Objectives. To review the systemic impact of smoking on
Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate
Objectives. 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
Electrical impedance spectroscopy measurements might be used for real-time monitoring of
The re-establishment of vascularity is an early event in fracture healing; upregulation of angiogenesis may therefore promote the formation of bone. We have investigated the capacity of vascular endothelial growth factor (VEGF) to stimulate the formation of bone in an experimental atrophic nonunion model. Three groups of eight rabbits underwent a standard nonunion operation. This was followed by interfragmentary deposition of 100 μg VEGF, carrier alone or autograft. After seven weeks, torsional failure tests and callus size confirmed that VEGF-treated osteotomies had united whereas the carrier-treated osteotomies failed to unite. The biomechanical properties of the groups treated with VEGF and autograft were identical. There was no difference in bone blood flow. We considered that VEGF stimulated the formation of competent bone in an environment deprived of its normal vascularisation and osteoprogenitor cell supply. It could be used to enhance the healing of fractures predisposed to nonunion.
In chronically infected fracture non-unions, treatment requires extensive debridement to remove necrotic and infected bone, often resulting in large defects requiring elaborate and prolonged bone reconstruction. One approach includes the induced membrane technique (IMT), although the differences in outcome between infected and non-infectious aetiologies remain unclear. Here we present a new rabbit humerus model for IMT secondary to infection, and, furthermore, we compare
Growth factors produced by inflammatory cells and mesenchymal progenitors are required for proper bone regeneration. Signaling pathways activated downstream of these proteins work in concert and synergistically to drive osteoblast and/or chondrocyte differentiation. While dysregulation can result in abnormal healing, activating these pathways in the correct spatiotemporal context can enhance
Secondary
Bone regeneration is a complex but very well organized process in which the immune system has a decisive role. The adaptive immune system and its experience level (percentage of effector and memory T cells) has been proven to influence the healing cascade especially in the early healing phases. This opens the possibility of an early intervention to enhance
Introduction. Immunomodulation represents a novel strategy to improve
Abstract. OBJECTIVES. To determine if force measured using a strain gauge in circular external fixation frames is different for 1) different simulated stages of
Our previous rat study demonstrated an ex vivo-created “Biomimetic Hematoma” (BH) that mimics the intrinsic structural properties of normal fracture hematoma, consistently and efficiently enhanced the healing of large bone defects at extremely low doses of rhBMP-2 (0.33 μg). The aim of this study was to determine if an extremely low dose of rhBMP-2 delivered within BH can efficiently
In a consecutive retrospective analysis of 190 patients treated with the Masquelet technique at the BG Klinikum Hamburg from January 2012 to January 2022, defect-specific features such as the extent and morphology of the defect were recorded, and their influence on the time to reach full weight-bearing of the affected limb was investigated. A total of 217 defects were treated in 190 patients using the Masquelet technique. 70% of all defects were located in the tibia, followed by 22% in the femur and only about 7% in the upper extremity. The average length of all defects was 58 mm (+/−31 mm), with the largest defect measuring 180 mm and the smallest measuring 20 mm. 89% of the patients achieved full weight-bearing at the end of therapy. The average time from initiation of therapy to reaching safe full weight-bearing was 589 days. There was a significant correlation between defect length and time to reach full weight-bearing (p = 0.0134). These results could serve as a basis for creating a score for prognostics and evaluation of
Abstract. Objectives. Review the evidence of low intensity pulsed ultrasound (LIPUS) for fracture non-union treatment and the potential to treat fractures in patients with co-morbidities at risk of fracture non-union. Methods. Data was gathered from both animal and human studies of fracture repair to provide an overview of the LIPUS in
Introduction and Objective. The early pro-inflammatory hematoma phase of
Periosteal mesenchymal stem cells (PMSC) are an emerging niche of stem cells to enhance
Nitric oxide is a free radical which in vivo is solely produced during the conversion of the amino acid arginine into citrulline by nitric oxide synthase enzymes. Recently, the importance of nitric oxide on inflammation and bone metabolism has been investigated. However, the knowledge regarding possible in vitro effects of arginine supplementation on chondrogenic differentiation is limited. ATDC5, a cell line which is derived from mouse teratocarcinoma cells and which is characterized as chondrogenic cell line, were proliferated in Dulbecco's Modified Eagle Medium (DMEM)/F12 and subsequently differentiated in proliferation medium supplemented with insulin, transferrin and sodium-selenite and where arginine was added in four different concentrations (0, 7.5, 15 and 30 mM). Samples were harvested after 7 or 10 days and were stored at −80 °C for subsequent RNA isolation for qPCR analysis. To determine chondrogenic differentiation, Alcian Blue staining was performed to stain the proteoglycan aggrecan, which is secreted by differentiated ATDC5 cells. All measurements were performed in triplo. Alcian Blue staining showed a qualitative increase of proteoglycan aggrecan secretion in differentiated ATDC5 cells after treatment with 7 and 15 mM arginine, with additional increased expression of ColII, ColX, Bmp4 and Bmp6. Treatment with 30 mM arginine inhibited chondrogenic differentiation and expression of aforementioned genes, however, Cox-2 and Vegfa gene expression were increased in these samples. Bmp7 was not significantly expressed in any experimental condition. The obtained results are suggestive for a dose-dependent effect of arginine supplementation on chondrogenic differentiation and associated gene expression, with 7.5 and 15 mM as most optimal concentrations and implications for apoptosis after incubation with 30 mM arginine. A future recommendation would be to investigate the effects of citrulline in a similar experiment, as this shows even more promising results to enhance the nitric oxide metabolism in sepsis and
Virtual mechanical testing is a method for measuring
Mesenchymal stem cells (MSC) have potent immunomodulatory and regenerative effects via soluble factors. One approach to improve stem cell-based therapies is encapsulation of MSC in hydrogels based on natural proteins such as collagen and fibrin, which play critical roles in