Survived traumatic hemipelvectomy with salvage of the limb in a 14 months old toddler

We report on a 14 months old toddler who sustained a traumatic hemipelvectomy by being crushed between a car and a stone wall. After stabilization in the resuscitation room he was treated operatively by laparotomy, osteosynthesis of the pelvic ring, reconstruction of the both external iliac vessels and the urethra and reposition of the testicles. After 66 days he was discharged into rehabilitation. Implants were removed after eight months. 20 months after the injury, the leg was plegic, initial radiological signs of femoral head necrosis showed up but the infant was able to walk with an orthesis and a walker. Up to our knowledge, this is the youngest patient described in the literature with a survived traumatic hemipelvectomy and salvaged limb

Biomechanical comparison of different fixation methods in metatarsal shaft fractures: A cadaver study

Background: Various fixation methods are available for the operative treatment of metatarsal shaft fractures: Kirschner wire, Titanium elastic nail, plate, or an intramedullary bone stabilization system within a balloon catheter. The aim of this study was to compare the stability of these techniques. Methods: 72 metatarsals II to V from fresh frozen human cadaver feet were used. A shaft fracture was performed and fixed with a 1.6-mm Kirschner wire, a 1.5-mm Titanium elastic nail, a locking 6-hole-plate, or an intramedullary bone stabilization system. In a cantilever configuration, the head of the metatarsals was loaded statically (2 mm/min until failure; all groups) or cyclically (0 to 20 N for 1000 cycles with 10 mm/s, after 1000 cycles 2 mm/min until failure; plate and bone stabilization system). Findings: The mean failure strength for static loading was 17 N for Kirschner wire, 13 N for Titanium elastic nail, 73 N for plate and 34 N for the bone stabilization system (P < .01). For cyclic loading, the mean cycle of failure was 1000 for plate and 961 for the bone stabilization system (P = .76). The mean failure strength after cyclic loading was 73 N for plate and 48 N for the bone stabilization system (P = .03). Interpretation: Stability differs depending on the fixation method, with a plate showing the greatest stability and Kirschner wire or Titanium elastic nail the least. The stability of the bone stabilization system for fixing metatarsal shaft fractures is intermediate

Biomechanical comparison of conventional versus modified technique in distal chevron osteotomies of the first metatarsal: A cadaver study

Background: Distal chevron osteotomy can be performed using a conventional or a modified technique. The aim of this biomechanical study was to compare the stability of the two techniques. Methods: Eighteen first metatarsals from nine pairs of fresh frozen human cadaver feet were used. A distal chevron osteotomy was performed using the conventional technique in group 1 (n = 9) and using the modified technique in group 2 (n = 9). The head of the first metatarsals was loaded in two different configurations (cantilever and physiological), using a materials testing machine. Results: In the cantilever configuration, the relative stiffness of the osteosynthesis in comparison with intact bone was 60% (+/- 21%) in group 1 and 65% (+/- 25%) in group 2 (p = 0.61). In the physiological configuration, it was 47% (+/- 29%) in group 1 and 47% (+/- 21%) in group 2 (p = 0.98). The failure strength in the cantilever configuration was 235 N (+/- 128 N) in group 1 and 210 N (+/- 107 N) in group 2 (p = 0.47). Conclusions: The conventional and the modified technique for distal chevron osteotomy in the treatment of hallux valgus show a comparable biomechanical loading capacity in this cadaver study. (C) 2018 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved

Fast Proton Conduction Facilitated by Minimum Water in a Series of Divinylsilyl-11-silicotungstic Acid-<i>co</i>-Butyl Acrylate-<i>co</i>-Hexanediol Diacrylate Polymers

Studies of proton transport in novel materials are important to enable a large array of electrochemical devices. In this study, we show that heteropoly acids (HPAs) when immobilized in polymer matrixes have highly mobile protons. Divinyl-11-silicotungstic acid, an HPA, was copolymerized with butyl acrylate and hexanediol diacrylate at various weight percentage loadings from 25% to 85% using UV initiated polymerizations. The resultant films were tan colored flexible sheets of ca. 120 μm thickness. The morphology of these films varied with loading, showing phase separation into clustered HPA above a 50 wt % loading and lamella morphologies above an 80 wt % loading. Water uptake was strongly associated with the HPA clusters, which facilitated transport of protons. This was realized by proton conductivities as high as 0.4 S cm^–1 at 95 °C and 95% RH and 0.1 S cm^–1 at 85 °C and 50% RH. Pulse field gradient spin echo NMR measurements indicated that water self-diffusion was fast (1.4 × 10^–5 and 4.4 × 10^–5 cm² s^–1 for 50% and 100% RH, respectively) at 80 °C. We show that the water in these systems is highly associated with the HPA clusters and that fast proton transport is facilitated by as few as 3 water molecules per proton

Fast Proton Conduction Facilitated by Minimum Water in a Series of Divinylsilyl-11-silicotungstic Acid-co-Butyl Acrylate-co-Hexanediol Diacrylate Polymers

Studies of proton transport in novel materials are important to enable a large array of electrochemical devices. In this study, we show that heteropoly acids (HPAs) when immobilized in polymer matrixes have highly mobile protons. Divinyl-11-silicotungstic acid, an HPA, was copolymerized with butyl acrylate and hexanediol diacrylate at various weight percentage loadings from 25% to 85% using UV initiated polymerizations. The resultant films were tan colored flexible sheets of ca. 120 μm thickness. The morphology of these films varied with loading, showing phase separation into clustered HPA above a 50 wt % loading and lamella morphologies above an 80 wt % loading. Water uptake was strongly associated with the HPA clusters, which facilitated transport of protons. This was realized by proton conductivities as high as 0.4 S cm–1 at 95 °C and 95% RH and 0.1 S cm–1 at 85 °C and 50% RH. Pulse field gradient spin echo NMR measurements indicated that water self-diffusion was fast (1.4 × 10–5 and 4.4 × 10–5 cm2 s–1 for 50% and 100% RH, respectively) at 80 °C. We show that the water in these systems is highly associated with the HPA clusters and that fast proton transport is facilitated by as few as 3 water molecules per proton