Background: To compare structural features of the femoral bone of ovariectomized and non-ovariectomized rats after implantation of porous materials (TANTALUM, CONCELOC, TTM, ATLANT). Methods: Experiments were carried out on 56 white laboratory female rats aged 6 months. Rats were randomly assigned into groups: sham-operated control group (SH) or ovariectomy group (OVX). Four different commercial implant materials (TTM, CONCELOC, TANTALUM, ATLANT) were placed into the defects (diameter 2.5 mm, depth 3.0 mm) in the distal metaphysis of femurs. Rats were sacrificed 45 days after surgery. Histological study was performed and the percentage of the bone area (BA%) around the implant at a distance of 500 μm in the cancellous area was measured. Results: Formation of mature bone tissue of varying degrees around all of the implants was detected. In OVX rats cancellous bone defect zone was characterized by a high density of osteocytes on the surface. In the SH group, no differences in BA% among implant materials were found. In OVX rats, the BA% around ATLANT implants was 1.5time less (p = 0.002) than around TANTALUM. The BA% around the rest of the materials was not statistically different. Conclusions: Bone formation around the studied porous titanium and tantalum materials in the osteoporosis model was lower than in normal bone. There were differences in bone formation around the different materials in the osteoporosis model, while in the normal bone model, these differences were absent.
Degenerative spine diseases are common throughout the world. There are many factors that lead to these diseases. One of these exogenous factors may be Pb exposure. Most of the fundamental investigations about the negative effects of the Pb exposure have investigated the impact of high doses of Pb, while Pb exposure in low concentrations has been insufficiently studied. The nutrition of the intervertebral disc is provided by the vessels that grow into the vertebral bodies and the paravertebral tissue. This suggests the possibility that Pb penetrates from the bone to the intervertebral disc together with nutrients. This article reports an experimental study which was performed in rats aged 1.5 months (n = 40). Rats in the experimental group received lead acetate solution (230 mg of Pb per1 literof distilled water) as drinking water and the animals in the control group received distilled water for 10 weeks. In the isolated intervertebral discs, the content of Pb was determined by X-ray fluorescence spectrometry. The effect of lead on the structural organization of the intervertebral disc was investigated by light microscopy. The ultrastructural features of cells and the matrix intervertebral disc were studied by transmission electron microscopy. In the young animals after Pb exposure, a significant increase was found in the content of Pb in the intervertebral disc tissue, of 4.6 times compared to the control group. The histological analysis showed degenerative changes in the annulus fibrosus (AF) of the intervertebral disc. In the outer region cracks and defibration of the lamellae were observed. Large isogenic groups were detected in the inner region of the intervertebral disc. A decrease in the height by 12.2% in the outer parts and by 10% in the central part of the intervertebral disc was recorded. Also a reduction in the width of the lamellae by 8% was shown. Cell density of the annulus fibrous decreased by 12% and in the gelatinous nucleus pulposus (NP) by 24.2%. Electron microscopic analysis of the inner region of the AF of the intervertebral disc showed chondrocytes with electron-dense mitochondria, vacuolization of the cytoplasm, fragmented nuclei and destructive cavities. The matrix of the lamellae of the AF had a diverse electron density, so areas with high electron density of various sizes were observed. Collagen fibrils of the AF had blurred outlines, sometimes the transverse striation disappeared or it was irregular, which can indicate the matrix mineralization and possibly the accumulation of Pb in these areas. In the NP, the most notochordal cells revealed the formation of myelin figures. The effect of Pb at low concentration results in its accumulation in the tissues of the intervertebral disc of rats and causes degenerative changes in the intervertebral disc structure, leading to the reduction in the height of the intervertebral disc, decrease in the width of the lamellae and in cell density, thereby violating both the structures of matrix and cells. Future investigations of the collagen content of intervertebral disc after Pb exposure are needed.
The aim: To assess the bone remodeling around highly porous titanium cups TTM in patients with low bone mass one year after total hip arthroplasty (THA). Materials and methods: In this prospective study were included 18 patients (18 hips), whom was performed primary THA with the use of TTM cups. According to T-score of Lumbar Spine, patients were divided into 2 groups: normal bone mineral density (BMD) (n=9) if T-score ≥ –1, and low BMD (n=9) if T-score < –1. According to DeLee and Charnley’s model BMD in 3 periacetabular regions were evaluated 1 week and 1 year after THA. Results: One year after primary THA, BMD of all 3 periacetabular regions did not differ in patients of both groups comparing with initial data. One week after THA, it was found that BMD R1 and BMD R3 in low BMD group were lower by 1.4 times (p=0.035) and 1.5 times (р=0.001) respectively, BMD R2 did not differ from the normal BMD group. One year after THA it was found that in low BMD group BMD R1 and BMD R2 were lower by 1.5 times (р=0.005) and 1.3 times (р=0.050) respectively, BMD R3 did not differ from the group with normal BMD. Conclusions: The use of highly porous titanium cups TTM in patients with low bone mass did not lead to a bone loss in DeLee and Charnley periacetabular zones one year after THA. Consequently, the use of these cups in patients with low bone mass undergoing THA is a valuable treatment option.
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