Excellent Survival and Good Outcomes at 15 Years Using the Press-Fit Condylar Sigma Total Knee Arthroplasty.

BACKGROUND: We report 15-year survival, clinical, and radiographic follow-up data for the Press-Fit Condylar Sigma total knee arthroplasty. METHODS: Between October 1998 and October 1999, 235 consecutive TKAs were performed in 203 patients. Patients were reviewed at a specialist nurse-led clinic before surgery and at 5, 8-10, and 15 years postoperatively. Clinical outcomes, including Knee Society Score, were recorded prospectively at each clinic visit, and radiographs were obtained. RESULTS: Of our initial cohort, 99 patients (118 knees) were alive at 15 years, and 31 patients (34 knees) were lost to follow-up. Thirteen knees (5.5%) were revised; 5 (2.1%) for infection, 7 (3%) for instability, and 1 (0.4%) for aseptic loosening. Cumulative survival with the end point of revision for any reason was 92.3% at 15 years and with revision for aseptic failure as the end point was 94.4%. The mean Knee Society Score knee score was 77.4 (33-99) at 15 years, compared with 31.7 (2-62) preoperatively. Of 71 surviving knees for which X-rays were available, 12 (16.9%) had radiolucent lines and 1 (1.4%) demonstrated clear radiographic evidence of loosening. CONCLUSION: The Press-Fit Condylar Sigma total knee arthroplasty represents a durable, effective option for patients undergoing knee arthroplasty, with excellent survival and good clinical and radiographic outcomes at 15 years.

Metaphyseal Sleeves for Revision Total Knee Arthroplasty: Good Short-Term Outcomes.

Metaphyseal sleeve prostheses have shown promising results in the management of bone defects at revision TKA. We present a study of their use in aseptic revision TKA. Thirty-five revisions were included in 34 patients with wear or aseptic loosening indicated in 71% of cases. The majority of cases (63%) were AORI grade 2 or greater on the tibia or femur. Knee Society scores were excellent or good in 83% of patients with the same percentage having no or only mild pain. One patient suffered a sleeve-related complication with femoral condylar fractures three years postoperatively; these united with good outcomes. All radiographs were satisfactory; no patient required a further revision. We report good outcomes with the use of metaphyseal sleeves in revision TKA.

Results of Using a "2-in-1" Single-Stage Revision Total Knee Arthroplasty for Infection with Associated Bone Loss: Prospective 2-Year Follow-Up.

Prosthetic joint infections provide a complex challenge for management, owing to their often difficult diagnoses, need for multiple surgeries, and increased technical and financial requirements. The '2 in 1' single-stage approaches have been recently advocated in the field of arthroplasty on account of their reduction in risks, costs, and complications. The aim of our study was to investigate the outcomes of this variant of single-stage revision, which is used in the setting of infection following primary total knee replacement (TKR) and associated bone loss. Prospective data were collected from all patients presenting with an infection following primary TKR over an 8-year period (2009-2017). We examined revision procedures that were undertaken as a single-stage procedure and had bone loss present. Patients were followed-up for evidence of recurrent infection. Functional assessments were conducted using range of motion, Oxford Knee Score (OKS), American Knee Society Score (AKSS), and Short Form-12 (SF-12) survey. Twenty-six patients were included in the analysis, two of whom had previously failed 2 stage revision; another three among them had failed debridement, antibiotics, irrigation, and implant retention procedures. The mean age was 72.5 years, mean body mass index was 33.4, and median American Society of Anesthesiologists (ASA) physical status classification was 2. The mean time to revision was 3.5 years (3 months to 12 years). Six patients had actively been discharging sinuses at the time of surgery. Only 4/26 patients possessed no positive microbiological cultures from deep tissue samples or joint aspirates. One patient was afflicted with a recurrence of infection. This patient did not require further surgery and was successfully treated with the help of long-term antibiotic suppression. There were statistically significant improvements in both the pain component of AKSS scores (preoperative 4.3 to postoperative 32.4) and the functional component of AKSS scores (preoperative 10.7 to postoperative 15.7). There was no significant improvement in flexion; however, mean extension (increased from 18.5 to 6.9 postoperative) and total range of motion (increased from 69.2 preoperative to 90.3 postoperative) both showed statistically significant improvements. The use of "2-in-1" single-stage revision can be considered as an effective option for treating infection following TKR and associated bone loss.

High resolution time- and angle-resolved photoemission spectroscopy with 11 eV laser pulses.

Performing time- and angle-resolved photoemission (tr-ARPES) spectroscopy at high momenta necessitates extreme ultraviolet laser pulses, which are typically produced via high harmonic generation (HHG). Despite recent advances, HHG-based setups still require large pulse energies (from hundreds of µJ to mJ) and their energy resolution is limited to tens of meV. Here, we present a novel 11 eV tr-ARPES setup that generates a flux of 5 × 1010 photons/s and achieves an unprecedented energy resolution of 16 meV. It can be operated at high repetition rates (up to 250 kHz) while using input pulse energies down to 3 µJ. We demonstrate these unique capabilities by simultaneously capturing the energy and momentum resolved dynamics in two well-separated momentum space regions of a charge density wave material ErTe3. This novel setup offers the opportunity to study the non-equilibrium band structure of solids with exceptional energy and time resolutions at high repetition rates.

Inverse correlation between quasiparticle mass and T c in a cuprate high-T c superconductor.

Close to a zero-temperature transition between ordered and disordered electronic phases, quantum fluctuations can lead to a strong enhancement of electron mass and to the emergence of competing phases such as superconductivity. A correlation between the existence of such a quantum phase transition and superconductivity is quite well established in some heavy fermion and iron-based superconductors, and there have been suggestions that high-temperature superconductivity in copper-oxide materials (cuprates) may also be driven by the same mechanism. Close to optimal doping, where the superconducting transition temperature T c is maximal in cuprates, two different phases are known to compete with superconductivity: a poorly understood pseudogap phase and a charge-ordered phase. Recent experiments have shown a strong increase in quasiparticle mass m* in the cuprate YBa2Cu3O7-δ as optimal doping is approached, suggesting that quantum fluctuations of the charge-ordered phase may be responsible for the high-T c superconductivity. We have tested the robustness of this correlation between m* and T c by performing quantum oscillation studies on the stoichiometric compound YBa2Cu4O8 under hydrostatic pressure. In contrast to the results for YBa2Cu3O7-δ, we find that in YBa2Cu4O8, the mass decreases as T c increases under pressure. This inverse correlation between m* and T c suggests that quantum fluctuations of the charge order enhance m* but do not enhance T c.

Which Personality Attributes Are Most Important in the Workplace?

Employees face a variety of work demands that place a premium on personal attributes, such as the degree to which they can be depended on to work independently, deal with stress, and interact positively with coworkers and customers. We examine evidence for the importance of these personality attributes using research strategies intended to answer three fundamental questions, including (a) how well does employees' standing on these attributes predict job performance?, (b) what types of attributes do employers seek to evaluate in interviews when considering applicants?, and (c) what types of attributes are rated as important for performance in a broad sampling of occupations across the U.S. economy? We summarize and integrate results from these three strategies using the Big Five personality dimensions as our organizing framework. Our findings indicate that personal attributes related to Conscientiousness and Agreeableness are important for success across many jobs, spanning across low to high levels of job complexity, training, and experience necessary to qualify for employment. The strategies lead to differing conclusions about the relative importance of Emotional Stability and Extraversion. We note implications for job seekers, for interventions aimed at changing standing on these attributes, and for employers.

Estimating the transfusion risk following total knee arthroplasty.

Patients undergoing total knee arthroplasty (TKA) are likely to receive a blood transfusion, which may increase the risk of complications and prolong hospital stay. Considerable variation exists in transfusion practice among orthopedic surgeons following elective TKA. Previous studies have investigated the relationship between preoperative risk factors and the requirement for blood transfusions in patients undergoing a total hip or knee arthroplasty, but few have focused on transfusion risk in those specifically undergoing TKA.The authors performed a retrospective review of a prospectively collected database of 2281 patients undergoing unilateral TKA in a district general hospital over a 10-year period. Multiple regression analysis models were used to identify risk factors associated with postoperative blood transfusion. A predictive model was created based on the regression coefficients and factor levels. The risk of transfusion was independently predicted by the patients' age at surgery (P<.001), preoperative hemoglobin (P<.001), weight (P=.009) and lateral retinacular release (P<.001). The preoperative variables of age, hemoglobin, and weight were incorporated into a model to provide an estimation of the transfusion risk. The area under the receiver operating characteristic curve was 74% (95% confidence interval, 70%-77.5%). This study identifies risk factors independently associated with the risk of requiring a blood transfusion following TKA. The predictive model stratifies the risk according to the individual patient in the preoperative setting, allowing preventative measures to take place preoperatively. It also helps in the counseling of patients at high risk of requiring a postoperative blood transfusion.