Objectives. The clinical utility of routine cross sectional imaging of the abdomen and pelvis in the screening and surveillance of patients with primary soft-tissue sarcoma of the extremities for metastatic disease is controversial, based on its questionable yield paired with concerns regarding the risks of radiation exposure, cost, and morbidity resulting from false positive findings. Methods. Through retrospective review of 140 patients of all ages (mean 53 years; 2 to 88) diagnosed with soft-tissue sarcoma of the extremity with a mean follow-up of 33 months (0 to 291), we sought to determine the overall incidence of isolated abdominopelvic metastases, their temporal relationship to chest involvement, the rate of false positives, and to identify disparate rates of metastases based on sarcoma subtype. Results. A total of four patients (2.9%) exhibited isolated abdominopelvic metastatic disease during the surveillance period. In all cases of concomitant chest and abdominopelvic disease, chest involvement preceded abominopelvic involvement. There was a significant false positive rate requiring invasive workup. Conclusions. In the setting of a relative paucity of evidence concerning a rare disease process and in difference to recently published investigations, we add a clinical cohort not supportive of routine cross sectional imaging of the abdomen and pelvis. Cite this article: Bone Joint Res 2015;4:45–9

Human mesenchymal stem cells are considered the golden standard for clinical application in regenerative medicine for their multilineage differentiation potential, best candidates to treat diseases such as osteoarthritis and osteogenesis imperfecta. In the past few years several molecules have been described to induce the hMSCs differentiation into osteo cell progenitors, mainly discovered by screening of single metabolites bioactivity. However, hMSCs osteogenic differentiation potential is still poor, and the discovery of differentiation inducers with high efficiency is needed. Thanks to automated processes, High Throughput Screening (HTS) strategies shorten the metabolites bioactivity investigation timeline, allowing testing of many molecules simultaneously. In this work, reliable assays for natural products bioactivity investigation detection were developed using HTS methodologies and validated by testing 15 purified compounds derived by marine fungi and sponges. The HTS cytotoxicity investigation using HepG2 cells allowed to test in a single experiment, 15 metabolites in 4 concentrations ranging from 1 to 20µM. Low cytotoxicity was detected for metabolites concentrations from 1 to 10µM and so set as treatment concentrations to be tested in further assays. Anti-inflammatory bioactivity was tested on THP1 cells triggered by LPS. Five out of 15 metabolites showed to prevent the LPS induced THP1 inflammatory activation by lowering the TNF-α production. The metabolites pro-osteogenic potential was investigated using hMSCs: their differentiation was evaluated by calcium mineralization after 10 days differentiation. Pro-osteogenic molecules were not detected in this screening, but the method validation represents a powerful tool for future natural product and synthetic molecules libraries screenings

Vertebral metastases are the most common type of malignant lesions of the spine. Although this tumour is still considered incurable and standard treatments are mainly palliative, the standard approach consists in surgical resection, which results in the formation of bone gaps. Hence, scaffolds, cements and/or implants are needed to fill the bone lacunae. Here, we propose a novel approach to address spinal metastases recurrence, based on the use of anti-tumour metallic-based nanostructured coatings. Moreover, for the first time, a gradient microfluidic approach is proposed for the screening of nanostructured coatings having anti-tumoral effect, to determine the optimal concentration of the metallic compound that permits selective toxicity towards tumoral cells. Coatings are based on Zinc as anti-tumour agent, which had been never explored before for treatment of bone metastases. The customized gradient generating microfluidic chip was designed by Autodesk Inventor and fabricated from a microstructured mould by using replica moulding technique. Microstructured mould were obtained by micro-milling technique. The chip is composed of a system of microfluidic channels generating a gradient of 6 concentrations of drug and a compartment with multiple arrays of cell culture chambers, one for each drug concentration. The device is suitable for dynamic cultures and in-chip biological assays. The formation of a gradient was validated using a methylene blue solution and the cell loading was successful. Preliminary biological data on 3D dynamic cultures of stromal cells (bone-marrow mesenchymal stem cells) and breast carcinoma cells (MDA-MB-231) were performed in a commercial microfluidic device. Results showed that Zn eluates had a selective cytotoxic effect for tumoral cells. Indeed, cell migration and cell replication of treated tumoral cells was inhibited. Moreover, the three-dimensionality of the model strongly affected the efficacy of Zn eluates, as 2D preliminary experiments showed a high cytotoxic effect of Zn also for stromal cells, thus confirming that traditional screening tests on 2D cultured cells usually lead to an overestimation of drug efficacy and toxicity. Based on preliminary data, the customized platform could be considered a major advancement in cancer drug screenings as it also allows the rapid and efficient screening of biomaterials having antitumor effect

Objectives. Surgeons face a substantial risk of infection because of the occupational exposure to blood-borne pathogens (BBPs) from patients undergoing high-risk orthopaedic procedures. This study aimed to determine the seroprevalence of four BBPs among patients undergoing joint arthroplasty in Shanghai, China. In addition, we evaluated the significance of pre-operative screening by calculating a cost-to-benefit ratio. Methods. A retrospective observational study of pre-operative screening for BBPs, including hepatitis B and C viruses (HBV and HCV), human immunodeficiency virus (HIV) and Treponema pallidum (TP), was conducted for sequential patients in the orthopaedic department of a large urban teaching hospital between 01 January 2009 and 30 May 2016. Medical records were analysed to verify the seroprevalence of these BBPs among the patients stratified by age, gender, local origin, type of surgery, history of previous transfusion and marital status. Results. Of the subjects who underwent arthroplasty surgery in our institution, pre-operative screening tests were available for 96.1% (11 609 patients). The seroprevalence of HBV, HCV, HIV and TP was 5.47%, 0.45%, 0.08% and 3.6%, respectively. A total of 761 seropositive cases (68.4%) were previously undiagnosed. Pre-operative screening for HIV resulted in a low cost to benefit ratio, followed by HCV and HBV. Conclusion. Routine HCV and HIV screening prior to joint arthroplasty is not a cost-effective strategy. Considering the high rate of undiagnosed patients and the shortage of protective options, targeted pre-operative screening for HBV and syphilis should be considered for the protection of healthcare workers in China who have not been vaccinated. Cite this article: Bone Joint Res 2017;6:566–571

Introduction and Objective. The osteocyte, recognized as a major orchestrator of osteoblast and osteoclast activity, is the most important key player during bone remodeling processes. Imbalances that occur during bone remodeling, caused by hormone perturbations or alterations in mechanical loading, can induce bone disease as osteoporosis. Due to limited understanding of the underlying mechanisms, current therapies for osteoporosis cannot adequately address this imbalance because current studies of osteocytes rely on conventional cell culture that cannot recapitulate local in vivo microenvironments for the lack of control of the spatial/temporal distribution of cells and biomolecules. Microfluidics is the science and technology of microscale fluid manipulating and sensing and can help fill this gap. Materials and Methods. We used a microfluidic device to enable the culture of osteocyte-like cells (MLO-Y4 and MLO-A5) in a 3D fashion. Osteocytes were cultured in a perfused and 160 μm high channel and embedded in a bone-like extracellular matrix: osteocytes were embedded in a matrigel- and collagen-based hydrogel enriched with nanostructured hydroxypatite crystals (HA-NP) to mimic bone. To set up the best combination of matrigel enriched with Type I collagen we used fluorescent microspheres and confocal analysis. To evaluate the viability and the expression of osteocytic markers, we used live-dead assay amd immunofluorescent staining and confocal analysis combined with automated quantification. For mineralization, we performed alizarin red staining. Results. Osteocytes in the organ-on-a-chip model showed high viability and, in respect to 2D conventional cell cultures an increased differentiation, as assessed by a live-dead assay and the staining of the osteocytic markers connexin-43 and alkaline phosphatase and the increased mineralization activity. Furthermore, the addition of HA-NP significantly increased the formation of dendrite-like structures spreading through the xyz-axes, as assessed after G-actin immunofluorescence. Conclusions. Using a microfluidic device for MLO-Y4 and MLO-A5 cell cultures, compared to the 2D surfaces, we demonstrated a significant difference in cell differentiation and morphology. In particular, 3D cultures allowed the formation of 3D cell networks and the osteogenic phenotype. As a platform technology, this microfluidic device can function as a novel cell culture model that enables further studies of osteocytes and 3D co-culturing with other bone cells for the screening of anti-osteoporotic drugs

Evaluation of different biomaterials is being performed with various methods trying to simulate the closest hostile-like in vitro environments. However the complexity of the conditions usually limits practically feasible combination of most relevant chemical, biological, biomechanical parameters in one single test. Many biomaterials and tissue engineering developments rely on high-throughput screening to multiply number of specimens and thus to gather sufficient data. The price to be paid for these methods is limited number of physical readouts, increased inter-specimens scatter, and unavoidable spatial constrains driving the conditions away of the clinical scenarios. For orthopaedic biomaterials this is of a particular concern, as implantation site conditions cannot be squeezed too much without lost of natural-mimicking stimuli. Here we are presenting another approach based on high-output screening of biomaterials, which is based on the strategy of raising the number of readouts obtainable from every specimen at more clinically-relevant conditions. On the contrary to common methods like ISO 10993 or simplified biomechanical tests, the biomaterials enhanced simulation testing (BEST) evaluates specimens without pre-selected biomaterial model, assessing the whole specimen as would happen in the implantation site. Besides reducing the risk of improper conclusions caused by wrong material model choice, the data processing with non-local method intrinsically includes the test history bypassing common challenges usually seen with hereditary integration. For properly designed experiment, readouts might include invariant moduli, viscous stiffness, fluidity, fluid permittivity and diffusivity (without need for pressure-driven separate tests), fluid source, effective channel size, and swelling pressure (if swelling is present) in addition to conventional biomechanical parameters. New solutions in advanced and consistent evaluations for biomaterials allow better risks control, shorten lead development time and costs, and compliant with 3R-strategy (2010/63/EC) and new regulatory requirements (2012/0266/COD in EU and FY2017 regulatory priorities by FDA). The approach shown is able to combine scientifically based tests with multi-purpose protocols to secure patient safety by screening of biomaterials under proper conditions. The authors thank Finnish Agency for Innovations (Tekes) for providing partial financial support

Introduction. In 2011 the Scottish Government published national MRSA screening requirements. A comparison of Orthopaedic and ENT elective surgery intended to juxtapose a specialty known to take MRSA screening seriously with one that has little clinical concern with regards MRSA infection. ENT surgery parallels Orthopaedics in using implants and there potentially being MRSA colonisation at or close to the site of surgery. In Orthopaedics MRSA infection is infrequent, but implant infection with antibiotic resistant bacteria has a particularly poor prognosis. In ENT MRSA infection is rare and colonisation does not influence patient care. Aims. An evaluation of MRSA screening practice for elective Orthopaedics and ENT surgery at Gartnavel General Hospital with regards strategy and implementation. Method. Review of 342 consecutive elective ENT patients and 325 Orthopaedic patients attending for inpatient or day case surgery. The reference standards were the regional and national guidelines on MRSA screening. Results. Overall screening rates were 145 (42%) of 342 ENT patients and 270 (83%) of 326 Orthopaedic patients. 100% of Orthopaedic patients admitted (154) were screened, in compliance with both regional and national policy. 91 (70%) of 130 ENT patients admitted were screened for MRSA, and no risk assessment was carried out, which was not in compliance with either regional or national policy. Discussion. Orthopaedic surgery has an established and reliable practice of screening elective inpatient cases, and when identified MRSA colonisation results in a change in patient management. ENT surgery should have established a similar practice according to existing local guidelines. The Government consider ENT a lower risk speciality for MRSA, but still require as a minimum a documented MRSA risk assessment process

It has been recently being investigated how the pressure distribution beneath the foot points to the active usage of the foot in standing adults. Nevertheless, it offers new perspectives in postural research by introducing foot-triggered sensory-motor control strategies in quiet standing dynamics. Furthermore, the spatiotemporal evolution of physiological postural control strategies has not clearly been identified yet. Thus, we have chosen developmental aspects of the infant's postural adjustments as a media to explore learning of biped standing. This study investigates developmental changes in active usage of a contact surface and pressure distribution beneath infants’ foot during learning of upright posture. We started studying longitudinally on 22 female and 22 male infants at their 12.5. th. months (1. st. trimester, T1) and kept on screening the same subjects at every three months (19 females and 12 males at 15.5. th. months (T2), 17 females and 7 males at 18.4. th. months (T3)), during their normal checkup appointments in Gazi University Hospital, Social Pediatrics Department-Ankara/Turkey. Each trial was fulfilled by an infant standing on a pressure pad placed on top of a force plate to collect the pressure distribution data beneath the feet for 15 sec at T1, and 25-sec long duration at T2 and T3 and was repeated at least three times. During the data collection, infants’ parents were beside them trying to get infants’ attention towards themselves preventing them from being distracted and/or moving and walking around. The data collection setup additionally contained one camera for videotaping the infants’ reactions. Our main research interest in this study was to explore the spatiotemporal evolution of the behavioral characteristics of human postural sway. We expected to monitor the developmental changes at an infant's standing experience during their 2. nd. -year epoch through time-frequency domain analyses and explorative/exploitative informatics’ metrics. We computed Center of Pressure (CoP) time signal from the data collected by the force plate and the pressure pad. In time domain, mean and the variance at the CoP time signal were estimated in both antero-posterior (CoPx) and medio-lateral (CoPy) directions. In the frequency domain, 50% and 95% power frequency, centroidal frequency (CF), and frequency dispersion were calculated. We observed substantial developmental changes in every trimester, each being comparable with the previous one, which points to infants experiencing a major developmental milestone that can be noticed considerably even in the shorter time intervals. The phase plane analysis performed through the time signals and their time derivatives (estimated velocity of CoPx and CoPy) revealed a shrinkage in the characteristic pattern observed through the following epochs. One-Way ANOVA analysis demonstrated significant differences in 50% and 95% power and centroidal frequency of CoPx (p=0.001, p=0.000, p=0.000) and CoPy (p=0.002, p=0.000, p=0.000) respectively. Further, post hoc analyses demonstrated a significant difference at T1 compared against T2 and T3 for all three frequency domain metrics. Particularly speaking, CF dropped from 2.39 to 1.65 Hz, and from 2.86 to 1.70 Hz for CoPx and CoPy respectively, while passing from T1 to T2. The current status of this research managed to grasp the developmental aspects of infant standing through frequency domain metrics and reconstructed phase space analysis up to their 18 months old

Summary Statement. Routine metal allergy screening prior to joint arthroplasty is not essential and the use of cobalt chromium or stainless steel implants is recommended regardless of the patient's metal allergy status. Introduction. This study was undertaken to obtain a consensus amongst joint arthroplasty experts with regards to metal allergy screening prior to joint arthroplasty and the choice of implant in patients with potential metal allergy. Patients & Methods. A web based Delphi consensus study was used including orthopaedic surgeons that had previously published on the topic of knee, hip or shoulder arthroplasty. Two rounds of questionnaires were sent via electronic mail. Consensus was considered if agreement was 60% or higher. Results. 18 surgeons responded to the first and 17 to the second round of questionnaires. There was consensus that patients having metal arthroplasty surgery should not be routinely questioned about metal allergy prior to surgery. There was consensus that patch testing is not necessary even if metal allergy is suspected. Most respondents agreed in proceeding with cobalt chromium or stainless steel implant in patients suspected of metal allergy regardless of the results of cutaneous patch testing. Discussion/Conclusion. This consensus study suggests that routine metal allergy screening prior to joint arthroplasty is not essential. The use of traditional cobalt chromium/stainless steel implants is recommended regardless of the patient's metal allergy status

Abstract

Summary Statement. It is now possible to diagnose osteoporosis using incidental CT scans; this approach has been used to objectively demonstrate the role of osteoporosis in fracture in ankylosing spondylitis patients. Background. In advanced disease, Ankylosing Spondylitis (AS) is frequently associated with a reduction in bone mineral density (BMD), this contributes to pain and predisposes to fractures. Quantifying this reduction in BMD is complicated by the simultaneous processes occurring, in which there is both an overgrowth of bone (syndesmophytes) and a concurrent loss of trabecular bone. Traditional methods such as dual-energy X-ray absorptiometry (DXA) struggle to generate accurate estimates for BMD in these patients. It has recently become possible to diagnose osteoporosis, with a high sensitivity and specificity, using incidental CT scans of the L1 vertebra. The purpose of this study was to evaluate the use of opportunistic CT screening in the diagnosis of osteoporosis in patients with AS who had sustained vertebral fractures. Patients & Methods. Following Institutional review board approval, patients with AS who presented, with acute fractures of the spine, to our facility between 2004 and 2013 were reviewed to assess whether or not they had a Computed Tomography (CT) scan of the abdomen on admission or in the 6 months before or after injury. In addition, patients were also required to have signs of advanced AS such as the presence of syndesmophytes and syndesmophyte bridging; patients with fractures through L1 were excluded. Of those fitting the criteria, a region of Interest (ROI) was generated over the body of L1, Hounsfield unit (HU) were then measured. Results. Of the 42 patients reviewed, a total of 17 AS patients fit the above criteria. 15 were male and 2 were female, mean age of the whole cohort was 69.9years (range 22–85; SD 15.9). Using a threshold balanced for sensitivity and specificity (<135 HU) which differentiates between osteopenia and osteporosis, 14 (82%) patients were found to have a BMD less than 135HU; a higher threshold (<160 HU) with 90 % sensitivity for differentiating osteoporosis from osteopenia was applied to the group, and 15 patients (88%) were found to be osteoporotic. Of note all the females in the study were osteoporotic. Discussion and Conclusion. This study demonstrates, for the first time, using opportunistic CT screening, that a high proportion of AS patients who sustain fractures have osteoporosis; this overcomes the difficulties that have been encountered with the use of DXA in this unique group of patients. This simple and accessible method saves on excess cost and exposure to radiation. With a high sensitivity, patients identified using this method can then be managed more proactively. We believe these data have the potential to significantly impact the day to day management of patients with spondyloarthropathies

Objective. The STarT Back Screening Tool (STarT) is a 9-item patient self-report questionnaire that classifies low back pain patients into low, medium or high risk of poor prognosis. When assessed by GPs, these subgroups can be used to triage patients into different evidence-based treatment pathways. The objective of this study was to translate the English version of STarT into Danish (STarT-dk) and test its discriminative validity. Methods. Translation was performed using methods recommended by best practice translation guidelines. Psychometric validation of the discriminative ability was performed using the AUC statistic. The AUC was calculated for seven of the nine items where reference standards were available and compared with the original English version. Results. The linguistic translation required minor semantic and layout alterations. The response options were changed from “agree/disagree” to “yes/no” for four items. No patients reported item ambiguity using the final version. The AUC ranged from .735 to .855 (CI95% .678 to .897) in a Danish cohort (n=311) and .840 to .925 (CI95% .772 to .948) in the original English cohort (n=500). On four items, the AUC was statistically similar between the two cohorts but lower on three psychosocial sub-score items. Conclusions. The translation was linguistically accurate and the discriminative validity broadly similar, with some differences probably due to differences in severity between the cohorts and the Danish reference standard questionnaires not having been validated. Despite those differences, we believe the results show that the STarT-dk has sufficient patient acceptability and discriminative validity to be used in Denmark. Conflicts of interest. None. Sources of funding. This study was financed by a grant from the Region of Southern Denmark. This has not been presented at a national meeting

Low back pain admission to orthopaedics, aged >55, routinely received a myeloma screen (protein electrophoresis and urinary Bence Jones proteins). Myeloma association guidelines outline the symptoms that should trigger investigation. Acute admissions for back pain alone do not form part of this. We aimed to establish the number of emergency back pain admissions, >55, in our unit over two years. We wished to identify all patients who had protein electrophoresis and/or urinary Bence Jones proteins taken, the number of positive results and diagnoses of myeloma. From our database all patients >55 admitted with back pain in 2009 and 2010 were identified. Using the electronic laboratory reporting system we recorded FBC/ESR/Electrophoresis/Urinary Bence-Jones Proteins. There were 7682 admissions from January 2009–December 2010. 87 were for back pain (1.4%). 55 patients were aged >55 years. Within this group – 22 had protein electrophoresis and 23 had Bence-Jones Proteins. All were negative. 36 patients had an ESR taken, 9 were elevated. None were subsequently found to have haematological malignancy. 53 patients had an FBC taken (5 were anaemic, 8 had leucocytosis and 3 had thrombocytopenia). 20 patients had a vertebral fracture (36.4%). There were no documented cases of myeloma. The Information & Statistics Division of NHS Scotland published figures that demonstrate in 2006–2010, in patients > 55, there were 716 new cases of myeloma in the West of Scotland. Extrapolating this to our unit, on average, we would expect 24 new cases / year in this age group from all presentations. Performing myeloma screens on all back pains does not fulfil recognised screening criteria. We propose myeloma screens are not performed routinely in patients >55 admitted with back pain. It would be reasonable to do so where there is evidence of bone marrow failure, or plasmocytoma on Xray, associated with non-mechanical back pain

Summary Statement. Using abdominal CT scans to evaluate bone mineral density following acute fractures of the thoracic and lumbar spine demonstrates significant levels of osteoporosis in older patients; this approach may help save on time and resources, and reduce unnecessary radiation exposure. Introduction. While a reduction in bone mineral density (BMD) is associated with aging, relatively few patients have formal dual-energy X-ray absorptiometry (DXA) to quantify the magnitude of bone loss, as they age. This loss of bone may predispose to fractures. Recent data, which correlates mean Hounsfield units (HU) in an area of the L1 vertebra with BMD, now makes it possible to screen for osteoporosis using incidental abdominal Computed Tomography (CT) scans to measure bone density. This innovation has the potential to reduce both cost and radiation exposure, and also make it easier to identify patients who may be at risk. The aims of this study were to evaluate the utility of this approach in patients with acute thoracic and lumbar spine fractures and to evaluate the impact of aging on BMD, using CT screening. Patients & Methods. Following institutional review board approval, we performed a retrospective study of patients who presented to a level I trauma center with acute fractures of the thoracic and lumbar spine between 2010 and 2013; patients also had to have had an abdominal (or L1) CT scan either during the admission or in the 6 months before or after their injury. Using a picture archiving and communication (PACS) system, we generated regions of interest (ROI) of similar size in the body of L1 (excluding the cortex) and computed mean values for HU. Values derived were compared against threshold values which differentiate between osteoporosis and osteopenia - for specificity of 90%, a threshold of 110 was set; for balanced sensitivity and specificity, a threshold of <135 HU was set and for 90% sensitivity a threshold of <160 HU was set. A student's t test was used to compare the age stratified mean HU (younger than 65yrs; 65yrs and older), while Fisher's exact test was used to perform aged stratified comparisons between the proportions of patients above and below the thresholds outlined (in each of the three threshold groups). Results. A total of 124 patients were evaluated, with 74 having thoracic and 50 having lumbar fractures. Among those with thoracic fractures, there were 33patients in the younger cohort, who also had a mean BMD of 196.51HU and 41 in the older cohort, who had mean BMD of 105.90HU (p<0.001). In patients with lumbar fractures, 27 patients were in the younger cohort, with mean BMD of 192.26HU and 23 patients in the older cohort with mean BMD of 114.31HU (p<0.001). At the threshold of 110 HU, set for specificity, the magnitude of difference between the age stratified cohorts was greater in the thoracic spine (p<0.001 vs. p=0.003). At the other thresholds: 135HU (balanced for sensitivity and specificity) and 160 HU (90% sensitivity), age of 65 years or older was significantly associated with reduction in CT derived measure of BMD (p<0.001 in all cases). Discussion. This study demonstrates the relative frequency of osteoporosis in acute fractures of the thoracic and lumbar spine, and how this changes with age; it is also the first study to do this using opportunistic CT scans. There seems to be a strong association between a reduction in bone mineral density and advanced age, in patients presenting with acute fractures of the spine. This approach may save on the extra cost and additional radiation exposure that may be associated with DXA scanning; in addition, it may help provide clinicians and patients with an approach to monitor developing problems with BMD before it becomes clinically apparent, especially in younger patients

In this study we aimed to identify which anatomical site was the most effective for methicillin resistant staphylococcus aureus (MRSA) detection within an elective orthopaedic setting. A retrospective review was performed of 13,373 elective orthopaedic patients from pre-assessment and admission screening swabs taken over a five year period (2005-2010). Swabs were taken from the nose, the axilla and either the groin or perineum. MRSA was identified in 136(1.02%) of patients. The nose was found to be positive for MRSA in 89.6% of cases identified. Therefore only 10.4% of the MRSA carriers (0.1% of all admissions) would not have been identified had a single nasal swab been taken. There was no additional benefit in swabbing the axilla. We believe that for the majority of orthopaedic elective admissions a single nasal swab should be sufficient. In hip arthroplasty patients it may be beneficial to additionally swab the groin given the close proximity of the surgical wound

Cartilage-bone interactions play a critical role in joint diseases and the osteochondral junction has been identified as a locus of osteoarthritis development. However, it is challenging to study osteochondral (OC) interaction in vitro, since cartilage and bone require very different environments. We developed a new medium-to-high throughput osteochondral microphysiological system bioreactor to culture biphasic native or engineered constructs and that can be used to study any musculoskeletal tissue interfaces. We developed engineered constructs from hMSCs on a porous polymeric matrix with a gradient in pore size to assess the supportive effect of the local topology on cartilaginous and osseous differentiation. Furthermore, we developed a triphasic, vascualized osteochondral constructs based on porous polycaprolactone and methacrylated gelatin scaffolds to study the specific effects of vasculature on cartilage and bone. We also cultured native OC tissues from postmenopausal women, exposing either cartilage or bone to sex hormones studying their protective effects. Finally, our bioreactor is being implemented for use on the International Space Station to study countermeasures against microgravity bone loss. Overall, our bioreactor maintains media separation for in vitro culture and engineering of OC tissues and constructs of progressively greater complexity, and it preserves the possibility of direct cartilage-bone crosstalk opening new opportunities to study interactions across the osteochondral junction.

Summary Statement

It is now possible to diagnose osteoporosis using incidental abdominal CT scans; applying this approach to fractures of the cervical spine demonstrates levels of osteoporosis in patients over 65.

Osteoporosis is a progressive, chronic disease of bone metabolism, characterized by decreased bone mass and mineral density, predisposing individuals to an increased risk of fractures. The use of animal models, which is the gold standard for the screening of anti-osteoporosis drugs, raises numerous ethical concerns and is highly debated because the composition and structure of animal bones is very different from human bones. In addition, there is currently a poor translation of pre-clinical efficacy in animal models to human trials, meaning that there is a need for an alternative method of screening and evaluating new therapeutics for metabolic bone disorders, in vitro. The aim of this project is to develop a 3D Bone-On-A-Chip that summarizes the spatial orientation and mutual influences of the key cellular components of bone tissue, in a citrate and hydroxyapatite-enriched 3D matrix, acting as a 3D model of osteoporosis. To this purpose, a polydimethylsiloxane microfluidic device was developed by CAD modelling, stereolithography and replica molding. The device is composed by two layers: (i) a bottom layer for a 3D culture of osteocytes embedded in an osteomimetic collagen-enriched matrigel matrix with citrate-doped hydroxyapatite nanocrystals, and (ii) a upper layer for a 2D perfused co-culture of osteoblasts and osteoclasts seeded on a microporous PET membrane. Cell vitality was evaluated via live/dead assay. Bone deposition and bone resorption was analysed respectively with ALP, Alizarin RED and TRACP staining. Osteocytes dendrite expression was evaluated via immunofluorescence. Subsequently, the model was validated as drug screening platform inducing osteocytes apoptosis and administrating standard anti-osteoporotic drugs. This device has the potential to substitute or minimize animal models in pre-clinical studies of osteoporosis, contributing to pave the way for a more precise and punctual personalized treatment

An international Consensus Group has by a Delphi approach identified the topic of host factors affecting pin site infection to be one of the top 10 priorities in external fixator management. The aim of this study was to report the frequency of studies reporting on specific host factors as a significant association with pin site infection. Host factors to be assessed was: age, smoking, BMI and any comorbidity, diabetes, in particular. The intention was an ethological review, data was extracted if feasible, however no meta-analysis was performed. A systematic literature search was performed according to the PRISMA-guidelines. The protocol was registered before data extraction in PROSPERO. The search string was based on the PICO criterias. A logic grid with key concept and index terms was made. A search string was built assisted by a librarian. The literature search was executed in three electronic bibliographic databases, including Embase MEDLINE (1111 hits) and CINAHL (2066 hits) via Ovid and Cochrane Library CENTRAL (387 hits). Inclusion criteria: external fixation, >1 pin site infection, host factor of interest, peer-reviewed journal. Exclusion criteria: Not written in English, German, Danish, Swedish, or Norwegian, animal or cadaveric studies, location on head, neck, spine, cranium or thorax, editorials or conference abstract. The screening process was done using Covidence. A total of 3564 titles found. 3162 excluded by title and abstract screening. 140 assessed for full text eligibility. 11 studies included for data extraction. The included studies all had a retrospective design. Three identified as case-control studies. Generally the included studies was assessed to have a high risk of bias. A significant associations between pin site infection for following host factors: a) increased HbA1C level in diabetic patients; b) congestive heart failure in diabetic patients; c) less co-morbidity; d) preoperative osteomyelitis was found individually. This systematic literature search identified a surprisingly low number of studies examining for risk of pin site infection and host factors. Thus, this review most of all serves to demonstrate a gap of evidence about correlation between host factors and risk of pin site infection, and further studies are warranted

Many age-related diseases affect our skeletal system, but bone health-targeting drug development strategies still largely rely on 2D in vitro screenings. We aimed at developing a scaffold-free progenitor cell-based 3D biomineralization model for more physiological high-throughput screenings. MC3T3-E1 pre-osteoblast spheroids were cultured in V-shaped plates for 28 days in alpha-MEM (10% FCS, 1% L-Gln, 1X NEAA) with 1% pen/strep, changed every two days, and differentiation was induced by 10mM b-glycerophosphate and 50µg/ml ascorbic-acid. Osteogenic cell differentiation was assessed through profiling mRNA expression of selected osteogenic markers by efficiency corrected normalized 2^DDCq RT-qPCR. Biomineralization in spheroids was evaluated by histochemistry (Alizarin Red/von Kossa staining), Alkaline phosphatase (Alp) activity, Fourier transform infrared spectroscopy (FTIR) analyses, micro-CT analyses, and scanning electron microscopy on critical point-dried samples. GraphPad Prism 9 analyses comprised Shapiro-Wilk and Brown-Forsythe tests as well as 2-way ANOVA with Tukey post-hoc and non-parametric Kruskal-Wallis with Dunn post-hoc tests. During mineralization, as opposed to non-mineralizing conditions, characteristic mRNA expression profiles of selected early and late osteoblast differentiation markers (e.g., RunX, Alp, Col1a1, Bglap) were observed between day 0 and 28 of culture; Alp was strongly upregulated (p<0.001) from day 7 on, followed by its enzymatic activity (p<0.001). Bglap and Col1a1 expression peaked on (p<0.001) and from day 14 on (p<0.05), respectively. IHC revealed osteocalcin staining in the spheroid core regions at day 14, while type I collagen staining of the cores was most prominent from day 21 on. Alizarin Red and Von Kossa confirmed central and radially outwards expanding mineralization patterns between day 14 and day 28, which was accompanied by a steady increase in extracellular calcium deposition over time (p<0.001). Micro-CT analyses allowed quantitative appreciation of the overall increase in mineral density over time (day21, p<0.05; d28, p<0.001), while SEM-EDX and FTIR ultimately confirmed a bone-like hydroxyapatite mineral deposition in 3D. A novel and thoroughly characterized versatile bone-like 3D biomineralization in vitro model was established, which allows for studying effects of pharmacological interventions on bone mineralization ex vivo under physiomimetic conditions. Ongoing studies currently aim at elucidating in how far it specifically recapitulates intramembranous ossification