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The understanding of foot and ankle biomechanics is improving as new technology provides more detailed information about the motion of foot and ankle bones with biplane fluoroscopy, as well as the ability to analyze the hindfoot under weightbearing conditions with weightbearing computed tomography. Three-dimensional anatomical coordinate systems are necessary to describe the 3D alignment and kinematics of the foot and ankle. The lack of standard coordinate systems across research study sites can significantly alter experimental data analyses used for pre-surgical evaluation and post-operative outcome assessments. Clinical treatment paradigms are changing based on the expanding knowledge of complex pes planovalgus morphologies or progressive collapsing foot deformity, which is present in both neurologic and non-neurologic populations. Four patient cohorts were created from 10 flexible PCFD, 10 rigid PCFD, 10 adult cerebral palsy, and 10 asymptomatic control patients. Six coordinate systems were tested on both the talus and calcaneus for all groups. The aim of this study was to evaluate axes definitions for the subtalar joint across four different patient populations to determine the influence of morphology on the implementation of previously defined coordinate systems. Different morphologic presentations from various pathologies have a substantial impact on coordinate system definitions, given that numerous axes definitions are defined through geometric fits or manual landmark selection. Automated coordinate systems that align with clinically relevant anatomic planes are preferred. Principal component axes are automatic, but do not align with clinically relevant planes and should not be used for such analysis where anatomic planes are critical. [ABSTRACT FROM AUTHOR]

Accurate anatomical coordinate systems for the foot and ankle are critical for interpreting their complex biomechanics. The tibial superior-inferior axis is crucial for analyzing joint kinematics, influencing bone motion analysis during gait using CT imaging and biplane fluoroscopy. However, the lack of consensus on how to define the tibial axis has led to variability in research, hindering generalizability. Even as advanced imaging techniques evolve, including biplane fluoroscopy and weightbearing CT, there exist limitations to imaging the entire foot together with the full length of the tibia. These limitations highlight the need to refine axis definitions. This study investigated various superior-inferior axes using multiple distal tibia lengths to determine the minimal field of view for representing the full tibia long-axis. Twenty human cadaver tibias were imaged and segmented to generate 3D bone models. Axes were calculated based on coordinate definitions that required user manual input, and a gold standard mean superior-inferior axis was calculated based on the population's principal component analysis axis. Four manually calculated superior-inferior tibial axes groups were established based on landmarks and geometric fittings. Statistical analysis revealed that geometrically fitting a cylinder 1.5 times the mediolateral tibial width, starting 5 cm above the tibial plafond, yielded the smallest angular deviation from the gold standard. From these findings, we recommend a minimum field of view that includes 1.5 times the mediolateral tibial width, starting 5 cm above the tibial plafond for tibial long-axis definitions. Implementing these findings will help improve foot and ankle research generalizability and impact clinical decisions. [ABSTRACT FROM AUTHOR]

De manie`re ge´ne´rale, dans les pays a` faibles et moyens revenus, ou` la motorisation est un phe´nome`ne re´cent, l'inse´curite´ routie`re devient un proble`me de plus en plus aigu¨. Cet article analyse les raisons spe´cifiques de ce proble`me et apporte un certain nombre d'e´le´ments de re´ponse qui concernent tant les apports possibles d'une coope´ration bien comprise avec les pays plus avance´s que la politique des bailleurs de fond internationaux sur cette question. [Copyright 2002 Elsevier]

To explore the efficacy of injectable collagenase Clostridium histolyticum (CCH) in distal interphalangeal (DIP) joint contractures in Dupuytren disease. A retrospective review was conducted for patients with DIP joint contractures treated with CCH. Baseline contracture and posttreatment residual contracture were recorded. The primary end point was achievement of 0° to 5° of residual contracture 30 days postmanipulation. Recurrence and adverse events are also reported. Twenty-one patients were treated with collagenase for DIP joint contractures and had a mean follow-up of 2.6 months. Seventeen of 21 patients reached the primary end point of less than 5° residual flexion contracture. Eleven of 21 patients experienced an adverse event, most commonly bruising and edema. No serious complications such as neurovascular injuries or tendon ruptures were recorded. Two patients had recurrence of disease. Injection with CCH is an option for the treatment of DIP joint contractures in Dupuytren disease. Therapeutic IV. [ABSTRACT FROM AUTHOR]

Host defense peptides play an important host-protective role by their microcidal action, immunomodulatory functions, and tissue repair activities. Proteolysis is a common strategy of pathogens used to neutralize host defense peptides. Here, we show that actin, the most abundant structural protein in eukaryotes, binds the LL-37 host defense peptide, protects it from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis, and enables its antimicrobial activity despite the presence of the proteases. Co-localization of LL-37 with extracellular actin was observed in necrotized regions of samples from oral lesions. Competition assays, crosslinking experiments, limited proteolysis, and mass spectrometry revealed that LL-37 binds by specific hydrophobic interactions to the His-40-Lys-50 segment of actin, located in the DNase I binding loop. The integrity of the binding site of both LL-37 and actin is a prerequisite to the binding. Our results demonstrate that actin, presumably released by dead cells and abundant in infected sites, might be utilized by the immune system to enhance spatio-temporal immunity in an attempt to arrest infection and control inflammation. [ABSTRACT FROM AUTHOR]