To analyze the effect of tooth extraction site preservation on bone mineral density 6 months after surgery. From 2020 to 2021, two adjacent teeth (37, 38) of the same patient were extracted at the same time, and then 37 were selected for site preservation, implanted with Bio-oss bone powder, covered with double Bio-gide membrane, reduce tension and sutured. After 6 months of self-healing, 38 was taken CBCT, and the gray value measurement tool in the software was used to measure the bone mineral density of 37 bone graft areas and 38 extraction sockets. Bone density was high in the center of the bone graft area after the extraction site, and the density decreased in the adjacent alveolar socket, but the gray value was still higher than 38 for natural healing. Extraction site
Segmental bone transport (SBT) using an external fixator is currently a standard treatment for large-diameter bone defects at the donor site with low morbidity. However, long-term application of the device is needed for bone healing. In addition, patients who received SBT treatment sometimes fail to show bone repair and union at the docking site, and require secondary surgery. The objective of this study was to investigate whether a single injection of recombinant human bone morphogenetic protein 2 (rhBMP-2)-loaded artificial collagen-like peptide gel (rhBMP-2/ACG) accelerates consolidation and bone union at the docking site in a mouse SBT model. Six-month-old C57BL/6J mice were reconstructed by SBT with external fixator that has transport unit, and a 2.0-mm bone defect was created in the right femur. Mice were divided randomly into four treatment groups with eight mice in each group, Group CONT (immobile control), Group 0.2mm/d, Group 1.0mm/d, and Group BMP-2. Mice in Group 0.2mm/d and 1.0mm/d, bone segment was moved 0.2 mm per day for 10 days and 1.0 mm per day for 2 days, respectively. Mice in Group BMP-2 received an injection of 2.0 μg of rhBMP-2 dissolved in ACG into the bone defect site immediately after the defect-creating
Introduction and Objective. Senescent bone cell overburden accelerates osteoporosis. Epigenetic alteration, including microRNA signalling and DND methylation, is one of prominent features of cellular senescence. This study aimed to investigate what role microRNA-29a signalling may play in the development of senile osteoporosis. Materials and Methods. Bone biopsy and serum were harvested from 13 young patients and 15 senior patients who required spine
Purpose. In patients with multiple trauma delayed fracture healing is often diagnosed, but the pathomechanisms are not well known yet. The purpose of the study is to evaluate the effect of a severe hemorrhagic shock on fracture healing in a murine model. Methods. 10 male C57BL/6N mice per group (Fx, TH, THFx, Sham) and point in time were used. The Fx-group received an osteotomy after implantation of a fixateur extern. The TH-group got a pressure controlled hemorrhagic shock with a mean arterial blood pressure of 35 mmHg over 90 minutes. Resuscitation with 4 times the shed blood volume of Ringer solution was performed. The THFx group got both. Sham-animals received the implantation of a catheter and a fixateur extern but no blood loss or osteotomy. After 1, 2, 3, 4 or 6 weeks the animals were sacrificed. For the biomechanics the bones were analyzed via X-ray, µCT and underwent a 3-point bending test. The nondecalcified histology based on slices of Technovit 9100. The signaling pathway was analyzed via RT. 2. Profiler™ PCR Array Mouse Osteoporosis, Western Blot and Quantikine ELISA for RankL and OPG. Statistical significance was set at p < 0.05. Comparisons between groups were performed using the Mann–Whitney U (Fx vs. THFx) or Kruskal-Wallis Test (other groups). Results. The experiment showed that after 1 week the bones of the Fx- and THFx-mice were macroscopically instable. After 2 weeks the Fx-group showed macroscopically a stable bridging whereas the bones of the THFx-group were partly not stable bridged. 3 weeks after
To prevent infections after orthopedic surgery, intravenous antibiotics are administered perioperatively. Cefazolin is widely used as the prophylactic antibiotic of choice. Systemic antibiotic therapy may however be less effective in longstanding
Little is known on how sensory nerves and osteoclasts affect degenerative processes in subchondral bone in osteoarthritis (OA). Substance P (SP) effects on bone are ambivalent but physiological levels are critical for proper bone quality whereas α-calcitonin gene-related peptide (αCGRP) has anabolic effects. Here, we aimed to analyse the influence of an altered sensory neuropeptide microenvironment on subchondral bone in murine OA. Transection of the medial meniscotibial ligament (DMM) of the right hind leg induced joint instability leading to development of OA. Subchondral bone of tibiae from wildtype (WT), alendronate-treated WT (ALN, osteoclast inhibition), αCGRP- and SP- (Tachykinin (Tac)1) knockout mice was analysed by micro-computed tomography 4 and 12 weeks after DMM or sham surgery. Bone resorption marker CTX-I was measured in serum. We observed osteophytosis in all DMM groups and ALN sham mice 4 weeks after surgery but also in sham groups 12 weeks after
Cellular movement and relocalisation are important for many physiologic properties. Local mesenchymal stem cells (MSCs) from injured tissues and circulating MSCs aid in fracture healing. Cytokines and chemokines such as Stromal cell-derived factor 1(SDF-1) and its receptor chemokine receptor type 4 (CXCR4) play important roles in maintaining mobilisation, trafficking and homing of stem cells from bone marrow to the site of injury. We investigated the differences in migration of MSCs from the femurs of young, adult and ovariectomised (OVX) rats and the effect of CXCR4 over-expression on their migration. MSCs from young, adult and OVX rats were put in a Boyden chamber to establish their migration towards SDF-1. This was compared with MSCs transfected with CXCR4, as well as MSCs differentiated to osteoblasts.Objectives
Methods
We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice.Objectives
Methods
Venous thromboembolism (VTE) is a major potential complication following orthopaedic surgery. Subcutaneously administered enoxaparin has been used as the benchmark to reduce the incidence of VTE. However, concerns have been raised regarding the long-term administration of enoxaparin and its possible negative effects on bone healing and bone density with an increase of the risk of osteoporotic fractures. New oral anticoagulants such as rivaroxaban have recently been introduced, however, there is a lack of information regarding how these drugs affect bone metabolism and post-operative bone healing. We measured the migration and proliferation capacity of mesenchymal stem cells (MSCs) under enoxaparin or rivaroxaban treatment for three consecutive weeks, and evaluated effects on MSC mRNA expression of markers for stress and osteogenic differentiation.Objectives
Methods
The weight-bearing status of articular cartilage has been shown to affect its biochemical composition. We have investigated the topographical variation of sulphated glycosaminoglycan (GAG) relative to the DNA content of the chondrocyte in human distal femoral articular cartilage. Paired specimens of distal femoral articular cartilage, from weight-bearing and non-weight-bearing regions, were obtained from 13 patients undergoing above-knee amputation. After papain enzyme digestion, spectrophotometric GAG and fluorometric DNA assays assessed the biochemical composition of the samples. The results were analysed using a paired Although there were no significant differences in cell density between the regions, the weight-bearing areas showed a significantly higher concentration of GAG relative to DNA when compared with non-weight-bearing areas (p = 0.02). We conclude that chondrocytes are sensitive to their mechanical environment, and that local loading conditions influence the metabolism of the cells and hence the biochemical structure of the tissue.