with masses M >= 6 M Jup and orbiting at a >= 100 AU with significant level of confidence. For closer orbits, brown dwarf companions can be rejected with a detection probability of 90% down to 80 AU (at 80% down to 60 AU). Our detection limits do not access the star environment close enough to fully exclude the presence of a brown dwarf or a massive planet within the disk inner activity (i.e at less than 30 AU). Only, further and higher contrast observations should unveil the existence of this putative companion inside the LkCa15 disk.Comment: 6 pages, 4 figures, accepted for publication in A&

First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations from the 2014 Long Baseline Campaign in dust continuum and spectral line emission from the HL Tau region. The continuum images at wavelengths of 2.9, 1.3, and 0.87 mm have unprecedented angular resolutions of 0.075 arcseconds (10 AU) to 0.025 arcseconds (3.5 AU), revealing an astonishing level of detail in the circumstellar disk surrounding the young solar analogue HL Tau, with a pattern of bright and dark rings observed at all wavelengths. By fitting ellipses to the most distinct rings, we measure precise values for the disk inclination (46.72pm0.05 degrees) and position angle (+138.02pm0.07 degrees). We obtain a high-fidelity image of the 1.0 mm spectral index ($\alpha$), which ranges from $\alpha\sim2.0$ in the optically-thick central peak and two brightest rings, increasing to 2.3-3.0 in the dark rings. The dark rings are not devoid of emission, we estimate a grain emissivity index of 0.8 for the innermost dark ring and lower for subsequent dark rings, consistent with some degree of grain growth and evolution. Additional clues that the rings arise from planet formation include an increase in their central offsets with radius and the presence of numerous orbital resonances. At a resolution of 35 AU, we resolve the molecular component of the disk in HCO+ (1-0) which exhibits a pattern over LSR velocities from 2-12 km/s consistent with Keplerian motion around a ~1.3 solar mass star, although complicated by absorption at low blue-shifted velocities. We also serendipitously detect and resolve the nearby protostars XZ Tau (A/B) and LkHa358 at 2.9 mm.Comment: 11 pages, 5 figures, 2 tables, accepted for publication in the Astrophysical Journal Letter

Circumstellar discs: What will be next?

This prospective chapter gives our view on the evolution of the study of circumstellar discs within the next 20 years from both observational and theoretical sides. We first present the expected improvements in our knowledge of protoplanetary discs as for their masses, sizes, chemistry, the presence of planets as well as the evolutionary processes shaping these discs. We then explore the older debris disc stage and explain what will be learnt concerning their birth, the intrinsic links between these discs and planets, the hot dust and the gas detected around main sequence stars as well as discs around white dwarfs.Comment: invited review; comments welcome (32 pages

An Overview of the 2014 ALMA Long Baseline Campaign

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the Astrophysical Journal Letters; this version with small changes to affiliation

Identification of amino acid residues responsible for von Willebrand factor binding to sulfatide by charged-to-alanine-scanning mutagenesis

von Willebrand factor (VWF) performs its hemostatic functions through binding to various proteins. The A1 domain of VWF contains binding sites of not only physiologically important ligands, but also exogenous modulators that induce VWF-platelet aggregation. Sulfatides, 3-sulfated galactosyl ceramides, that are expressed on oligodendrocytes, renal tubular cells, certain tumor cells and platelets, have been suggested to interact with VWF under some pathological conditions. The binding of VWF to sulfatide requires the A1 domain, but its binding sites have not been precisely identified. Here, we report that alanine mutations at Arg1392, Arg1395, Arg1399 and Lys1423 led to decreased VWF–sulfatide binding. These sites have been reported to be the binding sites for platelet membrane glycoprotein (GP) Ib and/or snake venom botrocetin, and, interestingly, are identical to the monoclonal antibody (mAb) NMC4 epitope previously reported to inhibit the VWF-GPIb interaction. We observed that NMC4 also inhibited VWF interaction with sulfatides in a dose-dependent manner. Thus, we conclude that VWF binding sites of sulfatide overlap those of platelet GPIb and botrocetin

Iliotibial band release as an adjunct to the surgical management of patellar stress fracture in the athlete: a case report and review of the literature

Stress fracture of the patella is rare. In this report, a case of patellar stress fracture occurring in an amateur athlete is presented, and an operative adjunct to the surgical management of this condition is proposed

The Event Horizon Telescope Image of the Quasar NRAO 530

We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5−7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of ∼20 μas, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of ∼5%-8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle ∼ −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin