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Biomedical subjects

L T Dambe

Publications and source records attributed to L T Dambe.

13 recordsLinked to original sources
PubMed1978

[Experimental studies of autograft with cancellous bone in the diaphysis of long bone (author's transl)].

The acceptance of fresh autologous cancellous bone in a wedge-shaped diaphysial cortical defect was examined in 2 groups of 5 dogs microangiographically and histologically 1,2,3,4 and 6 weeks after transplantation. The main recanalisation takes place after one week from the medullary canal, two weeks later periosteal vessels are connected and finally three weeks later the tender vessels of the Haversian canal system within the cortex are being integrated. Histologically, after one week active formation of fibrous bone can be seen adjacent to numerous capillaries originating within the medullary canal. Simultaneously, considerable degradation of transplanted trabeculae by mono- or polynuclear osteoclasts takes place. Formation of new bone occurs according to newly built capillaries. After 4 weeks, transplanted trabeculae can be found only sparsely, the new fibrous bone is being remodelled into lamellar bone. After 6 weeks, the entire fibrous bone has been transformed into lamellar bone and is calcified. A trajectorial orientation of the Haversian system according to that of the host cortical bone can be recognized vaguely.

Animals↗
PubMed1978

[The revascularisation of fresh homologous bone grafts in the diaphysis of long bones in dogs (author's transl)].

In two series each 5 X 2 grown up mongrel dogs we studied the healing process of fresh concellous and cortical homografts in a defect made in the diaphysis of the radius bone. The experiments cover microangiographical and histological weekly control in the first 6 weeks after transplantation. The results demonstrate that the fresh concellous homografts have a good revascularisation and produce early new bone in the first week. The revascularisation of the cortical grafts is delayed. The immune reaction, which begins after two weeks, is in concellous bone graft more vigorous than in the cortical graft. The reaction leads to vascular disruption prior to the degenerative and necrotic changes of the tissue cells in the grafts including the new bone formation. After overcoming the immune reaction the 2nd or the so called inductive phase of new bone formation starts. The integration of cortical grafts in the host bone is much slower than in concellous bone graft. The vigorous immune reaction followed by the avascular interval in the concellous homografts between the second and third week must be considered as a dangerous critical phase when using homografts in the clinic. Because of the less cell concentration in the cortical homografts there is less immune reaction. Revascularisation in cortical homografts is slow and consequently there is a delayed incorporation of the grafts in the clinical use.

Animals↗
PubMed1978

[Comparative studies on the incorporation of autologous and homologous spongiosa in the compact layer of long bones].

The healing of fresh autologous and homologous cancellous bone graft in gaps made in diaphysis was checked in a comparative test series of dogs. The general revascularization comes from the medulla. During the 2nd week the newly formed vessels in the homograft are obliterated. These are rebuilt during the 3rd week. At the same time new bone formation and reabsorption of the implanted bone by osteoclasts cease temporarily. After 6 weeks both grafts are remodeled in lamellar bone. The osseous trabeculae do not yet run parallel to Havers' system of the corticalis. The results verify the superiority of the autologous cancellous bone grafts.

Animals↗
PubMed1976

[Revascularization of hypertrophic pseudoarthroses after pressure-plate osteosynthesis].

In 6 adult mongrel dogs hypertrophic pseudarthroses in the radius were produced. The pseudarthroses were stabilized by compression plate osteosynthesis. The changes in the pattern of vascularization in pseudarthroses under stabilization were studied by means of microangiography. The interfragmental gap revascularization started early and came from medullary vessels of both fragments. Vessel anastomoses in interfragmental areas were observed. With time, medullary and periosteal hypervascularization were reduced. However, the hypervascularization in the remodeled corticalis was still evident after 3 months.

Animals↗
PubMed1976

[Revascularization of devitalized cortical segments under stabilizing encircling wires].

In 10 adult mongrel dogs isolated cortical fragments of the diaphysis of the radius were reimplanted and stabilized by encircling wires. The changes in the pattern of vascularization and the revitalization of the avascular fragment were investigated by microangiography. The revascularization arose from the medullary vessels that penetrated the avascular fragment. The fracture gap was bridged by intracortical anastomoses. After 6 weeks fracture healing was noted and the vessels showed a restoration of the physiologic pattern of vascularization.

Animals↗