Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Review conformation, self-aggregation, and membrane interaction of peptaibols as studied by pulsed electron double resonance spectroscopy

Pulsed EPR methods, in particular pulsed electron double resonance (PELDOR) [or double electron-electron resonance (DEER)], are very sensitive to the dipole \ub7\ub7\ub7 dipole interaction between electron spins in a pair of free radicals. Using PELDOR, the conformations of a number of double radical-containing biomolecules have been determined. In this review article, we focused our attention on the application of this spectroscopy to nitroxide-labeled peptaibols. This is an emerging class of naturally occurring, relatively short, linear, helical peptide molecules endowed with hydrophobic character, capability to interact with and to alter the structure of membranes, and antibiotic activity. We extracted detailed information on the secondary structures of specifically site-directed, double nitroxide-labeled peptaibols under a variety of experimental conditions, including biologically relevant environments. Moreover, we examined in-depth peptaibol clustering, related to the marked propensity of these molecules to undergo self-association in model and whole-cell membrane systems, using mainly mono-nitroxide-containing synthetic analogs. Finally, based on the PELDOR data accumulated, we proposed models of supramolecular (quaternary) structures of peptaibols and their binding modes to membranes