ISSLS PRIZE in Clinical Science 2023: comparison of degenerative MRI features of the intervertebral disc between those with and without chronic low back pain. An exploratory study of two large female populations using automated annotation.

OBJECTIVES: The relationship of degeneration to symptoms has been questioned. MRI detects apparently similar disc degeneration and degenerative changes in subjects both with and without back pain. We aimed to overcome these problems by re-annotating MRIs from asymptomatic and symptomatics groups onto the same grading system. METHODS: We analysed disc degeneration in pre-existing large MRI datasets. Their MRIs were all originally annotated on different scales. We re-annotated all MRIs independent of their initial grading system, using a verified, rapid automated MRI annotation system (SpineNet) which reported degeneration on the Pfirrmann (1-5) scale, and other degenerative features (herniation, endplate defects, marrow signs, spinal stenosis) as binary present/absent. We compared prevalence of degenerative features between symptomatics and asymptomatics. RESULTS: Pfirrmann degeneration grades in relation to age and spinal level were very similar for the two independent groups of symptomatics over all ages and spinal levels. Severe degenerative changes were significantly more prevalent in discs of symptomatics than asymptomatics in the caudal but not the rostral lumbar discs in subjects < 60 years. We found high co-existence of degenerative features in both populations. Degeneration was minimal in around 30% of symptomatics < 50 years. CONCLUSIONS: We confirmed age and disc level are significant in determining imaging differences between asymptomatic and symptomatic populations and should not be ignored. Automated analysis, by rapidly combining and comparing data from existing groups with MRIs and information on LBP, provides a way in which epidemiological and 'big data' analysis could be advanced without the expense of collecting new groups. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

An NIHR-approved two-year observational study on magnetically controlled growth rods in the treatment of early onset scoliosis.

Aims: The primary aim of this study was to evaluate the performance and safety of magnetically controlled growth rods in the treatment of early onset scoliosis. Secondary aims were to evaluate the clinical outcome, the rate of further surgery, the rate of complications, and the durability of correction. Patients and Methods: We undertook an observational prospective cohort study of children with early onset scoliosis, who were recruited over a one-year period and followed up for a minimum of two years. Magnetically controlled rods were introduced in a standardized manner with distractions performed three-monthly thereafter. Adverse events which were both related and unrelated to the device were recorded. Ten children, for whom relevant key data points (such as demographic information, growth parameters, Cobb angles, and functional outcomes) were available, were recruited and followed up over the period of the study. There were five boys and five girls. Their mean age was 6.2 years (2.5 to 10). Results: The mean coronal Cobb angle improved from 57.6° (40° to 81°) preoperatively, 32.8° (28° to 46°) postoperatively, and 41° (19° to 57°) at two years. Five children had an adverse event, with four requiring return to theatre, but none were related to the device. There were no neurological complications or infections. No devices failed. One child developed a proximal junctional kyphosis. The mean gain in spinal column height from T1 to S1 was 45.4 mm (24 to 81) over the period of the study. Conclusion: Magnetically controlled growth rods provide an alternative solution to traditional growing rods in the surgical management of children with early onset scoliosis, supporting growth of the spine while controlling curve progression. Their use has clear psychosocial and economic benefits, with the reduction of the need for repeat surgery as required with traditional growing rods. Cite this article: Bone Joint J 2018;100-B:507-15.

Top ten research priorities for spinal cord injury: the methodology and results of a British priority setting partnership.

STUDY DESIGN: This is a mixed-method consensus development project. OBJECTIVES: The objective of this study was to identify a top ten list of priorities for future research into spinal cord injury (SCI). SETTING: The British Spinal Cord Injury Priority Setting Partnership was established in 2013 and completed in 2014. Stakeholders included consumer organisations, healthcare professional societies and caregivers. METHODS: This partnership involved the following four key stages: (i) gathering of research questions, (ii) checking of existing research evidence, (iii) interim prioritisation and (iv) a final consensus meeting to reach agreement on the top ten research priorities. Adult individuals with spinal cord dysfunction because of trauma or non-traumatic causes, including transverse myelitis, and individuals with a cauda equina syndrome (henceforth grouped and referred to as SCI) were invited to participate in this priority setting partnership. RESULTS: We collected 784 questions from 403 survey respondents (290 individuals with SCI), which, after merging duplicate questions and checking systematic reviews for evidence, were reduced to 109 unique unanswered research questions. A total of 293 people (211 individuals with SCI) participated in the interim prioritisation process, leading to the identification of 25 priorities. At a final consensus meeting, a representative group of individuals with SCI, caregivers and health professionals agreed on their top ten research priorities. CONCLUSION: Following a comprehensive, rigorous and inclusive process, with participation from individuals with SCI, caregivers and health professionals, the SCI research agenda has been defined by people to whom it matters most and should inform the scope and future activities of funders and researchers for the years to come. SPONSORSHIP: The NIHR Oxford Biomedical Research Centre provided core funding for this project.

Measuring the rib hump in scoliosis with ISIS2.

The three-dimensional shape of the back of 60 patients attending a spinal deformity clinic was measured using ISIS2, a non-commercial surface topography system using digital photography and structured light. Wire-frame and contour plots were displayed, presenting quantitative information and providing a useful pictorial representation of the whole back. A numerical parameter representing the height of the rib hump was also recorded. Repeat measurements, with the patient walking around the room between photographs were carried out. The mean difference between the pairs of measurements was -0.08 mm (sd 4.18 mm) and the 95% tolerance limits were -9.82 mm to 9.66 mm. Changes of greater than +/-10 mm are therefore necessary as indicative of clinical change.

Thoracic kyphosis angle measurements with ISIS2.

Thoracic kyphosis angle measurements using surface topography with ISIS2 were carried out to estimate the inherent variability in the parameter caused by natural change in the patient's stance, breathing and muscle tension. A mean kyphosis angle of 33.8 degrees (sd 13.4 degrees , range 6 degrees -66 degrees ) was measured from repeat tests on 61 patients. The mean difference between the pairs of measurements was -0.02 degrees (sd 3.18 degrees ) and the 95% tolerance limits were -7.41 degrees to 7.38 degrees . This variability is lower than the clinically significant change in kyphosis angle reported in the literature. Thus kyphosis angle in ISIS2 is suitable for monitoring progress in kyphotic deformities.

New method of Scoliosis Deformity Assessment: ISIS2 System.

Scoliosis deformity has been assessed using radiographic angle measurements. Surface topography systems are an alternative and complementary methodology. Working systems include the original ISIS1 system, Quantec and COMOT techniques. Over the last five years the new ISIS2 (Integrated Shape Imaging System) has been developed from basic principles to improve the speed, accuracy, reliability and ease of use of ISIS1. The aim of this study was to confirm that ISIS2 3D back shape measurements are valid for assessment and follow up of patients with scoliosis. Three-dimensional back measurements were performed in Oxford. ISIS2 includes a camera/projector stand, patient stand with a reference plane, and Mac computer. Pixel size is approximately 0.5 mm with fringe frequency of approximately 0.16 fringes/mm ( approximately 6.5 mm/fringe). Clinical reports in pdf format are of coloured images with numerical values. Reports include a height map, contour plot, transverse section plots, coronal plot, sagittal sections and bilateral asymmetry maps. A total of 520 ISIS2 scans on 242 patients were performed from February 2006 to December 2007. There were 58 male patients (median age 16 years, SD 3.71, min 7, max 25) and 184 female patients (median age 14.5 years, SD 3.23, min 5, max 45). Average number of scans per patient was 2.01 with the range of 1-10 scans. Right sided thoracic curves were the most frequent pattern. The median values and 95% CI are reported of back length; pelvic rotation; flexion/extension; imbalance; lateral asymmetry; skin angle; kyphosis angle; lordosis angle; volumetric asymmetry. ISIS2 scoliosis measurements are non-invasive, low-cost, three-dimensional topographic back measurements which can be confidently used in scoliosis assessment and monitoring of curve progression.

The internal pressure and stress environment of the scoliotic intervertebral disc--a review.

The aetiology, in terms of both initiation and progression, of the deformity in idiopathic scoliosis is at present unclear. Even in neuromuscular cases, the mechanisms underlying progression are not fully elucidated. It is thought, however, that asymmetrical loading is involved in the progression of the disease, with evidence mainly from animal studies and modelling. There is, however, very little direct information as to the origin or mechanism of action of these forces in the scoliotic spine. This review describes the concept of intervertebral disc pressure or stress and examines possible measurement techniques. The biological and mechanical consequences of abnormalities in these parameters are described. Future possible studies and their clinical significance are also briefly discussed. Techniques of pressure measurement have culminated in the development of 'pressure profilometry', which provides stress profiles across the disc in mutually perpendicular axes. A hydrated intervertebral disc exhibits mainly hydrostatic behaviour. However, in pathological states such as degeneration and scoliosis, non-hydrostatic behaviour predominates and annular peaks of stress occur. Recent studies have shown that, in scoliosis, high hydrostatic pressures are seen with asymmetrical stresses from concave to convex sides. These abnormalities could influence both disc and endplate cellular activity directly, causing asymmetrical growth and matrix changes. In addition, disc cells could be influenced via nutritional changes consequent to end-plate calcification. Evidence suggests that the stress environment of the scoliotic disc is abnormal, probably generated by high and asymmetrical loading of non-muscular origin. If present in the scoliotic spine during daily activities, this could generate a positive feedback of cellular changes, resulting in curve progression. Future advances in understanding may rely on the development of computer models owing to the difficulties of in-vivo invasive measurements.

Development of a German version of the Oswestry Disability Index. Part 2: sensitivity to change after spinal surgery.

When functional scales are to be used as treatment outcome measures, it is essential to know how responsive they are to clinical change. This information is essential not only for clinical decision-making, but also for the determination of sample size in clinical trials. The present study examined the responsiveness of a German version of the Oswestry Disability Index version 2.1 (ODI) after surgical treatment for low back pain. Before spine surgery 63 patients completed a questionnaire booklet containing the ODI, along with a 0-10 pain visual analogue scale (VAS), the Roland Morris disability questionnaire, and Likert scales for disability, medication intake and pain frequency. Six months after surgery, 57 (90%) patients completed the same questionnaire booklet and also answered Likert-scale questions on the global result of surgery, and on improvements in pain and disability. Both the effect size for the ODI change score 6 months after surgery (0.87) and the area under the receiver operating characteristics (ROC) curve for the relative improvement in ODI score in relation to global outcome 6 months after surgery (0.90) indicated that the ODI showed good responsiveness. The ROC method revealed that a minimum reduction of the baseline (pre-surgery) ODI score by 18% (equal to a mean 8-point reduction in this patient group) represented the cut-off for indicating a "good" individual outcome 6 months after surgery (sensitivity 91.4% and specificity 82.4%). The German version of the ODI is a sensitive instrument for detecting clinical change after spinal surgery. Individual improvements after surgery of at least an 18% reduction on baseline values are associated with a good outcome. This figure can be used as a reliable guide for the determination of sample size in future clinical trials of spinal surgery.

Development of a German version of the Oswestry Disability Index. Part 1: cross-cultural adaptation, reliability, and validity.

Patient-orientated assessment methods are of paramount importance in the evaluation of treatment outcome. The Oswestry Disability Index (ODI) is one of the condition-specific questionnaires recommended for use with back pain patients. To date, no German version has been published in the peer-reviewed literature. A cross-cultural adaptation of the ODI for the German language was carried out, according to established guidelines. One hundred patients with chronic low-back pain (35 conservative, 65 surgical) completed a questionnaire booklet containing the newly translated ODI, along with a 0-10 pain visual analogue scale (VAS), the Roland Morris Disability Questionnaire, and Likert scales for disability, medication intake and pain frequency [to assess ODI's construct (convergent) validity]. Thirty-nine of these patients completed a second questionnaire within 2 weeks (to assess test-retest reliability). The intraclass correlation coefficient for the test-retest reliability of the questionnaire was 0.96. In test-retest, 74% of the individual questions were answered identically, and 21% just one grade higher or lower. The standard error of measurement (SEM) was 3.4, giving a "minimum detectable change" (MDC(95%)) for the ODI of approximately 9 points, i.e. the minimum change in an individual's score required to be considered "real change" (with 95% confidence) over and above measurement error. The ODI scores correlated with VAS pain intensity (r = 0.78, P < 0.001) and Roland Morris scores (r = 0.80, P < 0.001). The mean baseline ODI scores differed significantly between the surgical and conservative patients (P < 0.001), and between the different categories of the Likert scales for disability, medication use and pain frequency (in each case P < 0.001). Our German version of the Oswestry questionnaire is reliable and valid, and shows psychometric characteristics as good as, if not better than, the original English version. It should represent a valuable tool for use in future patient-orientated outcome studies in German-speaking lands.

Internal fixation for osteomyelitis of cervical spine: the issue of persistence of culture positive infection around the implants.

BACKGROUND: We describe the management of osteomyelitis of the cervical spine, utilizing internal fixation with subsequent removal and culture of the implants. Four out of five patients had evidence of bacterial colonisation in close proximity to the internal fixation device. METHODS: Five consecutive patients (all female, ranging in age from 50 to 74 yrs) presenting with unstable cervical osteomyelitis were treated by surgical decompression, primary internal fixation followed by three months of intravenous antibiotics. The internal fixation was removed in 4 out of 5 cases within a year of stopping the intravenous regime. The remaining patient was deemed medically unfit for further operation. Multiple specimens from the screw sites were taken at the time of metal removal. A final course of oral antibiotics was prescribed based on the results of these specimens. FINDINGS: Four patients, who had removal of the implants, had positive cultures growing different bacteria from the primary infection, at the time of removal of the implant. None of the patients developed instability after removal of the implant. INTERPRETATION: Asymptomatic bacterial colonisation of a metallic implant has profound management implications. We recommend long-term oral antibiotic regimes after insertion of internal fixation devices in the face of infection and eventual removal of these implants and microbiological re-sampling.

Clinical importance of the intervertebral disc, or back pain for biochemists.

The object of this paper is to give biochemists some insight into current thinking on back pain. I shall discuss the important, but limited, relationship of back pain to the principal pathological changes in the lumbar intervertebral discs. I shall point out some of the areas where scientists may be able to help clinicians understand and treat this common, but complex, condition. The literature on back pain is enormous, so I have made no attempt to select even a small part of it for this article.

Instability due to unrecognised fracture-subluxations after apparently isolated injuries of the cervical spine.

Instability may present at a different level after successful stabilisation of an unstable segment in apparently isolated injuries of the cervical spine. It can give rise to progressive deformity or symptoms which require further treatment. We performed one or more operations for unstable cervical spinal injuries on 121 patients over a period of 90 months. Of these, five were identified as having instability due to an initially unrecognised fracture-subluxation at a different level. We present the details of these five patients and discuss the problems associated with their diagnosis and treatment.

Electrochemical measurement of transport into scoliotic intervertebral discs in vivo using nitrous oxide as a tracer.

STUDY DESIGN: An in vivo study measuring nitrous oxide concentrations in scoliotic intervertebral discs during surgery. OBJECTIVES: To determine pathways for nutrient transport into scoliotic human discs in vivo. SUMMARY OF BACKGROUND DATA: The intervertebral disc is the largest avascular structure in the body. Disc cells in the nucleus rely on the blood supply from the vertebral bodies for supply of nutrients and removal of waste. Loss of nutrient supply is thought to lead to disc degeneration, but solute transport has not been measured in vivo in humans. METHODS: We measured solute transport into the disc using N2O as a tracer, in 19 human discs from five patients with neuromuscular scoliosis (6-19 years of age) during surgery for correction of scoliotic deformities. During anesthesia N2O diffuses into the disc at a rate governed by effective permeability of the vertebral body-disc interface. Intradiscal N2O concentrations were measured amperometrically using silver needle microelectrodes, which were inserted into the discs once they were exposed by an anterior approach. RESULTS: For all spines N2O concentrations were very low in the disc at the curve apex (6% those expected from unimpeded diffusion) and, although still low, were significantly higher 2 discs below or above the apex. CONCLUSIONS: Because flux into the apical disc is most restricted, the decrease in solute transport is possibly induced by changes in mechanical stress on the disc; microfocal radiographs of a scoliotic spine suggest that increased endplate calcification could be partly responsible for limiting solute diffusion.

Intervertebral disc composition in neuromuscular scoliosis: changes in cell density and glycosaminoglycan concentration at the curve apex.

STUDY DESIGN: An analysis of the variation in glycosaminoglycan, water content, and cell density with disc level in patients with neuromuscular scoliosis. OBJECTIVES: To determine whether the composition of the apical disc differed from that of adjacent discs in the same spine. SUMMARY OF BACKGROUND DATA: Compositional differences between the convex and concave sides of scoliotic discs have been noted and are thought to be secondary to altered loading. However, there is little information on changes relative to the apex. METHODS: Intact wedges of disc obtained during anterior fusion procedures were taken from 23 discs of 6 patients with neuromuscular scoliosis. Radial profiles of glycosaminoglycan, water content, and cell density were measured. Concentrations were compared at a standard distance (5 mm) into the disc and plotted versus spinal level. RESULTS: Glycosaminoglycan and water content were lowest in the outer annulus and increased steadily toward the disc center, whereas the cell density was highest in the outer 2 mm, fell steeply and then remained constant. At 5 mm from the annulus edge, cell density was lowest in apical discs and, in most cases, was noticeably higher in adjacent discs of the same spine. At the same point, there was no consistent change in glycosaminoglycan/dry weight from disc to disc, indicating no significant proteoglycan loss. However, glycosaminoglycan/tissue water, and therefore swelling pressure, was highest in the apical discs, suggesting that these discs were the most heavily loaded. CONCLUSIONS: The loss of cells from the disc at the curve apex probably arose because this disc experiences greater mechanical stress or is more deformed than its neighbors. The decrease in cell density was not associated with major changes in tissue composition, possibly because rates of degradation and of synthesis were reduced, leaving the matrix largely unchanged.

Measuring exposure to racism: development and validation of a Race-Related Stressor Scale (RRSS) for Asian American Vietnam veterans.

This article describes the development and validation of the Race-Related Stressor Scale (RRSS), a questionnaire that assesses exposure to race-related stressors in the military and war zone. Validated on a sample of 300 Asian American Vietnam veterans, the RRSS has high internal consistency and adequate temporal stability. Hierarchical regression analyses revealed that exposure to race-related stressors accounted for a significant proportion of the variance in posttraumatic stress disorder (PTSD) symptoms and general psychiatric symptoms, over and above (by 20% and 19%, respectively) that accounted for by combat exposure and military rank. The RRSS appears to be a psychometrically sound measure of exposure to race-related stressors for this population. Race-related stressors as measured by the RRSS appear to contribute uniquely and substantially to PTSD symptoms and generalized psychiatric distress.

The Oswestry Disability Index.

STUDY DESIGN: The Oswestry Disability Index (ODI) has become one of the principal condition-specific outcome measures used in the management of spinal disorders. This review is based on publications using the ODI identified from the authors' personal databases, the Science Citation Index, and hand searches of Spine and current textbooks of spinal disorders. OBJECTIVES: To review the versions of this instrument, document methods by which it has been validated, collate data from scores found in normal and back pain populations, provide curves for power calculations in studies using the ODI, and maintain the ODI as a gold standard outcome measure. SUMMARY OF BACKGROUND DATA: It has now been 20 years since its original publication. More than 200 citations exist in the Science Citation Index. The authors have a large correspondence file relating to the ODI, that is cited in most of the large textbooks related to spinal disorders. METHODS: All the published versions of the questionnaire were identified. A systematic review of this literature was made. The various reports of validation were collated and related to a version. RESULTS: Four versions of the ODI are available in English and nine in other languages. Some published versions contain misprints, and many omit the scoring system. At least 114 studies contain usable data. These data provide both validation and standards for other users and indicate the power of the instrument for detecting change in sample populations. CONCLUSIONS: The ODI remains a valid and vigorous measure and has been a worthwhile outcome measure. The process of using the ODI is reviewed and should be the subject of further research. The receiver operating characteristics should be explored in a population with higher self-report disabilities. The behavior of the instrument is incompletely understood, particularly in sensitivity to real change.