• Levine Schou posted an update 4 days, 12 hours ago

    Spectral properties of the electroencephalogram (EEG) are commonly analyzed to characterize the brain’s oscillatory properties in basic science and clinical neuroscience studies. The spectrum is a function that describes power as a function of frequency. To date inference procedures for spectra have focused on constructing confidence intervals at single frequencies using large sample-based analytic procedures or jackknife techniques. These procedures perform well when the frequencies of interest are chosen before the analysis. When these frequencies are chosen after some of the data have been analyzed, the validity of these conditional inferences is not addressed. If power at more than one frequency is investigated, corrections for multiple comparisons must also be incorporated. To develop a statistical inference approach that considers the spectrum as a function defined across frequencies, we combine multitaper spectral methods with a frequency-domain bootstrap (FDB) procedure. The multitaper method is optimal for minimizing the bias-variance tradeoff in spectral estimation. ABC294640 The FDB makes it possible to conduct Monte Carlo based inferences for any part of the spectrum by drawing random samples that respect the dependence structure in the EEG time series. We show that our multitaper FDB procedure performs well in simulation studies and in analyses comparing EEG recordings of children from two different age groups receiving general anesthesia.Pes anserine syndrome is a cause of inferomedial knee pain. It occurs in patients with diabetes mellitus, osteoarthritis, rheumatoid arthritis and in overweight patients. It is a challenge to identify the causes of knee pain following knee replacement surgery. We present a case report of pes anserine syndrome in a 79-year-old female who had undergone knee arthroplasty 13 years prior. She was pain free until one year ago when her knee pain resurfaced without any symptoms of infection or history of trauma. She was successfully treated with a combination of stretching exercise and steroid local steroid injection. We want to highlight that such common condition as pes anserine syndrome, could occur in total knee arthroplasty, and should be considered as one of the possible diagnosis. © 2018 Delhi Orthopedic Association. All rights reserved.Background Metallosis is a syndrome of metal-induced synovitis caused by friction between two metal surfaces. In contrast to the hip joint after resurfacing arthroplasty or metal-on-metal (MoM) total hip replacement, metallosis of the knee is extremely rare. Materials We describe 4 patients who underwent revision total knee replacement because of disabling pain and implant loosening after a mean time of 21 (range 13-30) years of knee replacement surgery. They were all females with a mean age of 79 (range 75-82) years. Septic loosening was excluded through microbiological examination and synovial fluid analysis. Results Direct metal-on-metal contact at the tibiofemoral interface was confirmed intraoperatively in all cases. All knees showed severe metallosis with advanced osteolysis and pseudotumor formation. In one knee there was a complete fracture of the tibial tray. All patients had a one-stage revision surgery with implant removal, profound synovectomy and implantation of a constrained modular revision knee system. Long modular stems with offset adapters, wedges and/or blocks were used in all cases. Conclusion Metallosis-associated osteolysis should be suspected in cases with radiologically evident polyethylene wear after knee replacement. Recognizing that revision arthroplasty is very technically demanding in such cases, surgeons should have a back-up with modular revision components and a ready access to reconstructive options at this revision setting. © 2019 Delhi Orthopedic Association. All rights reserved.Purpose Our study compares the outcome and cost of distal femoral arthroplasty to that of Fixation (Plating/Retrograde Nailing) in the management of distal femur peri-prosthetic fractures. Methods We reviewed our database for patients admitted with peri-prosthetic distal femoral fractures between 2005 and 2013 (n = 61). The patients were stratified into 2 groups based on management method. The Distal Femoral Arthroplasty group (Group A) had 21 patients and the Fixation group (Group B) had 40 patients. Outcome & cost were compared. Minimum follow-up was 3 years. Results The mean length of stay in group A was 9 days whereas in group B was 32 days. All patients were fully weight bearing by day 3 in group A, compared to a mean of 11 weeks in group B. Mean OKS was 28 and KSS score was 70 in group A compared to 27 and 68 in group B. In group A, there were 2 deaths, 1 superficial infection, and 1 DVT. In group B, there were 6 deaths, 1 failure of fixation, 6 mal-unions, 1 non-union and 2 infections. Overall, the distal femoral arthroplasty procedure costs approximately £9600 and the fixation group costs were on average of £9800. Conclusion Distal femoral arthroplasty appears to provide good clinical results, with comparable overall costs to fixation. © 2019 Delhi Orthopedic Association. All rights reserved.Background Total knee arthroplasty (TKA) with fixed-bearing (FB) implants have demonstrated impressive functional results and survival rates. Meanwhile, rotating-platform (RP) constructs have biomechanically shown to reduce polyethylene wear, lower the risk of component loosening, and better replicate anatomic knee motion. There is growing question of the clinical impact these design changes have long-term.Questions/purposes The aim of this double-blinded prospective randomized trial was to compare function and implant survival in patients who received either FB or RP press-fit condylar Sigma (PFC Sigma, DePuy, Warsaw, IN) total knee replacements at a minimum follow-up of twelve years. Patients and methods Patient reported outcome measures used included the functional Knee Society Score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores, Medical Outcomes Short Form-36 (SF-36) score, and satisfaction assessment on a four-point Likert scale. The data was collected from times preoperative, two-years, and final encounter (mean 13.