External fixation as a primary and definitive treatment for tibial diaphyseal fractures

The aim of this study was to evaluate the effectiveness of unilateral external fixator as primary and definitive treatment for open tibial fractures, fractures with severe soft tissues injuries, threatened compartment syndrome, and in multiply injured patients. Two hundred and twenty-three tibial shaft fractures (212 patients) were treated. In open fractures, union was achieved in 25 weeks, while in closed in 21. There were 18 nonunions, 21 delayed unions, 4 malunions, 58 pin infections and 3 osteomyelitis. A reoperation was performed in 42 patients. Fat embolism was diagnosed in three patients, pulmonary embolism in five and deep venous thrombosis in 14. The external fixator was definitive treatment in 87.27%. Unilateral external fixators can be used as primary and definitive treatment for complicated tibia shaft fractures. Re-operation or change of the method must be performed only when there is a delay in callus formation

Polarization Modulation in Quantum-Dot Spin-VCSELs for Ultrafast Data Transmission

Spin-Vertical Cavity Surface Emitting Lasers (spin-VCSELs) are undergoing increasing research effort for new paradigms in high-speed optical communications and photon-enabled computing. To date research in spin-VCSELs has mostly focused on Quantum-Well (QW) devices. However, novel Quantum-Dot (QD) spin-VCSELs, offer enhanced parameter controls permitting the effective, dynamical and ultrafast manipulation of their light emissions polarization. In the present contribution we investigate in detail the operation of QD spin-VCSELs subject to polarization modulation for their use as ultrafast light sources in optical communication systems. We reveal that QD spin-VCSELs outperform their QW counterparts in terms of modulation efficiency, yielding a nearly two-fold improvement. We also analyse the impact of key device parameters in QD spin-VCSELs (e.g. photon decay rate and intra-dot relaxation rate) on the large signal modulation performance with regard to optical modulation amplitude and eye-diagram opening penalty. We show that in addition to exhibiting enhanced polarization modulation performance for data rates up to 250Gbps, QD spin-VCSELs enable operation in dual (ground and excited state) emission thus allowing future exciting routes for multiplexing of information in optical communication links

Neck fracture of a cementless forged titanium alloy femoral stem following total hip arthroplasty: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Fractures of the neck of the femoral component have been reported in uncemented total hip replacements, however, to our knowledge, no fractures of the neck of a cementless forged titanium alloy femoral stem coated in the proximal third with hydroxy-apatite have been reported in the medical literature.</p> <p>Case presentation</p> <p>This case report describes a fracture of the neck of a cementless forged titanium alloy stem coated in the proximal third with hydroxy-apatite.</p> <p>Conclusion</p> <p>The neck of the femoral stem failed from fatigue probably because of a combination of factors described analytically below.</p