In 2019, Lin et al. published a proof-of-concept study of electrical impedance spectroscopy as a simple and low-cost method to characterize progression of fracture repair (Lin et al., Sci Rep 2019). However, the electrical impedance sensors were placed in the fracture site which may impair the transfer to clinical use. To further explore the concept of monitoring fracture healing by electrical impedance spectroscopy, we established a tibial fracture model in the rabbit where sensors are positioned in proximity to the fracture site but without being placed in the fracture site. The aim of this pilot study was to explore whether distinct patterns of electrical impedance would evolve as tibial fractures in rabbits were evaluated until radiographic signs of healing.

Approval was granted from the Inspectorate of the Animal Experimentation under the Danish Ministry of Justice. Four rabbits were anaesthetized, and in each rabbit a tibial osteotomy was made and stabilized by an external fixator. Electrical impedance was measured immediately postoperative and hereafter daily until euthanization after 3 weeks. Recordings were obtained within a wide frequency range (10 Hz to 1 MHz) from an inner electrode placed into the medullary canal and an outer electrode placed extracortical on the lateral with a distance of 3 mm to the defect.

A similar pattern of electrical impedance over time was observed in the four rabbits. During the very early stages of fracture healing, an initial fluctuation in electrical impedance occurred. However, after 10 days the curves revealed a steady daily increase in electrical impedance. The first radiological signs of bone healing were detected after 14 days and progressed in all four rabbits in accordance with increments in the electrical impedance until termination of the pilot study after 21 days.

Consistent electrical impedance patterns were detected during bone healing in a pilot study of four rabbits. Further research is needed to explore whether the presented method of electrical impedance measurements can be used to monitor bone healing over time.

Achilles tendinopathy is classically defined as a tendinosis devoid of an inflammatory cell population. However, recent literature suggests inflammation as a mediator in the pathogenesis. These finding were mainly based on semi-quantative immunohistochemistry. We therefore used flow cytometry to obatain a more accurate identification and quantification of the different cell types involved. Thirty-two samples were obtained from twelve patients with chronic tendinopathic lesions undergoing Achilles tendon surgery. Samples obtained from three patients with hemiplegia requiring surgical release due to spastic Achilles tendons served as control. We used two panels to identify the myeloid and lymphoid population targeting the following markers: CD45, CD3, CD8, CD4, CD19, CD11b, CD56, CD14, CD16, Vα7.2, 6b11, CD161, TCRγδ. To assess the presence of fibroblasts CD90 was targeted. The mean count of CD45+ hematopoietic cells in the tendinopathic samples was significantly higher than in the control samples, respectively 13.27% and 3.24% of the total cell count (P<0.001). The mean fraction of CD3+ cells present in the complete cell population was significantly higher in pathological samples than in control samples, respectively 1.70% and 0.37% (P<0.05). Presence of CD19+ B cells was not reported. The mean fraction of γδ T cells was significantly higher in tendinopathic samples compared to blood samples of the same patient and consisted of 12.9% and 5.8% γδ T cells respectively (P<0.05). These findings support an inflammatory cell infiltration in midportion Achilles tendinopathy that show similarities to enthesitis in SpA. This implies a potential target to investigate in novel treatment modalities.

Introduction

The purpose of this study was to evaluate the outcome of vascularized iliac bone grafting for idiopathic osteonecrosis of the femoral head.

Introduction. The healing of rotator cuff injuries poses significant challenges, primarily due to the complexity of recreating the native tendon-to-bone interface, characterized by highly organized structural and compositional gradients. Addressing this, our innovative approach leverages bioprinted living tissue constructs, incorporating layer-specific growth factors (GFs) to facilitate enthesis regeneration. This method aims to guide in situ zonal differentiation of stem cells, closely mirroring the natural enthesis tissue architecture. Method. Our strategy involves the utilization of advanced bioprinting technology to fabricate living tissue constructs. These constructs are meticulously designed with embedded microsphere-based delivery carriers, ensuring the sustained release of tenogenic, chondrogenic, and osteogenic growth factors. This layer-specific release mechanism is tailored to promote the precise differentiation of stem cells across different regions of the construct, aligning with the gradient nature of enthesis tissues. Result. In vitro studies demonstrated that our layer-specific tissue constructs significantly outperformed basal constructs without GFs, achieving region-specific differentiation of stem cells. More critically, in a rabbit model of rotator cuff tear, these bioprinted living tissue constructs expedited enthesis regeneration. Key outcomes included improved biomechanical properties, enhanced collagen deposition and alignment, and the formation of a gradient fibrocartilage interface with aligned collagen fibrils. After 12 weeks, the constructs achieved an ultimate load failure of 154.3 ± 9.5 N resembling that of native enthesis tissues, marking a notable achievement in tissue engineering. Conclusion. Our exploration introduces a viable and innovative strategy for engineering living tissue constructs that exhibit region-specific differentiation capabilities. This approach holds significant promise for the functional repair of gradient enthesis tissues, potentially revolutionizing the treatment of rotator cuff injuries by closely replicating the natural tendon-to-bone interface, thus offering a promising avenue for future clinical applications

Introduction. Supraspinatus tears comprise most rotator cuff injuries, the leading cause of shoulder pain and an increasing problem with ageing populations. Surgical repair of considerable or persistent damages is customary, although not invariably successful. Tissue engineering presents a promising alternative to generate functional tissue constructs with improved healing capacities. This study explores tendon tissue constructs’ culture in a platform providing physiological mechanical stimulation and reports on the effect of different loading regimes on the viability of human tendon cells. Method. Porcine decellularized tendon scaffolds were fixed into flexible, self-contained bioreactor chambers, seeded with human tenocytes, allocated in triplicates to either static control, low (15±0.8Newtons [N]), medium (26±0.5N), or high (49±2.1N)-force-regime groups, connected to a perfusion system and cultured under standard conditions. A humanoid robotic arm provided 30-minute adduction/abduction stimulation to chambers daily over a week. A metabolic activity assay served to assess cell viability at four time points. Statistical significance = p<0.05. Result. One day after beginning mechanical stimulation, chambers in the medium and high-force regimes displayed a rise in metabolic activity by 3% and 5%, respectively. By the last experimental day, all mechanical stimulation regimes had induced an augment in cell viability (15%, 57% and 39% with low, medium, and high loads, respectively) matched against the static controls. Compared to all other conditions, the medium-force regime prompted an increased relative change in metabolic activity for every time point set against day one (p<0.05). Conclusion. Human tenocytes’ viability reflected by metabolic activity in a physiologically relevant bioreactor system is enhanced by loading forces around 25N when mechanically stimulating using adduction/abduction motions. Knowing the most favourable load regime to stimulate tenocyte growth has informed the ongoing exploration of the distinctive effect of different motions on tendon regeneration towards engineering tissue grafts. This work was supported by the Engineering and Physical Sciences Research Council EP/S003509/1

Abstract. Objectives. Biomechanics is an essential form of measurement in the understanding of the development and progression of osteoarthritis (OA). However, the number of participants in biomechanical studies are often small and there is limited ways to share or combine data from across institutions or studies. This is essential for applying modern machine learning methods, where large, complex datasets can be used to identify patterns in the data. Using these data-driven approaches, it could be possible to better predict the optimal interventions for patients at an early stage, potentially avoiding pain and inappropriate surgery or rehabilitation. In this project we developed a prototype database platform for combining and sharing biomechanics datasets. The database includes methods for importing and standardising data and associated variables, to create a seamless, searchable combined dataset of both healthy and knee OA biomechanics. Methods. Data was curated through calls to members of the OATech Network+ (. https://www.oatechnetwork.org/. ). The requirements were 3D motion capture data from previous studies that related to analysing the biomechanics of knee OA, including participants with OA at any stage of progression plus healthy controls. As a minimum we required kinematic data of the lower limbs, plus associated kinetic data (i.e. ground reaction forces). Any additional, complementary data such as EMG could also be provided. Relevant ethical approvals had to be in place that allowed re-use of the data for other research purposes. The datasets were uploaded to a University hosted cloud platform. The database platform was developed using Javascript and hosted on a Windows server, located and managed within the department. Results. Three independent datasets were curated following the call to OATech Network+ members. These originated from separate studies collected from biomechanics labs at Cardiff University, Keele University, and Imperial College London. Participants with knee OA were at various stages of progression and all datasets included healthy controls. The total sample size of the three datasets is n=244, split approximately equally between healthy and knee OA participants. Naming conventions and formatting of the exported data varied greatly across datasets. Datasets were therefore formatted into a common format prior to upload, with guidelines developed for future contributions. Uploading data at the marker set level was too complicated for combination at the prototype stage. Therefore, processed variables relating to joint angles and joint moments were used. The resulting prototype database included an import function to align and standardise variables. A a simple query tool was further developed to extract outputs from the database, along with a suitable user interface for basic data exploration. Conclusion. Combining biomechanics dataset presents a wide range of challenges from both a technical and data governance context. Here we have taken the first steps to demonstrate a proof-of-concept that can combine heterogenous data from independent OA-related biomechanics studies into a combined, searchable resource. Expanding this in the future to a fully open access database will create an essential resource that will facilitate the application of data-driven models and analyses for better understanding, stratification and prediction of OA progression. 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

Introduction and Objective. Bone remodelling is a continuous process whereby osteocytes regulate the activity of osteoblasts and osteoclasts to repair loading-induced microdamage. While many in vitro studies have established the role of paracrine factors (e.g., RANKL/OPG) and cellular pathways involved in bone homeostasis, these techniques are generally limited to two-dimensional cell culture, which neglects the role of the native extracellular matrix in maintaining the phenotype of osteocyte. Recently, ex vivo models have been used to understand cell physiology and mechanobiology in the presence of the native matrix. Such approaches could be applicable to study the mechanisms of bone repair, whilst also enabling exploration of biomechanical cues. However, to date an ex vivo model of bone remodelling in cortical bone has not been developed. In this study, the objective was to develop an ex vivo model where cortical bone was subjected to cyclic strains to study the remodelling of bone. Materials and Methods. Ex vivo model of bone remodelling induced by cyclic loading: At the day of culling, beam-shape bovine bone samples were cut and preserved in PBS + 5% Pen/Strep + 2 mM L-Glut overnight at 37°C. Cyclic strains were applied with a three-point bend system to induce damage with a regime at 16.66 mm/min for 5,000 cycles in sterile PBS in Evolve® bags (maximum strain 6%). A control group was cultured under static conditions. Metabolic activity: Alamar Blue assays were performed after 1 and 7 days of ex vivo culture for each group (Static, Loaded) and normalized to weight. Bone remodelling: ALP activity was assessed in the media at day 1 and 7. After 24 hours cell culture conditioned media (CM) was collected from each group and stored at −80°C. RAW264.7 cells were cultured with CM for 6 days, after which the samples were stained for TRAP, to determine osteoclastogenesis, and imaged. Histomorphometry: Samples were cultured with calcein for 3 days to label bone formation between day 4 and 7. Fluorescent images were captured at day 7. μCT scanning was performed at 3 μm resolution after labelling samples with BaSO. 4. precipitate to quantify bone damage. Results. Bone was sectioned and cultured to maintain live osteoblasts and osteocytes. CM that was obtained 24 hours after cyclic loading and added to RAW264.7 cells cultures, resulted in significantly increased osteoclastogenic potential compared to that from static samples (4.245±1.65% vs 0.88±0.48%, p<0.001). Calcein and HE staining indicated the presence of structures similar to bone remodelling cones in both groups after 7 days of culture. Also, 7 days post-loading, matrix microdamage in the stimulated area, detected with the BaSO. 4. precipitate, were not significantly increased under the load point in loaded samples (0.11±0.05% of bone volume), while at the support areas it was significantly higher (0.2387±0.06%, p<0.001) compared to the static (0.062±0.02%). Conclusions. This study demonstrates that (1) cyclic strains applied on ex vivo bovine cortical bone successfully induced remodelling as characterized by the formation of bone resorption cones, along with an increase of osteoclast formation, and (2) there was an induction of microdamage post loading as shown by the significant increases in microdamage labelled. This supports previous in vivo studies with an increase in osteoclastogenesis up to 7 days post loading. This is the first evidence of the development of an ex vivo model to study osteon remodelling that could be applied to study bone physiology and repair

Abstract. Objectives. Musculoskeletal injuries are the leading contributor to disability globally, yet current treatments do not offer complete restoration of the tissue. This has resulted in the exploration of novel interventions based on tissue engineering as a therapeutic solution. This study aimed to explore novel collagen sponges as scaffolds for bone tissue engineering as an initial step in the construction of tendon-bone co-culture constructs in vitro. Methods. Collagen sponges (Jellagen, UK), manufactured from Jellyfish collagen were seeded with 10,000 rat osteoblast cells (dROBs) and maintained in culture for 6 days (37°C, 5% CO. 2. ). Qualitative viability was assessed by a fluorescent Calcein-AM live cell stain and quantitively via the CYQUANT cell viability assay (Invitrogen, UK) on days 0, 1, 4 and 6 in culture (n=3 per time point). Digital imaging was also used to assess size and shape changes to the collagen sponge in culture. Results. The collagen sponge biomaterial supported dROB adhesion, viability and proliferation with an abundance of viable cells detected by fluorescent microscopy on day 6. Indeed, the quantitative assessment confirmed that cellular proliferation was evident with increases in fluorescence detected from 517 (± 88) RFU to 8730 ± (2228) RFU from day 0 to 6. In addition, the size of the collagen sponges appeared to decrease over time, indicating contraction of the collagen sponges in culture. Conclusions. This preliminary study has demonstrated that the novel collagen sponges support cellular attachment and proliferation of osteoblasts, and is an important first step in building a bone-tendon construct in vitro. Our future work is focussed on using the osteoblast-seeded sponges in combination with tendon cells, to build a co-culture to represent the bone-tendon interface in vitro. This work has the potential to advance the clinical translation of tissue-engineered tendons to the clinic. 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

Background. Despite arthroscopy being the gold standard for long head of biceps pathology, the literature is seemingly lacking in any critical appraisal or validation to support its use. The aim of this study was to evaluate its appropriateness as a benchmark for diagnosis. The objectives were to evaluate whether the length of the tendon examined at arthroscopy allows visualisation of areas of predilection of pathology and also to determine the rates of missed diagnoses when compared to an open approach. Methods. A systematic review of cadaveric and clinical studies was performed. The search strategy was applied to Medline, PubMed and Google Scholar databases. All relevant articles were included. Critical appraisal of clinical studies was performed using a validated quality assessment scale. Results. Six articles were identified for inclusion in the review. This included both clinical and cadaveric studies. The overall population comprised 25 cadaveric specimens and 575 patients. Cadaveric studies showed that the use of a hook probe allowed arthroscopic visualisation of between 28% and 48% of the overall length of the LHB. In the clinical series the rate of missed diagnoses at arthroscopy when compared to open exploration ranged between 33% and 49%. Conclusions. The standard technique of pulling the LHB tendon into the joint at glenohumeral arthroscopy provides only limited excursion and does not allow visualisation of areas of predilection of pathology. This is confirmed by an extremely high rate of missed diagnoses when comparing arthroscopy to open exploration. It is important that clinicians recognise that a “normal” arthroscopic examination of the LHB tendon does not exclude pathology and that published literature reporting sensitivities and specificities for physical examination and imaging tests based on arthroscopy as a gold standard are invalid. Level of evidence. IIa – systematic review of cohort studies. Conflict of Interests. The authors confirm that they have no relevant financial disclosures or conflicts of interest. Ethical approval was not sought as this was a systematic review

The treatment of extremity ballistic injury is challenging in that the zone of injury can be extensive and determining the surgical exposure can be difficult. We describe a method of pre-operative evaluation of the zone of injury in conjunction with the regional anesthesiologist utilizing ultrasound to determine the presence of nerve disruption. This non-invasive method of examination may elucidate whether significant nerve exists and may also serve to pinpoint the location of injury. Such information allows the surgeon to more effectively and efficiently surgically expose the zone of injury and understand the boundaries of the nerve outside the zone of injury. Moreover, such preoperative evaluation may at times obviate the need for exploratory surgery at all. It is important for the anesthesiologist and surgeon to work together with respect to the ability to both interpret the ultrasound images and to clinically correlate the findings. The zone of tissue disruption in ballistic injuries is extremely variable. It is beneficial to both the surgeon and patient to engage in a collaborative effort with an experienced regional anesthesiologist who is well-versed in interpretation of ultrasound images and tissue plane disruption in an effort to minimize surgical time and the potential unintended consequences of unnecessary exploration. We present a series of cases representing instances wherein the zone of injury was small, extensive, and a unique situation in which there was in fact no injury present despite clinical symptoms and MRI consistent with radial nerve disruption

All types of regenerative materials, including metal implants, porous scaffolds and cell-laden hydrogels, interact with the living tissue and cells. Such interaction is key to the settlement and regenerative outcomes of the biomaterials. Notably, the immune reactions from the host body crucially mediate the tissue-biomaterials interactions. Macrophages (as well as monocytes and neutrophils), traditionally best known as defenders, accumulate at the tissue-biomaterials interface and secrete abundant cytokines to create a microenvironment that benefits or inhibits regeneration. Because the phenotype of these cells is highly plastic in response to varying stimuli, it may be feasible to manipulate their activity at the interface and harness their power to mediate bone regeneration. Towards this goal, our team have been working on macrophage-driven bone regeneration in two aspects. First, targeting the abundant, glucan/mannan-recognising receptors on macrophages, we have devised a series of glucomannan polymers that can stimulate macrophages to secrete pro-osteogenic cytokines, and applied them as coating polymer of mesenchymal stem cells-laden hydrogels. Second, targeting the toll-like receptors (TLRs) on macrophages, we have screened TLR-activating polysaccharides and picked up zymosan (beta-glucan) to be modified onto titanium and glass implants. We evaluated both the efficacy of integration and safety of immune stimulation in both in vitro and in vivo models. Our future exploration lies in further elaborating the different roles and mechanisms of macrophages of various types and origins in the regenerative process

Mesenchymal stem cells (MSC) have a well recognised potential for tissue repair. This potential is two pronged: they can differentiate into the functional cell types of the damaged tissues and they can support tissue recovery by secreting trophic factors, depositing an extracellular matrix (ECM) and dampening inflammation. Three-dimensional microscopy recently shown that MSCs in the bone marrow create an intricate proteo-cellular scaffold with the ECM forming an interconnected cellular continuum whose structure is guided by the deposited ECM. This proteo-cellular scaffold controls bone marrow functions from hematopoiesis to osteogenesis. In the current study we aimed to optimise ECM production under in vitro conditions by immortalised MSCs with the view that the generated ECM can be utilised for tissue repair. With immunocytochemistry we determined the deposition of bone marrow-characteristic ECM proteins: collagen I, III, IV, V, VI, laminin and fibronectin. While primary MSCs produced slightly higher amount ECM proteins than immortalised MSCs, the relative abundancy of the ECM proteins was very similar. In order to isolate the ECM, we optimised a decellularisation method based on gentle lysis with sodium-deoxycholate and DNase digestion. Immunostaining for collagen I, III, VI and fibronectin and labelling the nuclei with Hoechst-33342 confirmed removal of all cells while retaining the ECM in its original architecture. Ideally, the decellularised ECM retains associated cytokines and chemokines, such as CXCL12, important for attracting MSCs. To test this, we seeded Molm-13 leukemia cells on decellularised ECM as MSC-produced CXCL12- and other cytokines protect leukemia cells against chemotherapeutics. We found that the decellularisation process however removed these factors and thus for therapeutic purposes, the decellularised ECM would need to be re-loaded with the essential chemo/cytokines. Overall, we developed a system for decellularised ECM production by immortalised MSCs and the results warrant further exploration of this avenue

Aims

This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with iron overload, and also explore the role of VIT in osteoblast and osteoclast differentiation.

Background. Multiple randomised controlled trials have demonstrated that arthroscopy provides little benefit in patients with knee osteoarthritis. In 2008, NICE released guidelines to reflect this evidence. Implementation has been sporadic, and arthroscopy for knee osteoarthritis is commonly performed with an annual incidence of 9.9 per 10,000 in England. Our aim was to establish whether previous arthroscopy affects Patient Reported Outcome Measures (PROMs) in Total Knee Replacement (TKR) patients. Methods. Data was retrospectively collected from 2010–2012 from a University hospital. Pre-operative and one-year post-operative PROMs were collected on patients who had undergone arthroscopy and then TKR, or only TKR. The change in PROMs score over TKR was then compared between groups. Results. Complete data was available for 85 patients: 36 had arthroscopy prior to TKR, with 49 receiving only TKR. There was no difference between the groups with regard to age and gender. Oxford Knee Score (OKS) before TKR for both groups were similar (arthroscopy group 41.9, non-arthroscopy 40.8). At arthroscopy 81% of patients had grade IV arthritis, with 19% demonstrating grade III. Patients who had arthroscopy before TKR had a worse response to TKR compared to those who did not have an arthroscopy (respective mean change of 23.79%, 38.4%, p< 0.001). Conclusions. Although this exploratory study is small and subject to selection bias, our data suggest that arthroscopy may have a detrimental effect on patient function after TKR. This may be due to psychological factors, as there is growing evidence to suggest stress and anxiety negatively affect PROMs4. Medicalisation of patients through arthroscopic procedures may contribute to poor PROMs. This study offers a potential pre-operative factor that may explain some of the variability in outcome seen with TKR. This relationship requires confirmation and exploration in larger studies with correction for confounding factors. Level of evidence. III

Background. The two-stage revision strategy has been claimed as being the “gold standard” for treating prosthetic joint infection. The one-stage revision strategy remains an attractive alternative option, however, its effectiveness in comparison to the two-stage strategy remains uncertain. A systematic review and meta-analysis was conducted to compare the effectiveness of one- and two-stage revision strategies to prevent re-infection after prosthetic hip infection. Methods. Cohort studies (prospective or retrospective) conducted in unselected patients with infection treated exclusively by one- or two-stage revision and reporting re-infection outcomes within two years of revision were retrieved from MEDLINE, EMBASE, Web of Science, Cochrane databases, manual search of bibliographies to March 2015, and email contact with investigators. Data were extracted by two independent investigators and a consensus was reached with involvement of a third. Rates of re-infection were aggregated using random-effect models after arcsine transformation, and were grouped by study and population level characteristics. Results. In 38 one-stage studies, the rate (95% confidence intervals) of re-infection was 8.2% (6.0–10.8). The corresponding re-infection rate for 60 two-stage studies was 7.9% (6.2–9.7). Re-infection rates remained generally similar when grouped by several study and population level characteristics. There was no evidence of publication bias among contributing studies. Conclusion. Among unselected populations, evidence from aggregate published data suggest similar re-infection rates after one- or two-stage revision. More detailed analyses under a broader range of circumstances and exploration of other sources of heterogeneity will require collaborative pooling of individual participant data, which is ongoing within our Global Infection Orthopaedic Management (INFORM) collaboration. Level of evidence. Level 2a - Systematic reviews of cohort studies. Funding statement. This abstract presents independent research funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research scheme (grant number: RP-PG-1210-12005). The views expressed in this abstract are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health

This case series highlights the use of the Ganz approach and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chrondromatosis of the hip, which has never been described for use with all three tumours together. These are rare benign tumours, which were found incidentally and required excision. We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum allowing easy inspection, exploration and debridement of these three tumours of the hip

Demographics changes and the increasing incidence of metastatic bone disease are driving the significant issues of vertebral body (VB) fractures as an important consideration in the quality of life of the elderly. Whilst osteoporotic vertebral fractures have been widely studies both clinically and biomechanically, those fractures arising from metastatic infiltration in the spine are relatively poorly understood. Biomechanical in-vitro assessment of these structurally weaker specimens is an important methodology for gaining an understanding of the mechanics of such fractures in which a key aspect is the development of methodologies for predicting the failure load. Here we report on a method to predict the vertebral strength by combining computed tomography assessment with an engineering beam theory as an alternative to more complex finite element analyses and its verification within a laboratory scenario. Ninety-two human vertebral bodies with 3 different pathologies: osteoporosis, multiple myeloma (MM) and specimens containing cancer metastases were loaded using a define protocol and the failure loads recorded. Analysis of the resulting data demonstrated that the mean difference between predicted and experimental failure loads was 0.25kN, 0.41kN and 0.79 kN, with adjunct correlation coefficients of 0.93, 0.64 and 0.79 for osteoporotic, metastatic and MM VBs, respectively. Issues in predicting vertebral fracture arise from extra-vertebral bony formations which add to vertebral strength in osteoporotic VB but are structurally incompetent in metastatic disease. The methodology is currently used in providing better experimental design/benchmarking within in-vitro investigations together with further exploration of its utility in the clinical arena

Current knowledge regarding upper limb myotomes is based on historic papers. Recent advances in magnetic resonance imaging (MRI) and surgical exploration with intraoperative nerve stimulation now allow accurate identification of nerve root injuries in the brachial plexus. The aim of this study is to identify the myotome values of the upper limb associated with defined supraclvicular brachial plexus injuries. 57 patients with partial supraclavicular brachial plexus injuries were identified from the Scottish brachial plexus database. The average age was 28 years and most injuries secondary to motor cycle accidents or stabbings. The operative and MRI findings for each patient were checked to establish the root injuries and the muscle powers of the upper limb documented. The main patterns of injuries identified involved (C5,6), (C5,6,7), (C5,6,7,8) and (C8, T1). C5, 6 injuries were associated with loss of shoulder abduction, external rotation and elbow flexion. In 30% of the 16 cases showed some biceps action from the C7 root. C5,6,7 injuries showed a similar pattern of weakness with the additional loss of flexor carpi radialis and weakness but not total paralysis of triceps in 85% of cases. C5,6,7,8 injuries were characterised by loss of pectoralis major, lattisimus dorsi, triceps, wrist extension, finger extension and as well as weakness of the ulnar intrinsic muscles. We identified weakness of the flexor digitorum profundus to the ulnar sided digits in 83% of cases. T1 has a major input to innervation of flexors of the radial digits and thumb, as well as intrinsics. This is the largest study of myotome values in patients with surgically or radiologically confirmed injuries in the literature and presents information for general orthopaedic surgeons dealing with trauma patients for the differentiation of different patterns of brachial plexus injuries. In addition we have identified new anatomical relationships not previously described in upper limb myotomes

Purpose of study. To explore the clinical reasoning strategies used by extended scope physiotherapists (ESPs) when assessing patients with low back pain. Background. Extended scope physiotherapists commonly work in back pain services and their training emphasises the acquisition of clinical skills and possible diagnostic tests (including MRI) to aid clinical reasoning and diagnosis. Whilst there has been some exploration of reasoning strategies of other professional groups (notably medically qualified) to date, the clinical reasoning strategies of ESP clinicians have not been reported. Methods. A qualitative study, with three focus groups, explored clinical reasoning by ESPs and non-ESPs, to compare how these clinicians assess patients' with back pain. This informed a second study, using a ‘think-aloud’ technique with 10 participants from four NHS sites, examining their reasoning strategies, immediately after completing initial consultations. Analysis was informed by a grounded theory approach. Results. Themes identified relating to clinical reasoning were prior thinking, patient interaction, gut-feeling, and formal testing. The differences in practice between ESP and non-ESP appeared to be driven by differences in accountability, safety and external influences. A key difference between the accounts of clinical reasoning provided by ESPs and non-ESPs centred on the role and appropriateness of ‘gut feeling’ in diagnostic decision making. The analysis explores the apparent tension between this instinctive contribution to reasoning and evidence-based practice. The paper explores the legitimacy of gut feeling. Conclusions. Extended scope physiotherapists appear to employ different clinical reasoning strategies to their non-ESP colleagues, highlighting the additional burden of responsibility and tension created by the use of gut feeling. No conflicts of interest. No funding obtained. This abstract has not been previously published in whole or in part; nor has it been presented previously at a national meeting