[Clavicle fractures: practical approach in clinical routine]. / Klavikulafrakturen ­ praktisches Vorgehen im klinischen Alltag.

Fractures of the clavicle are among the most common fractures. They typically result from a fall onto the lateral shoulder or the extended arm and are often related to sports and bicycle accidents. Obtaining the exact trauma mechanism, proper clinical findings and adequate X­rays usually lead to the correct diagnosis. Non-displacement fractures can be treated conservatively with good results. Unstable and displaced fractures should be treated operatively. Open fractures or looming penetration are emergencies und should be treated immediately. In addition to fracture classification and morphology, other factors such as additional injuries and patient-related factors need to be considered in order to make an individualized therapy decision. In operative treatment, angular stable plating is the therapy of choice, and in most cases early functional aftercare is possible.

Local Application of Mineral-Coated Microparticles Loaded With VEGF and BMP-2 Induces the Healing of Murine Atrophic Non-Unions.

Deficient angiogenesis and disturbed osteogenesis are key factors for the development of nonunions. Mineral-coated microparticles (MCM) represent a sophisticated carrier system for the delivery of vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-2. In this study, we investigated whether a combination of VEGF- and BMP-2-loaded MCM (MCM + VB) with a ratio of 1:2 improves bone repair in non-unions. For this purpose, we applied MCM + VB or unloaded MCM in a murine non-union model and studied the process of bone healing by means of radiological, biomechanical, histomorphometric, immunohistochemical and Western blot techniques after 14 and 70 days. MCM-free non-unions served as controls. Bone defects treated with MCM + VB exhibited osseous bridging, an improved biomechanical stiffness, an increased bone volume within the callus including ongoing mineralization, increased vascularization, and a histologically larger total periosteal callus area consisting predominantly of osseous tissue when compared to defects of the other groups. Western blot analyses on day 14 revealed a higher expression of osteoprotegerin (OPG) and vice versa reduced expression of receptor activator of NF-κB ligand (RANKL) in bone defects treated with MCM + VB. On day 70, these defects exhibited an increased expression of erythropoietin (EPO), EPO-receptor and BMP-4. These findings indicate that the use of MCM for spatiotemporal controlled delivery of VEGF and BMP-2 shows great potential to improve bone healing in atrophic non-unions by promoting angiogenesis and osteogenesis as well as reducing early osteoclast activity.