The LOV-domain blue-light receptor LreA of the fungus Alternaria alternata binds predominantly FAD as chromophore and acts as a light and temperature sensor.

Light and temperature sensing are important features of many organisms. Light may provide energy but may also be used by non-photosynthetic organisms for orientation in the environment. Recent evidence suggests that plant and fungal phytochrome and plant phototropin serve dual functions as light and temperature sensors. Here we characterized the fungal LOV-domain blue-light receptor LreA of Alternaria alternata and show that it predominantly contains FAD as chromophore. Blue-light illumination induced ROS production followed by protein agglomeration in vitro. In vivo ROS may control LreA activity. LreA acts as a blue-light photoreceptor but also triggers temperature-shift-induced gene expression. Both responses required the conserved amino acid cysteine 421. We therefore propose that temperature mimics the photoresponse, which could be the ancient function of the chromoprotein. Temperature-dependent gene expression control with LreA was distinct from the response with phytochrome suggesting fine-tuned, photoreceptor-specific gene regulation.

[Osteoporotic bone fractures: intramedullary augmentation and hybrid osteosynthesis]. / Frakturen des osteoporotischen Knochens: intramedulläre Augmentation und Hybridosteosynthese.

The increasing number of people who are living longer and have a far more active lifestyle is inevitably associated with greater numbers of fractures. Stabilization of these fractures in older patients with plates and screws is complicated by fragile bone substance, especially in osteoporotic bone, since osteosynthesis with a conventional plate depends exclusively on the holding power of the screws. Therefore, treatment requires new stabilization technologies designed for these specific tasks. A small diameter polyethylene terephthalate (PET, Dacron®) balloon is delivered in a minimally invasive fashion and placed within the canal, transversing the fracture. Once positioned, the balloon is expanded with a liquid monomer to fill the medullary canal. The liquid monomer is then rapidly cured using visible blue light, forming a patient-customized intramedullary implant that stabilizes the entire length of the bone in contact with the implant. The described intramedullary implant can be easily drilled in any position or location, providing a substantial increase in screw holding power. Thus, a major advantage of the technique is the possibility to augment the newly formed balloon "nail" with a conventional plate and screws at the primary stabilization or at any later time.

Effective Management of Bone Fractures with the Illuminoss® Photodynamic Bone Stabilization System: Initial Clinical Experience from the European Union Registry.

The IlluminOss® system (IS) uses a light-curable polymer contained within an inflatable balloon catheter, forming a patient customized intramedullary implant. A registry was established in Germany and The Netherlands to prospectively collect technical and clinical outcomes in patients treated with IS for fractures of the phalange, metacarpal, radius, ulna, distal radius, fibula, clavicle and/or olecranon. Humeral, femoral, tibial and pelvic fractures were included under compassionate use. Procedural success included successful placement of the device at the target fracture site and achievement of fracture stabilization. Clinical and radiographic assessments were made postoperatively through 12 months. One hundred thirty two patients (149 fractures) were enrolled with most fractures (85%) resulting from low-energy trauma. Simple fractures predominated (47%) followed by complex (23%) and wedge (16%) fractures. Procedural success was achieved in all patients and no implants required removal or revision. Normal range of motion was realized in 87% of fractures. Radiographically, there was substantial cortical bridging, total dissolution of the fracture line, and complete fracture healing. Across a variety of fracture types, the IS provides a safe and effective approach for rapid healing and functional recovery.

Reconstruction of a Bryan and Morrey type I capitellar fracture in a sawbone model with four different fixation devices: an experimental study.

BACKGROUND: We evaluated 4 different fixation devices for the reconstruction of a standardised Bryan and Morrey capitellar shear fracture in a sawbone model. Outcome measurements were the quality of reduction, time for reconstruction and stability. METHODS: 80 standardised Bryan and Morrey type I fractures were created for 5 different orthopaedic surgeons in 80 sawbones. Each surgeon reconstructed 16 fractures with 2mm K-wires, 3mm Herbert screws, 2.7 mm AO screws and 2.2mm fine-threaded wires (Fragment Fixation System: FFS). 4 fractures were allocated to each method with a standardised reconstruction procedure. Quality of reduction and time for reconstruction were measured after definitive fixation. Biomechanical testing was performed using a shear loading model with the application of monocyclic or polycyclic stress to the reconstructed capitulum. RESULTS: There was no difference in the quality of reduction with the different fixation devices. Herbert and AO screw fixation was slower than the other implants (p<0.05). No difference in the time for reconstruction was observed with K-wires and FFS. Failure load was less for K-wires compared to FFS, Herbert screws and AO screws (p<0.05). With polycyclic loading, residual deformation was higher with K-wire reconstruction compared to FFS, Herbert screws and AO screws (p<0.05). CONCLUSION: When using four different fixation devices, the fixation of standardised Bryan and Morrey type I fractures in the sawbone model differs when it comes to the time needed for reduction, but not in the quality of reduction. Stability was the same for the implants used, except for the K-wires. There is no argument in favour one of the screw implants over another in clinical use.

Reconstruction of radial capitellar fractures using fine-threaded implants (FFS).

Fractures of the capitulum humeri are rare and challenging injuries to the elbow and outcome results are limited to case series, often with different fixation devices. This article aims to present 15 patients with a fracture of the capitulum humeri treated with the same implant, fine-threaded Kirschner wires (FFS). Besides range of motion and grip strength, outcome measurements include the following scores: the Mayo Elbow Performance index (MEPI); the American Shoulder and Elbow Surgeons' Elbow Assessment (ASES) Form; the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire; and the Broberg-Morrey score. Using the modified Bryan and Morrey classification, there were seven type-I injuries, three type-II, two type-III and three type-IV fractures. In addition to fractures of the capitellum, five patients were diagnosed with a complex ligamentous injury and three had suffered radial head fractures. After a minimum follow-up of 12 months, we obtained a range of motion in flexion and extension of 124° and a pro- and supination of 173°. The mean DASH showed 10.84 and the Broberg-Morrey score reached 90.8. ASES and MEPI scores were 91.5 and 90, respectively. The mean grip strength of the injured side was 217.9N versus 236.4N on the healthy side. The use of FFS for capitellar fractures of the humerus achieved good clinical results and these implants can be considered as a treatment option for this fracture entity.

Treatment of displaced proximal fifth metatarsal fractures using a new one-step fixation technique.

BACKGROUND: Fractures of the tuberosity of the fifth metatarsal are common after foot twisting injuries, and operative treatment is recommended in cases of displacement. The purpose of this study was to report the radiologic outcome and clinical results of displaced fractures of the tuberosity of the fifth metatarsal treated using fine-threaded K-wires (FFS). METHODS: In 3 years' time, in a total of 35 cases, patients had an initial fracture displacement of more than 2 mm for isolated extraarticular fractures and an involvement of the cuboidal joint surface of more than 30%. After 15 months to 60 months (mean, 30.6), 32 of these patients participated in a clinical follow-up examination and questionnaire according to a clinical rating system for midfoot fractures. Radiologic outcome measurements were the remaining postoperative intraarticular step off and the healing time. RESULTS: The mean midfoot scale score was 96.5 points. All the patients returned to prior activities after operative treatment. Seven patients reported minor pain during longer periods of walking. One patient with secondary wound healing experienced frequent pain. Radiologically, in 32 of 35 patients, there was a remaining step off of less than 1 mm and in three patients less than 3 mm. All fractures except one healed within the first 3 months to 6 months. CONCLUSION: Operative treatment of displaced proximal fifth metatarsal fractures using the FFS system leads to a good clinical and radiologic outcome. The FFS system provides a new treatment option for this fracture type.

[Distraction arthrodiatasis in elbow stiffness]. / Die Distraktionsarthrolyse bei Arthrofibrose des Ellenbogengelenks.

OBJECTIVE: Loss of motion of the elbow is not uncommon after trauma, burns, or coma and severely impairs upper limb function. Loss of motion may be difficult to avoid and is challenging to treat. Detailed analysis of the etiology and diagnostic evaluation are of utmost importance for planning any surgical intervention for elbow stiffness. Most activities of daily living are possible, if the elbow has a range of motion of 100 degrees (30-130 degrees of flexion, Morrey's arc of motion). INDICATIONS: Stiff elbow, usually defined as less than 30 degrees extension or less than 130 degrees flexion. CONTRAINDICATIONS: Poor compliance, poorly controlled diabetes mellitus, active hepatitis B and C infection, HIV infection, acute articular infection. SURGICAL TECHNIQUE: Current operative techniques, such as closed distraction with external fixation (arthrodiatasis), are presented and evaluated. Elbow arthrolysis is a technically demanding procedure. POSTOPERATIVE MANAGEMENT: If indication and techniques are used correctly and surgeon, physiotherapist, and patient are familiar with the procedure, good long-term results may be achieved. RESULTS: In 14 children and adolescents the results after 5 years showed an increase of preoperative range of motion from 37 degrees to 108 degrees (flexion/extension; 75-130 degrees ) postoperatively.