Aim. To systematically review the literature and anatomical atlases on LM morphology. Methods. Relevant studies were searched in PubMed (Medline) and Science Direct. Anatomical atlases were retrieved from multiple university libraries and online. Included atlases and studies were assessed at five items: visuals present(y/n), quality of visuals(in-/sufficient), labelling of multifidus (y/n), clear description of region of interest(y/n), description of plane has been described(y/n). This risk of bias assessment tool was developed to assess the quality of description of anatomy, since existing risk of bias tables have only been developed to assess the methodology of studies. Results. In total 69 studies and 19 anatomical atlases were included. Studies. - 52 of 69 studies, LM was described as a superficial muscle at the levels L4 – S1. Others presented the LM as deep intrinsic muscle. - Most used methods: MRI, ultrasound imaging or drawings. - 32 of 69 studies scored a total of five points at the risk of bias assessment, which means low risk of bias. Anatomical atlases. - LM is shown as a deep intrinsic back muscle covered by the erector spinae and fascia thoracolumbalis. - Most anatomical atlases (8/19) had a score of four points at the risk of bias assessment. Conclusion. Anatomy atlases reported different LM morphology compared to anatomical studies. Even between studies, there appears to be inconsistent reporting in LM anatomy. Variation in research methods that are used for measuring LM morphology could influence variation in describing and presenting LM morphology. Standardization of research methodology is recommended in order to compare studies. No conflicts of interest. Sources of Funding: SIA RAAK-Publiek

Aims. The aim of the present study was to answer the question whether curve morphology and location have an influence on rigid conservative treatment in patients with adolescent idiopathic scoliosis (AIS). Methods. We retrospectively analyzed AIS in 127 patients with single and double curves who had been treated with a Chêneau brace and physiotherapeutic specific exercises (B-PSE). The inclusion criteria were the presence of structural major curves ≥ 20° and < 50° (Risser stage 0 to 2) at the time when B-PSE was initiated. The patients were divided into two groups according to the outcome of treatment: failure (curve progression to ≥ 45° or surgery) and success (curve progression < 45° and no surgery). The main curve type (MCT), curve magnitude, and length (overall, above and below the apex), apical rotation, initial curve correction, flexibility, and derotation by the brace were compared between the two groups. Results. In univariate analysis treatment failure depended significantly on: 1) MCT (p = 0.008); 2) the apical rotation of the major curve before (p = 0.007) and during brace treatment (p < 0.001); 3) the initial and in-brace Cobb angles of the major (p = 0.001 and p < 0.001, respectively) and minor curves (p = 0.015 and p = 0.002); 4) major curve flexibility (p = 0.005) and the in-brace curve correction rates (major p = 0.008, minor p = 0.034); and 5) the length of the major curve (LoC) above (p < 0.001) and below (p = 0.002) the apex. Furthermore, MCT (p = 0.043, p = 0.129, and p = 0.017 in MCT comparisons), LoC (upper length p = 0.003, lower length p = 0.005), and in-brace Cobb angles (major p = 0.002, minor p = 0.027) were significant in binary logistic regression analysis. Conclusion. Curve size, location, and morphology were found to influence the outcome of rigid conservative treatment of AIS. These findings may improve future brace design and patient selection for conservative treatment. Cite this article: Bone Joint J 2021;103-B(2):373–381

There is evidence that various anatomical structures have altered morphology with ageing, and anecdotal evidence of changing lumbar spinous process (LSP) morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment. 200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions and lumbar lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed. The smallest LSP is at L5. The male LSP is on average 2-3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P<10. -5. at L2). The LSPs increase in height by 2-5mm between 20-85 years of age (P<10. -6. ), which was as much as 31% at L5 (P<10. -8. ). Width increases proportionally more, by 3-4mm or greater than 50% at each lumbar level (P<10. -11. ). Lumbar lordosis decreases in relation to increasing LSP height (P<10. -4. ) but is independent of increasing LSP width (P=0.2). The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to sagittal plane imbalance

Introduction. Type 1 neurofibromatosis is a serious hereditary disease in which mainly skin, nervous, muscular, and bone systems are damaged. In bone systems the most common deformities are thoracic kyphosis and scoliosis. Data for morphological changes in the structural components of spine in neurofibromatosis are scarce. Thus our study aimed to investigate morphological changes in structural components of the spine in NF1 neurofibromatosis. Methods. Growth plates, intervertebral discs, and fragments of vertebral bodies from deformed and adjacent segments of the spine were obtained from 15 patients aged 10–14 years with scoliosis (Cobb angle 90–120°) caused by neurofibromatosis. Preoperative examination included MRI study of the spine and brain to exclude intracanal masses, and radiographic study of the spine. Patients did not present any neurological symptoms. All children underwent anterior release and interbody fusion. Structural spinal components from children aged 12–14 years collected at forensic autopsy were used as controls. Tissues were investigated by conventional histochemical and ultrastructural methods. The levels of aggrecan and NF1 gene expression were studied with the PCR method. Results. The study of growth plate and intervertebral disc specimens removed during surgery for scoliosis in neurofibromatosis showed a clear boundary between their convex and concave sides. Both growth plate and intervertebral disc in convex side retain their architectonic and histochemical characteristics. The concave side of the growth plate is presented by small chondroblasts densely spaced without a definite orientation and surrounded by homogeneous matrix, which is made up of chondroitin sulphates. These embryonic-type chondroblasts are poorly differentiated. Chondroblasts proliferate beyond the growth plate. Proliferating cells invade into vertebral body and are bordered by thin bone lamellae, causing the scalloping of vertebral body as a radiological symptom of the pathology. Changes occurring in the intervertebral disc are of considerable interest. Concave-side disc is characterised by isolated proliferation zones containing poorly differentiated chondroblasts and fibroblasts, and neurinoma-like masses. Bone trabeculae inside a concave-side vertebra are passing the stage of osteogenesis imperfecta. Detected morphological changes in spinal structures are consistent with findings of Stevenson, who registered cartilage and bone deficiencies in animal model (mice with NF1 genemutation). Thus, morphological studies testify to structural disorder in concave side of the growth plate, but unchanged regularities and stages of chondroblast differentiation and adequate osteogenesis in the convex side. NF1 gene regulates the growth, differentiation, and proliferation of chondroblasts at the early stage of embryogenesis. Gene inactivation at a somite stage results in altered development of definitive spinal structures. Continued growth with adequate proliferation, differentiation, osteogenesis, and topochemical characteristics occurs in the convex-side growth plate, and growth disorder in the concave-side part with continued load cause growth asymmetry and development of spinal deformity. Scoliosis associated with neurofibromatosis is notable for deformity progression and pseudoarthrosis development after surgery. Deformity progression (modulation) should be considered in connection with disorder in osteogenic potency of osteoblasts. Conclusions. The causal factor of spinal deformity development in NF1 neurofibromatosis is NF1 gene mutation. Inactivation of NF1 gene results in disorder in chondrogenesis and osteogenesis within structurally altered zones. A continued load causes development of scoliotic spinal deformity

The objective of this study was to assess the reliability and appropriateness of statistical shape modelling for capturing variation in thoracic vertebral anatomy for future use in assessing scoliotic vertebral morphology. Magnetic resonance (MR) images of the thoracic vertebrae were acquired from 20 healthy adults (12 female, 8 male) using a 1.5 T MR scanner (Intera, Philips). A T1 weighted spin-echo sequence (repetition time = 294 ms, echo time = 8 ms, number of signal averages = 3) was used. A set of slices (number = 27, thickness = 1.9 mm, gap = 1.63 mm, pixel size = 0.5 mm) were acquired for each vertebrae, parallel to the mid-transverse plane of the vertebral body. Repeated imaging, including participant repositioning, was performed for T4, T8 and T12 to assess reliability. Landmark points were placed on the images to define anatomical features consisting of the vertebral body and foramen, pedicles, transverse and spinous processes, inferior and superior facets. A statistical shape model was created using software tools developed in MATLAB (R2013a, The MathWorks Inc.). The model was used to determine the mean vertebral shape and ‘modes of variation’ describing patterns in vertebral shape. Analysis of variance was used to test for differences between vertebral levels and subjects and reliability was assessed by determining the within-subject standard deviation from the repeated measurements. The first three modes of variation, shown below (green = mean, red and blue = ±2 standard deviations about the mean), accounted for 70% of the variation in thoracic vertebral shape (Mode 1 = 44%, Mode 2 = 19%, Mode 3 = 4%). Visual inspection indicated that these modes described variation in anatomical features such as the aspect ratio of the vertebral bodies, width and orientation of the pedicles, and position and orientation of the processes and facet points. Variation in shape along the thoracic spine, characterised by these modes of variation, was consistent with that reported in the literature. Significant differences (p< 0.05) between vertebral levels and between some subjects were found. The reliability of the method was good with low relative error (Mode 1 = 5%, Mode 2 = 8%, Mode 3 = 19%). Statistical shape modelling provides a reliable method for characterizing many anatomical features of the thoracic vertebrae in a compact number of variables. This is useful for robustly assessing morphological differences between scoliotic and non-scoliotic vertebrae and in assessing entry points and trajectories for pedicle screws

Aim. To evaluate the effect of corrective surgery for adolescent idiopathic scoliosis on pelvic morphology. Introduction. Pelvic incidence increases linearly with age during childhood and adolescence before stabilising in adulthood. Most scoliosis surgery occurs before adulthood. We tested the hypothesis that during growth, scoliosis surgery alters the normal linear relationship between pelvic incidence and age. Methods. One hundred patients with 200 radiographs who had undergone surgery for scoliosis were identified. Thirty-eight patients were excluded due to other diagnoses. All patients had posterior surgery for adolescent idiopathic scoliosis. Pre and post-operative lateral radiographs taken at 6 weeks were assessed. Spino-pelvic indices measured were Pelvic Incidence (PI), Sacral Slope (SS), Pelvic Tilt (PT) and the C7 plumb line. Results. There were 62 patients: 58 females and 4 males. Median age was 14 (range 12-17). Median pelvic parameters pre-operatively were 49, 39 and11 degrees for PI, SS and PT respectively. Post operative median values were 48, 36 and14 degrees for PI, SS and PT. Statistical analysis showed no significant differences in pelvic incidence, pelvic tilt or the C7 plumbline between pre- and post-operative values. There was a significant decrease in sacral slope from a median of 39 degrees pre-operatively to 36 degrees post operatively (p=0.007). There was no statistical difference between these variables when analysed by age or gender, nor were there any correlations between the change in variables. All values fell within the normal ranges for age related spino-pelvic parameters. Conclusion. Corrective surgery for adolescent idiopathic scoliosis does not alter pelvic morphology even in the growing adolescent group. Previous studies have documented the pre and post operative correlation between pelvic geometry and spinal alignment in normal and surgical subjects. This study investigates whether surgery affects pelvic morphology during its developmental stages. This to our knowledge has not been described previously

The purpose of this study was to establish the relationship between the anterior and posterior spinal elements and identify which morphological changes in the ageing spine has the greatest influence in determining the loss of lumbar lordosis. Method. 224 patients' (98 male, 126 female) erect plain lumbar radiographs were reviewed. Lateral plane projections were used to measure the lumbar angle (lordosis), spinous process (SP) height, the interspinous gap (ISG) height, the mid-vertebral body (MVB) height and the mid inter-vertebral disc (MIVD) height of vertebral bodies L1 to L5. The relationship between the heights of these structures and their relative influence and effect on the lumbar angle was investigated using a multiple linear regression model. Results. SP, ISG, MVB and MIVD heights all had a statistically significant influence on determining the lumbar angle (p < 10. −3. ). All heights decreased with age except for the SP height (Graph 1). Age was associated with a decreasing lumbar angle (p 0.134) – (Graph 2). Increasing SP height had an inverse relationship on the lumbar angle. The increase in the SP height had the greatest influence on the lumbar angle (Beta coefficient of -0.71), whilst the MVB and MIVD heights had a lesser influence on determining the lumbar angle (Beta coefficients 0.29 and 0.53 respectively). Conclusion. This study demonstrates that the changing morphology of the SP height in the ageing lumbar spine has the greatest influence on determining the lumbar angle of our measured variables. The relative cumulative effect of the increase in the height of the posterior spinal elements has a greater influence on the loss of the lumbar angle than the cumulative loss of height in the anterior spinal elements in the ageing lumbar spine

Chordomas are slowly growing, locally aggressive primary malignant neoplasms derived from primitive notochordal cells. They tend to occur at the extreme of ages and at the two ends of the spinal column. The purpose of this study was to evaluate the presentation, morphology and behaviour of 20 non-clival, non-sacral chordoma cases. Details of 20 cases of histologically confirmed Chordomas of the mobile spine (Cervical-7, Thoracic-7, Lumbar-6) between 1967 and 2006, were extracted from the Scottish Bone Tumour Registry. The casenotes and radiographs were retrospectively reviewed. Non-sacral chordomas comprised 48.7% (20/41 cases) of total chordomas registered. There was a slight feminine predominance (11/20 cases). Mean age was 58.1 years (range, 12 to 82 years). Progressively worsening back pain was the first symptom in all the patients. Seven had intra-lesional (five recurred), six marginal (1 recurred) and 2 wide resections (none recurred). Eleven of the twenty-one patients were treated with adjuvant radiation therapy. In five patients, the chordoma was inoperable and all but one were treated with radiotherapy. There were 2 recurrences in the group of patients treated without adjuvant radiotherapy. Six patients (40%) developed local recurrences and 3 patients (15%) developed metastases. There were 4 survivors including one with local recurrence. Sixteen patients died including 3 with metastases, 7 with persistent primary disease, 1 with local recurrence and 5 with no evidence of disease or died of unrelated causes. Median survival was 19 months (mean-30.2 months), with 5- and 10-year survival rates 10% and 0.0% respectively. We found that non-sacral/non-clival chordomas had a much poorer prognosis than published in the literature. Local recurrences occurred in 40%. Intra-lesional resection should be avoided as it is associated with 71.4% local recurrence in our series

The footplate in the current available TDR is flat without any allowance for endplate concavity in the sagittal plane. To assess the morphology of the endplates of the lower lumbosacral in the sagittal plane, and to identify the frequently occurring shape patterns of the end plates at each level. Retrospective Study. 200 consecutive magnetic reasonance imaging (MRI) scans of patients between the age of 30 and 60 years were analysed. In each endplate, the anteroposterior width, the height of concavity of the endplate, and the distance of the summit from the anterior vertebral body margin were noted. The shape of the endplate was noted as oblong (o) if the curve was uniform starting from the anterior margin and finishing at the posterior margin, eccentric (e) if the curve started after a flat portion at the anterior border and then curving backwards, and flat (f) if there is no curve in the sagittal plane. The shape of the end plate is mostly oblong at L3 IEP(59%), equally distributed between oblong and eccentric at L4 SEP (o=43.5%, e=46.5%), eccentric at L4 IEP (e=62.5%), eccentric at L5 SEP (e = 59.0%), eccentric at L5 IEP (e=94.0%), and flat at S1 SEP (f=82.5%). As there is a difference in the shape of the endplate at each level and they are not uniform, there is a need to focus on the sagittal shape of the footplate to avoid subsidence and mismatch of the footplate in cases of endplate concavity

Generally, it is considered to be safe in preventing iatrogenic instability if half of the facet joint is left intact during decompression surgeries.

By removing half of the facets can we get adequate decompression of the nerve roots? Is there a difference at different levels in the lower lumbar spine? What is the inclination of the facet joint at each level and how does it affect the stability?

Retrospective study

We analysed 200 consecutive magnetic reasonance imaging (MRI) scans of the lumbosacral spine at L3/4, L4/5, and L5/S1 levels. We measured the difference in the distance from midline to the lateral border of the foramen and from midline to the middle of the facet joint at each level on either sides. The angle of the facet joint was also noted.

The distance to the foramen from the level of the middle of the facet joints seem to be between 5-6mm lateral at every level. The angle of the facet joints at L3/4 is 35.9°+/−7.4°, while at L4/5 it is 43.2°+/−8.0°, and at L5/S1 it is 49.4°+/−10.1°.

In lumbar spine decompression surgeries, after the midline decompression extending up to half of the facet joints, a further undercutting of the facet joints to 5-6mm is therefore required to completely decompress the nerve root in the foramen. The more coronal orientation of the facet joint at L5/S1 conforms better stability than that at L3/4level. Therefore, stabilisation of the spine should be considered if more than 2cm of the posterior elements are removed from midline at L3/4 level.

Auckland City Hospital, Auckland, New Zealand.

To show that the spinous processes (SPs) increase in size with age.

To investigate the incidence of SP abutment, relationship to disc degeneration and age related kyphosis.

Describe patterns of SP neoarticulation in relation to back pain and intersegmental axial rotation and deformity.

We reviewed 200 Abdominal CTs, CT myelograms and 100 standing x-rays (age 18-90 years).

We measured SP size, interspinous gap, patterns of neoarticulation, disc height, lumbar lordosis and axial rotation.

We compared symptomatic and asymptomatic groups.

A 30-50% increase in SP size coupled combined with a loss of disc height leads to increasing rates of SP abutment after the age of 35 years. 30% of people over the age of 60 years have SP abutment.

There is a 15 degree increase in standing lumbar kyphosis with age.

Four patterns of SP neoarticulation are seen. Degenerative changes in the SP articulation increase by more than 80% in a symptomatic cohort.

Oblique SP articulation is 2.5 times more likely in symptomatic individuals and associated with a rotational intersegmental deformity.

Ageing is accompanied by SP enlargement and abutment, contributing to a loss of lumbar lordosis.

Patterns of neoarticulation and degeneration appear associated with back pain and rotational deformity.

Aims. Although lumbosacral transitional vertebrae (LSTV) are well-documented, few large-scale studies have investigated thoracolumbar transitional vertebrae (TLTV) and spinal numerical variants. This study sought to establish the prevalence of numerical variants and to evaluate their relationship with clinical problems. Methods. A total of 1,179 patients who had undergone thoracic, abdominal, and pelvic CT scanning were divided into groups according to the number of thoracic and lumbar vertebrae, and the presence or absence of TLTV or LSTV. The prevalence of spinal anomalies was noted. The relationship of spinal anomalies to clinical symptoms (low back pain, Japanese Orthopaedic Association score, Roland-Morris Disability Questionnaire) and degenerative spondylolisthesis (DS) was also investigated. Results. Normal vertebral morphology (12 thoracic and five lumbar vertebrae without TLTV and LSTV) was present in 531 male (76.7%) and 369 female patients (75.8%). Thoracolumbar transitional vertebrae were present in 15.8% of males and 16.0% of females. LSTV were present in 7.1% of males and 9.0% of females. The prevalence of the anomaly of 16 presacral mobile vertebrae (total number of thoracolumbar vertebrae and TLTV) without LSTV was 1.0% in males and 4.1% in females, and that of the anomaly of 18 vertebrae without LSTV was 5.3% in males and 1.2% in females. The prevalence of DS was significantly higher in females with a total of 16 vertebrae than in those with normal morphology. There was no significant correlation between a spinal anomaly and clinical symptoms. Conclusion. Overall, 24% of subjects had anomalies in the thoracolumbar region: the type of anomaly differed between males and females, which could have significant implications for spinal surgery. A decreased number of vertebrae was associated with DS: numerical variants may potentially be a clinical problem. Cite this article: Bone Joint J 2021;103-B(7):1301–1308

Aims. The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment. Methods. Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery. Results. The baseline Cobb angles were similar (p = 0.374) in patients whose curves progressed (32.7° (SD 10.7)) and in those whose curves remained stable (31.4° (SD 6.1)). High supine flexibility (odds ratio (OR) 0.947 (95% CI 0.910 to 0.984); p = 0.006) and correction rate (OR 0.926 (95% CI 0.890 to 0.964); p < 0.001) predicted a lower incidence of progression after adjusting for Cobb angle, Risser sign, curve type, menarche status, distal radius and ulna grading, and brace compliance. ROC curve analysis identified a cut-off of 18.1% for flexibility (sensitivity 0.682, specificity 0.704) and a cut-off of 28.8% for correction rate (sensitivity 0.773, specificity 0.691) in predicting a lower risk of curve progression. A SCI of greater than 1.21 predicted a lower risk of progression (OR 0.4 (95% CI 0.251 to 0.955); sensitivity 0.583, specificity 0.591; p = 0.036). Conclusion. A higher supine flexibility (18.1%) and correction rate (28.8%), and a SCI of greater than 1.21 predicted a lower risk of progression. These novel parameters can be used as a guide to optimize the outcome of bracing. Cite this article: Bone Joint J 2022;104-B(4):495–503

Objectives. This study aims to investigate whether bacteria are present in intervertebral discs (IVDs) and their influence. Causality between chronic infection of the IVD and its degenerative process gained great interest recently. Granville Smith et al. (2021) identified 36 articles from 34 research studies investigating bacteria in IVDs, from these 27 studies found, Cutibacterium acnes being the most abundant. However, whether bacteria identified were present in vivo or if they represent contamination remains unclear. Methods. Human IVD tissue was fixed in paraffin and Immunohistochemical stained for Gram-positive bacteria. NP cells in monolayer have been stimulated with LPS (0.1–50 µg/ml) and Peptidoglycan (0.1–50 µg/ml) for 24, 48 and 72 hrs to investigate their influence. The concentration of proinflammatory and catabolic cytokines in the media is being measured using ELISA. RNA extracted and RT-qPCR utilised for factors associated with disc degeneration matrix genes, matrix degrading enzymes, cytokines, neurotrophic factors and angiogenic factors. Results. Bacteria were detected within IVD tissue. Bacteria was internalized by the NP cells and influenced the nuclei morphology. Preliminary results of the exposure of NP cells to bacterial components demonstrate that ADAMTS4 as well as IL-8 were showed an increase in gene expression after LPS and peptidoglycan treatment compared to the non-treated control. Underlining these results, IL-8 protein was increased in treated groups, whereas peptidoglycan treated groups showed a dose dependence. Conclusion. This study demonstrates that Gram positive bacteria are present within the IVD. The exposure of NP cells to peptidoglycans indicates that bacterial components trigger a stress response. Conflicts of Interest: No conflict 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)

Introduction. Vertebral compression fractures are the most common type of osteoporotic fracture. Though 89% of clinical fractures occur anteriorly, it is challenging to replicate these ex vivo with the underlying intervertebral discs (IVDs) present. Furthermore, the role of disc degeneration in this mechanism is poorly understood. Understanding how disc morphology alters vertebral strain distributions may lead to the utilisation of IVD metrics in fracture prediction, or inform surgical decision-making regarding instrumentation type and placement. Aim. To determine the effect of disc degeneration on the vertebral trabecular bone strain distributions in axial compression and flexion loading. Methods. Eight cadaveric thoracolumbar segments (T11-L3) were prepared (N=4 axial compression, N=4 flexion). µCT-based digital volume correlation was used to quantify trabecular strains. A bespoke loading device fixed specimens at the resultant displacement when loaded to 50N and 800N. Flexion was achieved by adding 6° wedges. Disc degeneration was quantified with Pfirrmann grading and T2 relaxation times. Results. Anterior axial strains were 80.9±39% higher than the posterior region in flexion (p<0.01), the ratio of which was correlated with T2 relaxation time (R. 2. =0.80, p<0.05). In flexion, the central-to-peripheral axial strain ratio in the endplate region was significantly higher when the underlying IVDs were non-degenerated relative to degenerated (+38.1±12%, p<0.05). No significant differences were observed in axial compression. Conclusion. Disc degeneration is a stronger determinant of the trabecular strain distribution when flexion is applied. Load transfer through non-degenerate IVDs under flexion appears to be more centralised, suggesting that disc degeneration predisposes flexion-type compression fractures by shifting high strains anteriorly. Conflicts of interest. The authors declare none. Sources of funding. This work was funded by the Engineering & Physical Sciences Research Council (EP/V029452/1), and Back-to-Back

Background. In vivo evaluation of IVD strains is crucial to better understand normal and pathological IVD mechanics, and to evaluate the effectiveness of treatments. This study aimed to 1) develop a novel in vivo technique based on 3T MRI and digital volume correlation (DVC) to measure strains within IVDs and 2) to use this technique to resolve 3D strains within IVDs of healthy volunteers during extension. Methods. This study included 40 lumbar IVDs from eight healthy subjects. The optimal MR sequence to minimise DVC uncertainties was identified by scanning one subject with four different sequences: CISS, T1VIBE, T2SPACE, and T2TSE. To assess the repeatability of the strain measurements in spines with different anatomical and morphological variations four subjects were scanned with the optimal sequence, and uncertainties of the strain measurements were quantified. Additionally, to calculate 3D strains during extension, MRIs were acquired from six subjects in both the neutral position and after full extension. Results. Measurement errors were lowest when using the T2TSE sequence (precision=0.33 ± 0.10%, accuracy=0.48 ± 0.11%). The largest average maximum tensile and shear strains were seen at the L2-L3 level in all volunteers (7.2 ± 1.5% and 6.8 ± 1.1%, respectively), while the L5-S1 level experienced the lowest average tensile and shear strains (3.5 ± 1.0% and 3.9 ± 0.7%, respectively). Conclusion. The findings of this study establish clinical MRI-based DVC (MRI-DVC) as a new tool for in vivo strain measurement within human IVDs. MRI-DVC successfully provided internal strain distributions within IVDs and has great potential to be used for a wide range of clinical applications. Conflict of interest: No conflicts of interest. Source of funding: This work was supported by the EPSRC, New Investigator Award, EP/V029452/1

Purpose and Background. Both overall spine shape and the size and shape of individual vertebrae undergo rapid growth and development during early childhood. Motor development milestones such as age of walking influence spine development, with delayed ambulation linked with spinal conditions including spondylolysis. However, it is unclear whether associations between motor development and spine morphology persist into older age. Therefore, these associations were examined using data from the MRC National Survey of Health and Development, a large nationally-representative British cohort, followed up since birth in 1946. Methods and Results. Statistical shape modelling was used to characterise spinal shape (L5-T10) and identify modes of variation in shape (SM) from dual energy x-ray absorptiometry images of the spine taken at age 60–64 years (N=1327 individuals; 51.8% female). Associations between walking age in months (reported by mothers at 2 years) and SMs were examined with adjustment for sex, birthweight, socioeconomic position, height, lean mass and fat mass. Later onset of independent walking was weakly associated with greater lordosis (SM1; P=0.05) and more uniform antero-posterior vertebral size along the spine (SM6, P=0.07). Later walking age was also associated with smaller relative anterior-posterior vertebral dimensions (SM3) among women whereas the opposite was found for men (P <0.01 for sex interaction). Conclusions. Spinal morphology in early old age was associated with the age that individuals began walking independently in childhood, potentially due to altered mechanical loading. This suggests that motor development may have a persisting effect on clinically-relevant features of spine morphology throughout life. Conflict of interest: None. Funded by the UK Medical Research Council (Grant MR/L010399/1) which supported FRS, SGM and AVP

Aims

The aims of this study were first, to determine if adding fusion to a decompression of the lumbar spine for spinal stenosis decreases the rate of radiological restenosis and/or proximal adjacent level stenosis two years after surgery, and second, to evaluate the change in vertebral slip two years after surgery with and without fusion.

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.

Aims

The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.