Reaction of bone tissue to cemented total hip replacement in sheep Reaction of bone tissue to cemented total hip replacement in sheep

Sheep were used as a model for the examination of radiological and histological changes in bone tissue Sheep were used as a model for the examination of radiological and histological changes in bone tissue following total hip replacement. A unilateral total hip replacement procedure was carried out in sheep with following total hip replacement. A unilateral total hip replacement procedure was carried out in sheep with radiological examinations at 1, 3 and 6 months after surgery. After six moths, the sheep were euthanized and radiological examinations at 1, 3 and 6 months after surgery. After six moths, the sheep were euthanized and the bone tissue was collected for histology. The histological examination was focused on superfi cial reactive the bone tissue was collected for histology. The histological examination was focused on superfi cial reactive changes, bone reactive changes and type and numbers of the cells present. Radiological examination showed no changes, bone reactive changes and type and numbers of the cells present. Radiological examination showed no pathological changes. Histological examination revealed new bone formation and remodelling in all samples, pathological changes. Histological examination revealed new bone formation and remodelling in all samples, three of them (12.5%) exhibiting changes in resorption and new bone formation at the osteoid level. Cellular three of them (12.5%) exhibiting changes in resorption and new bone formation at the osteoid level. Cellular reaction involving the presence of reactive cells was minimal in all samples (macrophages, fi broblasts). Changes reaction involving the presence of reactive cells was minimal in all samples (macrophages, fi broblasts). Changes characteristic of the development of completely mature bone with evident bone structures, including the Hawers characteristic of the development of completely mature bone with evident bone structures, including the Hawers system, were observed in eleven samples (45.83%). Disturbances of intactness of the cement coat resulted in system, were observed in eleven samples (45.83%). Disturbances of intactness of the cement coat resulted in cellular activity and aseptic loosening. In our case, cellular activity was minimal and some samples allowed cellular activity and aseptic loosening. In our case, cellular activity was minimal and some samples allowed us to observe signs of mature bones which indicated strong fi xation of endoprosthesis in the bone tissue and us to observe signs of mature bones which indicated strong fi xation of endoprosthesis in the bone tissue and alterations at cellular level ongoing even at sixth months following the total hip replacement. alterations at cellular level ongoing even at sixth months following the total hip replacement.