[Metastatic disease in long bones : Review of surgical treatment options]. / Metastasen der Extremitäten : Übersicht über operative Versorgungsstrategien.

Surgery in metastatic bone disease is currently the most frequent type of surgery in orthopedic oncology. Improved survival rates and an increasing incidence of bone metastasis have led to an increase in complications caused by metastatic disease, such as pathological fractures or hardware failure after operative treatment. Although surgery of metastatic lesions remains a palliative therapy concept, because of sufficient therapy for the primary carcinomas, tumor-specific-oriented follow-up protocols and a variation in the prognosis for the individual entities, an individually adapted treatment strategy is necessary. Depending on the life expectancy, more aggressive surgical procedures with the goal of adequate local tumor control have come into focus. Therefore, prognosis-tailored treatment requires an experienced team and should be performed in a multidisciplinary tumor center. The current article provides an overview of recent therapy concepts for the surgical treatment including endoprosthetic reconstruction, internal fixation with either intramedullary nailing or plate fixation devices, often augmented with bone cement.

Physicobiochemical synergism through gene therapy and functional tissue engineering for in vitro chondrogenesis.

Mechanical and chemical stimulation have been shown to enhance in vitro chondrogenesis. The aim of this study was to analyze and compare combined physicobiochemical effects. Bovine articular chondrocytes were retrovirally transduced to express bone morphogenetic protein-2 (BMP-2) or left as naïve controls. Cells were seeded in three-dimensional polyurethane scaffolds and further cultured under static conditions or exposed to dynamic compression and shear in a joint-specific bioreactor. Four groups: control (A), load (B), BMP-2-infected (C), and BMP-2-infected plus load (D) were analyzed for DNA and glycosaminoglycan (GAG) content; collagen I, II, and X; aggrecan, (cartilage oligomeric protein (COMP), superficial zone protein, matrix metalloproteinase (MMP)-3; MMP-13 mRNA; histology; and immunohistochemistry at 7, 21, and 35 days post-seeding. Synergistic effects (D) were higher than the sum of the individual treatments (B and C) for GAG/DNA, collagen II, and COMP. Histology revealed a functional organization in D including an intense safranin O staining in C and D superior to that in A and B. Immunostaining for collagen II and aggrecan was detected in C and D and was strongest in D. The results show that both stimuli augment in vitro chondrogenesis better than in controls. Biochemical manipulation proved to be predominantly more effective than load, and synergistic effects were demonstrated.

Non-destructive visualisation of protective proteins in the in situ pellicle.

Several salivary anti-microbial and buffering components are part of the acquired in vivo pellicle. The purpose of the present in situ study was to visualise these proteins within the in situ formed pellicle and to investigate their distribution with respect to pellicle formation time and intra-oral localisation. Bovine enamel slabs were fixed on individual splints. They were carried by 6 subjects buccally and palatally in the region of the upper first molar teeth over 30 and 120 min, respectively, for in situ pellicle formation. After intra-oral exposure, enamel specimens were processed for transmission electron microscopy. Secretory immunoglobulin A (sIgA), lactoferrin, lysozyme, carbonic anhydrase (CA) I and II were visualised successfully in the in situ pellicle layer by gold immuno-labelling. All components were found to be distributed randomly within all layers of the pellicle. Significantly higher amounts of the proteins were detected after 120 min of formation time. Furthermore, significantly more labelled lactoferrin and lysozyme were found on buccal surfaces compared with palatal sites. For CA I, CA II and sIgA, no significant influence of the localisation was detected. All investigated anti-bacterial and buffering proteins are distributed randomly in the in situ formed pellicle layer and thus could contribute to its protective properties as an early defence barrier.