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Biomedical subjects

H Siebert

Publications and source records attributed to H Siebert.

At least 55 records · Page 3Linked to original sources
PubMed1980

[Experimental fundamental of secondary osteosynthesis (author's transl)].

The process of fracture healing in rats -- femur shaft fractures stabilised by intramedullary nailing -- immediately after osteotomy of 7 -- 21 days afterwards shows the same morphological picture of events. 40 -- 45 days after stabilisation the fracture repair was in the same stadium of woven bone bridging the fracture gap independent of the date the nailing had been performed, with the exception of those animals which had been stabilised 3 days after the osteotomy; these showed morphological signs of different grades of osteitis. In animals which had had internal plate fixation at different times after fracture the definite date of fixation correlated with the occurrence of osteitis. The later the fracture had been stabilised the more frequently delayed union occurred according to instability. Hence, intramedullary nailing of bone fractures should be done at times before or after the phase of massive cell proliferation and infiltration to prevent infection of the bone. Internal plate fixation is more successful when callous tissue is removed from the fracture gap in order to achieve a close bone reduction.

Animals↗
PubMed1980

[Secondary intramedullary nailing osteosynthesis in primarily conservative treatment of fractures of tibia and fibula shafts (author's transl)].

In a retrospective trial 235 patients with fractures of the tibia and/or fibula shafts were followed up. In 16 cases non-union of the fracture occurred after closed reduction and plaster cast treatment. In 16 of these patients closed nailing of the tibia was performed 8--14 weeks after the accident. The healing of the fracture was uncomplicated and occurred in 10--14 weeks p. op. The results in primary nailing cases 8--14 days after the accident were much better than in cases treated with plaster casts, with regard to joint mobility, venous insufficiency and duration of treatment; however two serious complications occurred. In two patients, osteitis occurred after primary nailing of the tibia. Localisation of the fractures (distal part of the tibia) and type of the fracture (short torsion fracture) correlated more frequently with formation of non-union than the rare changes in blood chemistry observed in our study. We regard intramedullary nailing of the tibia as the best available method in treating non-union or pseudarthrosis of the tibia.

Adult↗
PubMed1980

[Microangiographic and histologic findings in the tibiae of rats after implantation of bone cement (author's transl)].

The reaction of bone tissue to the filling of the medullary cavity with acrylic bone cement was studied in the rat by histological and microangiographic methods. Three months after plugging, the fibrous borderline tissue between cement and bone had changed into newly formed bone with a secondary medullary cavity, depending on the content of monomer next to the tissue. The blood support of the bone came from periosteal vessels. After 6 months a definitive secondary medullary cavity had been established, the cement was enveloped by newly formed primary bone, and the inner and middle portions of the cortical bone had been invaded by vessels originating from the secondary medullary cavity.

Angiography↗
PubMed1978

[Concentration of lysozyme during mineralization in callous tissue of healing fractures (author's transl)].

Investigations have suggested that lysozyme (E.C. 3.2.1.17) is involved in bone mineralization. High concentrations of lysozyme is found in the growth plate near cartilage bone junction, where it is located at the collagen fibrils and in the ground substance. Quantitative studies of lysozyme levels were made in ossifying tissue of healing fractures, to confirm the existence of this relationship on bone repair. Callous tissue, serum samples and normal bone was collected from 42 rats at 15 intervalls during a 50 day healing period. Agar gel diffusion test was used for quantitation of lysozyme. Electrophoresis of tissue extract and standard henn egg white lysozyme served as control. Lysozyme levels in callous tissue increased significantly (4--5-fold) from 4.--21. day p. trauma and subsequently decreased. The concentration in serum samples did not change significantly. Changes in Ca concentration and histological studies during tests confirm a direct relationship between bone mineralization and lysozyme level changes.

Animals↗