Aims. Malreduction of the syndesmosis has been reported in up to 52% of patients after fixation of ankle fractures. Multiple radiological parameters are used to define malreduction; there has been limited investigation of the accuracy of these measurements in differentiating malreduction from inherent anatomical asymmetry. The purpose of this study was to identify the prevalence of positive malreduction standards within the syndesmosis of native, uninjured ankles. Methods. Three observers reviewed 213 bilateral lower limb CT scans of uninjured ankles. Multiple measurements were recorded on the axial CT 1 cm above the plafond: anterior syndesmotic distance; posterior syndesmotic distance; central syndesmotic distance; fibular rotation; and sagittal fibular translation. Previously studied malreduction standards were evaluated on bilateral CT, including differences in: anterior, central and posterior syndesmotic distance; mean syndesmotic distance; fibular rotation; sagittal translational distance; and syndesmotic area. Unilateral CT was used to compare the anterior to posterior syndesmotic distances. Results. A difference of anterior to posterior syndesmotic distance > 2 mm was observed in 89% of ankles (n = 190) on unilateral CT assessment. Using bilateral CT, we found that 35% (n = 75) of normal ankles would be considered malreduced by current malreduction parameters. In 50 patients (23%), only one parameter was anomalous, 18 patients (8%) had two positive parameters and seven patients (3%) had three. Difference in fibular rotation had the lowest false positive rate of all parameters at 6%, whereas posterior syndesmotic distance difference had the highest at 15%. Conclusion. In this study, 35% of native, uninjured syndesmoses (n = 75) would be classified as malreduced by current diagnostic standards on bilateral CT and 89% had an asymmetric incisura on unilateral CT (n = 190). Current radiological parameters are insufficient to differentiate mild inherent anatomical asymmetry from malreduction of the syndesmosis. Cite this article: Bone Joint J 2021;103-B(1):178–183

The burden of osteoporosis (OP), and its accompanied low energy fractures, is ever increasing. Targeted therapies are under development to stem the tide of the disease, with microRNAs identified as biomarkers and potential targets. Assessing the functional capacity of bone marrow mesenchymal stromal cells (BMSC) from patients with low energy neck of femur fractures (NOF) will identify the expected outcomes to be achieved from new, targeted osteogenic therapies. Two patient groups were assessed; low energy NOF and osteoarthritic. Bone marrow aspirates were taken at time of arthroplasty surgery. The adherent fraction was cultured and assessed by flow cytometry, microRNA expression and differentiation functionality. Both patient groups demonstrated characteristic extracellular markers of BMSCs. 3 key markers were significantly reduced in their expression in the NOF group (CD 90, 13, 166 P=0.0286). Reduced differentiation capacity was observed in the NOF group when cultured in osteogenic and adipogenic culture medium. 105 microRNAs were seen to be significantly dysregulated, with microRNAs known to be crucial to osteogenesis and disease process such as osteoporosis abnormally expressed. This data demonstrates the impaired functional capacity of BMSCs and their abnormal microRNA expression in patients who suffer a low energy NOF. Future targeted therapies for OP must address this to maximise their restorative effect on diseased bone. The important role microRNAs can play as biomarkers and target sites has been further reinforced

Mesenchymal stem cells (MSCs) reside around blood vessels in all organs. This reservoir of progenitors can be ‘recruited’ in response to injury. The ability to manipulate stem cells therapeutically within injured tissue provides an attractive alternative to transplantation. Stem cells are regulated by neighbouring cells. We hypothesized that endothelial cells (ECs) influence MSC differentiation into bone and fat. MSCs were sorted from fat using fluorescent activated sorting. Their capacity to differentiate into bone, fat and cartilage was used to confirm MSC phenotype. MSCs and ECs were cultured in two-dimensions (standard culture dishes) and three-dimensions (vascular networks suspended in gel). Cocultures were exposed to osteogenic and adipogenic media. The role of EC-released factors on MSC differentiation was determined using a system in which cells share media but do not contact. Wnt pathway modulators were used to investigate the role of Wnt signalling. MSCs differentiated into bone, fat and cartilage. MSCs and ECs integrated in two- and three-dimensions. MSCs and ECs formed vessel-like structures in three-dimensions. When cultured with ECs, MSC differentiation to bone was accelerated while differentiation to fat was inhibited. This effect on osteogenesis was maintained when cells shared media but did not contact. Coculture with Wnt modulators confirmed that this effect is in part, mediated through Wnt signalling. Our data suggest that ECs influence MSC differentiation. Therapeutic targeting of EC-MSCs signalling may enable manipulation of MSCs in vivo avoiding the need for cell transplantation. This could enable trauma and orthopaedic patients who have healthy resident stem cells to self-repair

Osteoporosis is a major healthcare burden, responsible for significant morbidity and mortality. Manipulating bone homeostasis would be invaluable in treating osteoporosis and optimising implant osseointegration. Strontium increases bone density through increased osteoblastogenesis, increased bone mineralisation, and reduced osteoclast activity. However, oral treatment may have significant side effects, precluding widespread use. We have recently shown that controlled disorder nanopatterned surfaces can control osteoblast differentiation and bone formation. We aimed to combine the osteogenic synergy of nanopatterning with local strontium delivery to avoid systemic side effects. Using a sol-gel technique we developed strontium doped and/or nanopatterned titanium surfaces, with flat titanium controls including osteogenic and strontium doped media controls. These were characterised using atomic force microscopy and ICP-mass spectroscopy. Cellular response assessed using human osteoblast/osteoclast co-cultures including scanning electron microscopy, quantitative immunofluorescence, histochemical staining, ELISA and PCR techniques. We further performed RNAseq gene pathway combined with metabolomic pathway analysis to build gene/metabolite networks. The surfaces eluted 800ng/cm2 strontium over 35 days with good surface fidelity. Osteoblast differentiation and bone formation increased significantly compared to controls and equivalently to oral treatment, suggesting improved osseointegration. Osteoclast pre-cursor survival and differentiation reduced via increased production of osteoprotegrin. We further delineated the complex cellular signalling and metabolic pathways involved including unique targets involved in osteoporosis. We have developed unique nanopatterned strontium eluting surfaces that significantly increase bone formation and reduce osteoclastogenesis. This synergistic combination of topography and chemistry has great potential merit in fusion surgery and arthroplasty, as well as providing potential targets to treat osteoporosis

Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. The need for a novel, cost effective treatment option for osteochondral defects has therefore never been greater. As an emerging technology, three-dimensional (3D) bioprinting has the capacity to deposit cells, extracellular matrices and other biological materials in user-defined patterns to build complex tissue constructs from the “bottom up”. Through use of extrusion bioprinting and fused deposition modelling (FDM) 3D printing, porous 3D scaffolds were successfully created in this study from hydrogels and synthetic polymers. Mesenchymal stem cells (MSCs) seeded onto polycaprolactone scaffolds with defined pore sizes and porosity maintained viability over a 7-day period, with addition of alginate hydrogel and scaffold surface treatment with NaOH increasing cell adhesion and viability. MSC-laden alginate constructs produced via extrusion bioprinting also maintained structural integrity and cell viability over 7 days in vitro culture. Growth within osteogenic media resulted in successful osteogenic differentiation of MSCs within scaffolds compared to controls (p<0.001). MSC spheroids were also successfully created and bioprinted within a novel, supramolecular hydrogel with tunable stiffness. In conclusion, 3D constructs capable of supporting osteogenic differentiation of MSCs were biofabricated via FDM and extrusion bioprinting. Future work will look to increase osteochondral construct size and complexity, whilst maintaining cell viability

Objectives. The biomembrane (induced membrane) formed around polymethylmethacrylate (PMMA) spacers has value in clinical applications for bone defect reconstruction. Few studies have evaluated its cellular, molecular or stem cell features. Our objective was to characterise induced membrane morphology, molecular features and osteogenic stem cell characteristics. Methods. Following Institutional Review Board approval, biomembrane specimens were obtained from 12 patient surgeries for management of segmental bony defects (mean patient age 40.7 years, standard deviation 14.4). Biomembranes from nine tibias and three femurs were processed for morphologic, molecular or stem cell analyses. Gene expression was determined using the Affymetrix GeneChip Operating Software (GCOS). Molecular analyses compared biomembrane gene expression patterns with a mineralising osteoblast culture, and gene expression in specimens with longer spacer duration (> 12 weeks) with specimens with shorter durations. Statistical analyses used the unpaired student t-test (two tailed; p < 0.05 was considered significant). Results. Average PMMA spacer in vivo time was 11.9 weeks (six to 18). Trabecular bone was present in 33.3% of the biomembrane specimens; bone presence did not correlate with spacer duration. Biomembrane morphology showed high vascularity and collagen content and positive staining for the key bone forming regulators, bone morphogenetic protein 2 (BMP2) and runt-related transcription factor 2 (RUNX2). Positive differentiation of cultured biomembrane cells for osteogenesis was found in cells from patients with PMMA present for six to 17 weeks. Stem cell differentiation showed greater variability in pluripotency for osteogenic potential (70.0%) compared with chondrogenic or adipogenic potentials (100% and 90.0%, respectively). Significant upregulation of BMP2 and 6, numerous collagens, and bone gla protein was present in biomembrane compared with the cultured cell line. Biomembranes with longer resident PMMA spacer duration (vs those with shorter residence) showed significant upregulation of bone-related, stem cell, and vascular-related genes. Conclusion. The biomembrane technique is gaining favour in the management of complicated bone defects. Novel data on biological mechanisms provide improved understanding of the biomembrane’s osteogenic potential and molecular properties. Cite this article: Dr H. E. Gruber. Osteogenic, stem cell and molecular characterisation of the human induced membrane from extremity bone defects. Bone Joint Res 2016;5:106–115. DOI: 10.1302/2046-3758.54.2000483

Introduction. Infection of endoprostheses is a serious complication in orthopedic surgery. As silver is known for its antibactierial effects, silver-coated endoprostheses have gained increased attention to decrease infection rates. However, cytotoxic effects of silver on bone cells have not been investigated in detail. We aimed to investigate whether silver nano-/microparticles and ionic silver exert cytotoxic effects on osteoblasts and osteoclasts in vitro and to correlate potential effects with the antibacterial effect on Staph. epidermidis. Methods. Murine osteoclasts (OC) and murine osteoblasts (OB) were treated with silver particles (avg. sizes: 50nm, 3μm, 30μm, 8μg/ml–500μg/ml) and Ag+NO3- (0.5μg/ml–500μg/ml). Silver treatment started on day 3 to prevent interference with cell adhesion. XTT assays were performed to assess cell viability. Tartrate resistant acidic phosphatase (TRAP) activity and alkaline phosphatase (ALP) activity served as measures for OC and OB differentiation, respectively. The release of silver ions from silver particles was quantified with atomic emission spectometry (AES). Titanium particles (avg. sizes: 50nm and 30μm) were used as controls to investigate whether potential silver effects were particle- or ion-mediated. The antimicrobial activity of silver ions and particles was tested with Staph. epidermidis agar inhibition assays. Results. Ionic silver had the strongest impact on cell differentiation and viability of OC and OB (OC differentiation: mean IC50 = 5 μg/ml, OC viability: mean IC50 = 14 μg/ml, OB differentiation: mean IC50 = 1 μg/ml, OB viability: mean IC50 = 1 μg/ml). Silver nanoparticles decreased cell differentiation and viability in a dose dependent manner (OC differentiation: mean IC50 = 5μg/ml, OC viability: mean IC50 = 14μg/ml, OB differentiation: mean IC50 = 1μg/ml, OB viability: mean IC50 = 1μg/ml). Silver microparticles as well as titanium nano- and microparticles had no effect on cell differentiation and viability. AES showed a size and dose dependent release of silver ions from silver nano- and microparticles. Agar inhibition assays showed a dose correlation of the antibacterial effect of silver with the cytotoxic effects on OB and OC. Conclusion. Silver nanoparticles and silver ions exert dose-dependent cytotoxic effects on OB and OC in vitro resulting in a severe alteration of cell differentiation and viability. The effect of silver on OB and OC seems to be mediated primarily by silver ions and correlates with the substance's antibacterial effects. The cytotoxicity of silver nanoparticles is mediated primarily by the size-dependent liberation of silver ions. Disturbance of OB and OC survival may have deleterious effects on the osseointegration of orthopedic implants. Further in vivo studies are needed to investigate the osseointegration of silver coated implants prior to their widespread clinical application

The scarcity of mesenchymal stem cells (MSCs) in iliac crest bone marrow aspirate (ICBMA), and the expense and time in culturing cells, has led to the search for alternative harvest sites. The reamer-irrigation-aspirator (RIA) provides continuous irrigation and suction during reaming of long bones. The aspirated contents pass via a filter, trapping bony fragments, before moving into a ‘waste’ bag from which MSCs have been previously isolated. We examined the liquid and solid phases, performed a novel digestion of the solid phase, and made a comparative assessment in terms of number, phenotype and differentiation capacity with matched ICBMA. The solid fraction from the filtrate was digested for 60 minutes at 37°C with collagenase. Enumeration was performed via the colony-forming unit fibroblast (CFU-F) assay. Passage (P2) cells were differentiated towards osteogenic, adipogenic and chondrogenic lineages, and their phenotypes assessed using flow cytometry (CD33, CD34, CD45, CD73, CD90, and CD105). MSCs from the RIA phases were able to differentiate at least as well as those from ICBMA, and all fractions had phenotypes consistent with other established sources. The median number of colonies for the three groups was: ICBMA = 8.5 (2 to 86), RIA-liquid = 19.5 (4 to 90), RIA-solid = 109 (67 to 200) per 200 μl. The mean total yield of cells for the three groups was: ICBMA = 920 (0 to 4275), RIA-liquid = 114 983 (16 500 to 477 750), RIA-solid = 12 785 (7210 to 28 475). The RIA filtrate contains large numbers of MSCs that could potentially be extracted without enzymatic digestion and used for bone repair without prior cell expansion

Aims

Patients with proximal femoral fractures (PFFs) are often multimorbid, thus unplanned readmissions following surgery are common. We therefore aimed to analyze 30-day and one-year readmission rates, reasons for, and factors associated with, readmission risk in a cohort of patients with surgically treated PFFs across Austria.

Engineered bone tissue to recreate the continuity of damaged skeletal segments is one of the field of interest of tissue engineering. Trabecular titanium has very good mechanical properties and high in vitro and in vivo biocompatibility: it can be used in biomedical applications to promote osteointegration demonstrating that it can be successfully used for regenerative medicine in orthopaedic surgery (1). Purpose of this investigation was to evaluate the behavior of adipose tissue derived stem cells (hASCs) cultured on scaffolds of Trabecular TitaniumTM (Lima-Lto) (TT). hASCs are considered to be multipotent mesenchymal stem cells that are easily induced to differentiate into functional osteoblasts both in vitro and in vivo (2). The hASCs were obtained from the subcutaneous adipose tissue of healthy donors during total hip replacement procedures after digestion with collagenase. They were seeded on monolayer and on the TT scaffolds, and incubated at 37 degrees C in 5% CO2 with osteogenic medium or control medium. The expression of bone-related genes using RT-PCR, time course of alkaline phosphatase activity and morphological investigation with Scanning Electron Microscopy (SEM) were performed to evaluate the osteogenic differentiation of hASCs. Alkaline phosphatase activity, marker of the differentiation toward the osteogenic pattern, was significantly higher in hASCs grown with osteogenic medium than in cells grown with control medium, both in monolayer and TT scaffolds; moreover, also alkaline phosphatase of hASCs grown on TT scaffolds in the presence of control medium increased with time, differently from that of cells grown on monolayer. The osteogenic differentiated hASCs expressed the bone-related genes type I collagen, osteocalcin, Runx-2 and alkaline phosphatase. SEM observations showed that hASCs differentiated toward osteoblast-like cells: they produced a big amount of extracellular matrix that covered the surface of the porous scaffolds with bridges between the pore walls. These data suggest that hASCs are able to adhere to TT scaffolds, to acquire an osteoblastic phenotype and to produce abundant extracellular matrix, with but also without osteogenic medium. We can therefore conclude that this material carries osteinductive properties being responsible of ostegenic differentiation; consequently, this scaffold/cells construct is effective to regenerate damaged tissue and to restore the function of bone tissue

Aims

The aim of this study was to examine perioperative blood transfusion practice, and associations with clinical outcomes, in a national cohort of hip fracture patients.

Osteoinductive bone substitutes are in their developmental infancy and a paucity of effective grafts options persists despite clinical demand. Bone mineral substitutes such as hydroxyapatite cause minimal biological activity when compared to osteoinductive systems present biological growth factors in order to drive bone regeneration. We have previously demonstrated the in-vitro efficacy of a bioengineered system at presenting growth factors at ultra low-doses. This study aimed to translate this growth factor delivery system towards a clinically applicable implant. Osteoinductive surfaces were engineered using plasma polymerisation of poly(ethyl acrylate) onto base materials followed by adsorption of fibronectin protein and subsequently growth factor (BMP-2). Biological activity following ethylene oxide (EO) sterilisation was evaluated using ELISAs targeted against BMP-2, cell differentiation studies and atomic force microscopy. Scaffolds were 3D printed using polycaprolactone/hydroxyapatite composites and mechanically tested using a linear compression models to calculate stress/strain. In-vivo analysis was performed using a critical defect model in 23 mice over an 8 week period. Bone formation was assessed using microCT and histological analysis. Finally, a computer modelling process was developed to convert patient CT images into surface models, then formatted into 3D-printable scaffolds to fill critical defects. Following EO sterilisation, there was no change in scaffold surface and persistent availability of growth factors. Scaffolds showed adequate porosity for cell migration with mechanical stiffness similar to cancellous bone. Finally, the in vivo murine model demonstrated rapid bone formation with evidence of trabecular remodelling in samples presenting growth factors compared to controls

Aims

The aim of this study was to investigate the association between additional rehabilitation at the weekend, and in-hospital mortality and complications in patients with hip fracture who underwent surgery.

Aims

Despite multiple trials and case series on hip hemiarthroplasty designs, guidance is still lacking on which implant to use. One particularly deficient area is long-term outcomes. We present over 1,000 consecutive cemented Thompson’s hemiarthroplasties over a ten-year period, recording all accessible patient and implant outcomes.

Introduction. The concept of “bone graft expanders” has been popularised to increase the volume and biological activity of the implanted Material. HYPOTHESIS. Orthoss® granules support exogenously seeded MSCs and attract neighbouring host MSCs. Methods. In 3-D cultures’ Orthoss® granules were seeded with 2×10. 5. bone marrow MSCs/granule and maintained in MSC expansion or differentiation media for 21 days. In homing experiments’ bone autografts were placed in close proximity to Orthoss®. Scaffold colonisation and MSC differentiation were assessed by confocal microscopy’ standard electron microscopy’ and energy-dispersive X-ray spectroscopy. Results. Long-term incubation of MSC/scaffold resulted in formation of multiple cell-matrix layers lining the scaffold pores as well as outer surfaces. MSC differentiation to osteoblasts was evident as strong deposition of Calcium and Phosphorus was detected in both MSC expansion and osteogenic conditions. Cell egress experiments demonstrated the migration of cells from neighbouring autografts and their attachment and re-settlement on Orthoss®. Discussion & Conclusions. Orthoss® scaffolds support MSC attachment’ growth and osteogenic differentiation whereas resident bone subpopulations can rapidly migrate towards’ attach’ and expand on them. These results indicate that Orthoss® can serve as a graft expander for repairing large bone defects in trauma patients

Introduction. Recently, some case reports have been published, in which nonunions were successfully healed with parathyroid hormone 1–34 (PTH) administration. Previously, we demonstrated that the intervening tissue at the nonunion site contains multilineage mesenchymal progenitor cells and plays an important role during the healing process of nonunion. We investigated the effect of PTH on osteogenic differentiation of human nonunion tissue-derived cells (NCs) in vitro. Hypothesis. We hypothesized that PTH directly promoted osteogenic differentiation of NCs. Materials & Methods. NCs were isolated from 4 patients, and cultured. The cells were divided into two groups: (1) PTH (−) group: cells cultured in osteogenic medium (OM), (2) PTH (+) group: cells cultured in OM with PTH. Osteogenic differentiation potential was analyzed. Results. Real-time PCR analysis showed that gene expression levels of Runx2, ALP, OC and PTHR1 in PTH (+) group were lower than PTH (−) group at day 14. In both groups, there was no significant difference in ALP activity at days 8 and 14, and in the intensity of Alizarin red S staining at day 20. Discussion. Treatment of PTH did not lead to increase osteogenic differentiation of NCs. Nonunion healing by PTH administration may be caused by other mechanisms such as mobilization and recruitment of osteoprogenitor cells

Aims

The aim of this study was to describe the demographic details of patients who sustain a femoral periprosthetic fracture (PPF), the epidemiology of PPFs, PPF characteristics, and the predictors of PPF types in the UK population.

Aims

The aim of this study was to describe the management and associated outcomes of patients sustaining a femoral hip periprosthetic fracture (PPF) in the UK population.

Aims

The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR).

Introduction. MSCs have long promised benefits of synthesising bone/cartilage, treating non-unions and potentially accelerating fracture repair. This potential has been tempered by MSC scarcity in the ‘gold-standard’ iliac crest bone marrow aspirate (ICBMA) and the resulting need to expand numbers via cell-culture. Culture of MSCs is time-consuming, expensive and results in cells with a reduced differentiation capacity. The reamer-irrigator-aspirator (RIA) is an innovation designed to reduce intra-medullary (IM) pressures during reaming of long-bones via continuous irrigation and suction. Aspirated contents are passed via a coarse filter, which traps bony-fragments before moving into a ‘waste’ bag - from which MSCs have been previously isolated. We examined liquid and solid phases found in this ‘waste’, performed a novel digestion of the solid phase and made a comparative assessment in terms of number, phenotype and differentiation capacity with matched ICBMA. Methods. The filtrate ‘waste’ bag from RIA reaming (6 patients) was filtered (70μm) and the solid fraction digested for 60min (37°C) with collagenase. MSCs were isolated from liquid & solid fractions and from 10ml matched ICBMA. Enumeration of MSCs was achieved via colony-forming-unit-fibroblast (CFUF) assay and flow-cytometry on fresh sample using CD45low, CD271+. MSCs were cultured by virtue of their plastic adherence and passaged in standard, non-haematopoietic media. Passage (P2) cells were differentiated towards osteogenic, adipogenic and chondrogenic lineages with their phenotype assessed with flow cytometry CD33 CD34 CD45 CD73 CD90 CD105. Results. We found MSCs were in all fractions/patients. Using the CFU-F assay median number of colonies: ICBMA=8 (2–21), RIA-liquid=12 (4–41), RIA-solid=115 (67–200) per 200μl of sample. Total yield of cells was calculated from volume of sample: ICBMA=670 (228–4275), RIA-liquid=39000 (16500–83700), RIA-solid=9400 (7210–28475). MSC frequency as a percentage of total cells using flow-cytometry on fresh sample found similar frequencies. MSCs isolated from the RIA phases differentiated into osteogenic, chondrogenic and adipogenic lineages at least as well as ICBMA. Passaged (P2) cells, from all fractions/patients, had a phenotype consistent with other reported sources. Discussion. The RIA filtrate bag is typically discarded at operation. These results show that this ‘waste’ represents a significant source of MSCs that could be isolated for autologous/allogenous use. Concentration of the liquid-phase/brief enzymatic digestion of the solid-phase offers the possibility of large numbers of MSCs being obtained without/with minimal culture expansion