Aims. During revision procedures for aseptic reasons, there remains a suspicion that failure may have been the result of an undetected subclinical infection. However, there is little evidence available in the literature about unexpected positive results in presumed aseptic revision spine surgery. The aims of our study were to estimate the prevalence of unexpected positive culture using sonication and to evaluate clinical characteristics of these patients. Patients and Methods. All patients who underwent a revision surgery after instrumented spinal surgery at our institution between July 2014 and August 2016 with spinal implants submitted for sonication were retrospectively analyzed. Only revisions presumed as aseptic are included in the study. During the study period, 204 spinal revisions were performed for diagnoses other than infection. In 38 cases, sonication cultures were not obtained, leaving a study cohort of 166 cases. The mean age of the cohort was 61.5 years (. sd. 20.4) and there were 104 female patients. Results. Sonication cultures were positive in 75 cases (45.2%). Hardware failure was the most common indication for revision surgery and revealed a positive sonication culture in 26/75 cases (35%) followed by adjacent segment disease (ASD) in 23/75 cases (30%). Cutibacterium acnes and Staphylococcus epidermidis were the most commonly isolated microorganisms, observed in 45% and 31% of cases, respectively. C. acnes was isolated in 65.2% of cases when the indication for revision surgery was ASD. Conclusion. Infection must always be considered as a possibility in the setting of spinal revision surgery, especially in the case of hardware failure, regardless of the lack of clinical signs. Sonication should be routinely used to isolate microorganisms adherent to implants. Cite this article: Bone Joint J 2019;101-B:621–624

Background. Intervertebral disc degeneration is implicated as a major cause of chronic lower back pain. Current therapies for lower back pain are aimed purely at relieving the symptoms rather than targeting the underlying aberrant cell biology. As such focus has shifted to development of cell based alternatives. Notochordal cells are progenitors to the adult nucleus pulposus that display therapeutic potential. However, notochordal cell phenotype and suitable culture conditions for research or therapeutic application are poorly described. This study aims to develop a suitable culture system to allow comprehensive study of the notochordal phenotype. Methods & Results. Porcine notochordal cells were isolated from 6 week post natal discs using dissection and enzymatic digestion and cultured in vitro under different conditions: (1)DMEM vs αMEM (2)laminin-521, fibronectin, gelatin and untreated tissue culture plastic (3)2% 02 vs normoxia (4)αMEM (300 mOsm/L) vs αMEM (400 mOsm/L). Notochordal cells were cultured in alginate beads as a control. Adherence, cell viability, morphology and expression of known notochordal markers (CD24, KRT8, KRT18, KRT19 and T) were assessed throughout the culture period. Use of αMEM media and laminin-521 coated surfaces displayed the greatest cell adherence, viability and retention of notochordal cell morphology and gene expression, which was further enhanced through culture in hypoxia and hyperosmolar media mimicking the intervertebral disc niche. Conclusions. Assessment of the therapeutic potential of notochordal cells is potentially valuable to development of a cell based therapy for chronic lower back pain. Our model has provided a system in which notochordal cells can be studied extensively. Conflicts of Interest: None. Funding obtained from the Henry Smith Charity, London

Aims. Gram-negative infections are associated with comorbid patients, but outcomes are less well understood. This study reviewed diagnosis, management, and treatment for a cohort treated in a tertiary spinal centre. Methods. A retrospective review was performed of all gram-negative spinal infections (n = 32; median age 71 years; interquartile range 60 to 78), excluding surgical site infections, at a single centre between 2015 to 2020 with two- to six-year follow-up. Information regarding organism identification, antibiotic regime, and treatment outcomes (including clinical, radiological, and biochemical) were collected from clinical notes. Results. All patients had comorbidities and/or non-spinal procedures within the previous year. Most infections affected lumbar segments (20/32), with Escherichia coli the commonest organism (17/32). Causative organisms were identified by blood culture (23/32), biopsy/aspiration (7/32), or intraoperative samples (2/32). There were 56 different antibiotic regimes, with oral (PO) ciprofloxacin being the most prevalent (13/56; 17.6%). Multilevel, contiguous infections were common (8/32; 25%), usually resulting in bone destruction and collapse. Epidural collections were seen in 13/32 (40.6%). In total, five patients required surgery, three for neurological deterioration. Overall, 24 patients improved or recovered with a mean halving of CRP at 8.5 days (SD 6). At the time of review (two to six years post-diagnosis), 16 patients (50%) were deceased. Conclusion. This is the largest published cohort of gram-negative spinal infections. In older patients with comorbidities and/or previous interventions in the last year, a high level of suspicion must be given to gram-negative infection with blood cultures and biopsy essential. Early organism identification permits targeted treatment and good initial clinical outcomes; however, mortality is 50% in this cohort at a mean of 4.2 years (2 to 6) after diagnosis. Cite this article: Bone Jt Open 2024;5(5):435–443

Purpose and background. Although clinical guidelines recommend that low back pain (LBP) is best managed in primary or community care, in the UK and globally, LBP accounts for around 4% of emergency department (ED) attendances. Organising and delivering healthcare to be safe, effective, and acceptable requires hearing patients’ perspectives; this study therefore aimed to explore patients’ experiences of attending the ED for LBP. Methods and results. This was a multisite qualitative interview study with 47 adults (aged 23–79 years) who, in the past six weeks, had attended one of four UK NHS emergency departments for LBP (all types and durations). Purposive sampling was used to gain variation in the recruiting site, and LBP and demographic characteristics. Data were collected using individual, semi-structured, telephone interviews (median 45mins). Interviews were audio-recorded, transcribed verbatim, and analysed thematically. We identified significant variation in patients’ experiences of ED care for LBP, which we argue reflects contrasting cultures of ED care. We present three cultures, emergency screening only, ‘cynicism and neglect’, and ‘kindness’; these cultures differ in how they navigate the tension between the ED remit and patients’ perceived needs of care. We draw on Bourdieu's notions of field and habitus and professional identity theory to help explain these findings. Conclusion. Our findings suggest unwarranted variation in ED care for LBP. Implications include the need for urgent access to primary and community care and clarity about best practice managing LBP in the ED; best practice guidance and strategies to implement this should be informed by notions of culture and professional identity. No conflicts of interest.  . Sources of funding. Health Education England & National Institute of Health and Care Research (ICA-CDRF-2018-04-ST2-040)

Background. We have previously reported an injectable hydrogel (NPgel), which could deliver patients own stem cells, via small bore needles, decreasing damage to the annulus fibrosus. NPgel drives differentiation to NP cells and can inhibit the degenerate niche. However, clinical success of NPgel is dependent on the capacity to inject NPgel into naturally degenerate human discs, restore mechanical function to the IVD, prevent extrusion during loading and induce regeneration. This study assessed injectability of NPgel into human IVD, influence on mechanical properties, regeneration ability in an ex vivo culture system and retention under failure testing. Methodology. Cadaveric human discs were used to calculate disc height and to determine Youngs Modulus during simulated walking pre and post injection of NPgel, extrusion testing performed. Whole human IVDs were injected with NPgel +/− human BMPCs and maintained in culture under physiological loading regime for 4 weeks. Pre and post culture MRI imaging and in line biomechanical characteristics determined. Histology and immunochemistry performed for anabolic and catabolic factors. Results. NPgel injection significantly increased disc height and Youngs modulus with no extrusion observed during failure testing. T1ρ intensity was increased during culture in those injected with NPgel +/− cells compared to non-injected discs, and biomechanical restoration. Histological analysis has demonstrated excellent tissue attachment to the injected gel, and cellular migration into acellular gel systems. With increased matrix production and decreased catabolic factor expression. Conclusion. These results provide essential proof of concept data supporting the use of NPgel as an injectable therapy for disc regeneration. Conflict of interest: C Le Maitre & C Sammon are inventors on the hydrogel discussed. Funding: This work was funded by MRC and Versus Arthritis

Background. Current clinical treatment for spinal instability requires invasive spinal fusion with cages and screw instrumentation. We previously reported a novel injectable hydrogel (Bgel), which supports the delivery and differentiation of mesenchymal stem cells (MSCs) to bone forming cells and supports bone formation in vivo. Here, we investigated whether this system could be utilised to induce bone formation within intervertebral disc tissue as a potential injectable spinal fusion approach. Methodology. Bovine and Human Nucleus pulpous tissue explants were injected with Bgel with and without MSCs. Tissue samples were cultured under hypoxia (5%) in standard culture media for 4 weeks. Cell viability, histological assessment of matrix deposition, calcium formation, and cell phenotype analysis using immunohistochemistry for NP matrix and bone markers. Results. Following injection of B-gel into tissue explants following culture for 4 weeks, cells were visualized within the regions of the B-gel. Demonstrating that native cells were able to migrate into regions of B-gel. Increased collagen deposition was seen in tissue explants injected with Bgel, with increased collagen type I and X but decreased collagen type II staining in explants injected with Bgel. Tissue explants, in the absence of Bgel, showed limited calcium deposition, which was increased in B-gel injected explants. Furthermore, disc cells increased expression of bone markers (alkaline phosphatase & osteocalcin), but decreased NP matrix (Aggrecan and Collagen type II) following Bgel injection. Conclusion. This system could have potential to support spinal fusion via direct injection into the disc. Conflict of interest: C Le Maitre & C Sammon are inventors on the hydrogel discussed. Funding: This work was funded by GrowMed Tech Proof of Concept funding

Purpose of study. Cauda Equina Syndrome (CES) is a surgical emergency. With Physiotherapists increasingly taking on first-contact and spinal triage roles, screening for CES must be as thorough and effective as possible. This study explores whether Physiotherapists are asking the correct questions, in the correct way and investigates their experiences when screening for this serious condition. Background. Thirty physiotherapists working in a community musculoskeletal service were purposively invited to participate in semi-structured interviews. Data was transcribed and thematically analysed. Methods and Results. All participants routinely asked bladder, bowel function and saddle anaesthesia screening questions although only 9 routinely asked about sexual function. Whether questions are asked in the correct way has never been studied. Sufficient depth of questioning was achieved by 63% of participants, 76% used lay terminology and 73% used explicit language. Only 43% framed the questions before asking them and only 16% combined all four dimensions. Whilst most participants (n = 25) felt comfortable asking general CES questions, 50% reported feeling uncomfortable when asking about sexual function. Issues around; gender, culture and language were also highlighted. Conclusion. Four main themes emerged from this study; i) Physiotherapists ask the right questions but frequently omit sexual function questions, ii) mostly, Physiotherapists ask CES questions in a way that patients understand however, there needs to be improvement in framing the context of the questions, iii) Physiotherapists generally feel comfortable with CES screening but there is some awkwardness surrounding discussion of sexual function and iv) Physiotherapists perceive there to be barriers to effective CES screening caused by culture and language. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained. Previously presented poster at BritSpine 2021 and VPUK 2021

Introduction. Pulmonary Tuberculosis (TB) can be detected by sputum cultures. However, Extra Pulmonary Spinal Tuberculosis (EPSTB), diagnosis is challenging as it relies on retrieving a sample. It is usually discovered in the late stages of presentation due to its slow onset and vague early presentation. Difficulty in detecting Mycobacterium Tuberculosis bacteria from specimens is well documented and therefore often leads to culture negative results. Diagnostic imaging is helpful to initiate empirical therapy, but growing incidence of multidrug resistant TB adds further challenges. Methods. A retrospective analysis of cases from the Infectious Disease (ID) database with Extra Pulmonary Tuberculosis (EPTB) between 1. st. of January 2015 to 31. st. of January. Two groups were compared 1) Culture Negative TB (CNTB) and 2) Culture Positive TB (CPTB). Audit number was. Results. 31 cases were identified with EPSTB. 68% (n=21) were male. 55% (n=17) patients were Asian, (19% (n=6) were black and 16% (n=5) were of white ethnicity. 90.4% (n=28) patients presented with isolated spinal TB symptoms. No patient had evidence of HBV/HCV/HIV infections. CPTB Group was 51.6% (n=16) compared to CNTB Group with 48.4% (n=15) 48% (15) lumbar involvement, 42% (13) thoracic and 10% (3) cervical. 38.7% (12) patients presented with late neurology, equally in both groups. 56% CPTB patients showed signs of vertebral involvement on plain radiograph compared to 13.3% in CNTB patients. 68.7% CPTB patients had pathological changes or paraspinal collections seen on CT scan compared to 53.3% of CNTB patients. 81% of CPTB showed positive MRI findings compared to 86% in CNTB. Both groups were treated with Anti-TB medications according to local guidelines. 83% patients were followed up till the end of the treatment course. 22.5% (n=7) patients had Ultrasound guided aspiration. 29% (n=9) patients underwent surgical intervention. 3 patients had Laminectomy for decompression. 6 patients underwent Spinal Decompression and Fixation due to extensive bone destruction. No mortality occurred. Conclusion. TB continues to be a growing problem in the developed world with high numbers of patients travelling from endemic regions. 75% of our cases were from Asian or Black ethnicity. The thoracolumbar region was most commonly effected (90%). Approximately 50% of cases of extrapulmonary spinal TB were culture negative. Neurological deficit occurred in 40% patients and 30% of patients required surgery. Standard anti-TB treatment was however effective in all cases with no significant drug resistant variants noted. MRI and CT imaging remain the superior diagnostic tests in the presence of high CN EPSTB

Aims. The aims of this study were to determine the diagnostic yield of image-guided biopsy in providing a final diagnosis in patients with suspected infectious spondylodiscitis, to report the diagnostic accuracy of various microbiological tests and histological examinations in these patients, and to report the epidemiology of infectious spondylodiscitis from a country where tuberculosis (TB) is endemic, including the incidence of drug-resistant TB. Methods. A total of 284 patients with clinically and radiologically suspected infectious spondylodiscitis were prospectively recruited into the study. Image-guided biopsy of the vertebral lesion was performed and specimens were sent for various microbiological tests and histological examinations. The final diagnosis was determined using a composite reference standard based on clinical, radiological, serological, microbiological, and histological findings. The overall diagnostic yield of the biopsy, and that for each test, was calculated in light of the final diagnosis. Results. The final diagnosis was tuberculous spondylodiscitis in 250 patients (88%) and pyogenic spondylodiscitis in 22 (7.8%). Six (2.1%) had a noninfectious condition-mimicking infectious spondylodiscitis, and six (2.1%) had no definite diagnosis and improved without specific treatment. The diagnosis was made by image-guided biopsy in 152 patients (56%) with infectious spondylodiscitis. Biopsy was contributory in identifying 132/250 patients (53%) with tuberculous spondylodiscitis, and 20/22 patients (91%) with pyogenic spondylodiscitis. Histological examination was the most sensitive diagnostic modality, followed by Xpert MTB/RIF assay. Conclusion. Image-guided biopsy has a reasonably high diagnostic yield in patients with suspected infectious spondylodiscitis. A combination of histological examination, Xpert MTB/RIF assay, bacterial culture, and sensitivity provides high diagnostic accuracy in a country in which TB is endemic. Cite this article: Bone Joint J 2022;104-B(1):120–126

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)

Aims. Non-coding microRNA (miRNA) in extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) may promote neuronal repair after spinal cord injury (SCI). In this paper we report on the effects of MSC-EV-microRNA-381 (miR-381) in a rodent model of SCI. Methods. In the current study, the luciferase assay confirmed a binding site of bromodomain-containing protein 4 (BRD4) and Wnt family member 5A (WNT5A). Then we detected expression of miR-381, BRD4, and WNT5A in dorsal root ganglia (DRG) cells treated with MSC-isolated EVs and measured neuron apoptosis in culture by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. A rat model of SCI was established to detect the in vivo effect of miR-381 and MSC-EVs on SCI. Results. We confirmed an interaction between miR-381 and BRD4, and showed that miR-381 overexpression inhibited the expression of BRD4 in DRG cells as well as the apoptosis of DRG cells through WNT5A via activation of Ras homologous A (RhoA)/Rho-kinase activity. Moreover, treatment of MSC-EVs rescued neuron apoptosis and promoted the recovery of SCI through inhibition of the BRD4/WNT5A axis. Conclusion. Taken altogether, miR-381 derived from MSC-EVs can promote the recovery of SCI through BRD4/WNT5A axis, providing a new perspective on SCI treatment. Cite this article: Bone Joint Res 2021;10(5):328–339

Aims

CRP is an acute-phase protein that is used as a biomarker to follow severity and progression in infectious and inflammatory diseases. Its pathophysiological mechanisms of action are still poorly defined. CRP in its pentameric form exhibits weak anti-inflammatory activity. The monomeric isoform (mCRP) exerts potent proinflammatory properties in chondrocytes, endothelial cells, and leucocytes. No data exist regarding mCRP effects in human intervertebral disc (IVD) cells. This work aimed to verify the pathophysiological relevance of mCRP in the aetiology and/or progression of IVD degeneration.

Purpose of study and background. We have previously reported the development of injectable hydrogels for potential disc regeneration (NPgel) or bone formation which could be utilized in spinal fusion (Bgel). As there are multiple sources of mesenchymal stem cells (MSCs), this study investigated the incorporation of patient matched hMSCs derived from adipose tissue (AD) and bone marrow (BM) to determine their ability to differentiate within both hydrogel systems under different culture conditions. Methods and Results. Human fat pad and bone marrow derived MSCs were isolated from femoral heads of patients undergoing hip replacement surgery for osteoarthritis with informed consent. MSCs were encapsulated into either NPgel or Bgel and cultured for up to 6 weeks in 5% (NPgel) or 21% (Bgel) O. 2. Histology and immunohistochemistry was utilized to determine phenotype. Both fat and bone marrow derived MSCs, were able to differentiate into both cell lineages. NPgel culture conditions increased expression of matrix components such as collagen II and aggrecan and NP phenotypic markers FOXF1 and PAX1, whereas Bgel induced expression of collagen I and osteopontin, indicative of osteogenic differentiation. Conclusion. NPgel and Bgel were able to differentiate patient derived MSCs from different sources into both NP and osteogenic lineages, which may give rise to novel treatment strategies for IVD degeneration and spinal fusion, enabling choice for cell source according to patients' circumstances and needs. C Le Maitre and C Sammon hold a patent for the hydrogel described. Funded by MRC and Versus Arthritis

Purpose of study and background. Degeneration of the intervertebral disc is a strong contributor of low back pain. Studies have shown that both, mechanical unloading and overloading, lead to disc degeneration. This is intuitively clear if one considers that an intervertebral disc essentially is a poro-elastic material embedded with cells, which depend on fluid flow for the transport of nutrients and waste products. As such, mechanical loading is also required for regeneration. It is unclear, however, how much loading is beneficial or detrimental for the healthy or degenerated disc. Methods and Results. We developed a loaded disc culture system for the long-term study of disc physiology. This way we could control both the mechanical and biochemical conditions. If no loading was applied, about half of the cells died within a week. Cells died under a low dynamic loading regime after three weeks. A diurnal loading regime rescued cell viability, gene expression profile and mechanical behavior of the discs. Both static and dynamic overloading induced damage to the discs and led to catabolic and inflammatory gene expressions. Conclusion. Intervertebral discs need a certain dosage of mechanical loading to remain viable. Under overloading, cells deform, change gene expression and become degenerative. The matrix is also remodeled, thereby further decreasing the hydrostatic pressure on the cells and increasing their deformation. This induces a vicious circle of disc degeneration, which needs to be reversed in order to repair the disc. The loaded disc culture system also allows evaluating new therapies for disc degeneration. There are no conflicts of interest. Funded by ZonMW program “Alternatives for live animal testing”, grant #11400090;. BioMedical Materials Program, grant # P2.01 IDiDas; Dutch Arthritis Funds, personal grant KSE

Background. Intervertebral disc (IVD) degeneration is a major cause of low back pain (LBP). We have developed an injectable hydrogel (NPgel), which following injection into bovine IVD explants, integrates with IVD tissue and promotes disc cell differentiation of delivered mesenchymal stem cells (MSCs) without growth factors. Here, we investigated the injection of NPgel+MSCs into IVD explants under degenerate culture conditions. Methods and Results. The NPgel integrated with bovine and human degenerate Nucleus Pulposus (NP) tissue and hMSCs produced matrix components: aggrecan, collagen type II and chondroitin sulphate in standard and degenerate culture conditions. Significantly increased cellular immunopositivty for aggrecan was observed within native NP cells surrounding the site where NPgel+MSCs were injected (P≤0.05). In NP explants a significant decrease in catabolic factors were observed where NPgel+MSCs was injected in comparison to controls. Conclusions. In agreement with our previous findings NPgel was sufficient alone to induce NP cell differentiation of MSCs following injection into NP tissue explants. Here, we have shown that viability is maintained even in degenerate conditions. Injection of NPgel with MSCs increased aggrecan expression and reduced MMP3 and IL-1R1 expression by native NP cells. The NPgel with incorporated MSCs has the potential to regenerate the NP and provide mechanical support, whilst reducing the catabolic phenotype of degenerate NP cells, as a treatment strategy for IVD degeneration. No conflicts of interest. Sources of funding: Funded by ARUK and MRC

Aims

This study was performed to explore the effect of melatonin on pyroptosis in nucleus pulposus cells (NPCs) and the underlying mechanism of that effect.

Aims. HIV predisposes patients to opportunistic infections. However, with the establishment of Highly Active Anti-Retroviral Therapy (HAART), patients’ CD4 counts are maintained, as is a near normal life expectancy. This study aimed to establish the impact of HIV on the bacteriology of spondylodiscitis in a region in which tuberculosis (TB) is endemic, and to identify factors that might distinguish between them. Patients and Methods. Between January 2014 and December 2015, 63 consecutive cases of spontaneous spondylodiscitis were identified from a single-centre, prospectively maintained database. Demographics, presenting symptoms, blood results, HIV status, bacteriology, imaging, and procedure undertaken were reviewed and comparisons made of TB, non-TB, and HIV groups. There were 63 patients (22 male, 41 female) with a mean age of 42.0 years (11 to 78; . sd. 15.0). Results. In total, 53 patients had tuberculous, nine bacterial, and one cryptococcal spondylodiscitis. There were 29 HIV-positive patients, 29 HIV-negative patients, and five patients with unknown HIV status. The local incidence of TB spondylodiscitis was 1.54/100 000 and that of non-TB spondylodiscitis was 0.29/100 000 per annum. TB patients were younger with similar clinical presentation and infective markers, but were more likely to have a paraspinal abscess. They were also less likely to have a hyperintense disc on MRI. There was no difference between the two HIV groups. Conclusion. In areas of endemic TB and HIV, TB remains the most common cause of spondylodiscitis at five times the rate of non-tuberculous causes. HIV managed with HAART increases the rate of infection but does not influence the bacteriology unless there is a low CD4. There was little to differentiate the groups. TB /HIV co-infected patients were younger than non-TB and HIV-negative patients. Non-TB patients were more likely to have disc hyperintensity on MRI and TB patients were more likely to have abscess formation, but as both groups exhibited these features, neither was diagnostic. Culture confirmation remains necessary. Cite this article: Bone Joint J 2019;101-B:617–620

Aims

Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date.

Aims

In this investigation, we administered oxidative stress to nucleus pulposus cells (NPCs), recognized DNA-damage-inducible transcript 4 (DDIT4) as a component in intervertebral disc degeneration (IVDD), and devised a hydrogel capable of conveying small interfering RNA (siRNA) to IVDD.

The lack of an accurate, rapid diagnostic test for mycobacterium tuberculosis (TB) is a major handicap in the management of spinal TB. GeneXpert, a new, rapid molecular diagnostic test is recommended as the first line investigation for suspected pulmonary TB in areas with a high prevalence of HIV or drug resistance, yet it has not been validated for the diagnosis of musculoskeletal TB. The aim of this study was to assess the accuracy of GeneXpert in diagnosing spinal TB. A prospective clinical study of 69 consecutive adults with suspected spinal TB was conducted at a tertiary hospital in an area with the highest incidence and prevalence of TB in the world. GeneXpert was used on tissue samples of the enrolled patients and its diagnostic accuracy compared with a reference standard of tissue in liquid culture. A total of 71 spine samples from 69 patients (two re-biopsies) were included in the study. The GeneXpert test showed a sensitivity of 95.6% and specificity of 96.2% for spinal TB. The results of the GeneXpert test were available within 48 hours compared with a median of 35 days (IQR 15 to 43) for cultures. All cases of multi-drug resistant TB (MDR TB) were diagnosed accurately with the GeneXpert test. The MDR TB rate was 5.8%. Cite this article: Bone Joint J 2014;96-B:1366–9