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Lumbar spinal stenosis (LSS) is a common skeletal system disease that has been partly attributed to genetic variation. However, the correlation between genetic variation and pathological changes in LSS is insufficient, and it is difficult to provide a reference for the early diagnosis and treatment of the disease.

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Bacteriophages infect, replicate inside bacteria, and are released from the host through lysis. Here, we evaluate the effects of repetitive doses of the Staphylococcus aureus phage 191219 and gentamicin against haematogenous and early-stage biofilm implant-related infections in Galleria mellonella.

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Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI).

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It has been established that mechanical stimulation benefits tendon-bone (T-B) healing, and macrophage phenotype can be regulated by mechanical cues; moreover, the interaction between macrophages and mesenchymal stem cells (MSCs) plays a fundamental role in tissue repair. This study aimed to investigate the role of macrophage-mediated MSC chondrogenesis in load-induced T-B healing in depth.

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Safety concerns surrounding osseointegration are a significant barrier to replacing socket prosthesis as the standard of care following limb amputation. While implanted osseointegrated prostheses traditionally occur in two stages, a one-stage approach has emerged. Currently, there is no existing comparison of the outcomes of these different approaches. To address safety concerns, this study sought to determine whether a one-stage osseointegration procedure is associated with fewer adverse events than the two-staged approach.

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The aim of this study was to determine the fracture haematoma (fxH) proteome after multiple trauma using label-free proteomics, comparing two different fracture treatment strategies.

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Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration.

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Exosomes (exo) are involved in the progression of osteoarthritis (OA). This study aimed to investigate the function of dysfunctional chondrocyte-derived exo (DC-exo) on OA in rats and rat macrophages.

1. Previous immunological studies have shown that homografts of fresh marrow-free iliac bone are only weakly, if at all, antigenic. 2. In view of this finding an attempt was made to produce a foreign bone graft capable of forming new bone as readily as an iliac autograft by the following method. Living cells of high osteogenic potential and of autologous type were introduced into the graft by combining homologous fresh marrow-free iliac bone with the animal's own red marrow to form a fresh composite homograft-autograft of cancellous bone. 3. Such fresh composite homograft-autografts were inserted into a muscular site in Wistar rats and removed for microscopical examination at intervals of one to seven days and at two, six and twelve weeks after transplantation. 4. It is found that bone and marrow together as a fresh composite homograft-autograft form considerably more new bone than do either of the components of the graft transplanted separately. Homografts of fresh marrow-free iliac bone form, in general, a small amount of early phase and late phase new bone. Autografts of red marrow transplanted alone to a muscular site formed new bone in thirteen to thirty experiments (43 per cent). 5. The stimulus to osteogenesis, and the cellular source of osteoblasts, in marrow autografts is discussed in the light of present knowledge. The concept is suggested that after its transplantation there develops in marrow an inductive system leading to osteoblastic differentiation and bone formation. It is proposed that the necrosis of a portion of a marrow graft liberates osteogenic substances which are taken up by primitive wandering cells derived from littoral cells lining the vascular sinusoids of the surviving portions of the marrow which are induced, thereby, to differentiate as osteoblasts. 6. The cellular source of osteoblasts in a fresh composite homograft-autograft of cancellous bone is discussed. It is deduced that the new bone is derived mainly from the contained marrow of the graft, by mechanisms similar to those leading to osteoblastic differentiation in transplanted autografts of marrow. 7. The stimulus to the greater formation of new bone by fresh composite autograft-homografts than by autografts of marrow transplanted alone is discussed. Two explanations are suggested: 1) a more extensive necrosis of marrow in a composite homograft-autograft than in marrow transplanted alone; and 2) an inductive effect of bone upon marrow. 8. The new bone formed by autografts of fresh marrow-containing iliac bone, it is concluded, is derived not only from osteoblasts on the surfaces of the grafted bone but also from primitive wandering cells derived from littoral cells lining the vascular sinusoids of the surviving portions of its marrow. 9. Mechanisms which may play a role in the histogenesis of woven bone are discussed. 10. The significance of the relation of bone and marrow is considered briefly in the light of knowledge concerning the venous patterns of bone and marrow

Periprosthetic bone loss after total joint arthroplasty is a major clinical problem resulting in aseptic loosening of the implant. Among many cell types, osteoblasts play a crucial role in the development of peri-implant osteolysis. In this study, we tested the effects of calcitriol (1α,25-dihydroxy-vitamin-D. 3. ) and the bisphosphonate pamidronate on titanium-particle- and TNF-α-induced release of interleukin-6 and suppression of osteoblast-specific gene expressions in bone-marrow-derived stromal cells with an osteoblastic phenotype. We monitored the expression of procollagen α1[1], osteocalcin, osteonectin and alkaline phosphatase mRNAs by Northern blots and real-time reverse transcription and polymerase chain reaction analyses. The release of various cytokines was also analysed by ELISA. We found that calcitriol or pamidronate could only partially recover the altered functions of osteoblasts when added alone. Only a combination of these compounds restored all the tested functions of osteoblasts. The local delivery of these drugs may have therapeutic potential to prevent or to treat periprosthetic osteolysis and aseptic loosening of implants

Relating the results of our investigations to the knowledge hitherto acquired about the etiology of osteoporosis (which I have already referred to), I am inclined to interpret the pathogenesis of osteoporosis in the following way: 1) Primary osteoblastic deficiency: congenital (Lobstein); involutive (senile osteoporosis?); 2) Reduced osteoblastic activity from absence of trophic stimuli: (inactivity, ovarian agenesia, eunuchoidism, menopause); 3) Reduced osteoblastic activity from inhibitory stimuli: (cortisone, adrenocorticotrophic hormone (A.C.T.H.), stress, Cushing's disease, thyrotoxicosis); 4) Normal osteoblastic activity but insufficiency of constructive material: (malnutrition, disturbances of the digestive system, insufficiency of vitamin C, diabetes, thyrotoxicosis, cortisone, A.C.T.H., stress, Cushing's disease). Osteoporosis may therefore be the consequence either of a congenital osteoblastic deficiency, such as that found in cases of osteogenesis imperfecta, or of reduced osteoblastic activity due to absence of trophic stimuli such as mechanical stress and the sex hormones, or of reduced activity of the bone cells due to anti-anabolic substances which inhibit them, such as cortisone and its derivatives and the thyroid hormone in strong doses, or lastly of reduced availability of construction material due to its introduction in reduced quantities (starvation, dysfunction of the digestive system) or due to hindering of synthesis (deficiency of vitamin C, diabetes, cortisone and its derivatives) or due to an excessive degree of destruction (thyrotoxicosis). In the case of anti-anabolic hormones from the adrenal cortex, the mechanism may thus be twofold: inhibition of the osteoblasts and deprivation of the osteoblasts of glucoprotein material due to a general anomaly of metabolism. This may perhaps explain the most serious forms of bone atrophy which are usually observable in cases of hyperfunction of the adrenal cortex. Senile osteoporosis should, in my opinion, be included in the first of our groups because it cannot be said to be brought about by any of the causes usually cited for osteoporosis– such as deficiency of sex hormones, excess of hormones from the adrenal cortex, deficiency of calcium, etc.–and in all probability it will depend on a progressive involution of the osteoblasts brought about by old age. Senile involution is an expression of the descending phase of life's parabola and it involves all the organs and all the parenchymatous tissues in the human body, but it does not cause a parallel reduction of functions and activities on all of them equally. The skeletal system is one of the first to feel these reductions, because in old age life necessarily becomes less intense. Consequently in the economy of the ageing subject the generally reduced level of metabolism brings about a sort of selection in the nourishment of the different organs and systems, and sometimes almost a dismantling of some of these in an attempt to fall in with the new and reduced level of activities of some of the parenchymatous tissues, activities which may be incomplete or even transferred elsewhere. We believe that the moment which originally determines the beginning of senile osteoporosis coincides with the involutional process of cellular metabolism that strikes at all parenchymatous tissue during old age–striking, in the case of osteoporosis, hardest of all at the bony tissues. There is, indeed, no doubt that certain essential processes of cellular metabolism do alter with age, and that the reduction in the activity of the gonads does have considerable importance. In any case, just as adolescence and old age cannot be explained only in terms of gonadal activity, so the involution of the skeleton cannot be due merely to the involution of the gonads. How should one then interpret the well known benefit afforded by administration of sex hormones in cases of osteoporosis? Probably the action of oestrogens and androgens is, in this case, of a pharmacological nature, and comparable, for instance, to the action of digitalis on the cardiac muscle. It will be remembered how digitalis acts almost exclusively on myofibrils which have become inadequate, and has little or no effect on a normal myocardium. Similarly, the sex hormones would seem to exert a stimulating action on osteoblasts that are on the way to involution, while they exert little or no action on normal osteoblasts. In support of this we have the findings of Urist and other workers, who demonstrated that the administration of sex hormones produces calcium and nitrogen retention only in osteoporotics, while in non-osteoporotic subjects of the same age it produces no effect. On the other hand, the action of the sex hormones might act in cases of senile osteoporosis by returning the changed level of protein metabolism to normal. From the data in the literature and from the results of our own investigations, I conclude that osteoporosis in general, and senile osteoporosis in particular, are first and foremost the result of a disturbance in the metabolism of bone, and that the metabolic disturbance is closely and exclusively related to the degree of activity and the state of activity of the cells in the bone. Lastly, I believe that senile osteoporosis should not be considered an actual disease but rather as one limited aspect of the normal descending parabola which affects to a greater or less degree all the tissues of the body

Aims

Biofilm-related infection is a major complication that occurs in orthopaedic surgery. Various treatments are available but efficacy to eradicate infections varies significantly. A systematic review was performed to evaluate therapeutic interventions combating biofilm-related infections on in vivo animal models.

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Despite the interest in the association of gut microbiota with bone health, limited population-based studies of gut microbiota and bone mineral density (BMD) have been made. Our aim is to explore the possible association between gut microbiota and BMD.

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Alcoholism is a well-known detrimental factor in fracture healing. However, the underlying mechanism of alcohol-inhibited fracture healing remains poorly understood.

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Osteoarthritis (OA) is a common degenerative joint disease. The osteocyte transcriptome is highly relevant to osteocyte biology. This study aimed to explore the osteocyte transcriptome in subchondral bone affected by OA.

Platelet-derived growth factor (PDGF) is known to stimulate osteoblast or osteoprogenitor cell activity. We investigated the effect of locally applied PDGF from poly-. d. ,l-lactide (PDLLA)-coated implants on fracture healing in a rat model. A closed fracture of the right tibia of four-month-old Sprague-Dawley rats (n = 40) was stabilised with implants coated with a biodegradable PDLLA versus implants coated with PDLLA and PDGF. Radiographs were taken throughout the study, and a marker of DNA activity, bromodeoxyuridine (BrdU), was injected before the rats were killed at three, seven and ten days. The radiographs showed consolidation of the callus in the PDGF-treated group compared with the control group at all three time points. In the PDGF-treated group, immunohistochemical staining of BrdU showed that the distribution of proliferating cells in all cellular events was higher after ten days compared with that at three and seven days. These results indicate that local application of PDGF from biodegradable PDLLA-coated implants significantly accelerates fracture healing in experimental animals. Further development may help fracture healing in the clinical situation.

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Distraction osteogenesis (DO) is a useful orthopaedic procedure employed to lengthen and reshape bones by stimulating bone formation through controlled slow stretching force. Despite its promising applications, difficulties are still encountered. Our previous study demonstrated that pulsed electromagnetic field (PEMF) treatment significantly enhances bone mineralization and neovascularization, suggesting its potential application. The current study compared a new, high slew rate (HSR) PEMF signal, with different treatment durations, with the standard Food and Drug Administration (FDA)-approved signal, to determine if HSR PEMF is a better alternative for bone formation augmentation.

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A growing number of fractures progress to delayed or nonunion, causing significant morbidity and socioeconomic impact. Localized delivery of stem cells and subcutaneous parathyroid hormone (PTH) has been shown individually to accelerate bony regeneration. This study aimed to combine the therapies with the aim of upregulating fracture healing.

Failure of bone repair is a challenging problem in the management of fractures. There is a limited supply of autologous bone grafts for treating nonunions, with associated morbidity after harvesting. There is need for a better source of cells for repair. Mesenchymal stem cells (MSCs) hold promise for healing of bone because of their capacity to differentiate into osteoblasts and their availability from a wide variety of sources. Our review aims to evaluate the available clinical evidence and recent progress in strategies which attempt to use autologous and heterologous MSCs in clinical practice, including genetically-modified MSCs and those grown on scaffolds. We have compared various procedures for isolating and expanding a sufficient number of MSCs for use in a clinical setting. There are now a number of clinical studies which have shown that implantation of MSCs is an effective, safe and durable method for aiding the repair and regeneration of bone