Aims

The aims of this study were to describe the epidemiology of metacarpal shaft fractures (MSFs), assess variation in treatment and complications following standard care, document hospital resource use, and explore factors associated with treatment modality.

Purpose and background. Cauda Equina Syndrome (CES), a rare (<1 per 100,000) and potentially devasting condition, involves compression of the lumbosacral nerve roots. If not quickly identified and treated, it can lead to lasting disability, and high medicolegal costs (>£186 million in the decade to 2018). This study identified why people with suspected CES attend the emergency department (ED) and explored any delays in attending. Methods and Results. The design was a secondary analysis of a qualitative dataset comprising patients with back pain who attended the ED, undertaken using an interpretivist approach. Fourteen patients (8M:6F, aged 23–63 years) with suspected CES were purposively sampled from 4 EDs (2 Northern and 2 Southern) in England between August and December 2021. Semi-structured interviews were conducted online, audio-recorded, transcribed verbatim and analysed thematically. Acopia with pain was the biggest factor in a participant's decision to attend the ED, along with the need for a diagnosis. This pain was the worst ever experienced and debilitating, leaving people unable to cope and desperate for relief. 12/14 were advised to attend the ED following identification of red flags by: GPs (n=9); physiotherapists (n=2); surgical colleague (n=1); and 111 (n=1). Factors such as guilt, previous experience of being disregarded, and symptom misattribution were seen to cause delays in seeking care. Conclusion. This paper revealed a disconnect between the priorities of patients and clinicians prior to attending the ED. Clinicians need to validate the pain experience, communicate clearly why signs and symptoms are concerning, and convey the urgency and potential impact of CES. Conflicts of interest. None. Sources of funding. Funding for primary data: Health Education England & National. Institute of Health and Care Research (ICA-CDRF-2018-04-ST2-040)

Background. Mobile apps have shown promise in helping people to self-manage conditions like chronic low back pain (CLBP). However, it is unclear who benefits most, why, and under what circumstances. This limits our understanding of how to maximize the potential of mobile app technology. Aim. This study aimed to test and refine programme theories about how mobile apps support people to self-manage CLBP in a real-world setting. The theories were based on a previously published realist review. Methods. A realist evaluation was conducted using one-to-one realist interviews by telephone with participants who had used the Curable app to self-manage their CLBP for three months. The interviews were guided by programme theories from the realist review. Analysis of the interviews used abductive and retroductive logic to create chains of inferences, which were then developed into context-mechanism-outcome configurations (CMOCs). These CMOCs offered causal explanations about who might benefit from a mobile app to self-manage CLBP, why and in what circumstances. Results. Ten interviews were conducted (nine with people with CLBP who trialled the app and one with a founding member of Curable LLC). Twenty CMOCs were created that identified key mechanisms such as agency, control and reassurance that interact with contextual factors such as acceptance, internal capacity, and a biopsychosocial approach to pain management. These factors influence whether a person with CLBP will benefit from a mobile app for self-management. Conclusions. Twenty CMOCs were created to support three programme theories centering around concepts of empowerment, burden of care, and timing. Conflicts of interest. None. Sources of funding. R Hunter's work was supported by the Inverness and Highland City-Region Deal Studentship Award [2018]. Presented at: 13th Congress of the European Pain Federation (EFIC), September 2023, Budapest, Hungary

Purpose and Background

Clinical practice guidelines (CPGs) recommend self-management for low back pain (LBP). Our recent narrative review on self-management needs revealed a consensus with respect to the critical components of self-management interventions. With mobile health advancements, apps offer innovative support for LBP management. This study aims to identify current apps for the self-management of LBP, assessing them for their quality, intervention content, theoretical approaches, and risk management approaches.

Purpose and background. Low back pain (LBP), a leading cause of chronic disability, is associated with high and disproportionate socioeconomic costs. Clinical assessment and triage via the NHS 111 service aims to reduce pressure on the urgent and emergency care system. Studies show that many attend the emergency department (ED) against advice, when they could be better managed elsewhere. The aim of this research was to explore how patients with LBP perceive and interact with NHS 111, and how this may have influenced their decision to attend ED. Methods and Results. This was a secondary analysis of a cross-sectional, qualitative dataset of 47 patients (26M:21F, aged 23–79 years) purposively sampled with LBP, who attended 1 of 4 EDs in the UK in 2021, (during the pandemic). The participants took part in online, semi-structured interviews, mean duration 45-minutes (range 23–156 minutes), within six weeks of their ED visit. The interviews were audio-recorded, transcribed verbatim and thematically analysed. Three key themes were identified: purpose, process and performance. The themes showed mixed understanding and low awareness of the purpose of NHS 111, despite its strong triage role. Long waits for call backs however, sometimes resulted in patients attending ED, along with previous negative perspectives and experiences. Conclusion. This research suggests enhanced visibility and knowledge of NHS 111 would increase its use by people with LBP. Further exploration comparing outcomes of callers to NHS 111 with those who seek care elsewhere, could help evaluate how NHS 111 can best help people with LBP and prevent unnecessary ED attendance. No conflicts of interest.  . Sources of funding. Funding for primary data: Health Education England & National Institute of Health and Care Research (ICA-CDRF-2018-04-ST2-040)

Purpose/Background. Health inequalities are defined as unfair and avoidable differences in health across the population. People belonging to inclusion health groups are most at risk of experiencing these inequalities and tackling them is an NHS priority. Inclusion health groups include ‘people in contact with the justice system’ and BCHC NHS FT is commissioned to provide physiotherapy to prisoners at HMP Birmingham. The purpose of this study was to better understand the MSK health-status and MSK conditions affecting this minoritised patient population. Methods/Results. The MSK service at HMP Birmingham collects the MSK-HQ PROM for all prisoners attending physiotherapy. A retrospective analysis of the electronic patient record was performed using convenience sampling, with baseline MSK-HQ scores of prisoners seen between 01/04/2023 and 01/02/2024 captured alongside the primary presenting MSK condition. Simple descriptive statistics were used to evaluate the data. A total of 129 patients attended initial physiotherapy appointments within the time-period. Baseline MSK-HQ was collected for 62 patients (48%) with a mean (SD) score of 23.08(11.38). The most common MSK condition was Back pain with a count of 12(19.35%). The mean (SD) MSK-HQ score for prisoners with back pain was 22.08(9.98). Conclusion. This is the first known evaluation in the published literature of the baseline MSK health-status and primary MSK conditions affecting prisoners. A published evaluation of baseline MSK health-status for patients attending a community MSK service reported a mean (SD) MSK-HQ of 28.59(10.80) indicating that, a poorer MSK health-status is experienced by this minoritised group. Further work, co-produced with prisoners, is planned to explore further. Conflicts of interest. None. Sources of funding. None

Purpose and background of the study. Self-management and behaviour change is at the core of back pain management. Despite the high-rate of recurrence and healthcare utilisation, clinical guidelines do not include guidance for clinicians on return consultations. This project aimed to identify primary care clinicians’ reported practices and experiences of delivering self-management advice for people returning with persistent low back pain (LBP), to inform future delivery of self-management care. Methods and Results. In this qualitative study involving 27 primary care clinicians, four focus groups and two semi-structure interviews were conducted online. GPs (n=5) and physiotherapists working in primary care roles (First contact practitioners n=7, community and interface roles n=7, and mixed roles n=8) in England and Scotland shared their experience of delivering self-management advice to people returning with persistent LBP. Video recordings were transcribed verbatim and analysed with reflexive thematic analysis. Clinicians unanimously shared their frustrations identifying the challenges involved in supporting people who return with LBP. Helpful strategies to support self-management in return consultations were identified by clinicians in addition to service and system-level changes vital to optimise care. Patient-factors affecting delivery of care, lack of defined responsibility and challenges in meeting patients’ expectations illustrated the tensions that exist in return consultations. Conclusion. This novel study provides insight into the experiences and practices of the frontline primary care workforce seeing patients return with persistent or recurrent LBP. It identifies the tensions that exist between services, professional roles and between clinicians and patients regarding self-management. Important practice implications have been identified to improve information-sharing, agenda-setting, and exploring expectations. No conflicts of interest.  . Source of funding. Lisa Osborn-Jenkins is funded by University Hospital Southampton NHS Foundation Trust (UHS) Research & Development PhD Fellowship [GRT0723]

Objectives. Understanding lumbar facet joint involvement and biomechanical changes post spinal fusion is limited. This study aimed to establish an in vitro model assessing mechanical effects of fusion on human lumbar facet joints, employing synchronized motion, pressure, and stiffness analysis. Methods and Results. Seven human lumbar spinal units (age 54 to 92, ethics 15/YH/0096) underwent fusion via a partial nucleotomy model mimicking a lateral cage approach with PMMA cement injection. Mechanical testing pre and post-fusion included measuring compressive displacement and load, local motion capture, and pressure mapping at the facet joints. pQCT imaging (82 microns isotropic) was carried out at each stage to assess the integrity of the vertebral endplates and quantify the amount of cement injected. Before fusion, relative facet joint displacement (6.5 ± 4.1 mm) at maximum load (1.1 kN) exceeded crosshead displacement (3.9 ± 1.5 mm), with loads transferred across both facet joints. After fusion, facet displacement (2.0 ± 1.2 mm) reduced compared to pre-fusion, as was the crosshead displacement (2.2 ± 0.6 mm). Post-fusion loads (71.4 ± 73.2 N) transferred were reduced compared to pre-fusion levels (194.5 ± 125.4 N). Analysis of CT images showed no endplate damage post-fusion, whilst the IVD tissue: cement volume ratio did not correlate with the post-fusion behaviour of the specimens. Conclusion. An in vitro model showed significant facet movement reduction with stand-alone interbody cage placement. This technique identifies changes in facet movement post-fusion, potentially contributing to subsequent spinal degeneration, highlighting its utility in biomechanical assessment. Conflicts of interest. None. Sources of funding. This work was funded by EPSRC, under grant EP/W015617/1

Background. Trunk muscles play an important role in supporting the spinal column. A decline in trunk muscle mass, as measured by bioelectrical impedance analysis (TMM–BIA), is associated with low back pain and poor quality of life. Purpose. The purpose of this study was to determine whether TMM–BIA correlates with quantitative and functional assessments traditionally used for the trunk muscles. Methods. We included 380 participants (aged ≥ 65 years; 152 males, 228 females) from the Shiraniwa Elderly Cohort (Shiraniwa) study, for whom the following data were available: TMM–BIA, lumbar magnetic resonance imaging (MRI), and back muscle strength (BMS). We measured the cross-sectional area (CSA) and fat-free CSA of the paravertebral muscles (PVM), including the erector spinae (ES), multifidus (MF), and psoas major (PM), on an axial lumbar MRI at L3/4. The correlation between TMM–BIA and the CSA of PVM, fat-free CSA of PVM, and BMS was investigated. Results. TMMBIA correlated with the CSA of total PVM and each individual PVM. A stronger correlation between TMM–BIA and fat-free CSA of PVM was observed. The TMM–BIA also strongly correlated with BMS. Conclusion. TMM–BIA is an easy and reliable way to evaluate the trunk muscle mass in a clinical setting. Conflict of interest. None. Sources of funding. None

Background. Disability is an important multifaceted construct. The aim of this study was to develop and evaluate a brief, generic self-reported disability questionnaire: the Universal Disability Index (UDI). Methods. Convenience sampling was used to collect general population data via an online survey. Data were randomly divided into training and validation subsets. The dimensionality and structure of eight UDI questionnaire items were evaluated using exploratory factor analysis (EFA, training subset) followed by confirmatory factor analysis (CFA, validation subset). To assess concurrent validity, the UDI summed score from the full dataset was compared to the Groningen Activity Restriction Scale (GARS) and the Graded Chronic Pain Scale (GCPS) disability scores. Internal consistency was also assessed. Results. 403 participants enrolled; 364 completed at least one UDI item. Three single-factor versions of the UDI were assessed (8-item, 7-item, and 6-item). All versions performed well during EFA and CFA (182 cases assigned to each), but none met the RMSEA (Root Mean Square Error of Approximation) criterion (≤ 0.08). All versions of the UDI had high internal consistency (Cronbach's α > 0.90) and were strongly correlated (Pearson's r > 0.7) with both GARS and GCPS disability scores, indicating concurrent validity. Conclusions. A brief, generic self-reported disability questionnaire was found to be valid and to possess good psychometric properties. The UDI has a single factor structure and either a 6-item, 7-item or 8-item version can be used to measure disability. For brevity and parsimony, the 6-item UDI is recommended, but further testing of all versions is warranted. Conflicts of interest. No conflicts of interest. Sources of funding. No funding obtained

Background. A local authority approached us, for a cost-beneficial solution to their increasing low back pain referrals. We proposed developing a student-led clinic – an intervention delivered by students but supervised by clinicians. We then conducted scoping reviews on student-led clinics in the management of health conditions and on the self-management of back pain. The findings suggested that student-led self-management interventions for low back health should be feasible. The next step was to co-construct the intervention with key stakeholders. Co-Construction. A hybrid of Action Research and Design Science methodology was used to co-construct the intervention with five key stakeholder groups (council staff, managers and human resources, employee healthcare, students, and lecturers). Three rounds of focus groups explored the ‘problem’, the possible solutions, the process, and the content. Themes were taken from each of these focus groups and the similarities and differences were analysed. This analysis and subsequent synthesis with the evidence base created potential intervention models, which were discussed and refined with the stakeholder groups. Intervention. The proposed intervention is focused on providing evidence informed biopsychosocial support for work-relevant back pain, based on identifying obstacles and solutions to improve coping with back health at work. An onboarding workshop challenges positively their thinking around back pain and work. This is followed by up to three 1:1 sessions that support the individual to identify work-relevant back health goals and agree a plan to achieve them using techniques to facilitate behaviour change. Conclusion. The intervention is evidence informed and aims to address the prioritised needs of the stakeholders. Conflicts of interest. No conflicts of interest. Sources of funding. National Health Service Education

Purpose and background. Nearly 70% of UK physiotherapists experience work-related musculoskeletal disorders (WRMSDs) during their career, with a significant proportion occurring in the back and being attributed to patient handling tasks. Evidence suggests that manual handling training alone is ineffective and interventions among nurses indicate that a tailored approach, including targeted exercise (TE), can reduce WRMSD rates. This study aimed to explore physiotherapists’ perspectives of WRMSDs, patient handling, and the role of TE in reducing WRMSDs among physiotherapists. Methods and Results. Key informant interviews were conducted with 4 physiotherapy operational leads and 1 manual handling trainer from NHS Grampian. Interviews were transcribed and Framework Analysis was utilised to identify key themes, including challenges, barriers, and facilitators. Following this, two online focus groups were conducted with 7 qualified NHS physiotherapists across the UK. Views of manual handling training varied across specialities, with some finding it comprehensive and adaptable, and others finding it less applicable to patients in their speciality or community setting. Physiotherapist views on fitness for work varied, with some highlighting the necessity of TE to ensure workforce health whilst others considered exercise to be a personal matter. Facilitators to implementation identified by participants were having support from management and a strong justification for the exercise content. Varied work schedules and facilities were identified as barriers to implementation of a work-based TE intervention. Conclusion. Varying perspectives on TE interventions and barriers to implementation were identified. This work will inform future research to develop TE interventions in consultation with key stakeholders. Conflicts of Interest. No conflicts of interest. Source of Funding. NHS Endowment Research Grant 22/001

Purpose and Background. Work-related musculoskeletal disorders (WRMSD) can affect 56–80% of physiotherapists. Patient handling is reported as a significant risk factor for developing WRMSD with the back most frequently injured. Physiotherapists perform therapeutic handling to manually assist and facilitate patients’ movement to aid rehabilitation, which can increase physiotherapists risk of experiencing high forces during patient handling. Methods and Results. A descriptive cross-sectional study was completed to explore and quantitatively measure the movement of ten physiotherapists during patient handling, over one working day, in a neurological setting. A wearable 3-dimensional motion analysis system, Xsens (Movella, Henderson, NV), was used to measure physiotherapist movement and postures in the ward setting during patient treatment sessions. The resulting joint angles were reported descriptively and compared against a frequently used ergonomic assessment tool, the Rapid Upper Limb Assessment (RULA). Physiotherapists adopted four main positions during patient handling tasks: 1) kneeling; 2) half-kneeling; 3) standing; and 4) sitting. Eight patient handling tasks were identified and described: 1) Lie-to-sit; 2) sit-to-lie; 3) sit-to-stand; facilitation of 4) upper limb; 5) lower limb; 6) trunk; and 7) standing treatments; and 8) walking facilitation. Kneeling and sitting positions demonstrated greater neck extension and greater lumbosacral flexion during treatments which scores highly with the RULA. Conclusion. This research identified that patient treatment tasks were more often performed in kneeling or sitting positions than standing. Current moving and handling guidance teaches moving and handling in a standing position; loading and stresses experienced by the physiotherapists may differ in sitting or kneeling positions. Conflicts of interest. None. Sources of funding. None. This work has been presented as a poster at the CSP conference Glasgow 2023

Purpose and background. Understanding patients’ expectations of back pain treatment can help improve their experiences, adherence and outcomes. Patients typically expect a diagnosis and exercise-based physiotherapy, but often undervalue the role of psychological factors. This study explored patients’ expectations of outpatient physiotherapy treatment for back pain in primary care. Methods and Results. The design, a secondary analysis of a qualitative cross-sectional study, involved 25 patients (13M:12F), aged 20–81, referred with low back pain (duration 7 weeks to 9 years). This sample did not include patients with serious spinal pathologies, known psychological disorders, or those unable to communicate without assistance. Face-to-face interviews were undertaken in patients’ homes, which were audio-recorded, transcribed verbatim and analysed using the six stages of thematic analysis outlined by Braun and Clarke. Patients expected a caring clinician and a strong therapeutic relationship, where they felt believed, openly communicated with and valued as an individual. Most patients expected a diagnosis and credible explanation for their pain. There was an almost equal split between those keen to take responsibility for their care and those who felt this was the clinicians’ role. Expectations of passive therapies were slightly higher in this study than existing research. Most patients were realistic about outcomes and expected treatment to reduce their pain, but not cure it. Conclusion. A positive experience mattered most to patients, valuing the relational aspects of their care more than the clinical content provided. Patients saw back pain through a biomedical lens, and most failed to recognise the role of psychosocial factors in their condition or treatment. Conflicts of interest. None. Sources of funding. Funding for primary data: Arthritis Research UK (now Versus Arthritis)

Background. Clinical guidelines recommend epidural steroid injection (ESI) for severe sciatica but there is uncertainty of effectiveness. The POiSE study aims to identify factors, routinely collected in clinical practice that predict outcome in patients who have ESI. This presentation describes characteristics and early clinical outcomes of POiSE participants. Methods. Prospective cohort study in 19 NHS spinal services in England, inviting patients with sciatica listed for an ESI. Participant baseline characteristics and 6-week follow-up outcomes are presented. Outcomes include pain intensity (0–10 NRS), disability (Oswestry Disability Index 0–100) and global change in symptoms. Results. Over 24 months, 693 patients were invited to participate and 353 (51%) completed baseline questionnaires. Mean (SD) age 49.0 years (14.4), 60% female, and 46% (n=101) of those in work had certified time-off for sciatica. Mean pain intensity was 7.2 (2.0) and 6.2 (2.7) for leg and back pain respectively and mean disability (ODI) was 46.5 (18). 60% (n=210) had leg pain for >6 months. Average confidence at baseline (0 to 10) that the ESI would help symptoms was 5.7 (2.4). Of 217 patients reaching 6-week follow-up, mean leg and back pain intensity is 5.0 (2.8) and 4.9 (2.9) respectively and ODI 36.6 (20.4), with 57% reporting improvement (completely recovered/much better/better). Follow-up data collection at 6, 12 and 24-weeks post-ESI is ongoing. Conclusion. Interim analysis shows only just over half of patients are reporting improvement at 6 weeks post ESI. The POiSE cohort study will help better identify the patients with sciatica who are most likely to benefit from this treatment. Conflicts of interest. None. Sources of funding. This study is supported by Health Education England and the National Institute for Health and Care Research (HEE/ NIHR ICA Programme Clinical Lectureship, Dr Siobhan Stynes, NIHR300441). The views expressed are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care

Study purpose and background. Kinematic variables have been identified as potential biomarkers for low back pain patients; however, an in-depth comparison between chronic (n=22), acute (n=15), and healthy controls (n=136) has not been done. This retrospective data analysis compared intervertebral lumbar motion parameters, angular range of motion, translation, maximum disc height, motion share inequality (MSI) and variability (MSV), and laxity, between these groups. Methods and results. Kinematic parameters were determined using video tracking techniques utilising quantitative fluoroscopy (QF), during both weight-bearing and recumbent controlled sagittal bending tasks. Data was analysed for normality, and appropriate statistical tests were applied to determine differences between groups. There were no significant differences between the groups for age, height, weight and sex. Whilst few differences were found between acute and healthy groups, differences were shown between both chronic and healthy, and acute and chronic groups for all six parameters. Of particular note were examples of differences in the motion share parameters between the acute and chronic populations, with an increased MSI in the chronic group during recumbent flexion, and MSV during recumbent extension, and inversely an increase in MSV in the acute group during weight-bearing flexion. Conclusion. Analysis of intervertebral lumbar motion provides valuable insights into kinematic differences between chronic, acute, and healthy control populations. These findings suggest that there is variation between the groups which is knowledge that may benefit management strategies. Further exploration of the time varying data is warranted to explore how such differences may relate to the motion share inequalities and variability shown. Conflicts of Interest. No conflicts of interest. Sources of Funding. No funding obtained

Purpose and Background. Guidelines recommend biopsychosocial care for chronic, complex musculoskeletal conditions, including non-specific low back pain. The aims were: 1/ to assess how patients with low back pain respond to osteopathic treatment, both before and after an osteopath has completed a Biopsychosocial Pain Management (BPM) course; and 2/ to assess if it is feasible and acceptable for osteopath participants to receive weekly SCED data and use it to guide patient management. Methods and Results. A multiple baseline single case experimental design trial (. clinicaltrials.gov. , on 18/10/2021, ID number NCT05120921) with 11 UK osteopaths was conducted. Patients were randomised to early, middle or late treatment start dates. Statistical analysis assessed the change between baseline, intervention and follow-up periods. Primary outcomes were the Numeric Pain Rating (NPR) and Patient Specific Function Scales (PSFS), measured during the baseline, the 6-week intervention, and during a 12-week follow-up period. At baseline, the osteopaths reported stronger biopsychosocial attitudes to pain, compared to biomedical beliefs (PABS: 34 behavioural scale; 29 biomedical scale). Overall, patient participants showed daily increases in symptoms during the pre-treatment phase (+0.24/day, p<0.001), and daily decreases during treatment (−2.94 over the treatment phase, p<0.001), which continued post-treatment (−3.36 over 12 weeks, p=0.04). Similar improvements were observed for function. Conclusion. Osteopathic care was shown to help patients with persistent low back pain. Patient recruitment was challenging because of the randomisation. With further development, the method shows feasibility as a means of enhancing research activity among practising clinicians. Previous presentations or publications of the work. The protocol was published (. https://doi.org/10.1016/j.ijosm.2023.100660. ) and presented at SBPR in 2022. The results were presented to an osteopathic conference in October 2023. Ethics approval was received from the University College of Osteopathy Research Ethics Committee. Conflicts of interests. Jerry Draper-Rodi receives fees from the sales of the e-learning course on the biopsychosocial management on the UCO CPD platform. Sources of funding. The research was funded by the Osteopathic Foundation

Background. Our current research aims to develop technologies to predict spinal loads in vivo using a combination of imaging and modelling methods. To ensure the project's success and inform future applications of the technology, we sought to understand the opinions and perspectives of patients and the public. Methods. A 90-minute public and patient involvement event was developed in collaboration with Exeter Science Centre and held on World Spine Day 2023. The event involved a brief introduction to the project goals followed by an interactive questionnaire to gauge the participants’ background knowledge and interest. The participants then discussed five topics: communication, future directions of the research, concerns about the research protocol, concerns about data, and interest in the project team and research process. A final questionnaire was used to determine their thoughts about the event. Results. Twelve adults attended the event, many motivated by their experience or interest in back pain. A thematic analysis was used to review participant comments on the research project, identifying the need to relate the research to everyday life, present risks in various ways, and be transparent about funding and data sharing. In terms of future applications, participants felt the technology should be used to understand normal spine behaviour, prevent problems, and improve treatment. Participants agreed that they had got something positive out of engaging in the event. Conclusion. Engagement with public and patient stakeholders is an essential activity that can generate vital information to inform and add value to technology development projects. Conflicts of interest. No conflicts of interest. Sources of funding. EPSRC grants EP/V036602/1 (Meakin, Holsgrove & Javadi) and EP/V032275/1 (Holt & Williams)

Aims

The aim of this study was to perform a systematic review and bias evaluation of the current literature to create an overview of risk factors for re-revision following revision total knee arthroplasty (rTKA).

Introduction. Multiple studies have identified Cutibacterium acnes (C.acnes) and other microbes in intervertebral disc tissue using 16S DNA Sequencing and microbial cultures. However, it remains unclear whether these bacteria are native to the discs or result from perioperative contamination. Our study aimed to detect Gram-positive bacteria in non-herniated human disc samples and explore correlations with Toll-like receptors (TLR) 2, TLR4, NLRP3, and Gasdermin D. Methods. Immunohistochemical staining was conducted on 75 human IVD samples for Gram-positive bacteria, S. aureus, C.acnes, TLR2, TLR4, NLRP3, and Gasdermin D. Cell detection and classification were performed using QuPath. NP cells were treated with Lipopolysaccharide (LPS) and Peptidoglycan (PGN) in monolayer and alginate beads for up to 72 hours, followed by secretome analysis using Luminex. Statistical analysis included Kruskal-Wallis, Dunn's multiple comparison test, and Pearson correlation. Results. Immunohistochemical staining revealed Gram-positive bacteria exclusively within cells, with C. acnes positivity ranging from 5–99% and correlating with patient age (r=0.41, p= 0.007). TLR2 positivity ranged from 5–99% and TLR4 from 3–72%, showing a strong correlation (r= 0.62, p= 1.5e-006). Females with mid-degenerative grades exhibited significantly decreased TLR2 expression compared to those without degeneration signs. Treatment with LPS and PGN increased catabolic cyto- and chemokines associated with IVD degeneration. Conclusion. In conclusion, this study confirms Gram-positive bacteria presence in non-herniated human disc samples and highlights their role in triggering a catabolic response in disc cells. No conflicts of interest.  . Sources of funding. This project is part of the Disc4All Training network to advance integrated computational simulations in translational medicine, applies to intervertebral disc degeneration and funded by Horizon 2020 (H2020-MSCA-ITN-ETN-2020 GA: 955735)