The use of tantalum cones and diaphyseal-engaging stems in tibial component revision: a consecutive series.

INTRODUCTION: Revision knee arthroplasty presents a number of challenges, including management of bone loss. The goal in managing moderate to large bone defects is fixation that is sufficient enough to allow early weight-bearing. The purpose of this study was to describe the surgical technique and clinical and radiographic outcomes of patients treated with porous tantalum metaphyseal cones in combination with long uncemented diaphyseal-engaging stems to manage tibial bone loss in revision total knee arthroplasty (TKA). MATERIALS AND METHODS: Thirty-six aseptic revision TKAs were performed at our institution between 2016 and 2019 by two senior authors. A single trabecular metal tantalum cone combined with a long (100 or 155 mm) press fit, diaphyseal-engaging stem was used in all cases to reconstruct metaphyseal bone defects and to augment tibial fixation. Cemented stems were excluded. The tibiofemoral angle was measured along the tibial and femoral shaft axes on the weight-bearing anteroposterior radiograph at final follow-up (range 15-56 months). All clinical and surgical complications, reoperations, and revisions of any component were recorded. Survivorship free of revision was evaluated at the time of the latest follow-up. RESULTS: The mean Knee Society Score (KSS) and Knee Society Function Score (KSS-F) improved significantly from 29.7 points preoperatively (range 11-54 points) to 86 points (range 43-99 points) and from 20.4 points preoperatively (range 0-55 points) to 72.3 points (range 30-90 points) (p < 0.05), respectively. Eleven tibial constructs (30.5%) had incomplete, nonprogressive radiolucent lines (≤ 2 mm). All tibial cones demonstrated osteointegration. One patient underwent a full revision for periprosthetic joint infection, and survivorship free of any component revision was 91.7% at final follow-up. CONCLUSIONS: Hybrid fixation with uncemented diaphyseal-engaging stems and porous tantalum metaphyseal cones resulted in radiographic lack of osteolysis, good clinical outcomes, and survivorship of 91.7% at a median follow-up of 33 months when considering all-cause revision as the endpoint.

Evaluation of the impact of enhanced recovery after surgery protocol implementation on maternal outcomes following elective cesarean delivery.

BACKGROUND: Despite significant improvements in outcomes following non-obstetric surgery with implementation of enhanced recovery after surgery (ERAS) protocols, development of these protocols for cesarean delivery is lacking. We evaluated implementation of an ERAS protocol for patients undergoing elective cesarean delivery, specifically the effect on opioid consumption, pain scores and length of stay as well as complications and re-admissions. METHODS: An ERAS protocol was developed and implemented for women undergoing elective cesarean delivery. The protocol construction included specific evidence-based items applicable to peripartum management and these were grouped into the three major phases of patient care: antepartum, intrapartum and postpartum. A before-and-after study design was used to compare maternal outcomes. To account for confounders between groups, a propensity matched scoring analysis was used. The primary outcome was postpartum opioid use in mg-morphine equivalents (MMEQ). RESULTS: We included 357 (n=196 before; n=161 after) women who underwent elective cesarean delivery. A significant difference in opioid consumption (28.4 ±â€¯24.1 vs 46.1 ±â€¯37.0 MMEQ, P <0.001) and in per-day postoperative opioid consumption (10.9 ±â€¯8.7 vs 15.1 ±â€¯10.3 MMEQ, P <0.001), lower peak pain scores (7 [5-9] vs 8 [7-9], P=0.007) and a shorter hospital length of stay (2.5 ±â€¯0.5 vs 2.9 ±â€¯1.2 days, P <0.001) were found after the introduction of the ERAS protocol. CONCLUSIONS: Implementation of ERAS protocols for elective cesarean delivery is associated with significant improvements in analgesic and recovery outcomes. These improvements in quality of care suggest ERAS protocols should be considered for elective cesarean delivery.

Lateral epicondylitis: This is still a main indication for extracorporeal shockwave therapy.

Extracorporeal shockwave therapy (ESWT) is used in a number of indications in the medical field. A number of tendinopathies show good and excellent results due to evidence based medicine. The treatment of lateral epicondylitis is known to show conflicting results. This overview of the published RCT's on ESWT for lateral epicondylitis tries to show the reasons for this conflicting data-base and point out, why we think that this is still a main indication for extracorporeal shockwave therapy.

Adult osteochondritis dissecans and focussed ESWT: A successful treatment option.

Extracorporeal shockwave therapy (ESWT) has gained acceptance in the medical field and in the treatment of non-unions and delayed bone healing. ESWT has been used effectively for many years as a noninvasive surgical procedure. The idea of treating Osteochondritis dissecans of knee and talus arose in the middle of the 1990's. OCD is known as a pre-arthritic factor in the long-term and still there is no consistent treatment. In the literature there is still only a small number of publications but international societies for shockwave treatment are convinced that ESWT on OCD shows to be an effective and safe method in the treatment of OCD in the early stages. We want to summarize the actual data on the treatment of OCD by ESWT.

The effects of a high-intensity free-weight back-squat exercise protocol on postural stability in resistance-trained males.

The purpose of this study was to investigate the effects of a high-intensity free-weight back-squat exercise on postural stability characteristics in resistance-trained males. Eighteen college-aged (mean ± SD: age = 22.9 ± 2.9 years; height = 175.8 ± 6.4 cm; mass = 86.3 ± 9.3 kg), resistance-trained males performed postural stability testing before and after completing five sets of eight repetitions of back-squat exercises at 80% of one-repetition maximum. A commercial balance testing device was used to assess sway index at pre- and at 0, 5, 10, 15 and 20 min post-exercise. Each balance assessment consisted of four, 20-s static stance conditions: eyes-open firm surface, eyes-closed firm surface, eyes-open soft surface and eyes-closed soft surface. Sway index was greater (P = 0.001-0.020) at Post 0 than at all other time points. No differences (P > 0.05) were observed between any other time phases. Sway index was greater (P < 0.001) for eyes-closed soft surface than all other conditions. These findings revealed sway index for all conditions significantly increased following completion of the back-squat; however, sway index recovered within 5 min of exercise. Higher sway index values as a result of neuromuscular fatigue induced by a back-squat exercise may have performance and injury risk consequences to subsequent activities that rely on postural stability. However, these findings suggest balance impairments may recover in ~5 min following high-intensity lower body resistance exercise.

Constitutional mismatch repair-deficiency and whole-exome sequencing as the means of the rapid detection of the causative MSH6 defect.

BACKGROUND: Cases of children with more than one type of cancer either diagnosed simultaneously or successively, rarely occur in pediatric oncology. A second malignant neoplasm may be caused by mutagenic effects of the treatment of the primary malignancy and/or may point towards an underlying genetic cancer susceptibility syndrome. One example of such a syndrome is constitutional mismatch repair-deficiency, (CMMR-D) which carries an increased risk of various tumors including childhood hematologic malignancies and Lynch syndrome associated tumors. Timely diagnosis of CMMR-D is crucial, since this diagnosis has implications for the entire family. PATIENT: We report the case of a 15-year-old girl who was born to consanguineous parents. At the age of 20 months she was diagnosed with a T-cell non-Hodgkin lymphoma. Treatment was given according to NHL-BFM 95. 12 years later, an invasive adenocarcinoma of the colon was surgically removed which relapsed shortly afterwards. METHODS: Whole-exome sequencing of germline DNA was employed to rapidly detect the underlying mutation in this suspected CMMR-D patient. RESULTS: After a short turnaround time of less than 3 weeks, the diagnosis of CMMR-D could be confirmed by the identification of a homozygous 29-bp deletion in MSH6 (exon 6), which was confirmed by independent methods. CONCLUSIONS: We demonstrate that "bed-side" whole-exome sequencing is both feasible and cost-effective and may be the method of choice to rapidly uncover the genetical basis of (inherited) diseases.

The impact of TEL-AML1 (ETV6-RUNX1) expression in precursor B cells and implications for leukaemia using three different genome-wide screening methods.

The reciprocal translocation t(12;21)(p13;q22), the most common structural genomic alteration in B-cell precursor acute lymphoblastic leukaemia in children, results in a chimeric transcription factor TEL-AML1 (ETV6-RUNX1). We identified directly and indirectly regulated target genes utilizing an inducible TEL-AML1 system derived from the murine pro B-cell line BA/F3 and a monoclonal antibody directed against TEL-AML1. By integration of promoter binding identified with chromatin immunoprecipitation (ChIP)-on-chip, gene expression and protein output through microarray technology and stable labelling of amino acids in cell culture, we identified 217 directly and 118 indirectly regulated targets of the TEL-AML1 fusion protein. Directly, but not indirectly, regulated promoters were enriched in AML1-binding sites. The majority of promoter regions were specific for the fusion protein and not bound by native AML1 or TEL. Comparison with gene expression profiles from TEL-AML1-positive patients identified 56 concordantly misregulated genes with negative effects on proliferation and cellular transport mechanisms and positive effects on cellular migration, and stress responses including immunological responses. In summary, this work for the first time gives a comprehensive insight into how TEL-AML1 expression may directly and indirectly contribute to alter cells to become prone for leukemic transformation.

Breakdown of the x-ray resonant magnetic scattering signal during intense pulses of extreme ultraviolet free-electron-laser radiation.

We present results of single-shot resonant magnetic scattering experiments of Co/Pt multilayer systems using 100 fs long ultraintense pulses from an extreme ultraviolet (XUV) free-electron laser. An x-ray-induced breakdown of the resonant magnetic scattering channel during the pulse duration is observed at fluences of 5 J/cm(2). Simultaneously, the speckle contrast of the high-fluence scattering pattern is significantly reduced. We performed simulations of the nonequilibrium evolution of the Co/Pt multilayer system during the XUV pulse duration. We find that the electronic state of the sample is strongly perturbed during the first few femtoseconds of exposure leading to an ultrafast quenching of the resonant magnetic scattering mechanism.

Electronic structure of an XUV photogenerated solid-density aluminum plasma.

By use of high intensity XUV radiation from the FLASH free-electron laser at DESY, we have created highly excited exotic states of matter in solid-density aluminum samples. The XUV intensity is sufficiently high to excite an inner-shell electron from a large fraction of the atoms in the focal region. We show that soft-x-ray emission spectroscopy measurements reveal the electronic temperature and density of this highly excited system immediately after the excitation pulse, with detailed calculations of the electronic structure, based on finite-temperature density functional theory, in good agreement with the experimental results.

Observation of ultrafast nonequilibrium collective dynamics in warm dense hydrogen.

We investigate ultrafast (fs) electron dynamics in a liquid hydrogen sample, isochorically and volumetrically heated to a moderately coupled plasma state. Thomson scattering measurements using 91.8 eV photons from the free-electron laser in Hamburg (FLASH at DESY) show that the hydrogen plasma has been driven to a nonthermal state with an electron temperature of 13 eV and an ion temperature below 0.1 eV, while the free-electron density is 2.8x10{20} cm{-3}. For dense plasmas, our experimental data strongly support a nonequilibrium kinetics model that uses impact ionization cross sections based on classical free-electron collisions.

Response of the oxygen sensor NreB to air in vivo: Fe-S-containing NreB and apo-NreB in aerobically and anaerobically growing Staphylococcus carnosus.

The sensor kinase NreB from Staphylococcus carnosus contains an O(2)-sensitive [4Fe-4S](2+) cluster which is converted by O(2) to a [2Fe-2S](2+) cluster, followed by complete degradation and formation of Fe-S-less apo-NreB. NreB.[2Fe-2S](2+) and apoNreB are devoid of kinase activity. NreB contains four Cys residues which ligate the Fe-S clusters. The accessibility of the Cys residues to alkylating agents was tested and used to differentiate Fe-S-containing and Fe-S-less NreB. In a two-step labeling procedure, accessible Cys residues in the native protein were first labeled by iodoacetate. In the second step, Cys residues not labeled in the first step were alkylated with the fluorescent monobromobimane (mBBr) after denaturing of the protein. In purified (aerobic) apoNreB, most (96%) of the Cys residues were alkylated in the first step, but in anaerobic (Fe-S-containing) NreB only a small portion (23%) were alkylated. In anaerobic bacteria, a very small portion of the Cys residues of NreB (9%) were accessible to alkylation in the native state, whereas most (89%) of the Cys residues from aerobic bacteria were accessible. The change in accessibility allowed determination of the half-time (6 min) for the conversion of NreB x [4Fe-4S](2+) to apoNreB after the addition of air in vitro. Overall, in anaerobic bacteria most of the NreB exists as NreB x [4Fe-4S](2+), whereas in aerobic bacteria the (Fe-S-less) apoNreB is predominant and represents the physiological form. The number of accessible Cys residues was also determined by iodoacetate alkylation followed by mass spectrometry of Cys-containing peptides. The pattern of mass increases confirmed the results from the two-step labeling experiments.

Thomson scattering on inhomogeneous targets.

The introduction of brilliant free-electron lasers enables new pump-probe experiments to characterize warm dense matter states. For instance, a short-pulse optical laser irradiates a liquid hydrogen jet that is subsequently probed with brilliant soft x-ray radiation. The strongly inhomogeneous plasma prepared by the optical laser is characterized with particle-in-cell simulations. The interaction of the soft x-ray probe radiation for different time delays between pump and probe with the inhomogeneous plasma is also taken into account via radiative hydrodynamic simulations. We calculate the respective scattering spectrum based on the Born-Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We can identify plasmon modes that are generated in different target regions and monitor their temporal evolution. Therefore, such pump-probe experiments are promising tools not only to measure the important plasma parameters density and temperature but also to gain valuable information about their time-dependent profile through the target. The method described here can be applied to various pump-probe scenarios by combining optical lasers and soft x ray, as well as x-ray sources.

Plasmon resonance in warm dense matter.

Collective Thomson scattering with extreme ultraviolet light or x rays is shown to allow for a robust measurement of the free electron density in dense plasmas. Collective excitations like plasmons appear as maxima in the scattering signal. Their frequency position can directly be related to the free electron density. The range of applicability of the standard Gross-Bohm dispersion relation and of an improved dispersion relation in comparison to calculations based on the dielectric function in random phase approximation is investigated. More important, this well-established treatment of Thomson scattering on free electrons is generalized in the Born-Mermin approximation by including collisions. We show that, in the transition region from collective to noncollective scattering, the consideration of collisions is important.

Bremsstrahlung and line spectroscopy of warm dense aluminum plasma heated by xuv free-electron-laser radiation.

We report the creation of solid-density aluminum plasma using free-electron laser (FEL) radiation at 13.5nm wavelength. Ultrashort pulses were focused on a bulk Al target, yielding an intensity of 2x10;{14}Wcm;{2} . The radiation emitted from the plasma was measured using an xuv spectrometer. Bremsstrahlung and line intensity ratios yield consistent electron temperatures of about 38eV , supported by radiation hydrodynamics simulations. This shows that xuv FELs heat up plasmas volumetrically and homogeneously at warm-dense-matter conditions, which are accurately characterized by xuv spectroscopy.

Diagnosis of gout by ultrasound.

OBJECTIVES: To establish the usefulness of ultrasonography (US) for diagnosing gout and to determine whether there are sonographic features that are characteristic for gout but not for other arthropathies. METHODS: We retrospectively compared joint images of gout patients with matching images from patients with other rheumatic conditions. Images of 37 joints of 23 patients with monosodium urate (MSU) crystal-proven gout were reviewed. MSU crystals were identified in at least one joint in each patient. Our control group had 23 randomly selected patients with 33 examined joints with rheumatic conditions other than gout. RESULTS: Specific diagnostic features included a hyperechoic, irregular band over the superficial margin of the articular cartilage described as a double contour sign in 92% of gouty joints and in none of the controls (P < 0.001); hypoechoic to hyperechoic, inhomogeneous material surrounded by a small anechoic rim, representing tophaceous material, was seen in all gouty metatarsophalangeal (MTP) joints, in all metacarpophalangeal (MCP) joints and in none of the controls (P < 0.001); erosions adjacent to tophaceous material were seen in 65% of MTP joints and in 25% of MCP joints. One erosion was seen in a MTP joint in a control patient with psoriatic arthritis. CONCLUSIONS: US can detect deposition of MSU crystals on cartilaginous surfaces (P < 0.001) as well as tophaceous material and typical erosions. US may serve as a non-invasive means to diagnose gout.

Observations of plasmons in warm dense matter.

We present the first collective x-ray scattering measurements of plasmons in solid-density plasmas. The forward scattering spectra of a laser-produced narrow-band x-ray line from isochorically heated beryllium show that the plasmon frequency is a sensitive measure of the electron density. Dynamic structure calculations that include collisions and detailed balance match the measured plasmon spectrum indicating that this technique will enable new applications to determine the equation of state and compressibility of dense matter.

[Current prescription practice of CSE inhibitors at clinic discharge after acute myocardial infarct]. / Aktuelle Verordnungspraxis von CSE-Hemmern bei Entlassung aus der Klinik nach akutem Myokardinfarkt.

We investigated the use of statins in clinical practice in patients with acute myocardial infarction in Germany in 17,732 consecutively included patients of the registries MIR-1 and MITRA-1. A clinical follow-up has been performed in the MITRA-1 study after a mean period of 18 months. In total 30% of all patients with acute myocardial infarction received statins at discharge. From 1994 to 1998 the use of statins increased from 6% to 44%; however in 1998 still less than half of the patients with acute myocardial infarction received statins at discharge. In a logistic regression model, concomittant diseases as renal failure (OR 0.7), heart failure (OR 0.7) and diabetes mellitus (OR 0.9) were associated with a lower use of statins. Age > 70 years (OR 0.5) was also associated with a lower use of statins at hospital discharge. Patients with statins at discharge had a lower long-term mortality of 5.8% versus 12.9% in patients without statins. After adjustment to age and comorbidity, use of statins at discharge was associated with a borderline significant reduction of long-term mortality (multivariate OR 0.7, 95% CI 0.4-1.0). In a subgroup analysis of therapeutic benefit, measured by the "number needed to treat" (NNT), the number of patients to treat with statins to save one life, patients with cardiovascular risk factors, as heart failure (NNT 7.5), diabetes mellitus (NNT 7.8) and age > 70 years (NNT 13.8) had a larger therapeutic benefit as patients without these risk factors (NNT 345). However, these high-risk patients received less often statins than patients without risk factors (use of statins 11.8% versus 19.8%).

Correlations between the duration of pain and the success of shock wave therapy.

Patients who have had successful treatment for either chronic heel pain (plantar fasciitis) or humeral epicondylitis subsequently were evaluated for a comparable problem in the contralateral heel or elbow. Patients who had experienced symptoms in the contralateral heel or elbow for a shorter period were less likely to have a positive result from shock wave therapy than those patients who had received treatments for more chronic symptoms.

Sepsis and catecholamine support are the major risk factors for critical illness polyneuropathy after open heart surgery'.

BACKGROUND: Critical illness polyneuropathy (CIP) remains a problem after open heart surgery. Recently, we reported about a retrospectively performed study pointing out that sepsis, the application of higher amounts of catecholamines and intervention such as chronic venovenous hemodiafiltration may be involved in the onset of CIP. A prospectively performed study is presented in order to evaluate the significance of risk factors initially after open heart surgery. METHODS: From June 1997 until September 1998, patients undergoing open heart surgery and being ventilated beyond 3 days were prospectively enrolled in the study and underwent a standard protocol of electromyographic investigation in order to determine CIP. Several items were recorded: amount of catecholamines, serum levels of urea, creatinine, albumin, and glucose. The duration of sepsis and chronic venovenous hemodiafiltration were reevaluated. Additionally the age, the left ventricular end-diastolic pressure prior to the operation, the time of ICU stay and the time of ventilatory support were compared. RESULTS: Within the observation period, 37 adult patients could be enrolled in the study, whereas 12 patients did develop CIP and 7 patients did not. Patients developing CIP required significantly different amounts of epinephrine (0.17 +/- 0.02 vs. 0.09 +/- 0.01 mg/kg/day, p < 0.05, t-test) higher amounts of norepinephrine (0.06 +/- 0.02 vs. 0.02 +/- 0.01 mg/kg/day, p<0.05, t-test), and lesser dosages of dobutamine (2.2 +/- 0.5 vs. 4.9 +/- 0.7, p<0.05, t-test). After cardiac surgery, the plasma levels of urea was initially significantly elevated in patients developing CIP (127.4 +/- 10.5 vs 97.3 +/- 18.5, p<0.05, t-test) Patients suffering from CIP stayed significantly longer in the ICU (40.3 +/- 11.7 vs. 19.6 +/- 11.3 days, p < 0.05 t-test) with an extended time of ventilator support. (769.6 +/- 05.0 vs 295.0 +/- 134.0 hours, p<0.05, t-test). Patients of the CIP group were suffering significant longer from sepsis than patients without CIP. CONCLUSIONS: Sepsis and catecholamine support and an increased level of urea were associated with the development of CIP. The prevention of sepsis and a modulation of the catecholamine support in order to improve microcirculatory flow may reduce the onset of CIP in patients undergoing open heart surgery.

Effect of intravenous magnesium on ventricular tachyarrhythmias associated with acute myocardial infarction.

Ventricular ectopy and left ventricular dysfunction are important predictive factors for an unfavourable outcome following an acute myocardial infarction (MI). Tachyarrhythmias are a major cause of death subsequent to MI. Magnesium was postulated to have an antiarrhythmic effect after MI. Therefore we have investigated the influence of intravenous and oral magnesium (Mg) therapy on ventricular tachyarrhythmias. 67 patients with myocardial infarction (MI) diagnosed according to the WHO criteria of anamnesis, infarct-specific electrocardiogram (ECG), and enzymatic status were included in a prospective study. 23 patients (group 1) received 2 g Mg per day (= 82 mmol Mg/24 h) intravenously for the first 3 days followed by oral magnesium adipate administration of 3 x 2 coated tablets of magnesium 50 Apogepha (= 300 mg Mg/24 h or 12.34 mmol Mg/24 h, respectively) for the full duration of the study. 26 patients (group 2) received only i.v. magnesium for the first 3 days after admission (2 g Mg/24 h). The results of this treatment were compared to those of a control group of 18 MI patients without magnesium administration. All groups were identical with regard to other forms of treatment. The magnesium levels in serum and erythrocytes of all patients were measured at the following time points: days 0 (admission time), 1, 2, the day of discharge (about day 20) and after 12 weeks. The tachyarrhythmias were monitored by 24-h-continuous-electrocardiography on days 0, 1 and on the day before discharge (about day 20). The serum magnesium levels rose significantly during i.v. Mg-administration (1 and 2 day) but decreased in group 2 subsequently until the time of discharge from hospital. In contrast group 1 patients receiving oral as well as intravenous magnesium did not show this drop. The uptake of magnesium into the erythrocytes was less obvious. The erythrocyte magnesium concentration of the control group remained significantly low in serum and red blood cells. Significantly less ventricular premature beats and runs (< 5 ventricular premature beats and > 5 ventricular premature beats) compared to admission day were observed in both treated groups. These data suggest that the frequency of ventricular tachyarrhythmias is reduced by administration of intravenous magnesium and support an early high dose administration of intravenous magnesium in the wake of myocardial infarction.