Aim. To investigate the role of websites in enhancing patients' understanding of reason and risk of surgery as a part of informed consent for elective un-instrumented lumbar spine surgery (EULSS). Methodology. This was a National Research Ethical Committee approved RCT study. 63 patients underwent EULSS, out of which 14(29%) declined participation and 14(29%) were excluded. One did not have surgery therefore 34 were randomised to Standard (S) and intervention group (I) using sealed envelope. Standard group were given verbal information & leaflet while the Intervention group were given information on relevant section of . www.eurospine.org. and . www.spinesurgeons.ac.uk. websites. A 13 item Informed Consent Questionnaire (ICQ) was used to collect data. The primary outcomes were patients' perceived understanding of reason and risk of EULSS. Results. Average age was 54 (21–82) years, with similar demographics in both groups. Complete data was available for 20 (13 Standard and 7 Intervention group). No difference (χ. 2. = 0.42, df=1, p= 0.52) was observed on perception of reason and risk of surgery between two groups. Website usage increased from 30% to 50% in intervention group who continued to use the website. Conclusion. Website use appears to be useful to participants. Although support has not been found to accept the experimental hypothesis, valuable information has been gained that will serve to facilitate larger study to further explore the effectiveness of websites in enhancing of EULSS. No Conflict of interest. No funding obtained. This abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting

The process of gaining informed consent can be a complex and much debated pursuit, especially within a paediatric setting. The role of the trainee surgeon and its explanation to children and their families prior to an operation has not been explored from the resident surgeons' point of view. Ten face-to-face interviews were conducted with orthopaedic surgery trainees at a tertiary level paediatric hospital in Toronto, Canada. These were transcribed and subsequently thematically coded by 3 reviewers. Three main themes were identified from the interviews. 1) Surgical trainees feel their level of participation and autonomy gradually increases dependent on their observed skills and level of training. 2) Trainees feel the consent process is adequate but acknowledge it is often purposely vague with regards to their intra-operative involvement as this is often unpredictable and it avoids patient/family anxiety. 3) Trainees believe families are aware of their participation however most likely underestimate their role during operations. Trainees in surgical specialties believe their level of autonomy is variable dependent on a number of factors and that this impacts on the ability to be more specific when gaining informed consent. This must be balanced with a family's right to an appropriate understanding of their child's operation and who is performing it. It may be that further patient education regarding trainees and their role in operations would help develop a more thorough and patient centred informed consent process

Obtaining informed consent for an operation is a fundamental daily interaction between orthopaedic surgeon and patient. It is based on a patient's capacity to understand and retain information about the proposed procedure, the potential consequences of having it and the alternative options available. We used validated tests of memory on 59 patients undergoing lower limb arthroplasty to assess how well they learned and recalled information about their planned procedure. All patients showed an ability to learn new material, however, younger age and higher educational achievement correlated with better performance. These results have serious implications for orthopaedic surgeons discussing planned procedures. They identify groups of patients who may require enhanced methods of communicating the objectives, risks and alternatives to surgery. Further research is necessary to assess interventions to improve communication prior to surgery

Abstract

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

Traumatic acute or chronic tendon injuries are a wide clinical problem in modern society, resulting in important economic burden to the health system and poor quality of life in patients. Due to the low cellularity and vascularity of tendon tissue the repair process is slow and inefficient, resulting in mechanically, structurally, and functionally inferior tissue. Tissue engineering and regenerative medicine are promising alternatives to the natural healing process for tendon repair, especially in the reconstruction of large damaged tissues. The aim of TRITONE project is to develop a smart, bioactive implantable 3D printed scaffold, able to reproduce the structural and functional properties of human tendon, using FDA approved materials and starting from MSC and their precursor, MPC cell mixtures from human donors. Total cohort selected in the last 12 months was divided in group 1 (N=20) of subjects with tendon injury and group 2 (N=20) of healthy subject. Groups were profiled and age and gender matched. Inclusion criteria were age>18 years and presence of informed consent. Ongoing pregnancy, antihypertensive treatment, cardiovascular diseases, ongoing treatment with anti-aggregants, acetylsalicylic-acid or lithium and age<18 years were exclusion criteria. Firstly, we defined clinical, biological, nutritional life style and genetic profile of the cohort. The deficiency of certain nutrients and sex hormonal differences were correlated with tendon-injured patients. It was established the optimal amount of MPC/MSC human cell (collected from different patients during femoral neck osteotomy). Finally, most suitable biomaterials for tendon regeneration and polymer tendon-like structure were identified. Hyaluronic acid, chemical surface and soft-molecular imprinting (SOFT-MI) was used to functionalize the scaffold. These preliminary results are promising. It will be necessary to enroll many more patients to identify genetic status connected with the onset of tendinopathy. The functional and structural characterization of smart bioactive tendon in dynamic environment will represent the next project step

Autografts containing bone marrow (BM) are current gold standard in the treatment of critical size bone defects, delayed union and bone nonunion defects. Although reaching unprecedented healing rates in bone reconstruction, the mode of action and cell-cell interactions of bone marrow mononuclear cell (BM-MNC) populations have not yet been described. BM-MNCs consist of a heterogeneous mixture of hematopoetic and non-hematopoetic lineage fractions. Cell culture in a 3D environment is necessary to reflect on the complex mix of these adherend and non-adherend cells in a physiologically relevant context. Therefore, the main aim of this approach was to establish conditions for a stable 3D BM-MNC culture to assess cellular responses on fracture healing strategies. BM samples were obtained from residual material after surgery with positive ethical vote and informed consent of the patients. BM-MNCs were isolated by density gradient centrifugation, and cellular composition was determined by flow cytometry to obtain unbiased data sets on contained cell populations. Collagen from rat tail and human fibrin was used to facilitate a 3D culture environment for the BM-MNCs over a period of three days. Effects on cellular composition that could improve the regenerative potential of BM-MNCs within the BM autograft were assessed using flow cytometry. Cell-cell-interactions were visualized using confocal microscopy over a period of 24 hours. Cell localization and interaction partners were characterized using immunofluorescence labeled paraffin sectioning. Main BM-MNC populations like Monocytes, Macrophages, T cells and endothelial progenitor cells were determined and could be conserved in 3D culture over a period of three days. The 3D cultures will be further treated with already clinically available reagents that lead to effects even within a short-term exposure to stimulate angiogenic, osteogenic or immunomodulatory properties. These measures will help to ease the translation from “bench to bedside” into an intraoperative protocol in the end

Partial meniscectomy patients have a greater likelihood for the development of early osteoarthritis (OA). To prevent the onset of early OA, patient-specific treatment algorithms need to be created that predict patient risk to early OA after meniscectomy. The aim of this work was to identify patient-specific risk factors in partial meniscectomy patients that could potentially lead to early OA. Partial meniscectomy patients operated between 01/2017 and 12/2019 were evaluated in the study (n=317). Exclusion criteria were other pathologies or surgeries for the evaluated knee and meniscus (n = 114). Following informed consent, an online questionnaire containing demographics and the “Knee Injury and Osteoarthritis Outcome Score” (KOOS) questionnaire was sent to the patient. Based on the KOOS pain score, patients were classified into “low” (> 75) and “high” (< 75) risk patients, indicating risk to symptomatic OA. The “high risk” patients also underwent a follow-up including an MRI scan to understand whether they have developed early OA. From 203 participants, 96 patients responded to the questionnaire (116 did not respond) with 61 patients considered “low-risk” and 35 “high-risk” patients. Groups that showed a significant increased risk for OA were patients aged > 40 years, females, overweight (BMI >25 kg/m2 ≤ 30 kg/m2), and smokers (*p < 0.05). The “high-risk”-follow-up revealed a progression of early osteoarthritic cartilage changes in seven patients, with the remaining nineteen patients showing no changes in cartilage status or pain since time of operation. Additionally, eighteen patients in the high-risk group showed a varus or valgus axis deviation. Patient-specific factors for worse postoperative outcomes after partial meniscectomy and indicators for an “early OA” development were identified, providing the basis for a patient-specific treatment approach. Further analysis in a multicentre study and computational analysis of MRI scans is ongoing to develop a patient-specific treatment algorithm for meniscectomy patients

Arthritis is a common and debilitating disease and is associated with an increased fall risk. The purpose of this study was to examine the effect of impacted joint and limb on fall risk as measured by the margin of stability (MOS). There were 110 participants, including healthy controls (HC; n=30), ankle arthritis (AA; n=30), knee arthritis (KA; n=20) and hip arthritis (HA; n=30) patients. All protocols were Institutional Review Board approved and all participants signed informed consent. Participants walked approximately 6 meters at a self-selected pace. MOS was calculated in the foot coordinate system in the anterior/posterior (AP) and medial/lateral (ML) directions at heel strike. A one-way ANOVA was used to examine group effects (HC, AA, KA, HA) on gait speed. A two-way repeated measures ANOVA was used to examine the effects of limb (Non-Surgical, Surgical) and group on AP and ML MOS. HC had the fastest gait speed (1.40±0.24 m/s; p<0.001) when compared to AA (0.85±0.24 m/s), KA (0.94±0.22 m/s) and HA (1.05±0.22 m/s). HA participants had a greater gait speed compared to AA (p=0.004). AP MOS was greater in the surgical limb compared to the non-surgical limb for AA (p<0.001) and HA (p<0.001). AP MOS was smaller in HC compared to AA, KA, and HA, regardless of limb (p<0.030). AP MOS was similar between AA, KA, and HA for the non-surgical limb (p>0.194) and the surgical limb (p>0.096). ML MOS was greater in the surgical compared to non-surgical limb (p=0.003). ML MOS was smaller in KA participants compared to all other groups (p<0.001). Our results demonstrate stability during gait varies between limbs in arthritis patients, with a more conservative pattern for the surgical limb and suggest KA may be at an increased risk of falls with a smaller ML MOS

Vacuum orthoses are being applied in the care of patients with foot and lower leg conditions, as ankle fractures or sprains. The lower leg is protected and immobilized, which increases mobility. Due to the design, the orthoses lead to a difference in leg length, i.e. the side with the orthosis becomes longer, which changes the gait kinematics. To prevent or mitigate the unfavourable effects of altered gait kinematics, leg length-evening devices (shoe lifts) are offered that are worn under the shoe on the healthy side. Our aim was to evaluate the effect of such a device on the normality of gait kinematics. Gait analysis was conducted with 63 adult, healthy volunteers having signed an informed consent form that were asked to walk on a treadmill at a speed of 4.5km/h in three different conditions:. barefoot - as reference for establishing the normality score baseline. with a vacuum orthosis (VACOPed, OPED GmbH, Germany) and a sport shoe. with a vacuum orthosis and a shoe lift (EVENup, OPED GmbH, Germany). Data was sampled using the gait analysis system MCU 200 (LaiTronic GmbH, Austria). The positions of the joint markers were exported from the software and evaluated for the joint angles during the gait cycle using custom software (implemented in DIAdem 2017, National Instruments). A normality score using a modification of the Gait Profile Score (GPS) was calculated in every 1%-interval of the gait cycle and evaluated with a Wilcoxon signed rank test. The GPS value was reduced by 0.33° (0.66°) (median and IQR) while wearing the shoe lift. The effect was statistically significant, and very large (W = 1535.00, p < .001; r (rank biserial) = 0.52, 95% CI [0.29, 0.70]). The significant reduction of the GPS value indicates a more normal gait kinematics while using the leg length-evening device on the contralateral shoe. This rather simple and inexpensive device thus might improve patient comfort and balance while using the vacuum orthoses

The effects of dexamethasone (dex), during in vitro human osteogenesis, are contrasting. Indeed, dex downregulates SOX9 during osteogenic differentiation of human bone marrow mesenchymal stromal cells (HBMSCs). However, dex also promotes PPARG expression, resulting in the formation of adipocyte-like cells within the osteogenic monolayers. The regulation of both SOX9 and PPARG seems to be downstream the transactivation activity of the glucocorticoid receptor (GR), thus the effect of dex on SOX9 downregulation is indirect. This study aims at determining whether PPAR-γ regulates SOX9 expression levels, as suggested by several studies. HBMSCs were isolated from bone marrow of patients with written informed consent. HBMSCs were cultured in different osteogenic induction media containing 10 or 100 nM dex. Undifferentiated cells were used as controls. Cells were treated either with a pharmacological PPAR-γ inhibitor T0070907 (donors n=4) or with a PPARG-targeting siRNA (donors n=2). Differentiation markers or PPAR-γ target genes were analysed by RT-qPCR. Mineral deposition was assessed by ARS staining. Two-way ANOVA followed by a Tukey's multiple comparison test compared the effects of treatments. At day 7, T0070907 downregulated ADIPOQ and upregulated CXCL8, respectively targets of PPAR-γ-mediated transactivation and transrepression. RUNX2 and SOX9 were also significantly downregulated in absence of dex. PPARG was successfully downregulated by siRNA. ADIPOQ expression was also inhibited, while CXCL8 did not show any significant difference between siRNA treatment groups. RUNX2 was downregulated by the PPARG-siRNA treatment in presence of 100 nM dexamethasone, while SOX9 levels were not affected. ARS showed no change in the mineralization levels when PPARG expression or activity was inhibited. Understanding how dex regulates HBMSC differentiation is of pivotal importance to refine current in vitro models. These results suggest that PPARG does not mediate SOX9 downregulation. Unexpectedly, RUNX2 expression was also unaltered or even downregulated after PPAR-γ inhibition. Acknowledgements: AO Foundation, AO Research Institute (CH) and PRIN 2017 MUR (IT) for financial support

Introduction. Polyacrylamide hydrogel (iPAAG. 1. ), is CE marked for treating symptomatic knee osteoarthritis (OA), meeting the need for an effective, long-lasting, and safe non-surgical option. This study evaluates the efficacy and safety of a single 6 ml intra-articular injection of iPAAG in participants with moderate to severe knee OA over a 5-year post-treatment period, presenting data from the 4-year follow up. Method. This prospective multicentre study (3 sites in Denmark) involved 49 participants (31 females) with an average age of 70 (range 44 – 86 years). They received a single 6 mL iPAAG injection. All participants provided informed consent and re-consented to continue after 1 year. The study followed GCP principles and was approved by Danish health authorities and local Health Research Ethics committees. Twenty-seven participants completed the 4-year follow-up. The study evaluated WOMAC pain, stiffness, function, and Patient Global Assessment (PGA) of disease impact. Changes from baseline were analysed using a mixed model for repeated measurement (MMRM). Sensitivity analyses were applied on the extension data, where the MMRM analysis was repeated only including patients in the extension phase and an ANCOVA model was used, replacing missing values at 4-years with baseline values (BOCF). Results. The planned MMRM analysis (n=49) revealed a statistically significant decrease in WOMAC pain subscale scores (-22.0; 95%CI: -29.5; -14.4) from baseline to 4-years. Analysis of the extension phase (n=27) showed similar results (-21.8; 95%CI: -29.0; -14.6) compared to the initial analysis. Furthermore, BOCF analysis indicated a statistically significant reduction in WOMAC pain subscale scores from baseline (-13.0 units). Four new adverse events were reported between the 3-year and 4-year visits; none were related to treatment. Conclusions. This study shows that single injections of 6 ml intra-articular iPAAG were well tolerated and continued to provide clinically important effectiveness at 4-years after treatment. Acknowledgements. The study was sponsored by Contura International A/S

Abstract. Objectives. The syndesmosis joint, located between the tibia and fibula, is critical to maintaining the stability and function of the ankle joint. Damage to the ligaments that support this joint can lead to ankle instability, chronic pain, and a range of other debilitating conditions. Understanding the kinematics of a healthy joint is critical to better quantify the effects of instability and pathology. However, measuring this movement is challenging due to the anatomical structure of the syndesmosis joint. Biplane Video Xray (BVX) combined with Magnetic Resonance Imaging (MRI) allows direct measurement of the bones but the accuracy of this technique is unknown. The primary objective is to quantify this accuracy for measuring tibia and fibula bone poses by comparing with a gold standard implanted bead method. Methods. Written informed consent was given by one participant who had five tantalum beads implanted into their distal tibia and three into their distal fibula from a previous study. Three-dimensional (3D) models of the tibia and fibula were segmented (Simpleware Scan IP, Synopsis) from an MRI scan (Magnetom 3T Prisma, Siemens). The beads were segmented from a previous CT and co-registered with the MRI bone models to calculate their positions. BVX (125 FPS, 1.25ms pulse width) was recorded whilst the participant performed level gait across a raised platform. The beads were tracked, and the bone position of the tibia and fibula were calculated at each frame (DSX Suite, C-Motion Inc.). The beads were digitally removed from the X-rays (MATLAB, MathWorks) allowing for blinded image-registration of the MRI models to the radiographs. The mean difference and standard deviation (STD) between bead-generated and image-registered bone poses were calculated for all degrees of freedom (DOF) for both bones. Results. The absolute mean tibia and fibula bone position differences (Table 1) between the bead and BVX poses were found to be less than 0.5 mm for both bones. The bone rotation differences were found to be less than 1° for all axes except for the fibula Z axis rotation which was found to be 1.46°. One study. 1. has reported the kinematics of the syndesmosis joint and reported maximum ranges of motion of 9.3°and translations of 3.3mm for the fibula. The results show that the accuracy of the methodology is sufficient to quantify these small movements. Conclusions. BVX combined with MRI can be used to accurately measure the syndesmosis joint. Future work will look at quantifying the accuracy of the talus to provide further understanding of normal ankle kinematics and to quantify the kinematics across a healthy population to act as a comparator for future patient studies. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Introduction. Skeletal muscle wasting is an important clinical issue following acute traumatic injury, and can delay recovery and cause permanent functional disability particularly in the elderly. However, the fundamental mechanisms involved in trauma-induced muscle wasting remain poorly defined and therapeutic interventions are limited. Objectives. To characterise local and systemic mediators of skeletal muscle wasting in elderly patients following acute trauma. Methods. Experiments were approved by a local NHS Research Ethics Committee and all participants provided written informed consent. Vastus lateralis biopsies and serum samples were taken from human male and female patients shortly after acute trauma injury in lower limbs (n=6; mean age 78.7±4.4 y) and compared to age-matched controls (n=6; mean age 72.6±6.3 y). Atrogenes and upstream regulators (MuRF1; MAFbx; IL6, TNFα, PGC-1α) mRNA expression was assessed in muscle samples via RT-qPCR. Serum profiling of inflammatory markers (e.g. IL6, TNFα, IL1β) was further performed via multiplex assays. To determine whether systemic factors induced by trauma directly affect muscle phenotype, differentiated primary human myotubes were treated in vitro with serum from controls or trauma patients (pooled; n=3 each) in the final 24 hours of differentiation. Cells were then fixed, stained for myogenin and imaged to determine minimum ferret diameter. Statistical significance was determined at P<0.05. Results. There was an increase in skeletal muscle mRNA expression for E3 ligase MAFbx and inflammatory cytokine IL-6 (4.6 and 21.5-fold respectively; P<0.05) in trauma patients compared to controls. Expression of myogenic determination factor MyoD and regulator of mitochondrial biogenesis PGC-1α was lower in muscle of trauma patients vs controls (0.5 and 0.39-fold respectively; P<0.05). In serum, trauma patients showed increased concentrations of circulating pro-inflammatory cytokines IL-6 (14.5 vs. 0.3 pg/ml; P<0.05) and IL-16 (182.7 vs. 85.2 pg/ml; P<0.05) compared to controls. Primary myotube experiments revealed serum from trauma patients induced atrophy (32% decrease in diameter) compared to control serum-treated cells (P<0.001). Conclusion. Skeletal muscle from patients following acute trauma injury showed greater expression of atrophy and inflammatory markers. Trauma patient serum exhibited higher circulating pro-inflammatory cytokine concentrations. Primary human myotubes treated with serum from trauma patients showed significant atrophy compared to healthy serum-treated controls. We speculate a mechanism(s) acting via circulating factors may contribute to skeletal muscle pathology following acute trauma. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Objectives. Investigate Magnetic Resonance Imaging (MRI) as an alternative to Computerised Tomography (CT) when calculating kinematics using Biplane Video X-ray (BVX) by quantifying the accuracy of a combined MRI-BVX methodology by comparing with results from a gold-standard bead-based method. Methods. Written informed consent was given by one participant who had four tantalum beads implanted into their distal femur and proximal tibia from a previous study. Three-dimensional (3D) models of the femur and tibia were segmented (Simpleware Scan IP, Synopsis) from an MRI scan (Magnetom 3T Prisma, Siemens). Anatomical Coordinate Systems (ACS) were applied to the bone models using automated algorithms. 1. The beads were segmented from a previous CT and co-registered with the MRI bone models to calculate their positions. BVX (60 FPS, 1.25 ms pulse width) was recorded whilst the participant performed a lunge. The beads were tracked, and the ACS position of the femur and tibia were calculated at each frame (DSX Suite, C-Motion Inc.). The beads were digitally removed from the X-rays (MATLAB, MathWorks) allowing for blinded image-registration of the MRI models to the radiographs. The mean difference and standard deviation (STD) between bead-generated and image-registered bone poses were calculated for all degrees of freedom (DOF) for both bones. Using the principles defined by Grood and Suntay. 2. , 6 DOF kinematics of the tibiofemoral joint were calculated (MATLAB, MathWorks). The mean difference and STD between these two sets of kinematics were calculated. Results. The absolute mean femur and tibia ACS position differences (Table 1) between the bead and image-registered poses were found to be within 0.75mm for XYZ, with all STD within ±0.5mm. Mean rotation differences for both bones were found to be within 0.2º for XYZ (Table 1). The absolute mean tibiofemoral joint translations (Table 1) were found to be within ±0.7mm for all DOF, with the smallest absolute mean in compression-distraction. The absolute mean tibiofemoral rotations were found to be within 0.25º for all DOF (Table 1), with the smallest mean was found in abduction-adduction. The largest mean and STD were found in internal-external rotation due to the angle of the X-rays relative to the joint movement, increasing the difficulty of manual image registration in that plane. Conclusion. The combined MRI-BVX method produced bone pose and tibiofemoral kinematics accuracy similar to previous CT results. 3. This allows for confidence in future results, especially in clinical applications where high accuracy is needed to understand the effects of disease and the efficacy of surgical interventions. Acknowledgements: This research was supported by the Engineering and Physical Sciences Research Council (EPSRC) doctoral training grant (EP/T517951/1). Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Background. Ultrasonic cutting of bone boasts many advantages over alternatively powered surgical instruments, including but not limited to: elimination of swarf, reduced reaction forces, increased precision in cutting and reduced adjacent soft tissue damage, reduced post-operative complications such as bleeding and bone fracture, reduced healing time, reduced intra-operative noise and ease of handling. Despite ultrasonic cutting devices being well established in oral and maxillofacial surgery, applications in orthopaedic surgery are more niche and are not as well understood. The aim of this study was to investigate the cutting speed (mm/s) and cutting forces (N) of orthopaedic surgeons using a custom-designed state of the art ultrasonic cutting tool to cut fresh human bone samples. Methods. A setup based on the Robot Operating System (ROS) and AprilTag was designed to track and to record the real time position of the ultrasonic cutting tool in space. Synchronised load cell axial force readings of three separate orthopaedic surgeons during ultrasonic cutting were recorded. Each surgeon was asked to find a comfortable position that reflects as close as possible their clinical handling of a cutting instrument used in surgery, and to perform two cuts in each of three samples of human cortical bone. Bone samples were obtained following ethical approval from an institutional review board (ethics approval number: SR1342) and prior informed consent was obtained from all patients. Bone samples were extracted from the femoral neck region of three hip osteoarthritis patients. During cutting, surgeons were allowed a total cutting time of one minute and cutting was conducted using an ultrasonic tool with frequency of a 35kHz (35.7 µm peak to peak displacement amplitude) under constant irrigation using a MINIPULS® 3 Peristaltic pump (38 revolutions per minute) using Phosphate-Buffered Saline (PBS) at 25°C. From the recorded data, the average instantaneous cutting velocity was calculated and the maximum cutting force was identified. Results. All surgeons assumed a back-and-forth cutting motion, variation in the applied cutting force was observed. The average vertical cutting speed, axial cutting force and cutting depth across all surgeons and all samples was 1.64 mm/s, 1.91 N and 0.73 mm, respectively. While increasing the axial cutting force resulted in a deeper cut, overloading of the ultrasound transducer occurred when the tool advanced too quickly into the bone tissue during cutting. The exact force threshold, or the optimal speed at which the surgeon can maintain a constant force during cutting, requires further investigation. Conclusions. In this study, all surgeons cut using a back-and-forth cutting motion, with variation in the applied cutting force which may ultimately inform which clinical applications in orthopaedic engineering are most suitable for this technology. Applying too much force caused overloading of the ultrasound transducer, which is a limitation with the current cutting tool. The results from this study may facilitate the eventual uptake of ultrasonic cutting tools for application in orthopaedic surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Hip Osteoarthritis (HOA) is the most common joint disorder and a major cause of disability in the adult population, leading to total hip replacement (THR). Recently, evidence has mounted for a prominent etiologic role of femoroacetabular impingement (FAI) in the development of early OA in the non-dysplastic hip. FAI is a pathological mechanical process, caused by abnormalities of the acetabulum and/or femur leading to damage the soft tissue structures. FAI can determine chondro-labral damage and groin pain in young adults and can accelerate HOA progression in middle-aged adults. The aim of the study was to determine if the presence of calcium crystal in synovial fluid (SF) at the time of FAI surgery affects the clinical outcomes to be used as diagnostic and predictive biomarker. 49 patients with FAI undergoing arthroscopy were enrolled after providing informed consent; 37 SFs were collected by arthrocentesis at the time of surgery and 35 analyzed (66% males), median age 35 years with standard deviation (SD) 9.7 and body mass index (BMI) 23.4 kg/m. 2. ; e SD 3. At the time of surgery, chondral pathology using the Outerbridge score, labral pathology and macroscopic synovial pathology based on direct arthroscopic visualization were evaluated. Physical examination and clinical assessment using the Hip disability & Osteoarthritis Outcome Score (HOOS) were performed at the time of surgery and at 6 months of follow up. As positive controls of OA signs, SF samples were also collected from cohort of 15 patients with HOA undergoing THR and 12 were analysed. 45% FAI patients showed CAM deformity; 88% presented labral lesion or instability and 68% radiographic labral calcification. 4 patients out of 35 showed moderate radiographic signs of OA (Kellegren-Lawrence score = 3). Pre-operative HOOS median value was 61.3% (68.10-40.03) with interquartile range (IQR) of 75-25% and post-operative HOOS median value 90% with IQR 93.8-80.60. In both FAI and OA patients the calcium crystal level in SFs negatively correlated with glycosaminoglycan (component of the extracellular matrix) released, which is a marker of cartilage damage (Spearman rho=-0.601, p<0.001). In FAI patients a worst articular function after surgery, measured with the HOOS questionnaire, was associated with both acetabular and femoral chondropathy and degenerative labral lesion. Moreover, radiographic labral calcification was also significantly associated with pain, worst articular function and labral lesion. Calcium crystal level in SFs was associated with labral lesions and OA signs. We concluded that the levels of calcium crystals in FAI patients are correlated with joint damage, OA signs and worst post-operative outcome. The presence of calcium crystals in SF of FAI patients might be a potential new biomarker that might help clinicians to make an early diagnosis, evaluate disease progression and monitor treatment response

Abstract. Focal articular cartilage defects do not heal and, left untreated, progress to more widespread degenerative changes. A promising new approach for the repair of articular cartilage defects is the application of cell-based regenerative therapies using mesenchymal stromal cells (MSCs). MSCs are however present in a number of tissues and studies suggest that they vary in their proliferation, cell surface characterisation and differentiation. As the phenotypic properties of MSCs vary depending on tissue source, a systematic comparison of the transcriptomic signature would allow a better understanding of these differences between tissues, and allow the identification of markers specific to a MSC source that is best suited for clinical application. Tissue was used from patients undergoing total knee replacement surgery for osteoarthritis following ethical approval and informed consent. MSCs were isolated from bone, cartilage, synovium and infrapatellar fat pad. MSC number and expansion were quantified. Following expansion in culture, MSCs were characterised using flow cytometry with several cell surface markers; the cells from all sources were positive for CD44, CD90 and CD105. Their differentiation potential was assessed through tri-lineage differentiation assays. In addition, bulk mRNA-sequencing was used to determine the transcriptomic signatures. Differentially expressed (DE) genes were predicted. An enrichment analysis focused on the DE genes, against GO and pathway databases (KEGG and Reactome) was performed; protein-protein interaction networks were also inferred (Metascape, Reactome, Cytoscape). Optimal sourcing of MSCs will amplify their cartilage regeneration potential. This is imperative for assessing future therapeutic transplantation to maximise the chance of successful cartilage repair. A better understanding of differences in MSCs from various sources has implications beyond cartilage repair

Introduction and Objective. Platelet-Rich-plasma (PRP) has been used in combination with stem cells, from different sources, with encouraging results both in vitro and in vivo in osteochondral defects management. Adipose-derived Stem Cells (ADSCs) represents an ideal resource for their ease of isolation, abundance, proliferation and differentiation properties into different cell lineages. Furthermore, Stem Cells in the adipose tissue are more numerous than from other sources. Aim of this study was to evaluate the potential of ADSCs in enhancing the effect of arthroscopic mesenchymal stimulation combined with infiltration of PRP. Materials and Methods. The study includes 82 patients. 41 patients were treated with knee arthroscopy, Steadman microfractures technique and intraoperative PRP infiltration, Group A. In the Group B, 41 patients were treated knee arthroscopy, Steadman microfractures and intraoperative infiltration of PRP and ADSCs (Group B). Group A was used as a control group. Inclusion criteria were: Age between 40 and 65 years, Outerbridge grade III-IV chondral lesions, Kellegren-Lawrence Grade I-II. Patient-reported outcome measures (PROMs) evaluated with KOOS, IKDC, VAS, SF-12 were assessed pre-operatively and at 3 weeks, 6 months, 1-year post-operative. 2 patients of Group A and 3 patients of Group B, with indication of Puddu plate removal after high tibial osteotomy (HTO), underwent an arthroscopic second look, after specific informed consent obtained. On this occasion, a bioptic sample was taken from the repair tissue of the chondral lesion previously treated with Steadman microfractures. Results. PROMs showed statistically significant improvement (p <0.05) with comparable results in both groups. The histological examination of the bioptic samples in Group B showed a repair tissue similar to hyaline cartilage, according to the International Cartilage Repair Society (ICRS) Visual Histological Assessment Scale. In Group A, the repair tissue was fibrocartilaginous. Conclusions. According to the PROMs and the histological results, showing repair tissue after Steadman microfractures qualitatively similar to hyaline cartilage, the combination of ADSCs and PRP could represent an excellent support to the arthroscopic treatment of focal chondral lesions and mild to moderate osteoarthritis

Abstract. Objectives. Our objective was to determine the incidence of post-operative COVID-19 infection within the first two weeks following treatment at the COVID-free site. During the COVID-19 pandemic our hospital saw one of the highest rates of COVID-19 infection in the United Kingdom. As a result, our trauma services were relocated to a vacant private elective hospital to provide a ‘COVID-free’ setting for trauma patients. Patients admitted to the COVID-free site were screened for coronavirus infection and only treated at that site if asymptomatic. Those with symptoms were treated at the ‘COVID’ site. Method. We collected data at the COVID-free site during the first seven weeks of its’ establishment. Inclusion criteria were all patients presenting for operative management of limb trauma; however, fragility hip fractures were excluded. All patients were screened for symptoms of COVID-19 infection at their 2-week follow-up appointment. Results. 72 patients presented to our service during the study period. The mean age was 34.9 years (21 to 89). 62 patients had general anaesthesia (86%), 7 patients had regional anaesthesia (10%) and 3 patients had local anaesthesia (4%). One asymptotic patient who was swabbed for COVID-19 on admission returned a positive result. This patient had contracted the infection before surgery and was excluded from further analysis. 71 patients (100%) remained asymptomatic at follow-up and none had required medical attention for suspected COVID-19 infection. Conclusion. A ‘COVID-free’ trauma service was established in a private elective hospital during the pandemic. None of the patients undergoing urgent trauma surgery in this setting developed COVID-19 symptoms as a result of their hospital admission. Establishing a separate site with screening to avoid admission of patients with COVID-19 infection can allow safe emergency surgery. This data can support informed consent and reassure patients of their risks when we resume day case and elective surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project