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.

Background. Intervertebral disc degeneration (DD) is a complex age-related condition that constitutes the main risk factor for disabling back pain. DD is assessed using different traits extracted from MR imaging (MRI), normally combined to give summary measures (e.g. Pfirmann score). The aetiology of DD is poorly understood and despite its high heritability (75%), the precise genetic predisposition is yet to be defined. Genome wide association study (GWAS) is used to discover genetic variants associated with a disease or phenotype. It tests variants across the whole genome. It requires large samples to provide adequate but unfortunately there is poor availability of spine imaging data due to the high cost of MRI. We have adopted new methods to examine different MRI traits independently and use the information of those traits to boost GWAS power using specialized statistical software for jointly analyse correlated traits. Methods/Results. We examined DD MRI features disc narrowing, disc bulge, disc signal intensity and osteophyte formation in the TwinsUK cohort who had undergone T2-weighted sagittal spine MRI. GWAS were performed on the four traits. MTAG software was used to boost single trait GWAS power using the information in the other trait GWAS. 9 different loci were identified. Conclusions. Preliminary results suggest genes GDF6, SP1/SP7 are associated with individual trait signal intensity. In addition, novel associated genes with potential for shedding new light on pathogenic mechanisms are identified. Additional cohorts will be included in the design as a replication to test reproducibility of the results. Conflicts of interest: No conflicts of interest. Sources of funding: Funded by Disc4All, EU Horizon 2020, MSCA-2020-ITN-ETN GA: 955735

Purpose of the study. To incorporate magnetic resonance (MR) image data in a finite element (FE) model to estimate intervertebral disc stress as a function of posture. Background. Determining the stresses on the intervertebral discs is important for understanding disc degeneration and developing treatment strategies. The effect of different postures on disc stress has previously been investigated through disc pressure measurements and through computational modelling. Kinematic data derived from MR images and used in an FE model may provide a non-invasive way of assessing a wide range of subjects and postures. Methods. Two-dimensional FE models of the lumbar spine were created for four subjects. Vertebral bodies were modelled as rigid bodies, the disc was modelled with an isotropic elastic annulus (E = 2.5 MPa, ν=0.4) and nucleus (E = 1 MPa, ν=0.45). The geometry was defined from MR image data obtained in the supine posture; vertebral body translation and rotation were determined from images acquired in standing and sitting. Results. The principle stress distribution in standing and sitting differed between subjects. Stress peaks occurred in different discs (L4L5 v L5S1) and in different regions of the annulus (anterior v posterior). In three subjects the compressive stress at L4L5 was largest in sitting, for the fourth subject it was largest in standing; shear stress at L4L5 was highest in sitting for all four subjects. Conclusion. Kinematic data from MR images provides a way of assessing the effect of postural change on disc stress; inter-subject differences in L4L5 compressive stress are consistent with disc pressure measurements

Aim. The purpose of this study is to compare the pre and post-operative magnetic resonance image clarity of titanium and PEEK based cervical arthroplasty devices at the level of implantation and adjacent level discs. Methodology and Results. This is a prospective, blinded, randomised study on imaging of cervical arthroplasty devices. The pre and postoperative MRI images of 16 patients who underwent cervical arthroplasty using Prestige LP(r) (Medtronic Sofamor Danek) and NuNec(tm) Cervical Arthroplasty System (Pioneer Surgical Technology, Marquette, Mich., USA) were assessed. Two independent radiologists who were blinded and provided with a sets of random images to score using a four point Jarvick grading system. Statistical analysis was completed using SPSS 16.0 statistical package (SPSS Inc, Chicago, IL) and analysis included comparing MR image quality before and after cervical arthroplasty at the operated and adjacent levels, and in between two types of implant. The pre-operative MR image quality at operated and adjacent levels was excellent in both groups. In the post-operative images, the adjacent level visualisation was adequate in both groups without much difference in average scores. However, at operated level, the quality of MR images in the NuNec group (PEEK on PEEK articulating disc) was excellent and clear visualisation of the cord, central canal, foramen and disc. Conclusion. Previous studies have shown that titanium devices allow satisfactory monitoring of adjacent and operated levels by providing good quality MRI images. Our studies confirm that using titanium based cervical arthroplasty implants provide clear visualisation of the adjacent level, however, provide less than satisfactory images at operated level. But the PEEK devices provide excellent quality images even at the operated level, with clear visualisation of neural structures and are valuable, if one wishes to assess the adequacy of neural decompression at operated level

Purpose. Distinguishing between sequestered disc fragments and tumours remains a diagnostic challenge, but one of paramount importance given the surgical management of these two clinical entities varies dramatically. Methods. Our experience over the last 3 years in managing this clinical challenge was analyzed. Patients referred to the regional neurosurgical unit for evaluation of possible spinal tumours whose imaging and clinical findings were atypical, were prospectively identified and the medical notes, operative records and MR imaging reviewed. Results. This is the single largest series of patients presenting as tumors that were later determined to be sequestered disc fragments. 17 patients(8 female and 9 male) were identified. The median age was 54 years (range 35-77) and the mean follow up time 20 months. The most common location (16/17) for discs mimicking tumours in our series was in the lumbar spine. The major differential diagnosis was of nerve sheath tumours, followed by metastasis. The signal characteristics of the lesions and contrast enhancement were variable. 35% of patients had the lesion surgically excised and the diagnosis of intervertebral disc made intraoperatively or on histology. The remainder were monitored clinically and with MR imaging, and required no surgical intervention in the follow up period. The features that favoured a diagnosis of disc rather than tumour included a rapid onset of symptoms and abatement of pain with time. Radiologically, sequestered disc was more likely if the lesion demonstrated contiguity with the disc space, the presence of other degenerate discs, no foraminal exit widening, and the absence of central enhancement. Conclusion. Urgent surgery is not mandatory and in our series a “watch and wait” approach was utilized safely. When atypical clinical and imaging findings are present in patients referred for management of spinal tumours, sequestered disc fragments should be considered as a possibility

Aim. To identify a means to reduce the duration and radiation dose coupled with fluoroscopic guided nerve root blocks (NRB). Method. Consecutive prospective two cohort comparative study. A similar method performed during CT guided NRBs was employed to guide needle placement for transforaminal nerve root injections with the aid of static MR images and fluoroscopy. Axial MR images at the level of the target nerve root were used. An angle of inclination of 60 degrees was created from the nerve root to the skin of the back, the apex of this to represent the site of needle introduction. Triangulation on the MRI enabled the lateral entry point to be determined. The transforaminal injections were then performed with the simple expedient of a skin marker line at the appropriate lateral distance from the midline for needle entry. The radiation dose and fluoroscopic time as measured by the image intensifier were recorded. This method was performed for 20 patients and compared to the same parameters for 23 previous patients in whom the transforaminal injections were performed without such a technique. Results. 20 patients in the navigated arm (group 1) and 23 in the non-navigated (group 2). Average fluoroscopic time (seconds) was 17.7 seconds (range 8-40) for group 1 and 16.4 seconds (range 6-45) for group 2 (P value 0.625). Radiation dose measured was 79.76 cgycm. 2. (range 8-212) for group 1 and 63.05 cgycm. 2. (range 8-260) for group 2 (P value 0.247). Conclusion. This method of navigating nerve root blocks via fluoroscopy did not appear to reduce the duration of the procedure or radiation dose involved on objective data. Subjectively it was found to be a useful training aid for triangulation for those new to the technique but the available objective evidence was not obtained

Purpose of study and background. Clinical researchers use Pfirrmann classification for grading intervertebral disc degeneration radiologically. Basic researchers have access to morphology and instead use the Thompson score. The aim of this study was to assess the inter-observer reliability of both classifications, along with their correlation. Methods and Results. We obtained T2-weighted MR images of 80 human lumbar intervertebral discs with various stages of degeneration to assess the Pfirrmann-score. Then the discs were dissected midsagittally to obtain the Thompson-score. The observers were typical users of both grading systems: a spine surgeon, radiology resident, orthopaedic resident, and a basic scientist, all experts on intervertebral disc degeneration. Cohen's kappa (CK) was used to determine inter-observer reliability, and intra-class correlation (ICC) as a measure for the variation between the outcomes. For the Thompson score, the average CK was 0.366 and ICC score 0.873. The average inter-observer reliability for the Pfirrmann score was 0.214 (CK) and 0.790 (ICC). Comparing the grading systems, the intra-observer agreement was 0.240 (CK) and 0.685 (ICC). Conclusion. With substantial variation between observers, the inter-observer agreements for the Pfirrmann and Thompson grading systems were moderate. This may explain the poor relationship between radiological and clinical observations in patients and raises questions about the validity of the Pfirrmann score. The mediocre intra-observer agreement between the Pfirrmann and Thompson score shows that there is no clear definition of intervertebral disc degeneration. The field is in need for a new, objective and quantitative classification system to better define and evaluate disc degeneration. There are no conflicts of interest. Funded in part by Annafonds Netherlands and Dutch Spine Society

Objective. Modic changes (MC) is a form of intervertebral disc degeneration visible as subchondral and vertebral bone marrow changes on spine magnetic resonance (MR). Their etiology is not understood, but microbial infection may be involved for some subtypes. This study set out to test for an association between MC and gut microbiome in a population sample. Methods. Presence of MC was evaluated in lumbar MR images and gut microbiome assessed using 16S sequencing in TwinsUK dataset (N=309). Cases were identified by the presence of MC of any type, while controls were those without MC. Amplicon sequence variants (ASVs) have been obtained for 16S sequences followed by relative abundance calculation and centred log-ratio transformation. Linear mixed-effects models were applied to test for association between the ASVs at different taxon levels and MC adjusting for technical covariates and demographics. Results. Nominally significant (p<0.05) associations with MC were obtained for 6 ASVs annotated to species level (min p = 0.0016 for Sanguibacteroides justesenii), 8 ASVs annotated to genus level (min p = 0.0091 for Syntrophomonas), and 2 ASVs annotated to family level (min p = 0.0099 for Syntrophomonadaceae). None of the associations were significant after correction for multiple testing. Also, no statistically significant difference in microbial diversity was found between MC cases and controls. Conclusions. The results of this pilot study provide limited evidence of association between MC and gut microbiome. Further studies including MC stratified by subtype are warranted as well as studies based on advanced metagenome sequencing rather than 16S approach. No conflicts of interest. The study was supported by Versus Arthritis grant # 21227

Objective. Modic changes (MC), a form of intervertebral disc degeneration visible as subchondral and vertebral bone marrow changes on spine magnetic resonance (MR), are known to be associated with low back pain. This study aimed to identify genes contributing to the development of MC using genome-wide association study. Methods. Presence of MC was evaluated in lumbar MR images in the Northern Finland Birth Cohort 1966 (NFBC1966, N=1182) and TwinsUK (N=647). Genome-wide association analyses were carried out in the cohorts separately using a linear regression model fitted to test for additive effects of SNPs and adjusting for age, sex, BMI, and either family relatedness via a kinship matrix (TwinsUK) or population stratification using principal components (NFBC1966). Meta-analysis of the two studies was carried out using the inverse-variance weighting approach. Results. A locus associated with MC reaching genome-wide significance (p<5e-8) was found on chromosome 9 with the lead SNP rs1934268 in intron 6 of the PTPRD gene. The SNP is located in the region of binding for a number of transcription factors which are involved in the development of the musculoskeletal system and spine cord. Conclusions. The first GWAS of MC has identified a likely functional intronic locus in PTPRD on chromosome 9 implicating musculoskeletal development. This work sheds light on the genesis of MC and paves the way for further studies on the shared genetic factors underlying the various features of spine degeneration. No conflicts of interest. Sources of Funding: The study was supported by EU FP7 project PainOMICs (grant agreement #602736), University of Oulu (grant #24000692), Oulu University Hospital (grant #24301140), and the European Regional Development Fund (grant # 539/2010 A31592). MBF, MK, and SS contributed equally to this study

Background. The factors influencing normal spine curvature in midlife are unknown. We performed an MR and plain radiograph study on well characterised, unselected twin volunteers from the TwinsUK register (. www.twinsuk.ac.uk. ) to determine the relative contributions of genetic and environmental factors to spine curve. Methods. T2 weighted MR scans and long spine standing radiographs were obtained at the same morning visit on twin pairs. Midline sagittal MR images were coded for 4 degenerative features. SpineviewTM software was applied plain films and calculated the angles of curvature. A classical twin study was performed. Multivariate regression analysis was used to determine the association between spine curves, LDD and confounders (age, body mass index). Results. Data were available on 110 monozygotic (MZ) and 136 dizygotic (DZ) female twins. Mean age was 64.3 years (range 40.1–79.3); age was associated with increasing lumbar lordosis (p=0.02). The AE model (comprising additive genetic and unique environmental factors) was the most suitable model for both lumbar lordosis and thoracic kyphosis (as determined by Akaike information criterion). Heritability estimates = 59% (42–71%) for lumbar lordosis; and 61% (46–74%) for thoracic kyphosis. After adjusting for age and BMI, lumbar lordosis was significantly associated with a number of features of LDD (p<0.001) including disc signal intensity and osteophytes. Conclusion. The twins are known to be representative of women in the general population. Lumbar lordosis and thoracic kyphosis of the spine have considerable heritable component in females suggesting that a search for individual gene variants would be a reasonable next step. This abstract was presented at 14th Congress of the International Society for Twin Studies. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained

Purpose and Background. Low birth weight is related to decreased lumbar spine vertebral canal size and bone mineral content later in life, suggesting that antenatal factors affect spine development. The purpose of this study was to explore associations between antenatal factors and lumbar spine morphology in childhood. Methods. Antenatal data and supine MR images of the lumbar spine were available for 161 children. Shape modelling, using principle components analysis, was performed on mid-sagittal images to quantify different modes of variation in lumbar spine shape. Previously collected measures of spine canal dimensions were analysed. Results. Almost 75 % of all of the variation in lumbar spine shape was explained by just three modes. Modes 1 and 3 described the total amount and the distribution of curvature along the spine, respectively. Mode 2 (M2) captured variation in vertebral shape and size; increasing mode scores represented flatter vertebral bodies with increasing anterior-posterior dimensions. We saw no significant associations between mode scores and birth weight z-scores, placental weight, gestation length and no effect of maternal smoking (P>0.05). Controlling for gestation length revealed a positive correlation between birth weight and M2 (P=0.02). Males, longer babies and those from heavier mothers had higher M2 scores (P<0.05). This sex difference remained even when controlling for the other factors (P<0.001). Modes 1 and 2 correlated with spine canal dimensions (P<0.05). Conclusions. Our results suggest that antenatal factors have some effect on vertebral body morphology but not overall lumbar spinal shape. Perhaps environmental factors during growth and genetics play a larger role in determining the overall spine shape. This abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting. Conflicts of interest: No conflicts of interest. Sources of funding: This work was supported by a studentship granted to the University and awarded to AVP

We examined the pathogenesis of Schmorl’s nodes, correlating the histological findings from 12 lumbar vertebrae with the corresponding conventional radiographs, tomographs, MR images and CT scans. The last revealed round, often multiple cystic lesions with indistinct sclerotic margins beneath the cartilaginous endplate. The appearances are similar to the typical CT changes of osteonecrosis. Histological examination of en-bloc slices through Schmorl’s nodes gave clear evidence of subchondral osteonecrosis. Beneath the cartilage endplate, we found fibrosis within the marrow cavities with the disappearance of fat cells. Osteocytes within bone trabeculae were either dead or had disappeared. We suggest that Schmorl’s nodes are the end result of ischaemic necrosis beneath the cartilaginous endplate and that herniation into the body of the vertebra is secondary

To analyse the pain distribution in the acute and chronic phase following thoracolumbar fractures. Prospective observational study. 39 patients with fractures between T11 and L2, with no neurological deficit, were treated conservatively. Strict inclusion and exclusion criteria were applied. All had X-rays and MR imaging (whole spine) at post-injury and one-year follow-up. The patients documented their pain distribution using pain drawing, along with 10 other domains of pain and functional outcomes for a period over 12 months. The pain distribution was analysed. The association of distal pain distribution to - other associated injury, resultant kyphosis, Pre-existing or increase in disc degeneration at the lower non-injured disc levels – were analysed and reviewed. The most common site of the pain distribution in both the acute (90%) and chronic phase (97%) was distal to the fracture (regions - iliac crest, lumbosacral junction and buttock). Factors mentioned above that could be related to distal pain distribution did not show any significant correlation (P>0.5) with different domains of pain outcome. Some of the commonly believed reasons for distal pain distribution like resultant kyphosis and associated disc/facet pathologies were not supported by our study findings. The distal pain distribution corresponds to the scelerotomal referred pain mapping, which could be the probable explanation. Thoracolumbar pathologies could be the source of pain in patients complaining of low back symptoms. Distal pain distribution of spine pathologies should not be attributed as functional

We studied MR images of the spine in a consecutive series of 100 patients with acute compression of the spinal cord due to metastases. All patients had documented neurological deficit and histologically proven carcinoma. MRI was used to localise bony metastatic involvement and soft-tissue impingement of the cord. A systematic method of documenting metastatic involvement is described. A total of 43 patients had compression at multiple levels; 160 vertebral levels were studied. In 120 vertebrae (75%), anterior, lateral and posterior bony elements were involved. Soft-tissue impingement of the spinal cord often involved more than one quadrant of its circumference. In 69 vertebrae (43%) there was concomitant anterior and posterior compression. Isolated involvement of a vertebral body was observed in only six vertebrae (3.8%). We have shown that in most cases of acute compression of the spinal cord due to metastases there is coexisting involvement of both anterior and posterior structures

Purpose. Lumbar paraspinal muscle dysfunction and low back pain are strongly correlated. Muscle atrophy is common in LBP and is recognised by MRI scan. Corticosteroid injections and physical rehabilitation programs are advocated for treatment of LBP. The purpose is to evaluate efficacy of specific lumbar multifidus muscle retraining exercises and perifacet multifidus injections in treatment of Low Back Pain (LBP) and referred leg pain. Method. 63 patients with non-specific LBP, with or without leg pain, were randomised to three treatment groups. MR images of paraspinal muscle and the atrophy classified. A-Control group, standard physiotherapy for 10 weeks. B-Multifidus rehabilitation program for 10 weeks. C-Perifacet injection (multifidus injection) with methylprednisolone. ODI was primary outcome measure and the SF-36, modified Zung Depression Index and others were secondary outcome measures. Results. 56 patients completed trial. ODI improved from a mean of 29.9 to 25.9, but there were no statistically significant differences between groups. 62% of patients were at risk/had major psychological overlay. LBP improved most in group C (Perifacet injection) (P< 0.02), mean improvement in SF-36 bodily pain score was 21.2 (with a 95% CI of 2.1-44.0) while PF and SF were improved most in group B (multifidus rehabilitation) (P< 0.03). Conclusion. Perifacet injection and a multifidus retraining program are more effective than standard physiotherapy in relieving pain and improving physical capacity respectively. Multifidus rehabilitation program is the recommended treatment for non-specific LBP, as the ultimate goal should be to restore function. Perhaps the combination of perifacet injection to relieve pain followed by multifidus retraining program is the best treatment option. No change in the multifidus muscle was seen over time

Peninsula Spinal Unit, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Foundation NHS Trust, Exeter, UK. A retrospective audit in 2000 of cases presenting with metastatic cord compression (MSCC) was conducted. In June 2009 we introduced the role of MSCC coordinator. We present the preliminary results from a 6 month comparative audit and discuss whether implementation of the NICE Guidelines have improved the care pathway. Prospective cohort study with retrospective controlled group. Adults with suspected MSCC. Length of time to MR imaging. % referred for surgical opinion. Length of time on bed rest. % undergoing surgery. Retrospective audit 2000. 38 cases confirmed MSCC. 11 did not have MRI and were treated on the basis of clinical symptoms. Average time from admission to MRI 42 hours. 8 patients (21%) referred for surgical opinion. None had surgery. 38 had radiotherapy. Spinal stability documented on 1 patient. 5.5 days average bed rest. Prospective audit 2009. 54 patients referred to co-ordinator as suspected MSCC. 52 had MRI and 2 had CT. Average time from referral to MRI 41 hours. Average time for patients with neurological deficit 7.6 hours. 54 patients (100%) referred for surgical opinion. 12 patients had surgery (22%). 100% patients had spinal stability documented. Average length of time on bed rest 2 days. It is uncertain whether these results are attributed to the introduction of the NICE guidelines or improved awareness of condition. However we feel that NICE guidelines have improved the care pathway of patients with MSCC. Statement of ethics and interests: Study was approved and registered with audit department

Background. We present the results of a single centre, prospective study to evaluate the clinical and radiographic outcomes of anterior cervical decompression and replacement (ACDR) using the NuNec(tm) Cervical Arthroplasty System (Pioneer Surgical Technology, Marquette, Mich., USA). Methodology and Results. 36 patients with radiculopathy/myelopathy, who failed to respond to conservative measures, were included. Pain and function were evaluated by Visual Analogue score for Neck pain (VAS-NP) and Arm pain (VAS-AP), Neck disability index (NDI) and SF-36 questionnaires. Radiological assessments include assessing overall range of movement (ROM) and at functional segment unit (FSU). Statistical analysis was completed using SPSS 16.0 statistical package (SPSS Inc, Chicago, IL). Appropriate parametric (A paired t-test) and non parametric tests (Wilcoxon signed-rank test) were used to assess the statistical significance (p<0.05). The average age at operation was 51 years (range 35 - 77years). 8 patients received ACDR at one-level, 15 had 2-level surgery, 12 had 3-level surgery and 1 had a 4-level surgery. At the time of final follow-up (Mean 14.25 months, Range 12- 22.5 months) the mean NDI improved from 49.35; to 33.78 (p< 0.001). There statistically significant improvement note in VAS-NP (Post-op3.65, Pre-op:8.16, p<0.001), VAS-AP (Post-op:3.12, Pre-op:7.32, p<0.001) and SF-36BP (pre-op:29.15, post-op:37.18, p<0.002). The overall global ROM movement was preserved (pre-op:46.80±10.52, post-op:45.04±11.53) and an improvement in ROM at FSU was observed (pre-op:16.60±8.50, post-op:20.22±12.22) at final follow–up. Conclusion. Our results of ACDR using the NuNec(tm) disc show statistically significant improvement in the outcome measures that are comparable to other types of ACDR. In addition, preservation of global cervical spine ROM and improvement in FSU ROM was observed despite single or multiple levels ACDR. Furthermore, NuNec(tm) ACDR gives excellent quality MR image during post-operative period. In our preliminary results, we report that NuNec(tm) ACDR device is safe, effective and has added design benefits

Objectives

To employ a simple and fast method to evaluate those patients with neurological deficits and misplaced screws in relatively safe lumbosacral spine, and to determine if it is necessary to undertake revision surgery.

Aims

The purpose of this study was to investigate the prevalence of sarcopenia and to examine its impact on patients with degenerative lumbar spinal stenosis (DLSS).

We carried out an MRI study of the lumbar spine in 15 patients with achondroplasia to evaluate the degree of stenosis of the canal. They were divided into asymptomatic and symptomatic groups. We measured the sagittal canal diameter, the sagittal cord diameter, the interpedicular distance at the mid-pedicle level and the cross-sectional area of the canal and spinal cord at mid-body and mid-disc levels.

The MRI findings showed that in achondroplasia there was a significant difference between the groups in the cross-sectional area of the body canal at the upper lumbar levels. Patients with a narrower canal are more likely to develop symptoms of spinal stenosis than others.