The tendency towards using inertial sensors for remote monitoring of the patients at home is increasing. One of the most important characteristics of the sensors is sampling rate. Higher sampling rate results in higher resolution of the sampled signal and lower amount of noise. However, higher sampling frequency comes with a cost. The main aim of our study was to determine the validity of measurements performed by low sampling frequency (12.5 Hz) accelerometers (SENS) in patients with knee osteoarthritis compared to standard sensor-based motion capture system (Xsens). We also determined the test-retest reliability of SENS accelerometers.

Participants were patients with unilateral knee osteoarthritis. Gait analysis was performed simultaneously by using Xsens and SENS sensors during two repetitions of over-ground walking at a self-selected speed. Gait data from Xsens were used as an input for AnyBody musculoskeletal modeling software to measure the accelerations at the exact location of two defined virtual sensors in the model (VirtualSENS). After preprocessing, the signals from SENS and VirtualSENS were compared in different coordinate axes in time and frequency domains. ICC for SENS data from first and second trials were calculated to assess the repeatability of the measurements.

We included 32 patients (18 females) with median age 70.1[48.1 – 85.4]. Mean height and weight of the patients were 173.2 ± 9.6 cm and 84.2 ± 14.7 kg respectively. The correlation between accelerations in time domain measured by SENS and VirtualSENS in different axes was r = 0.94 in y-axis (anteroposterior), r = 0.91 in x-axis (vertical), r = 0.83 in z-axis (mediolateral), and r = 0.89 for the magnitude vector. In frequency domain, the value and the power of fundamental frequencies (F₀) of SENS and VirtualSENS signals demonstrated strong correlation (r = 0.98 and r = 0.99 respectively). The result of test-retest evaluation showed excellent repeatability for acceleration measurement by SENS sensors. ICC was between 0.89 to 0.94 for different coordinate axes.

Low sampling frequency accelerometers can provide valid and reliable measurements especially for home monitoring of the patients, in which handling big data and sensors cost and battery lifetime are among important issues.

Osteoarthritis (OA) of the equine distal interphalangeal joint (DIPJ) is a common cause of lameness. MicroRNAs (miRNAs) from biofluids such as plasma and synovial fluid make promising biomarker and therapeutic candidates.

The objectives of this study are (1) Identify differentially expressed (DE) miRNAs in mild and severe equine DIPJ OA synovial fluid samples and (2) Determine the effects of DE miRNAs on equine chondrocytes in monolayer culture.

Synovial fluid samples from five horses with mild and twelve horses with severe DIPJ OA were submitted for RNA-sequencing; OA diagnosis was made from MRI T2 mapping, macroscopic and histological evaluation. Transfection of equine chondrocytes (n=3) was performed using the Lipofectamine® RNAiMAX system with a negative control and a miR-92a mimic and inhibitor. qPCR was used to quantify target mRNA genes.

RNA-seq showed two miRNAs (miR-16 and miR-92a) were significantly DE (p<0.05). Ingenuity Pathway Analysis (IPA) identified important downstream targets of miR-92a involved in the pathogenesis of osteoarthritis and so this miRNA was used to transfect equine chondrocytes from three donor horses diagnosed with OA. Transfection was successfully demonstrated by a 1000-20000 fold increase in miR-92a expression in the equine chondrocytes. There was a significant (p<0.05) increase in COMP, COL3A1 and Sox9 in the miR-92a mimic treatment and there was no difference in ADAMTS-5 expression between the miR-92 mimic and inhibitor treatment.

RNA-seq demonstrated miR-92a was downregulated in severe OA synovial fluid samples which has not previously been reported in horses, however miR-92a is known to play a role in the pathogenesis of OA in other species. Over expression of miR-92a in equine chondrocytes led to significantly increased COMP and Sox9 expression, consistent with a chondrogenic phenotype which has been identified in human and murine chondrocytes.

A novel ex vivo intervertebral disc (IVD) organ model and corresponding sample holder were developed according to the requirements for six degrees of freedom loading and sterile culture in a new generation of multiaxial bioreactors. We tested if the model can be maintained in long-term IVD organ culture and validated the mechanical resistance of the IVD holder in compression, tension, torsion, and bending.

An ex vivo bovine caudal IVD organ model was adapted by retaining 5-6 mm of vertebral bone to machine a central cross and a hole for nutrient access through the cartilaginous endplate. A counter cross was made on a customized, circular IVD holder. The new model was compared to a standard model with a minimum of bone for the cell viability and height changes after 3 weeks of cyclic compressive uniaxial loading (0.02-0.2 MPa, 0.2 Hz, 2h/ day; n= 3 for day 0, n= 2 for week 1, 2, and 3 endpoints). Mechanical tests were conducted on the assembly of IVD and holder enhanced with different combinations of side screws, top screws, and bone adhesive (n=3 for each test).

The new model retained a high level of cell viability after three weeks of in vitro culture (outer annulus fibrosus 82%, inner annulus fibrosus 69%, nucleus pulposus 75%) and maintained the typical values of IVD height reduction after loading (≤ 10%). The holder-IVD interface reached the following highest average values in the tested configurations: 320.37 N in compression, 431.86 N in tension, 1.64 Nm in torsion, and 0.79 Nm in bending.

The new IVD organ model can be maintained in long-term culture and when combined with the corresponding holder resists sufficient loads to study IVD degeneration and therapies in a new generation of multiaxial bioreactors.

Osteomyelitis is an inflammatory condition accompanied by the destruction of bone and caused by an infecting microorganism. Open contaminated fractures can lead to the development of osteomyelitis of the fractured bone in 3-25% of cases, depending on fracture type, degree of soft-tissue injury, degree of microbial contamination, and whether systemic and/or local antimicrobial therapies have been administered. Untreated, infection will ultimately lead to non-union, chronic osteomyelitis, or amputation.

We report a case series of 10 patients that presented with post-operative infected non-union of the distal femur with or without prior surgery. The cases were performed at Padmashree Dr. D. Y. Patil Hospital, Nerul, Navi Mumbai, India. All the patients’ consents were taken for the study which was carried out in accordance with the Helsinki Declaration. The methodology involved patients undergoing a two-stage procedure in case of no prior implant or a three-stage procedure in case of a previous implant. Firstly, debridement and implant removal were done. The second was a definitive procedure in form of knee arthrodesis with ring fixator and finally followed by limb lengthening surgery.

Arthrodesis was planned in view of infection, non-union, severe arthritic, subluxated knee, stiff knee, non-salvage knee joint, and financial constraints. After all the patients demonstrated wound healing in 3 months along with good radiographic osteogenesis at the knee arthrodesis site, limb lengthening surgeries by tibial osteotomy were done to overcome the limb length discrepancy. Distraction was started and followed up for 5 months. All 10 patients showed results with sound knee arthrodesis and good osteogenesis at the osteotomy site followed by achieving the limb length just 1-inch short from the normal side to achieve ground clearance while walking. Our case series is unique and distinctive as it shows that when patients with infected nonunion of distal femur come with the stiff and non-salvage knee with severe arthritic changes and financial constraints, we should consider knee arthrodesis with Ilizarov ring fixator followed by limb lengthening surgery.

Range of Motion (ROM) assessments are routinely used during joint replacement to evaluate joint stability before, during and after surgery to ensure the effective restoration of patient biomechanics. This study aimed to quantify axial torque in the femur during ROM assessment in total hip arthroplasty to define performance criteria against which hip instruments can be verified. Longer term, this information may provide the ability to quantitatively assess joint stability, extending to quantitation of bone preparation and quality.

Joint loads measured with strain-gaged instruments in five cadaveric femurs prepared using posterior approach were analysed. Variables such as surgeon-evaluator, trial offset and specimen leg and weight were used to define 13 individual setups and paired with surgeon appraisal of joint tension for each setup. Peak torque loads were then identified for specific motions within the ROM assessment.

The largest torque measured in most setups was observed during maximum extension and external rotation of the joint, with a peak torque of 13Nm recorded in a specimen weighing 98kg. The largest torque range (19.4Nm) was also recorded in this specimen. Other motions within the trial reduction showed clear peaks in applied torque but with lower magnitude. Relationships between peak torque, torque range and specimen weight produced an R2 value greater than 0.65.

The data indicated that key influencers of torsional loads during ROM were patient weight, joint tension and limb motion. This correlation with patient weight should be further investigated and highlights the need for population representation during cadaveric evaluation. Although this study considered a small sample size, consistent patterns were seen across several users and specimens. Follow-up studies should aim to increase the number of surgeon-evaluators and further vary specimen size and weight. Consideration should also be given to alternative surgical approaches such as the Direct Anterior Approach.

Excessive opioid prescriptions after total joint arthroplasty (TJA) increase risks for adverse opioid related events, chronic opioid use, and increase the availability of opioids for unlawful diversion. Thus, decreasing postoperative prescriptions may improve quality after TJA. Concerns exist that a decrease in opioids prescribed may increase complications such as readmissions, emergency department (ED) visits or worsened patient reported outcomes (PROs). The purpose of this quality improvement study was to explore whether a reduction in opioids prescribed after TJA resulted in increased complications.

Methods: Data originated from a statewide arthroplasty database (MARCQI). The database collects over 96% of all TJA performed in the state of Michigan, USA. Data was prospectively abstracted and included OMEs prescribed at discharge, readmissions, ED visits within 30 days and PROs. Data was collected one year before and after the creation of an opioid prescribing protocol that had decreased prescriptions by approximately 50% in opioid naive and tolerant patients. Trends were monitored using Shewhart control charts.

84,998 TJA over two-years were included. All groups showed a reduction in opioids prescribed. Importantly, no increased complications occurred concomitant to this reduction. No increases in ED visits or readmissions, and no decreases in KOOSJR/HOOSJR/PROMIS10 scores were noted in any of the groups.

Using large data sets and registries can drive performance and improve quality. The MARCQI Postoperative opioid prescription recommendations and performance measures decreased total oral morphine equivalents prescribed over a large and diverse population by approximately 50% without decreasing PROs or increasing ED visits or hospital readmissions. A reduction in opioids prescribed after TJA can be accomplished safely and without an increase in complications across a large population.

Higher uric acid levels or hyperuricemia is a product of more uric acid production, dysfunctional renal excretion, or a combination of both leading to deposition of urate crystals in the joints and kidneys and has been strongly linked with the development of gout, that is, acute inflammatory arthritis. Uric acid levels have been suggested to depend on multiple factors including lifestyle, diet, alcohol consumption, etc. As these are risk parameters for hyperuricemia and since lifestyle choices vary amongst different Indian communities, we sought to study the prevalence of hyperuricemia in these communities. Also, large-scale data (in terms of gender, age, lifestyle, community) on the prevalence of hyperuricemia in subjects amongst different community populations, Hindu, Muslim, Sikh, and Christian was generated.

In a retrospective study conducted at Dr. D. Y. Patil School of Medicine & Research Centre, Navi Mumbai from April 2018 to May 2021, information was gathered from four major communities on a range of indicators including serum uric acid levels followed by a thorough multilevel logistic analysis. We evaluated uric acid levels in 10,378 patients of four different communities. Outcomes were assessed biochemically as well as clinically based on the levels of serum uric acid.

The mean serum uric acid levels were highest in Sikhs (7.6 mg%, n=732) followed by Christians (7.3 mg%, n=892) and then by Hindus (5.9 mg%, n=6846) and Muslims (5.6 mg%, n=1908). About 83.7% of Christians consumed meat in a non-vegetarian diet followed by 45.7% Muslims. Percentage of Christians who binge drink were highest whereas percentage of Sikh people in the heavy drinkers’ category were 5.2%. Further, 9.5% Hindus were current smokers followed by 7.8% Sikhs who smoked at present.

Overall, our study of 10,378 patients demonstrated that the serum uric acid levels varied from one Indian community to another due to varying external factors like diet, age, lifestyle, and addictions. Thus, lifestyle modification in communities with higher serum uric acid levels is highly advocated and this may reduce the healthcare burden of gouty arthritis in these communities.

Osteoarthritis (OA) is a common cause of chronic pain. Subchondral bone is highly innervated, and bone structural changes directly correlate with pain in OA. Mechanisms underlying skeletal–neural interactions are under-investigated. Bone derived axon guidance molecules are known to regulate bone remodelling. Such signals in the nervous system regulate neural plasticity, branching and neural inflammation. Perturbation of these signals during OA disease progression may disrupt sensory afferents activity, affecting tissue integrity, nociception, and proprioception.

Osteocyte mechanical loading and IL-6 stimulation alters axon guidance signalling influencing innervation, proprioception, and nociception.

Human Y201 MSC cells, embedded in 3D type I collagen gels (0.05 × 106 cell/gel) in 48 well plastic or silicone (load) plates, were differentiated to osteocytes for 7 days before stimulation with IL-6 (5ng/ml) with soluble IL-6 receptor (sIL-6r (40ng/ml) or unstimulated (n=5/group), or mechanically loaded (5000 μstrain, 10Hz, 3000 cycles) or not loaded (n=5/group). RNA extracted 1hr and 24hrs post load was quantified by RNAseq whole transcriptome analysis (NovaSeq S1 flow cell 2 × 100bp PE reads and differentially expressed neurotransmitters identified (>2-fold change in DEseq2 analysis on normalised count data with FDR p<0.05). After 24 hours, extracted IL-6 stimulated RNA was quantified by RT-qPCR for neurotrophic factors using 2–∆∆Ct method (efficiency=94-106%) normalised to reference gene GAPDH (stability = 1.12 REfinder). Normally distributed data with homogenous variances was analysed by two-tailed t test.

All detected axonal guidance genes were regulated by mechanical load. Axonal guidance genes were both down-regulated (Netrin1 0.16-fold, p=0.001; Sema3A 0.4-fold, p<0.001; SEMA3C (0.4-fold, p<0.001), and up-regulated (SLIT2 2.3-fold, p<0.001; CXCL12 5-fold, p<0.001; SEMA3B 13-fold, p<0.001; SEMA4F 2-fold, p<0.001) by mechanical load. IL6 and IL6sR stimulation upregulated SEMA3A (7-fold, p=0.01), its receptor Plexin1 (3-fold, p=0.03). Neutrophins analysed in IL6 stimulated RNA did not show regulation.

Here we show osteocytes regulate multiple factors which may influence innervation, nociception, and proprioception upon inflammatory or mechanical insult. Future studies will establish how these factors may combine and affect nerve activity during OA disease progression.

Integrin α2β1 is one of the major transmembrane receptors for fibrillary collagen. In native bone we could show that the absence of this protein led to a protective effect against age-related osteoporosis. The objective of this study was to elucidate the effects of integrin α2β1 deficiency on fracture repair and its underlying mechanisms.

Standardised femoral fractures were stabilised by an intramedullary nail in 12 week old female C57Bl/6J mice (wild type and integrin α2^-/-). After 7, 14 and 28 days mice were sacrificed. Dissected femura were subjected to µCT and histological analyses. To evaluate the biomechanical properties, 28-day-healed femura were tested in a torsional testing device. Masson goldner staining, Alizarin blue, IHC and IF staining were performed on paraffin slices. Blood serum of the animals were measured by ELISA for BMP-2. Primary osteoblasts were analysed by in/on-cell western technology and qRT-PCR.

Integrin α2β1 deficient animals showed earlier transition from cartilaginous callus to mineralized callus during fracture repair. The shift from chondrocytes over hypertrophic chondrocytes to bone-forming osteoblasts was accelerated. Collagen production was increased in mutant fracture callus. Serum levels of BMP-2 were increased in healing KO mice. Isolated integrin deficient osteoblast presented an earlier expression and production of active BMP-2 during the differentiation, which led to earlier mineralisation. Biomechanical testing showed no differences between wild-type and mutant bones.

Knockout of integrin α2β1 leads to a beneficial outcome for fracture repair. Callus maturation is accelerated, leading to faster recovery, accompanied by an increased generation of extra-cellular matrix material. Biomechanical properties are not diminished by this accelerated healing. The underlying mechanism is driven by an earlier availability of BMP-2, one main effectors for bone development. Local inhibition of integrin α2β1 is therefore a promising target to accelerate fracture repair, especially in patients with retarded healing.

The goal was to analyze the cellular response, specifically the osteogenic capacity, of titanium (Ti) implants harbouring a novel laserbased-surface-structure with the overall aim: augmented osteointegration. Surface micro-/nanoproperties greatly influence cell behaviour at the tissue-implant-interface and subsequent osteointegration. We investigated Ti-materials subjected to a specially developed shifted-Laser-Surface-Texturing (sLST) technology and compared them to a standard roughening-technique (sand-blasting-acid-etching, SLA). The biological response was evaluated with hMSCs, which are naturally available at the bone-implant-interface. We hypothesized: the novel surface is beneficial for our three different (young/healthy-YH; aged/healthy-AH;aged/osteoporotic-OP) cohorts.

The sLST was performed using a SPI-G3-series laser (beam-wavelength=1064nm, pulse-duration=200ns). For the SLA surface, Ti was sandblasted, afterwards acid-etched (HCl/H2SO4). Three different hMSC cohorts were studied: YH: n=6,29±6; AH: n=5,79±5; OP: n=5,76±5 years (osteoporosis confirmed via DEXA-scan). OP hMSCs show e.g. ColI-deficient-matrix and decreased mineralization. Cells were examined for survival, cell proliferation and cytoskeleton arrangement. Osteogenic differentiation was carried out over 21 days, matrix mineralization was validated with Alizarin-Red-S-staining and quantification.

Laser-texturing generated precisely the desired microgeometry. On nanostructural level, differently-sized Ti-droplets were formed stochastically by laser-induced-Ti-plasma. Live/dead-/Actin-stainings showed comparable results for all cohorts and surfaces in terms of survival and cell shape. On Ti-materials, cell growth showed no significant difference between the 3 cohorts. Alizarin quantification revealed the highest levels on laser-textured-surfaces; highest value for YH, followed by AH, lastly OP; no significance between AH/YH, but between OP/YH (p<0.0001). However, mineralization of all cohorts cultured on laser-textured-surfaces increased significantly (p<0.0001) compared to respective SLA-group, with >20fold higher value in the OP-cohort (AH:11fold, YH:6fold).

The data proves the biocompatibility of the laser-structured-Ti for young+aged cohorts. Osteogenic differentiation was significantly augmented on laser-treated-Ti. Most intriguingly, OP-donors could reach manifold increased mineralization, suggesting the novel laser texturing can counteract the osteoporotic phenotype. As osteogenesis-enhancing capacities may be related to mechanisms controlling cellular shape/fate, further investigations referring to this are currently ongoing. In conclusion, our laser-textured-Ti-materials are safe, can have a demand-oriented designer-surface-topography and represent a great potential for development into next-generation-implants suitable for different patient-cohorts, especially osteoporosis patients.

Osteoporosis is a common problem in postmenopausal women and the elderly. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a bi-directional enzyme that primarily activates glucocorticoids (GCs) in vivo, which is a considerable potential target as treatment for osteoporosis. Previous studies have demonstrated its effect on osteogenesis, and our study aimed to demonstrate its effect on osteoclast activation.

In vivo, we used 11β-HSD1 knock-off (KO) and C57BL6/J mice to undergo the ovariectomy-induced osteoporosis (OVX). In vitro, In vivo, We used 11β-HSD1 knockoff (KO) and C57BL6/J mice to undergo the ovariectomy-induced osteoporosis (OVX). In vitro, bone marrow-derived macrophages (BMM) and bone marrow mesenchymal stem cell (BMSC) of KO and C57BL6/J mice were extracted to test their osteogenic and osteoclastic abilities. We then created osteoclastic 11β-HSD1 elimination mice (Ctsk::11β-HSD1fl/fl) and treated them with OVX. Micro-CT analysis, H&E, immunofluorescence staining, and qPCR were performed. Finally, we conducted the high-throughput sequencing to find out 11β-HSD1 and osteoclast activation related genes.

We collected 6w samples after modeling. We found that KO mice were resistant to loss of bone trabeculae. The same effect was observed in osteoclastic 11β-HSD1 elimination mice. Meanwhile, BVT-2733, a classic inhibitor of 11β-HSD1, inhibited the osteoclast effect of cells without affecting osteogenic effect in vitro. High-throughput sequencing suggested that glucocorticoid receptor (GR) may play a key role in the activation of osteoclasts, which was verified by immunofluorescence staining and WB in vivo and in vitro.

In the process of osteoporosis, 11β-HSD1 expression of osteoclasts is abnormally increased, which may be a new target for inhibiting osteoclast activation and treating osteoporosis.

In 2020 almost 90% of femoral heads for total hip implants in Germany were made of ceramic. Nevertheless, the cellular interactions and abrasion mechanisms in vivo have not been fully understood until now. Metal transfer from the head-neck taper connection, occurring as smear or large-area deposit, negatively influences the surface quality of the articulating bearing. In order to prevent metal transfer, damage patterns of 40 Biolox delta ceramic retrievals with CoC and CoPE bearings were analysed.

A classification of damage type and severity for each component (n=40) was done according to an established scoring system. To investigate the physical properties, the surface quality was measured using confocal microscopy, quantitative analysis of phase composition were performed by Raman spectroscopy and qualitative analysis of metal traces was done by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). The periprosthetic tissue was analysed for abrasion particles with SEM and EDX.

Both bearing types show different damage patterns. Dotted/ drizzled metal smears were identified in 82 % of CoC (n=16) and 96 % of CoPE (n=24) bearings. Most traces on the ceramic heads were identified in the proximal area while they were observed predominantly in the distal area for the ceramic inlays. The identified marks are similar to those of metallic bearings. Metallic smears lead to an increase of up to 30 % in the monoclinic crystalline phase of the ceramic. The roughness increases by up to six times to Ra=48 nm. Ceramic and metallic wear particles from the articulating surfaces or head neck taper junctions were found in the periprosthetic tissue.

Damage patterns on CoC hip implants seem to be similar to those of metallic implants. More detailed analysis of CoC implants are needed to understand the described damage patterns and provide advice for prevention.

Our previous research has demonstrated that minor adjustments to in vitro cellular aggregation parameters, i.e. alterations to aggregate size, can influence temporal and spatial mineral depositions within maturing bone cell nodules. What remains unclear, however, is how aggregate size might affect mineralisation within said nodules over long-term in vivo culture.

In this study, we used an osteoblast cell line, MLO-A5, and a primary cell culture, mesenchymal stem cells (MSC), to compare small (approximately 80 µm) with large (approximately 220 µm) cellular aggregates for potential bone nodule development after 8 weeks of culturing in a mouse model (n = 4 each group). In total, 30 chambers were implanted into the intra-peritoneal cavity of 20 male, immunocompromised mice (MF1-Nu/Nu, 4 – 5 weeks old). Nine small or three large aggregates were used per chamber. Neoveil mesh was seeded directly with 2 × 10³ cells for monolayer control. At 8 weeks, the animals were euthanised and chambers fixed with formalin. Aggregate integrity and extracellular material growth were assessed via light microscopy and the potential mineralisation was assessed via micro-CT.

Many large aggregates appeared to disintegrate, whilst the small aggregates maintained their form and produced additional extracellular material with increased sizes. Both MLO-A5 cells and MSC cells saw similar results. Interestingly, however, the MSCs were also seen to produce a significantly higher volume of dense material compared to the MLO-A5 cells from micro-CT analysis.

Overall, a critical cell aggregate size appeared to exist balancing optimal tissue growth with oxygen diffusion, and cell source may influence differentiation pathway despite similar experimental parameters. The MSCs, for example, were likely producing bone via the endochondral ossification pathway, whilst the matured bone cells, MLO-A5 cells, were likely producing bone via the intramembranous ossification pathway.

Mesenchymal stem cells (MSCs) have the potential to repair and regenerate damaged tissues in response to injury, such as fracture or other tissue injury. Bone marrow and adipose tissue are the major sources of MSCs. Previous studies suggested that the regenerative activity of stem cells can be enhanced by exposure to tissue microenvironments. The aim of our project was to investigate whether extracellular matrix (ECM) engineered from human induced pluripotent stem cells-derived mesenchymal-like progenitors (hiPSCs-MPs) can enhance the regenerative potential of human bone marrow mesenchymal stromal cells (hBMSCs).

ECM was engineered from hiPSC-MPs. ECM structure and composition were characterized before and after decellularization using immunofluorescence and biochemical assays. hBMSCs were cultured on the engineered ECM, and differentiated into osteogenic, chondrogenic and adipogenic lineages. Growth and differentiation responses were compared to tissue culture plastic controls.

Decellularization of ECM resulted in efficient cell elimination, as observed in our previous studies. Cultivation hBMSCs on the ECM in osteogenic medium significantly increased hBMSC growth, collagen deposition and alkaline phosphatase activity. Furthermore, expression of osteogenic genes and matrix mineralization were significantly higher compared to plastic controls. Chondrogenic micromass culture on the ECM significantly increased cell growth and expression of chondrogenic markers, including glycosaminoglycans and collagen type II. Adipogenic differentiation of hBMSCs on the ECM resulted in significantly increased hBMSC growth, but significantly reduced lipid vacuole deposition compared to plastic controls. Together, our studies suggest that BMSCs differentiation into osteogenic and chondrogenic lineages can be enhanced, whereas adipogenic activity is decreased by the culture on engineered ECM. Contribution of specific matrix components and underlying mechanisms need to be further elucidated.

Our studies suggest that the three-lineage differentiation of aged BMSCs can be modulated by culture on hiPSC-engineered ECM. Further studies are aimed at scaling-up to three-dimensional ECM constructs for osteochondral tissue regeneration.

Anterior cruciate ligament reconstruction (ACLR) using a semitendinosus (ST) autograft, with or without gracilis (GR), results in donor muscle atrophy and varied tendon regeneration. The effects of harvesting these muscles on muscle moment arm and torque generating capacity have not been well described. This study aimed to determine between-limb differences (ACLR vs uninjured contralateral) in muscle moment arm and torque generating capacity across a full range of hip and knee motions.

A secondary analysis of magnetic resonance imaging was undertaken from 8 individuals with unilateral history of ST-GR ACLR with complete ST tendon regeneration. All hamstring muscles and ST tendons were manually segmented. Muscle length (cm), peak cross-sectional area (CSA) (cm²), and volume (cm³) were measured in ACLR and uninjured contralateral limbs. OpenSim was used to simulate and evaluate the mechanical consequences of changes in normalised moment arm (m) and torque generating capacity (N.m) between ACLR and uninjured contralateral limbs.

Compared to uninjured contralateral limbs, regenerated ST tendon re-insertion varied proximal (+) (mean = 0.66cm, maximum = 3.44cm, minimum = −2.17cm, range = 5.61cm) and posterior (+) (mean = 0.38cm maximum = 0.71cm, minimum = 0.02cm, range = 0.69cm) locations relative to native anatomical positions. Compared to uninjured contralateral limbs, change in ST tendon insertion point in ACLR limbs resulted in 2.5% loss in peak moment arm and a 3.4% loss in peak torque generating capacity. Accounting for changes to both max isometric force and ST moment arm, the ST had a 14.8% loss in peak torque generating capacity.

There are significant deficits in ST muscle morphology and insertion points following ST-GR ACLR. The ST atrophy and insertion point migration following ACLR may affect force transmission and distribution within the hamstrings and contribute to persistent deficits in knee flexor and internal rotator strength.

The Royal College of Surgeons of England (RCS) Good Surgical Practice guidance identifies essential criteria for surgical operation note documentation. The current quality improvement project aims to identify if using pre-templated operation notes for documenting fractured neck of femur surgery results in improved documentation when compared to free hand orthopaedic operation notes.

A total of fourteen categories were identified from the RCS guidance as required across all the operations identified in this study. All operations for the month of October 2021 were identified and the operation notes analysed. Pre-templated operation notes were compared to free hand operation notes.

97 cases were identified, of which 74 were free hand operation notes and 23 were pre-templated fractured neck of femur operation notes. All fourteen categories were completed in 13 (57%) of the templated operation notes vs 0 (0%) in the free hand operation notes (odds ratio 0.0052, 95% CI 0.0003 to 0.0945, p < 0.001). The median total number of completed categories was significantly higher in the templated op-note group compared to the free hand op-note group (templated median 14, range 12-14, vs. free hand median 11, range 9 to 13, p < 0.001). Logistic regression analysis of operation notes written by Registrars or Consultants identified Registrars as more likely to document the antibiotic prophylaxis given (p = 0.025).

Use of pre-templated operation notes results in significantly improved documentation. Adoption of generic pre-templated operation notes to improve surgical documentation should be considered across all operations.

Nuclear factor erythroid 2–related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is key in maintaining redox homeostasis and the pathogenesis of osteoarthritis (OA) involves oxidative distress. We thus investigated whether Nrf2/ARE signaling may control expression of key chondrogenic differentiation and hyaline cartilage maintenance factor SOX9.

In human C-28/I2 chondrocytes SOX9 expression was measured by RT–qPCR after shRNA-mediated knockdown of Nrf2 or its antagonist the Kelch-like erythroid cell-derived protein with cap “n” collar homology-associated protein 1 (Keap1). Putative ARE-binding sites in the proximal SOX9 promoter region were inactivated, cloned into pGL3, and co-transfected with phRL–TK for dual-luciferase assays to verify whether Nrf2 transcriptionally regulates SOX9. SOX9 promoter activity without and with Nrf2-inducer methysticin were analyzed. Sox9 expression in articular chondrocytes was correlated to cartilage thickness and degeneration in wild-type (WT) and Nrf2-knockout mice. Data were analyzed by one-way ANOVA, a Student's t-test, or Wilcoxon rank-sum test, according to the normal distribution. Statistical significance was set to p < 0.05.

While Keap1-specific RNAi increased SOX9 expression, Nrf2-specific RNAi significantly decreased it. Putative ARE sites (ARE₁, ARE₂) were identified in the SOX9 promoter region. ARE₂ mutagenesis significantly reduced SOX9 promoter activity, while truncation of ARE₁ did not. A functional ARE₂ site was thus essential for methysticin-mediated induction of SOX9 promoter activity. Knee cartilage of young Nrf2-knockout mice further revealed significantly fewer Sox9-positive chondrocytes as compared to old Nrf2-knockout animals, which further showed thinner cartilage and more severe cartilage erosion.

Our data suggest that SOX9 expression in articular cartilage is directly Nrf2-dependent and that pharmacological Nrf2 activation may hold potential to diminish age-dependent osteoarthritic changes in knee cartilage through improving protective SOX9 expression.

Mechanical loading of joints with osteoarthritis (OA) results in pain-related functional impairment, altered joint mechanics and physiological nociceptor interactions leading to an experience of pain. However, the current tools to measure this are largely patient reported subjective impressions of a nociceptive impact. A direct measure of nociception may offer a more objective indicator. Specifically, movement-induced physiological responses to nociception may offer a useful way to monitor knee OA. In this study, we gathered preliminary data on healthy volunteers to analyse whether integrated biomechanical and physiological sensor datasets could display linked and quantifiable information to a nociceptive stimulus.

Following ethical approval, 15 healthy volunteers completed 5 movement and stationary activities in 2 conditions; a control setting and then repeated with an applied quantified thermal pain stimulus to their right knee. An inertial measurement unit (IMU) and an electromyography (EMG) lower body marker set were tested and integrated with ground reaction force (GRF) data collection. Galvanic skin response electrodes for skin temperature and conductivity and photoplethysmography (PPG) sensors were manually timestamped to the integrated system.

Pilot data showed EMG, GRF and IMU fluctuations within 0.5 seconds of each other in response to a thermal trigger. Preliminary analysis on the 15 participants tested has shown skin conductance, PPG, EMG, GRFs, joint angles and kinematics with varying increases and fluctuations during the thermal condition in comparison to the control condition.

Preliminary results suggest physiological and biomechanical data outputs can be linked and identified in response to a defined nociceptive stimulus. Study data is currently founded on healthy volunteers as a proof-of-concept. Further exploratory statistical and sensor readout pattern analysis, alongside early and late-stage OA patient data collection, can provide the information for potential development of wearable nociceptive sensors to measure disease progression and treatment effectiveness.

The purpose of the study was to compare the mechanical properties, oxidation and wear resistance of a vitamin E blended and moderately crosslinked polyethylene for total knee arthroplasty (MXE) in comparison with clinically established polyethylene materials.

The following polyethylene materials were tested: CPE (30 kGy e-beam sterilized), XLPE (75 kGy gamma crosslinked @ 100°C), ViXLPE (0.1 % vitamin E blended, 80 kGy e-beam crosslinked @ 100°C), and MXE (0.1 % vitamin E blended polyethylene, 30 kGy gamma sterilized). For the different tests, the polyethylene materials were either unaged or artificially aged for two or six weeks according to ASTM F2003-02.

The oxidation index was measured based on ASTM F2102 at a 1 mm depth. Small punch testing was performed based on ASTM F2977. Mechanical properties were measured on unaged materials according to ASTM D638.

Wear simulation was performed on a load controlled 3 + 1 station knee wear simulator (EndoLab GmbH, Thansau, Germany) capable of reproducing loads and movement of highly demanding activities (HDA) as well as ISO 14243-1 load profiles. The load profiles were applied for 5 million cycles (mc) or delamination of the polyethylene components. Medium size AS e.motion^® PS Pro (Aesculap AG, Tuttlingen, Germany) femoral and tibial components with a ZrN-multilayer surface, as well as Columbus^® CR cobalt-chrome alloy femoral and tibial components were tested. Particle analysis was performed on the serum samples of the ISO 14243-1 wear simulations based on ISO 17853:2011 and ASTM F1877.

The analysis of the mechanical properties show that moderately crosslinked polyethylene (MXE) might be a superior material for total knee arthroplasty applications [Schwiesau et al. 2021]. The addition of vitamin E in a moderately crosslinked polyethylene prevented its oxidation, kept its mechanical characteristics, and maintained a low wear, even under a HDA knee wear simulation.

Surgical debridement for medial epicondylitis (ME) is indicated for patients with refractory ME. The clinical efficacy of simple debridement has not been studied sufficiently. Moreover, authors experienced surgical outcome of ME was not as good as lateral epicondylitis. In this regard, authors have combined the atelocollagen injection in the debridement surgery of ME. The purpose of study was to compare clinical outcomes between simple debridement and debridement combined with atelocollagen injection in the ME.

Twenty-five patients with refractory ME and underwent surgical debridement were included in the study. Group A (n=13) was treated with isolated debridement surgery, and group B (n=12) was treated with debridement combined with 1.0 mL of type I atelocollagen. Pain and functional improvements were assessed using visual analogue scale, Mayo Elbow Performance Score (MEPS) and quick Disabilities of the Arm, Shoulder and Hand (DASH) scale respectively before surgery, at 3, 6 months after surgery and at the final follow-up.

Demographic data did not show significant difference between two groups before surgical procedures. Both groups showed improvement in pain and functional score postoperatively. However, at the 3 months after surgery, group B showed significantly better improvement as compared to group A(VAS 3.1 / 2.0, MEPS 71/82 qDASH 29/23). At the 6 months after surgery and final follow-up, both groups did not show any difference.

Surgical debridement combined with atelocollagen is effective treatment option in refractory ME and showed better short-term outcomes compared to isolated surgery.

Prosthetic Joint Infection (PJI) is a devastating complication that can occur after total joint replacement surgery. With increasing antimicrobial resistance, there is a need for non-antibiotic approaches to treat and prevent PJI. Doping calcium phosphates with antimicrobial ions shows promise for these purposes. This systematic review aims to search and summarise the evidence-base for the potential of calcium phosphates doped with different antimicrobial ions.

A systematic review was conducted on PubMed, Embase, Web-Of-Science, Cochrane Library and Emcare of in vitro and animal studies on the antimicrobial activity of (co)substituted calcium phosphates according to PRIMSA guidelines.. The research protocol, listing search terms and in/exclusion criteria, was registered a priori at https://doi.org/10.7910/DVN/HEP18U. Data was extracted regarding ions, micro-organisms and antimicrobial activity.

The search retrieved 1017 hits of which 148 papers were included. The substitution of 33 different ions was reported. Silver (n= 46), zinc (n=39), copper (n=18) and magnesium (n=14) were the most commonly doped ions. 36 different micro-organisms were studied of which E. coli (n=109), S. aureus (n=99), and C. albicans (n=22) were the most common. 6 different outcomes were reported, most commonly the K-ratio (n=53), the log CFU (n=41) and the bacterial inhibition zone (n=39). A validated outcome for the evaluation of biofilm prevention was lacking.

There was considerable heterogeneity in studied ions, micro-organisms and reported outcomes. A lack of clearly defined reporting guidelines in the field of antimicrobial materials has led to the use of clinically irrelevant micro-organisms and a general lack of consistency of the methods used and the reported results. Currently, there is no universally accepted measure for the effectiveness required from biomaterials for treatment and prevention of PJI.

Cartilage degeneration and loss are key events in the initiation and progression of osteoarthritis (OA). Changes to chondrocyte volume and morphology (in the form of cytoplasmic processes) and thus cell phenotype are implicated, as they lead to the production of a mechanically-weakened extracellular matrix. The chondrocyte cytoskeleton is intimately linked to cell volume and morphology and hence we have investigated alterations to levels and distribution of chondrocyte F-actin that occur during early OA.

The femoral heads (FH) from hip joints (N=16) were obtained with ethical permission and patient consent following femoral neck fracture. Cartilage was assessed as grade 0 (non-degenerate) and grade 1 (superficial fibrillation) using OARSI criteria. In situ chondrocyte volume and F-actin distribution were assessed using the fluorescent indicators (5-chloromethyl fluorescein diacetate (CMFDA)) and phalloidin, and imaged and quantified by confocal microscopy, Imaris^TM and ImageJ software.

There were no differences between the volume or total F-actin levels of in situ chondrocytes within the superficial zone of grade 0 (n=164 cells) compared to grade 1 (n=145) cartilage (P>0.05). However, a more detailed analysis of phalloidin labelling was performed, which demonstrated significant increases in both intense punctuate (IP) or intense areas (IA) (P<0.0001; P=0.0175 respectively). A preliminary analysis of IP and IA F-actin labelling suggested that while the former did not appear to be associated with changes to chondrocyte morphology, most of the cytoplasmic processes were associated with the presence of IA at the starting point of the protrusion.

These results demonstrate marked changes to F-actin distribution in chondrocytes in the very early stages of cartilage degeneration as occurs in OA. These subtle changes are probably an early indication of a change to the chondrocyte phenotype and thus worthy of further study as they may lead to deleterious alterations to matrix metabolism and ultimately cartilage weakening.

Solid organ transplant (SOT) recipients present an increased medical risk; however, few studies analyze the outcomes of these patients undergoing hip fracture surgery. This study aimes to determine the incidence of hip fracture in SOT patients and to compare the outcomes of SOT patients with matched non-SOT controls after hip fracture fixation.

A retrospective review identified 20 SOT patients with hip fracture at a single center from 2016 to 2021 and were matched (1:1) with a cohort of 20 patients with hip fracture without SOT. Patient outcomes, mortality/survival and clinical outcomes were compared between two groups.

The incidence of hip fracture in SOT patients was 20/1787, 1.1%. There were significant differences in mortality rate (73.3% SOT group vs. 26.7% non-SOT group; p<0.05). There were no differences in survival time (p=0.746). There were no differences in time to surgery (5.0 days SOT group vs. 3.1 days non-SOT group; p=0.109), however, there were significant differences in the hospital length of stay (14 days SOT group vs. 8.6 days non-SOT group; p=0.018). There were no differences regarding the complication rate between the two groups (9/20, 45% vs. 6/20, 30% in the SOT and non-SOT groups, respectively).

SOT patients with associated hip fracture required longer hospital length of stay than non-SOT patients. SOT patients did not show greater clinical complications; however, they presented higher mortality rate compared to non-SOT patients.

The purpose of the this survey study was twofold: 1) to examine different aspects of satisfaction with post-operative care in injured workers who have undergone rotator cuff surgery and 2) to examine the relationship between receiving a newly implemented summary report and the overall satisfaction with surgery and recovery.

The clinical communication summary report was given to injured workers following their review assessment to share with the family doctor or other health care providers. The form indicated a need for further assessments or investigations and return to work recommendations. The study involved using a satisfaction survey that examined different aspects of follow-up visit and workers’ opinion about their understanding of the nature of surgery, their progress, clinical management, and usefulness of the newly implemented summery report.

Eighty patients completed the questionnaire (mean age: 54 (8), 62(78%) males, of whom 26 (34%) had a rotator cuff decompression and 31 (40%) had a rotator cuff repair with 20 (26%) having both procedures and three missing data. There were no statistically significant relationships between the patient demographics (age, sex or type of surgery) and satisfaction. However, there was a significant correlation between how patients perceived the summary report in terms of helpfulness and the overall satisfaction with surgery (FTE<0.0004, p=0.001) and the satisfaction with recovery (FTE<0.0001, p=0.001). This may indicate that improvement in worker's understanding of their treatment recommendations and restrictions is associated with higher levels of overall satisfaction in this population.

Our results indicate a positive linear relationship between expressing a high satisfaction and the helpfulness of the summary report. As part of improving care, adding a summary report may facilitate sharing information with the injured workers, their care providers and their workplace.

Successful application of patient derived cells to engineer vascularized bone grafts is often hampered by low cell numbers and lengthy in vitro expansion. With sound induced morphogenesis (SIM), local cell density enhancement was shown to improve microvasculature formation at lower cell concentration than conventional methods [1]. SIM takes advantage of hydrodynamic forces that act on cells to arrange them within a hydrogel. Following, we are evaluating the potential of cell-hydrogel biografts with high local cell density to improve the therapeutic efficacy in clinical scenarios such as anastomosis or bone formation within non-union fractures.

To assess anastomosis, human umbilical vein endothelial cells (HUVEC) and human mesenchymal stromal cells (MSC) were mixed at a 1:1 ratio in PEG-based or Dextran-based hydrogels at a final concentration of 2×10⁶ cells×mL^-1. For ectopic bone formation, MSC were resuspended in PEG-based hydrogels at 2×10⁶ or 5×10⁶ cells×mL^-1, with or without BMP-2. Cells were assembled into distinct patterns at a frequency of 60 Hz. Four biografts of 4 × 9 mm² were implanted at the back of nude mice (total of 7 animals) and harvested after 2 or 8 weeks. Explants were fixed and imaged as whole constructs or embedded in paraffin for histological analysis.

Upon explantation, microscopic evaluation indicated that HUVEC were retained within the PEG-hydrogel after 2 weeks and formed a pre-vascular network. In the second study, ectopic bone formation was more pronounced in areas of higher local cell density based on visual inspection. Ongoing experiments are further characterizing bone formation by micro-CT and histological evaluation.

Our results indicate that local cell density enhancement by sound requires a lower initial cell concentration than conventional, static seeding methods to achieve comparable microvasculature structures or local osteogenesis.

Currently, fibrin glue obtained from fibrinogen and thrombin of human and animal blood are widely investigated to use as injectable hydrogel for tissue engineering which contributes to minimally invasive surgery, superior biodegradability, cell attachment, proliferation and regenerating new tissue. However, most of them fail to achieve to be used for tissue engineering application because of a risk of immune response and poor mechanical properties. To overcome the limitation of fibrin glue and to reduce the usage of products from human and animal blood, the artificial fibrin glue materials were developed. Recently, cellulose nanofiber (CNF) as reinforcing agent has been explored for many tissue engineering applications such as bone and cartilage due to its impressive biological compatibility, biodegradability and mechanical properties. CNF was extracted from cassava pulp. PEO-PPO-PEO diacrylate block copolymer is a biodegradable synthetic polymers which is water insoluble hydrogel after curing by UV light at low intensity. To enhance the cell adhesion abilities, gelatin methacrylate (GelMA), the denature form of collagen was used to incorporate into hydrogel. The aim of this study was to develop the artificial fibrin glue from CNF reinforced PEO-PPO-PEO diacrylate block copolymer/GelMA injectable hydrogel.

CNF/PEO-PPO-PEO diacrylate block copolymer/GelMA injectable hydrogels were prepared with 2-hydroxy-1-(4-(hydroxy ethoxy) phenyl)-2-methyl-1-propanone (Irgacure 2959) as a photoinitiator. The physicochemical properties were investigated by measuring various properties such as thickness, gel fraction, mechanical properties and water uptake.

At optimal preparation condition, CNF reinforced injectable hydrogel was successful prepared after curing with UV light within 7 minutes. This hydrogel showed gel fraction and water uptake of 81 and 85%, respectively. The cytotoxicity, cell adhesion and proliferation of CNF reinforced injectable hydrogel was presented.

Cellulose nanofiber from casava pulp was successfully used to prepare injectable hydrogel as artificial fibrin glue for tissue engineering. The hydrogel showed good physical properties which can be applied to use for tissue engineering application.

Implant removal after clavicle plating is common. Low-profile dual mini-fragment plate constructs are considered safe for fixation of diaphyseal clavicle fractures. The aim of this study was to investigate: (1) the biomechanical competence of different dual plate designs from stiffness and cycles to failure, and (2) to compare them against 3.5mm single superoanterior plating.

Twelve artificial clavicles were assigned to 2 groups and instrumented with titanium matrix mandible plates as follows: group 1 (G1) (2.5mm anterior+2.0mm superior) and group 2 (G2) (2.0mm anterior+2.0mm superior). An unstable clavicle shaft fracture (AO/OTA15.2C) was simulated. Specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with torsion around the shaft axis and compared to previous published data of 6 locked superoanterior plates tested under the same conditions (G3).

Displacement (mm) after 5000 cycles was highest in G3 (10.7±0.8) followed by G2 (8.5±1.0) and G1 (7.5±1.0), respectively. Both outcomes were significantly higher in G3 as compared to both G1 and G2 (p≤0.027). Cycles to failure were highest in G3 (19536±3586) followed by G1 (15834±3492) and G2 (11104±3177), being significantly higher in G3 compared to G2 (p=0.004). Failure was breakage of one or two plates at the level of the osteotomy in all specimens. One G1 specimen demonstrated failure of the anterior plate. Both plates in other G1 specimens. Majority of G2 had fractures in both plates. No screw pullout or additional clavicle fractures were observed among specimens.

Low-profile 2.0/2.0 dual plates demonstrated similar initial stiffness compared to 3.5mm single plates, however, had significantly lower failure endurance. Low-profile 2.5/2.0 dual plates showed significant higher initial stiffness and similar resistance to failure compared to 3.5mm single locked plates and can be considered as a useful alternative for diaphyseal clavicle fracture fixation. These results complement the promising results of several clinical studies.

An increasing elderly population means joint replacement surgery numbers are projected to increase, with associated complications such as periprosthetic joint infections (PJI) also rising. PJI are particularly challenging due to antimicrobial resistant biofilm development on implant surfaces and surrounding tissues, with treatment typically involving invasive surgeries and systemic antibiotic delivery. Consequently, functionalisation of implant surfaces to prevent biofilm formation is a major research focus. This study characterises clinically relevant antimicrobials including gentamicin, clindamycin, daptomycin, vancomycin and caspofungin within a silica-based, biodegradable sol-gel coating for prosthetic devices.

Antimicrobial activity of the coatings against clinically relevant microorganisms was assessed via disc diffusion assays, broth microdilution culture methods and the MBEC assay used to determine anti-biofilm activity. Human and bovine cells were cultured in presence of antimicrobial sol-gel to determine cytotoxicity using Alamar blue and antibiotic release was measured by LC-MS. Biodegradability in physiological conditions was assayed by FT-IR, ICP-MS and measuring mass change. Effect of degradation products on osteogenesis were studied by culturing mesenchymal stem cells in the presence of media in which sol-gel samples had been immersed.

Antimicrobial-loaded coatings showed strong activity against a wide range of clinically relevant bacterial and fungal pathogens with no loss of activity from antibiotic alone. The sol-gel coating demonstrated controlled release of antimicrobials and initial sol-gel coatings showed no loss of viability on MSCs with gentamicin containing coatings. Current work is underway investigating cytotoxicity of sol-gel compositions against MG-63 cells and primary osteoblasts.

This research forms part of an extended study into a promising antimicrobial delivery strategy to prevent PJI. The implant coating has potential to advance PJI infection prevention, reducing future burden upon healthcare costs and patient wellbeing.

Osteoprogenitors on the inner layer of periosteum are the major cellular contributors to appositional bone growth and bone repair by callus formation. Previous work showed that periosteal-derived cells have little or no osteogenic activity under standard in vitro osteogenic culture conditions. This study was conducted to determine what growth factor(s) can activate periosteal osteogenic capacity.

This study was conducted with IACUC approval. Periosteum from five equine donors was digested in collagenase for 3-4 hours at 37C. Isolated periosteal cells were maintained in DMEM/10% FBS medium and exposed to PDGF, Prostaglandin E2, BMP-2 and TGF-b3 at a range of concentrations for 72 hours. Changes in osteogenic gene expression (Runx2, OSX and ALP) were measured by qPCR. Periosteal cells were pre-treated with TGF-b3 or maintained in control medium were transferred into basal or osteogenic medium. Osteogenic status was assessed by Alizarin Red staining for mineralized matrix, ALP enzymatic activity and induction of osteogenic genes.

PDGF, PgE2 and BMP-2 had little impact on expression of osteogenic markers by periosteal cells. In contrast, TGF-b3 stimulated significant increases in Osterix (over 100-fold) ALP expression (over 70-fold). Pre-treating periosteal cells with TGF-b3 for 72 hours stimulated rapid cell aggregation and aggregate mineralization once cells were transferred to osteogenic medium, while cells not exposed to TGF-b3 exhibited minimal evidence of osteogenic activity.

This study indicate that TGF-b signaling is vital for periosteal osteogenic activity. Transient ‘priming’ of periosteal cells through TGF-b exposure was sufficient to activate subsequent osteogenesis without requiring ongoing growth factor stimulation. TGF beta ligands are secreted by many cell types, including periosteal progenitors and osteocytes, providing opportunities for both autocrine and paracrine pathways to regulate periosteal bone formation under homeostatic and reparative conditions.

We sought to determine the relationship between patient preoperative psychological factors and postoperative THA outcomes.

We performed an electronic search up to December 2021 using the following terms: “(mental OR psychological OR psychiatric) AND (function OR trait OR state OR predictor OR health) AND (outcome OR success OR recovery OR response) AND total joint arthroplasty)”. Peer-reviewed, English language studies regarding THA outcomes were analyzed for preoperative patient mental health metrics and objective postoperative results regarding pain, functionality and surgical complications. We extracted study data, assessed the risk of bias of included studies, grouped them by outcome measure and performed a GRADE assessment.

Seventeen of 702 studies fulfilled inclusion criteria and were included in the review. Overall, compared to cohorts with a normal psychological status, patients with higher objective measures of preoperative depression and anxiety reported increased postoperative pain, decreased functionality and greater complications following THA. Additionally, participants with lower self-efficacy or somatization were found to have worse functional outcomes. Following surgery, both early and late pain scores remained higher in patients with preoperative depression and anxiety.

Preoperative depression and anxiety may negatively impact patient reported postoperative pain, physical function and complications following THA. A meta-analysis was not performed because of the heterogeneity of studies, specifically the use of differing pain scales and measures of physical and psychological function as well as varied follow-up times. Future research could test interventions to treat pre-operative depression or anxiety and explore longitudinal outcomes in THA patients. Surgeons should consider the preoperative psychological status when counseling patients regarding expected surgical outcomes and attempt to treat a patient's depression or anxiety prior to undergoing total hip arthroplasty.

This study aimed to investigate the effect of irisin on human nucleus pulposus cells (hNPCs) in vitro. Our hypothesis was that irisin would improve hNPC metabolism and proliferation.

hNPCs were isolated from intervertebral discs and cultured in alginate beads. hNPCs were exposed to phosphate-buffered saline (PBS) or recombinant irisin (r-irisin) at 5, 10 and 25 ng/mL (n=4). Each experiment was performed in triplicate. Cell proliferation was assessed with trypan blue staining-automated cell counting and PicoGreen assay. Glycosaminoglycan (GAG) content was measured using the DMMB assay. Metabolic activity was assessed with the MTT assay and the Griess Reagent System. Gene expression of collagen type II (COL2), matrix metalloproteinase (MMP)-13, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and −3, aggrecan, interleukin (IL)-1β, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-5 was measured by RT-PCR. MTT assay and ADAMTS-5, COL2, TIMP-1 and IL-1β gene expression were evaluated following incubation with 5, 10 and 25 ng/mL r-irisin for 24 hours and subsequent culture with 10 ng/ml IL-1β and vice versa (incubation for 24 hours with IL-1β and subsequent culture with r-irisin).

Irisin increased hNPC proliferation (p<0.001), metabolic activity (p<0.05), GAG content (p<0.01), as well as COL2 (p<0.01), aggrecan (p<0.05), TIMP-1 and −3 (p<0.01) gene expression, while decreasing MMP-13 (p<0.05) and IL-1β (p<0.001) mRNA levels. r-irisin pretreatment of hNPCs cultured in pro-inflammatory conditions resulted in a rescue of metabolic activity (p<0.001) and a decrease of IL-1β (p<0.05) levels. Similarly, incubation of hNPCs with IL-1β and subsequent exposure to r-irisin increased hNPC metabolic activity (p<0.001), COL2 gene expression (p<0.05) and decreased IL-1β (p<0.05) and ADAMTS-5 levels (p<0.01).

Irisin stimulates hNPC proliferation, metabolic activity, and anabolism by reducing IL-1β and catabolic enzyme expression while promoting matrix synthesis.

Fracture related infection remains a major challenge in musculoskeletal trauma surgery. Despite best practice, treatment strategies suffer from high failure rates due to antibiotic resistance and tolerance. Bacteriophages represent a promising alternative as they retain activity against such bacteria. However, optimal phage administration protocols remain unknown, although injectable hydrogels, loaded with phage and conventional antibiotics, may support conventional therapy.

In this study we tested the activity of meropenem, and two newly isolated bacteriophages (ϕ9 and ϕ3) embedded within alginate-chitosan microbeads and a hydrogel. Antibiotic and phage stability and activity were monitored in vitro, over a period of 10 days. In vivo, the same material was tested in treatment of a 5-day old Pseudomonas aeruginosa infection of a tibial plate osteotomy in mice. Treatment involved debridement and 5 days of systemic antibiotic therapy plus: i- saline, ii-phages in saline, iii-phages and antibiotics loaded into a hydrogel (n=7 mice/group). To assess the efficacy of the treatments, the infection load was monitored during revision surgery with debridement of the infected tissue after 5,10 and 13 days (euthanasia) by CFU and PFU quantification.

In vitro testing confirmed that the stability of meropenem and activity of ϕ9 and ϕ3, was not affected within the alginate beads or hydrogel over 10 days. The in vivo study showed that all mice receiving phages and antibiotics loaded into a hydrogel survived the infection with a reduction of the bacterial load in the soft tissue. Active phages could be recovered from the infected site at euthanasia (10⁴ PFU/g).

The hydrogel loaded with bacteriophages and meropenem showed a positive result in locally reducing the infection load indicating a synergistic effect of the selected antimicrobials. Overall, our new strategy shows encouraging results for improving the treatment of antibiotic-resistant biofilm infections that are related to medical implants.

There is currently no commercially available and clinically successful treatment for scapholunate interosseous ligament rupture, the latter leading to the development of hand-wrist osteoarthritis. We have created a novel biodegradable implant which fixed the dissociated scaphoid and lunate bones and encourages regeneration of the ruptured native ligament. To determine if scaphoid and lunate kinematics in cadaveric specimens were maintained during robotic manipulation, when comparing the native wrist with intact ligament and when the implant was installed.

Ten cadaveric experiments were performed with identical conditions, except for implant geometry that was personalised to the anatomy of each cadaveric specimen. Each cadaveric arm was mounted upright in a six degrees of freedom robot using k-wires drilled through the radius, ulna, and metacarpals. Infrared markers were attached to scaphoid, lunate, radius, and 3rd metacarpal. Cadaveric specimens were robotically manipulated through flexion-extension and ulnar-radial deviation by ±40° and ±30°, respectively.

The cadaveric scaphoid and lunate kinematics were examined with 1) intact native ligament, 2) severed ligament, 3) and installed implant.

Digital wrist models were generated from computed tomography scans and included implant geometry, orientation, and location. Motion data were filtered and aligned relative to neutral wrist in the digital models of each specimen using anatomical landmarks. Implant insertion points in the scaphoid and lunate over time were then calculated using digital models, marker data, and inverse kinematics. Root mean squared distance was compared between severed and implant configurations, relative to intact.

Preliminary data from five cadaveric specimens indicate that the implant reduced distance between scaphoid and lunate compared to severed configuration for all but three trials.

Preliminary results indicate our novel implant reduced scapho-lunate gap caused by ligament transection. Future analysis will reveal if the implant can achieve wrist kinematics similar to the native intact wrist.

Regulation of articular cartilage homeostasis is a complex process in which biologic and mechanical factors are involved. Hyperactivation of Wnt signaling, associated with osteoarthritis (OA), could jeopardize the protective anabolic effect of physiological loading. Here, we investigated the role of excessive Wnt signalling in cartilage molecular responses to loading.

Human cartilage explants were harvested from hips of donors without OA. The Wnt agonist CHIR99021 was used to activate Wnt signalling 24 hours before cartilage explants were subjected to a loading protocol consisting of 2 cycles of 1 hour of 10% compression at 1 Hz, followed by 1-hour free swelling. Mechano-responsiveness was evaluated using the expression of type II collagen, aggrecan and MMP-13. Expression of known target genes TCF-1 and c-JUN was evaluated as positive control for Wnt and mechanical stimulation, respectively.

In the absence of loading, CHIR99021 decreased the expression of the cartilage anabolic genes type II collagen and aggrecan, and increased the levels of MMP-13, corroborating that Wnt hyperactivation disrupts cartilage homeostasis. In the absence of Wnt hyperactivation, the applied loading protocol, representative for a physiologic stimulation by mechanical loading, led to an increase in type II collagen and aggrecan levels. However, when cartilage explants were subjected to mechanical stimulation in the presence of CHIR99021, the expression of cartilage anabolic genes was decreased, indicating changes to the cells’ mechano-responsiveness. Interestingly, mechanical stimulation was able to reduce the expression levels of MMP-13 compared to the condition of CHIR stimulation without loading.

Hyperactivation of Wnt signaling switches the anabolic effect of physiologic compressive loading towards a potential catabolic effect and could contribute to the development and progression of OA.

Postoperative knee stability is critical in determining the success after reconstruction; however, only posterior and anterior stability is assessed. Therefore, this study investigates medial and lateral rotational knee laxity changes after partial and complete PCL tear and after PCL allograft reconstruction.

The extending Lachman test assessed knee instability in six fresh-frozen human cadaveric knees. Tibia rotation was measured for the native knee, after partial PCLT (pPCLT), after full PCLT (fPCLT), and then after PCLR tensioned at 30° and 90°. In addition, tests were performed for the medial and lateral sides. The tibia was pulled with 130N using a digital force gauge. A compression load of 50N was applied to the joint on the universal testing machine (MTS Systems) to induce contact. Three-dimensional tibial rotation was measured using a motion capture system (Optotrak).

On average, the tibia rotation increased by 33%-42% after partial PCL tear, and by 62%-75% after full PCL tear when compared to the intact case. After PCL reconstruction, the medial tibia rotation decreased by 33% and 37% compared to the fPCL tear in the case that the allograft was tensioned at 30° and 90° of flexion, respectively. Similarly, lateral tibial rotation decreased by 15% and 2% for allograft tensioned at 30° and 90° of flexion respectively, compared to the full tear. Rotational decreases were statistically significant (p<0.005) at the lateral pulling after tensioning the allograft at 90°.

PCLR with the graft tensioned at 30° and 90° both reduced medial knee laxity after PCLT. These results suggest that while both tensioning angles restored medial knee stability, tensioning the Achilles graft at 30° of knee flexion was more effective in restoring lateral knee stability throughout the range of motion from full extension to 90° flexion, offering a closer biomechanical resemblance to native knee function.

This study aimed to characterise the microarchitecture of bone in different species of animal leading to the development of a physiologically relevant 3D printed cellular model of trabecular (Tb) and cortical bone (CB). Using high resolution micro-computed tomography (μ-CT) bone samples from multiple species were scanned and analysed before creating in silico models for 3D printing. Biologically relevant printing materials with physical characteristics similar to that of in vivo bone will be selected and tested for printability.

Porcine and murine bone samples were scanned using μ-CT, with a resolution of 4.60 μM for murine and 11 μM for porcine and reconstructed to determine the architectural properties of both Tb and CB independently. A region of interest, 1 mm in height, will be used to generate an in-silico 3D model with dimensions (10 mm³) and suitable resolution before being translated into printable G code using CAD assisted software.

A 1 mm section of each bone was analysed, to determine the differences in the microarchitecture with the intent of setting a benchmark for the developmental 3D in vitro model to be comparable against. In contrast, porcine caudal vertebrae (PCV) have an increased volume due to the size of the bone sample. Interestingly, BV/TR for Tb is similar between species in all samples except murine femur. Murine tibia and PCV have a similar Tb. number and thickness, however different SMI shape and separation.

μ-CT scanning and analysis permits tessellation of the 3D output which will lead to the generation of an in silico printable model. Biomaterials are currently under optimisation to allow printability and shape integrity to reflect the morphological and physiological properties of bone.

Osteosarcoma and other types of bone cancers often require bone resection, and backfill with cement. A novel silorane-based cement without PMMA's drawbacks, previously developed for dental applications, has been reformulated for orthopedic use. The aim of this study is to assess each cement's ability to elute doxorubicin, maintain its potency, and maintain suitable weight-bearing strength.

The silorane-based epoxy cement was synthesized using a platinum-based Lamoreaux's catalyst. Four groups of cement were prepared. Two PMMA groups, one without any additives, one with 200 mg of doxorubicin. Two silorane groups: one without any additive, one with doxorubicin, added so that the w% of drug into both cements were equal. Pellets 6 × 12 mm were used for testing (ASTM F451). n=10. Ten pellets from each group were kept dry. All others were placed into tubes containing 2.5 mL of PBS and stored at 37 °C. Elution from doxorubicin-containing groups were collected every day for 7 days, with daily PBS changeout. Antibiotic concentrations were determined via HPLC. Compressive strength and compressive modulus of all groups were determined for unsoaked specimens, and those soaked for 7 and 14 days. MTT assays were done using an MG63 osteosarcoma cell line.

Both cements were able to elute doxorubicin over 7 days in clinically-favorable quantities. For PMMA samples, the incorporation of doxorubicin was shown to significantly affect the compressive strength and modulus of the samples (p<0.01). Incorporation of doxorubicin into silorane had no significant effect on either (p>.05). MTT assays indicated that doxorubicin incorporated into the silorane cement maintained its effectiveness whereas that into PMMA did not. At the dosing used, both cements remained above the 70 MPa.

Both PMMA and silorane-based cements can deliver doxorubicin. Doxorubicin, however, interacts chemically with PMMA, inhibiting polymerization and lowering the chemotherapeutic's effectiveness.

The computational modelling and 3D technology are finding more and more applications in the medical field. Orthopedic surgery is one of the specialties that can benefit the most from this solution. Three case reports drawn from the experience of the authors’ Orthopedic Clinic are illustraded to highlight the benefits of applying this technology.

Drawing on the extensive experience gained within the authors’ Operating Unit, three cases regarding different body segments have been selected to prove the importance of 3D technology in preoperative planning and during the surgery. A sternal transplant by allograft from a cryopreserved cadaver, the realization of a custom made implant of the glenoid component in a two-stage revision of a reverse shoulder arthroplasty, and a case of revision on a hip prosthesis with acetabular bone loss (Paprosky 3B) treated with custom system. In all cases the surgery was planned using 3D processing software and models of the affected bone segments, printed by 3D printer, and based on CT scans of the patients. The surgical implant was managed with dedicated instruments.

The use of 3D technology can improve the results of orthopedic surgery in many ways: by optimizing the outcomes of the operation as it allows a preliminary study of the bone loss and an evalutation of feasibility of the surgery, it improves the precision of the positioning of the implant, especially in the context of severe deformity and bone loss, and it reduces the operating time; by improving surgeon training; by increasing patient involvement in decision making and informed consent.

3D technology, by offering targeted and customized solutions, is a valid tool to obtain the tailored care that every patient needs and deserves, also providing the surgeon with an important help in cases of great complexity.

Biplane video X-ray (BVX) – with models segmented from magnetic resonance imaging (MRI) – is used to directly track bones during dynamic activities. Investigating tibiofemoral kinematics helps to understand effects of disease, injury, and possible interventions.

Develop a protocol and compare in-vivo kinematics during loaded dynamic activities using BVX and MRI.

BVX (60 FPS) was captured whilst three healthy volunteers performed three repeats of lunge, stair ascent and gait. MRI scans were performed (Magnetom 3T Prisma, Siemens). 3D bone models of the tibia and femur were segmented (Simpleware Scan IP, Synopsis). Bone poses were obtained by manually matching bone models to X-rays (DSX Suite, C-Motion Inc.). Mean range of motion (ROM) of the contact points on the medial and lateral tibial plateau were calculated using custom MATLAB code (MathWorks). Results were filtered using an adaptive low pass Butterworth filter (Frequency range: 5-29Hz).

Gait and Stair ascent activities from one participant's data showed increased ROM for medial-lateral (ML) translation in the medial compartment but decreased ROM in anterior-posterior (AP) translation when comparing against the same translations on the lateral compartment of the tibial plateau. Lunge activity showed increased ROM for both ML and AP translation in the medial compartment when compared with the lateral compartment.

These results highlight the variability in condylar translations between different activities. Understanding healthy in-vivo kinematics across different activities allows the determination of suitable activities to best investigate the kinematic changes due to disease or injury and assess the efficacy of different interventions.

Acknowledgements: This research was supported by the Engineering and Physical Sciences Research Council (EPSRC) doctoral training grant (EP/T517951/1).

A key cause of low back pain is the degeneration of the intervertebral disc (IVD). Causality between infection of the IVD and its degenerative process gained great interest over the last decade. Granville Smith et al. (2021) identified 36 articles from 34 research studies investigating bacteria in human IVDs. Bacteria was identified in 27 studies, whereas 9 attributed bacterial presence to contamination. Cutibacterium acnes was the most abundant, followed by coagulase-negative staphylococcus. However, whether bacteria identified were present in vivo or represent perioperative contamination remains unclear. This study investigated whether bacteria are present in IVDs and what potential effects they may have on native disc cells.

Immunohistochemical staining for Gram positive bacteria was performed on human IVD tissue to identify presence and characterise bacterial species. Nucleus pulposus (NP) cells in monolayer and 3D alginate were stimulated with LPS and Peptidoglycan (0.1-50 µg/ml) for 48hrs. Following stimulation qPCR for factors associated with disc degeneration including matrix genes, matrix degrading enzymes, cytokines, neurotrophic factors and angiogenic factors and conditioned media collected for ELISA and luminex analysis

Gram positive bacteria was detected within human IVD tissue. Internalisation of bacteria by NP cells influenced the cell and nuclei morphology. Preliminary results of exposure of NP cells to bacterial components indicate that LPS as well as Peptidoglycan increase IL-8 and ADAMTS-4 gene expression following 48 hours of stimulation with a dose response seen for IL-8 induction by peptidoglycan compared to the control group. Underlining these results, IL-8 protein release was increased for treated groups compared to non-treated control. Further analysis is underway investigating other output measures and additional biological repeats.

This study has demonstrated bacteria are present within IVD cells within IVD tissue removed from degenerate IVD and is determining the potential influence of these on disc degeneration.

Tendinopathy is the most frequent musculoskeletal disease that requires medical attention. Mechanical overload has been considered as a key driver of its pathology. However, the underline mechanism on how overload induces tendinopathy and inflammation is unclear. Extracellular mitochondria (EM) are newly identified as cell-to-cell communicators. The aim of this study is to elucidate the role of mitochondria in overload-induced inflammation.

We performed three-dimensional uniaxial stretching to mouse tendon organoid in bioreactors. Cyclic strain of uniaxial loadings included underload, normal load, and overload, according to previous work. We then harvested microvesicles including EM, from the bioreactor by differential centrifugation and evaluated their characteristics by flow cytometry and super-resolution confocal microscopy. Raw 264.7 mouse macrophage cell line was used for chemotaxis assay in a Boyden Chamber System with Magnetic-Activated Cell Sorting Technology. EM induced cytokines secretion by macrophages was analyzed by a bead-based multiplex assay panel. N-Acetyl-L-cysteine (NAC) was used as the antioxidant to tendon organoid to regulate mitochondrial fitness.

We showed mechanical load induced tendon organoid to release microvesicles including mitochondria. The size of microvesicles is mainly in the range from 220nm to 880nm. More than 75% of microvesicles could be stained by PKH26, confirming they were with lipophilic membrane. Super-resolution confocal microscopy identified two forms of mitochondria, including mitochondria encapsulated in vesicles and free mitochondria. Overload led to the degeneration of the organoid and induced microvesicles release containing most EM. Chemotaxis assay showed that EM from overloaded tendon organoid induced macrophages chemotaxis. In addition, microvesicles extracted from overloaded tendon organoid induced the production of proinflammatory cytokines including IL-6, KC (Keratinocyte-Derived Chemokine) and IL-18. NAC treatment to tendon cells could attenuate overload-induced macrophage chemotaxis.

Overload induces EM releasing from tendon cells, which leads to chemotaxis of macrophages toward tendon, resulting in induction of inflammation.

Due to the presence of megakaryocytes, platelets and clotting factors, bone marrow aspirate (BMA) tends to coagulate. For the first time, starting from our previous studies on mesenchymal vertebral stem cells, it has been hypothesized that coagulated BMA represents a safe and effective autologous biological scaffold for bone regeneration in spinal surgery. The present research involved advanced preclinical in vitro models and the execution of a pilot clinical study.

Evaluation of cell morphology, growth kinetics, immunophenotyping, clonogenicity, trilineage-differentiation, growth-factors and HOX and TALE gene expression were analyzed on clotted- and un-clotted human V-BMA. In parallel, a pilot clinical study on ten patients with degenerative spine diseases submitted to instrumented posterior arthrodesis, is ongoing to assess the ability of clotted-V-BMA to improve spinal fusion at 6- and 12-months follow-up.

Results demonstrated that clotted-V-BMA have significantly higher growth-factor expression and mesenchymal stem cell (MSCs) viability, homogeneity, clonogenicity, and ability to differentiate towards the osteogenic phenotype than un-clotted-V-BMA. Clotted-V-BMA also highlighted significant reduced expression of PBX1 and of MEIS3 genes negatively involved in osteoblast maturation and differentiation. From December 2020, eight patients have already been enrolled with first promising results that will be finally evaluated in the next two months.

The application of V-BMA-clot as carrier of progenitors and cytokines and as natural scaffold with a structural texture represents a point-of-care orthobiologic product to improve spinal fusion. Clinical application seems to be efficacy, and we will confirm and strengthen these data with the final results of the pilot clinical study.

Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. We previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine.

Fourteen patients (6 male, 8 female) were treated between June 2014 and December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12–60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits.

Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up.

The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective.

The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, data suggest that BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women.

Serial section electron microscopy (SSEM) was initially developed to map the neural connections in the brain. SSEM eventually led to the term ‘Connectomics’ to be coined to describe process of following a cell or structure through a volume of tissue. This permits the true three-dimensionality to be appreciated and relationships between cells and structures. The purpose of this study was to utilize this methodology to interrogate S. aureus infected bone.

Bone samples were harvested from mice tibia infected with S. aureus and were fixed, decalcified, and osmicated. The samples were paraffin embedded and 5-micron sections were cut to identify regions of bacterial invasion into the osteocyte-lacuna-canalicular-network (OLCN). This area was cut from the paraffin block, deparaffinized, post-fixed and reprocessed into epoxy resin. Serial sections were cut at 60nm and collected onto Kapton tape utilizing the Automated Tape-collecting Ultramicrotome (ATUMtome) system. Samples were mounted onto 4” silicon wafers and post-stained with 2% uranyl acetate followed by 0.3% lead citrate and carbon coated. A ZEISS GeminiSEM 450 scanning electron microscope fitted with an electron backscatter diffusion detector was used to image the sections. The image stack was aligned and segmented using the open-source software, VASTlite.

264 serial sections were imaged, representing approximately 40 × 45 × 15-micron (x, y, z) volume of tissue. 70% of the canaliculi demonstrated infiltration by S. aureus.

This study demonstrates that SSEM can be applied to the skeletal system and provide a new solution to investigate the OLCN system. It is feasible that this methodology could be implemented to investigate why some canaliculi are resistant to colonization and potentially opens up a new direction for the prevention of chronic osteomyelitis. In order to make this a realistic target, automated segmentation methodologies utilizing machine learning must be developed and applied to the bone tissue datasets.

Patients with bone and muscle weakness from disuse have higher risk of fracture and worse post-injury mortality rates. The goal of this current study was to better inform post-fracture rehabilitation strategies by investigating if physical remobilization following disuse by hindlimb unloading improves osteochondral callus formation compared to continued disuse by hindlimb suspension (HLS). We hypothesized that continued HLS would impair callus bone and cartilage formation and that physical rehabilitation after HLS would increase callus properties.

All animal procedures were approved by the VCU IACUC. Skeletally mature, male and female C57BL/6J mice (18 weeks) underwent HLS for 3 weeks. Mice then had their right femur fractured by open surgical dissection (stabilized with 24-gauge pin). Mice were then either randomly assigned to continued HLS or allow normal physical weight-bearing remobilization (HLS + R). Mice allowed normal cage activity throughout the experiment served as controls (GC). All mice were sacrificed 14-days following fracture with 4-8 mice (male and female) per treatment. Data analyzed by respective ANOVA with Tukey post-hoc (*p< 0.05; # p < 0.10)

Male and female mice showed conserved and significant decreases in hindlimb callus bone formation from continued HLS versus HLS + R. Combining treatment groups regardless of mouse sex, histological analyses using staining on these same calluses demonstrated that HLS resulted in trends toward decreased cartilage cross-sectional area and increased osteoclast density in woven bone versus physically rehabilitated mice.

In support of our hypothesis, physical remobilization increases callus bone formation following fracture compared to continued disuse potentially due to increased endochondral ossification and decreased bone resorption. In all, partial weight-bearing exercise immediately following fracture may improve callus healing compared to delayed rehabilitation regimens that are frequently used.

While cell morphology has been recognized as a fundamental regulator of cell behavior, few studies have measured the complex cell morphological changes of chondrocytes using quantitative cell morphometry descriptors in relation to inflammation and phenotypic outcome.

Acute vs. persistent exposure to IL-1β and how IL-1β modulated dynamic changes in cell morphology in relation to the phenotype, donor and OA grade in healthy and osteoarthritis (OA) chondrocytes was investigated. A panel of quantitative cell morphometry descriptors was measured using an automated high-throughput method. Absolute quantification of gene expression was measured by ddPCR followed by correlation analyses.

In OA chondrocytes, chronic IL-1β significantly decreased COL2A1, SOX9, and ACAN, increased IL-6 and IL-8 levels and caused chondrocytes to become less wide, smaller, longer, slimmer, less round and more circular, consistent with a de-differentiated phenotype. In healthy chondrocytes, 3 days after acute (72 h) IL-1β exposure, COL1A2 and IL-6 significantly increased but had minor effects on cell morphology. However, in healthy chondrocytes, persistent IL-1β led to more profound effects in all cell morphology descriptors and chondrocytes expressed significantly less COL2A1 and more IL-6 and IL-8 vs. controls and acutely-stimulated chondrocytes. In both OA and healthy chronically-stimulated chondrocytes, area, width and circularity were sensitive to the persistent presence of the IL-1β cytokine. Moreover, there were many significant and strong correlations among the measured parameters, with several indications of an IL-1β-mediated mechanism.

Cell morphology combined with gene expression analysis could guide researchers interested in understanding inflammatory effects in the complex domain of cartilage/chondrocyte biology. Use of quantitative cell morphometry could complement classical approaches by providing numerical data on a large number of cells, thereby providing a biological fingerprint for describing chondrocyte phenotype, which could help to understand how changes in cell morphology lead to disease progression.

Variations in pelvic anatomy are a major risk factor for misplaced percutaneous sacroiliac screws used to treat unstable posterior pelvic ring injuries. A better understanding of pelvic morphology improves preoperative planning and therefore minimises the risk of malpositioned screws, neurological or vascular injuries, failed fixation or malreduction. Hence a classification system which identifies the clinically important anatomical variations of the sacrum would improve communication among pelvic surgeons and inform treatment strategy.

300 Pelvic CT scans from skeletally mature trauma patients that did not have pre-existing posterior pelvic pathology were identified. Axial and coronal transosseous corridor widths at both S1 and S2 were recorded. Additionally, the S1 lateral mass angle were also calculated. Pelvises were classified based upon the sacroiliac joint (SIJ) height using the midpoint of the anterior cortex of L5 as a reference point. Four distinct types could be identified:

Differences in transosseous corridor widths and lateral mass angles between classification types were assessed using two-way ANOVAs.

Type-B was the most common pelvic type followed by Type-A, Type-C, and Type-D. Significant differences in the axial and coronal corridors was observed for all pelvic types at each level. Lateral mass angles increased from Types-A to C, but were smaller in Type-D.

This classification system offers a guide to surgeons navigating variable pelvic anatomy and understanding how it is associated with the differences in transosseous sacral corridors. It can assist surgeons’ preoperative planning of screw position, choice of fixation or the need for technological assistance.

Glenohumeral joint injuries frequently result in shoulder instability. However, the biomechanical effect of cartilage loss on shoulder stability remains unknown. The aim of the current study was to investigate biomechanically the effect of two severity stages of cartilage loss in different dislocation directions on shoulder stability. Joint dislocation was provoked for 11 human cadaveric glenoids in seven different dislocation directions between 3 o'clock (anterior) to 9 o'clock (posterior) dislocation. Shoulder stability ratio (SSR) and concavity gradient were assessed in intact condition, and after 3 mm and 6 mm simulated cartilage loss. The influence of cartilage loss on SSR and concavity gradient was statistically evaluated. Between intact state and 6 mm cartilage loss, both SSR and concavity gradient decreased significantly in every dislocation direction (p≤0.038), except the concavity gradient in 4 o'clock dislocation direction (p=0.088). Thereby, anterior-inferior dislocation directions were associated with the highest loss of SSR and concavity gradient of up to 59.0% and 49.4%, respectively, being significantly higher for SSR compared to all other dislocation directions (p≤0.04). The correlations between concavity gradient and SSR for pooled dislocation directions were significant for all three conditions of cartilage loss (p<0.001). From a biomechanical perspective, articular cartilage of the glenoid contributes significantly to the concavity gradient, correlating strongly with the associated loss in glenohumeral joint stability. The highest effect of cartilage loss was observed in anterior-inferior dislocation directions, suggesting that surgical intervention should be considered for recurrent shoulder dislocations in the presence of cartilage loss.

BMP-1 is the major procollagen-C-peptidase activating, besides fibrillar collagen types I-III, several enzymes and growth factors involved in the generation of extracellular matrix. This study investigated the effect of adding and inhibiting BMP-1 directly post fracture.

Standardised femoral fractures were stabilized by an intramedullary nail in 12 week-old female C57Bl/6J mice. We injected either 20 µL recombinant active BMP-1, activity buffer or the BMP-1 specific inhibitor “sizzled”. After 7, 14 and 28 days, mice were sacrificed. Femurs were dissected and paraffin slides were prepared. Callus composition was divided into soft tissue, mineralized and cartilaginous callus. Murine MC3T3 pre-osteoblastic cells were kept in culture adding BMP-1 and sizzled during osteoblastic differentiation. Putative cytotoxicity was determined using MTT-vitality assay. Cell calcification, collagen deposition, and BMP-2 and myostatin protein quantity were characterized.

Adding BMP-1 displayed a weak positive effect on the outcome. After 7 days, more mineralised callus was present, meanwhile the cartilaginous callus was apparently remodelled at higher rate. In the case of BMP-1 inhibition, we observed more cartilaginous callus, which may indicate reduced stability. In cell culture, we could observe a high interference with mineralisation capabilities depending on the stage of osteoblastic development when adding BMP-1 or inhibiting it. Addition and inhibition impaired myostatin (anti-osteogen) and BMP-2 (pro-osteogen) expression.

Interfering with BMP-1 homeostasis in this early stage of fracture repair seems to have rather negative effects. Inhibition apparently yields lower callus quality while the addition of BMP-1 does not significantly accelerate the healing outcome. Cell culture experiments show that BMP-1 application after 7 days of healing leads to higher collagen output but has no effect on mineralisation. This may suggest that BMP-1 application at a later time-point may lead to more pronounced beneficial effects on fracture repair.

Type-2 Diabetic (T2D) patients experience up to a 3-fold increase in bone fracture risk[1]. Paradoxically, T2D-patients have a normal or increased bone mineral density when compared to non-diabetic patients. This implies that T2D has a deleterious effect on bone quality, whereby the intrinsic material properties of the bone matrix are altered. Creating clinical challenges as current diagnostic techniques are unable to accurately predict the fracture probability in T2D-patients. To date, the relationship between cyclic fatigue loading, mechanical properties and microdamage accumulation of T2D-bone tissue has not yet been examined and thus our objective is to investigate this relationship.

Ethically approved femoral heads were obtained from patients, with (n=8) and without (n=8) T2D. To obtain the mechanical properties of the sample, one core underwent a monotonic compression test to 10% strain, the other core underwent a cyclic compression test at a normalized stress ratio between 0.0035mm/mm and 0.016mm/mm to a maximum strain of 3%. Microdamage was evaluated by staining the tissue with barium sulfate precipitate [2] and conducting microcomputed tomography scanning with a voxel size of 10μm.

The monotonically tested T2D-group showed no statistical difference in mechanical properties to the non-T2D-group, even when normalised against BV/TV. There was also no difference in BV/TV. For the cyclic test, the T2D-group had a significantly higher initial modulus (p<0.01) and final modulus (p<0.05). There was no difference in microdamage accumulation.

Previous population-level studies have found that T2D-patients have been shown to have an increased fracture risk when compared to non-T2D-patients. This research indicates that T2D does not impair the mechanical properties of trabecular bone from the femoral heads of T2D-patients, suggesting that other mechanisms may be responsible for the increased fracture risk seen in T2D-patients.