There is a need for non-radiographic, objective outcome measures for children with Adolescent Idiopathic Scoliosis (AIS). Standing balance and stability is altered in children with AIS. The Margin of Stability (MoS) has been used to compare gait stability in clinical populations. Our objective was to compare the MoS in anterior-posterior (MoS. AP. ) and mediolateral (MoS. ML. ) directions in girls with AIS to Controls. Girls with AIS and healthy girls walked at three speeds on an instrumented treadmill wearing retroreflective markers, surrounded by motion capture cameras. The MoS. AP/ML. was calculated at left and right heel strike. Data was processed in Visual 3D. A two-way ANOVA was used to compare MoS. AP/ML. between group, speed and the interaction between group and speed. Pearson's correlation coefficient was used to compare the MoS to Cobb angle. Statistical significance was accepted when p > 0.05. A priori power analysis suggested 12 participants per group. Three Cases and four Controls were recruited. Girls with AIS all had right-sided main thoracic curves (Lenke type 1a, 61.3° ± 10.0°). MoS. AP. was significantly bigger for Cases compared to Controls on the left (p=0.038) and right foot (p=0.041). There was no significant difference between Cases and Controls for MoS. ML. , but there was a visual trend for a smaller MoS. ML. in Cases. There was no significant difference for speed or the interaction between group and speed for MoS. AP. or MoS. ML. In Cases, MoS. AP. increased with increasing Cobb angle on the left (r. 2. =0.687, p=0.054) and right (r. 2. =0.634, p=0.067) and MoS. ML. decreased with increasing Cobb angle on the left (r. 2. =-0.912, p=0.002). Further subjects are being recruited. Girls with Lenke type 1a AIS are more stable in the AP direction and less stable in the ML direction than Controls during treadmill walking. AP stability increases and ML stability decreases with increasing Cobb angle. This research suggests that the MoS could be used as an outcome measure for children with AIS. Continued work is required to increase the power of this study. Further work could consider these changes during walking overground, measuring an MoS or MoS-like measure using a wearable device, and in different curve types

Background and Purpose:

The inability of intervertebral joints to resist perturbation due to laxity is traditionally measured in cadaveric specimens as their neutral zones (NZ). However in patients, quantitative fluoroscopic (QF) examinations substitute the Initial Attainment Rate for this. If these two measures correspond sufficiently, a clinical method for measuring segmental instability is possible. This study explored this by determining the criterion validity of the Initial Attainment Rate against the Dynamic NZ in an unloaded multilevel porcine spine.

Statement of Purpose

The purpose of this experiment was to characterize the biomechanical properties of a minimally-invasive flexion-restricting stabilization system (FRSS) developed to address flexion instability.

Purpose and Background. Clinical practice guidelines (CPGs) recommend self-management for low back pain (LBP). Our recent narrative review on self-management needs revealed a consensus with respect to the critical components of self-management interventions. With mobile health advancements, apps offer innovative support for LBP management. This study aims to identify current apps for the self-management of LBP, assessing them for their quality, intervention content, theoretical approaches, and risk management approaches. Methods and Results. We identified 69 apps for LBP self-management from a systematic search in the UK iTunes and Google Play stores. The most recommended interventions are muscle stretching (n=51, 73.9%), muscle strengthening (n=42, 60.9%), and core stability exercises (n=32, 46.4%). The average MARS (SD) overall score for the included apps was 2.4 (0.44) out of a possible 5 points, with the engagement and information dimension scoring the lowest at 2.1. In terms of theoretical and risk management approaches, no apps offered a theoretical care model and all failed to specify the age group targeted; only one (1.4%) provided a tailored care approach; 18 (26.1%) included intervention progression; and 11 (15.9%) reported management safety checks. Conclusion. This study shows that app developers generally select interventions endorsed by CPGs. However, the application of a biopsychosocial care model is not being considered. Most of them are of low quality, lacking theoretical approaches to care and consideration of associated risks. It is essential to involve clinicians and patients in developing LBP self-management apps to improve the quality and related approach. Conflicts of interest. None. Sources of funding. No funding obtained. This study has been published in JMIR mHealth and uHealth

Introduction. Patients with metastatic spinal cord compression (MSCC) or unstable spinal lesions warrant early surgical consultation. In multiple myeloma, chemotherapy and radiotherapy have the potential to decompress the spinal canal effectively in the presence of epidural lesions. Mechanical stability conferred by bracing may potentiate intraosseous and extraosseous bone formation, thus increasing spinal stability. This study aims to review the role of non-operative management in myeloma patients with a high degree of spinal instability, in a specialist tertiary centre. Methods. Retrospective analysis of a prospectively collected database of 83 patients with unstable myelomatous lesions of the spine, defined by a Spinal Instability Neoplastic Score (SINS) of 13–18. Data collected include patient demographics, systemic treatment, neurological status, radiological presence of cord compression, most unstable vertebral level and presence of intraosseous and extraosseous bone formation. Post-treatment scores were calculated based on follow-up imaging which was carried out at 2 weeks for cord compression and 12 weeks for spinal instability. A paired t-test was used to identify any significant difference between pre- and post-treatment SINS and linear regression was used to assess the association between variables and the change in SINS. Results. A significant reduction in SINS was observed from a pre-treatment average score of 14 to a score of 9, following treatment for myeloma (p<0.001). A higher initial score and a younger age were associated with a larger overall reduction in SINS (p<0.001 and p=0.02 respectively). No single variable (bisphosphates, chemotherapy, radiotherapy and steroids) had a significant association with SINS reduction. 25 (30%) patients had spinal cord compression, all of which showed radiological resolution of cord compression at 2 weeks. No patients developed neurological deterioration during treatment and all patients had an improvement in their pain scores. 64 (77%) patients had evidence of intraosseous and/or extraosseous bone formation on their follow-up scan. Conclusion. Non-operative management in the form of bracing and systemic therapy is a safe and effective treatment for spinal instability and spinal cord compression in myeloma. Treatment of unstable myelomatous lesions of the spine with or without cord compression should not follow traditional guidelines for MSCC. The decision to adopt a non-operative approach in this cohort of patients should ideally be made in a tertiary centre with expertise in multiple myeloma and in a multidisciplinary setting

Aims. The aim of this study was to systematically compare the safety and accuracy of robot-assisted (RA) technique with conventional freehand with/without fluoroscopy-assisted (CT) pedicle screw insertion for spine disease. Methods. A systematic search was performed on PubMed, EMBASE, the Cochrane Library, MEDLINE, China National Knowledge Infrastructure (CNKI), and WANFANG for randomized controlled trials (RCTs) that investigated the safety and accuracy of RA compared with conventional freehand with/without fluoroscopy-assisted pedicle screw insertion for spine disease from 2012 to 2019. This meta-analysis used Mantel-Haenszel or inverse variance method with mixed-effects model for heterogeneity, calculating the odds ratio (OR), mean difference (MD), standardized mean difference (SMD), and 95% confidence intervals (CIs). The results of heterogeneity, subgroup analysis, and risk of bias were analyzed. Results. Ten RCTs with 713 patients and 3,331 pedicle screws were included. Compared with CT, the accuracy rate of RA was superior in Grade A with statistical significance and Grade A + B without statistical significance. Compared with CT, the operating time of RA was longer. The difference between RA and CT was statistically significant in radiation dose. Proximal facet joint violation occurred less in RA than in CT. The postoperative Oswestry Disability Index (ODI) of RA was smaller than that of CT, and there were some interesting outcomes in our subgroup analysis. Conclusion. RA technique could be viewed as an accurate and safe pedicle screw implantation method compared to CT. A robotic system equipped with optical intraoperative navigation is superior to CT in accuracy. RA pedicle screw insertion can improve accuracy and maintain stability for some challenging areas. Cite this article: Bone Joint Res 2020;9(10):653–666

Aims

Symptomatic spinal stenosis is a very common problem, and decompression surgery has been shown to be superior to nonoperative treatment in selected patient groups. However, performing an instrumented fusion in addition to decompression may avoid revision and improve outcomes. The aim of the SpInOuT feasibility study was to establish whether a definitive randomized controlled trial (RCT) that accounted for the spectrum of pathology contributing to spinal stenosis, including pelvic incidence-lumbar lordosis (PI-LL) mismatch and mobile spondylolisthesis, could be conducted.

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.

Aims

The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF.

Aims

The aim of this study was to report the long-term prognosis of patients with multiple Langerhans cell histiocytosis (LCH) involving the spine, and to analyze the risk factors for progression-free survival (PFS).

Aims

To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation.

Aims

Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre.

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.

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.

This review provides a concise outline of the advances made in the care of patients and to the quality of life after a traumatic spinal cord injury (SCI) over the last century. Despite these improvements reversal of the neurological injury is not yet possible. Instead, current treatment is limited to providing symptomatic relief, avoiding secondary insults and preventing additional sequelae. However, with an ever-advancing technology and deeper understanding of the damaged spinal cord, this appears increasingly conceivable. A brief synopsis of the most prominent challenges facing both clinicians and research scientists in developing functional treatments for a progressively complex injury are presented. Moreover, the multiple mechanisms by which damage propagates many months after the original injury requires a multifaceted approach to ameliorate the human spinal cord. We discuss potential methods to protect the spinal cord from damage, and to manipulate the inherent inhibition of the spinal cord to regeneration and repair. Although acute and chronic SCI share common final pathways resulting in cell death and neurological deficits, the underlying putative mechanisms of chronic SCI and the treatments are not covered in this review.

Aims. Loosening of pedicle screws is a major complication of posterior spinal stabilisation, especially in the osteoporotic spine. Our aim was to evaluate the effect of cement augmentation compared with extended dorsal instrumentation on the stability of posterior spinal fixation. Materials and Methods. A total of 12 osteoporotic human cadaveric spines (T11-L3) were randomised by bone mineral density into two groups and instrumented with pedicle screws: group I (SHORT) separated T12 or L2 and group II (EXTENDED) specimen consisting of T11/12 to L2/3. Screws were augmented with cement unilaterally in each vertebra. Fatigue testing was performed using a cranial-caudal sinusoidal, cyclic (1.0 Hz) load with stepwise increasing peak force. Results. Augmentation showed no significant increase in the mean cycles to failure and fatigue force (SHORT p = 0.067; EXTENDED p = 0.239). Extending the instrumentation resulted in a significantly increased number of cycles to failure and a significantly higher fatigue force compared with the SHORT instrumentation (EXTENDED non-augmented + 76%, p < 0.001; EXTENDED augmented + 87%, p < 0.001). Conclusion. The stabilising effect of cement augmentation of pedicle screws might not be as beneficial as expected from biomechanical pull-out tests. Lengthening the dorsal instrumentation results in a much higher increase of stability during fatigue testing in the osteoporotic spine compared with cement augmentation. Cite this article: Bone Joint J 2016;98-B:1099–1105

Objectives. Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical in vitro study was to evaluate the effect of cement augmentation on the screw pull-out force in osteoporotic vertebrae, comparing different pedicle screws (solid and fenestrated) and cement volumes (0 mL, 1 mL or 3 mL). Materials and Methods. A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired t-test was used to compare the two screws within each vertebra. Results. Mean failure load was significantly greater for fenestrated cemented screws (+622 N; p ⩽ 0.001) and solid cemented screws (+460 N; p ⩽ 0.001) than for uncemented screws. There was no significant difference between the solid and fenestrated cemented screws (p = 0.5). In the lower thoracic vertebrae, 1 mL cement was enough to significantly increase failure load, while 3 mL led to further significant improvement in the upper thoracic, lower thoracic and lumbar regions. Conclusion. Conventional, solid pedicle screws augmented with high-viscosity cement provided comparable screw stability in pull-out testing to that of sophisticated and more expensive fenestrated screws. In terms of cement volume, we recommend the use of at least 1 mL in the thoracic and 3 mL in the lumbar spine. Cite this article: C. I. Leichtle, A. Lorenz, S. Rothstock, J. Happel, F. Walter, T. Shiozawa, U. G. Leichtle. Pull-out strength of cemented solid versus fenestrated pedicle screws in osteoporotic vertebrae. Bone Joint Res 2016;5:419–426

Aims

Anchorage of pedicle screw rod instrumentation in the elderly spine with poor bone quality remains challenging. Our study aims to evaluate how the screw bone anchorage is affected by screw design, bone quality, loading conditions, and cementing techniques.

Background. The rate of subsidence for lumbar fusion surgery is variable from 7- 89%. Subsidance can affect the outcome of surgery by compramising alignment, foraminal height and stability. Modic changes have been shown to affect the stiffness and strength of the vertebral end plate and shown to affect both fusion rates and clinical outcome. Ongoing laboratory investigations into the material properties of the degenerate lumbar spine show modic changes affect the end plate and trabecular bone mechanics. This study aims to bridge this basic science research into clinical practice. Methods. A retrospective analysis of all patients in two tertiary spinal centres who have undergone lumbar interbody fusion with the implantation of a ‘cage’ over the past 6 years were analysed by two independent spinal surgeons. Pre-operative MRI findings were correlated with post-operative interbody cage subsidence after 1 year. Results. A total of 108 Interbody cages were included. Comparison of demographics did not reveal and significant between group variations. Comparison made between those displaying no modic changes and those displaying any of the three modic change types revealed a significantly higher subsidence rate in those displaying modic changes (p=0.003). Subgroup analysis showed that Type 2 modic changes (n=27) had a significantly higher subsidence rate (p=0.002). Those displaying type 3 modic changes (n=7) did not have any incidents of subsidence. Conclusions. Type 2 modic changes are associated with a higher rate of Lumbar interbody cage subsidence in this study. Those displaying type 3 changes seem to be protected from interbody cage subsidence. No Conflict of Interest. Funding: Produced as part of a research grant from the Gwen Fish Trust and Action Arthritis

Background and Aim. Spinal stability is associated with low back pain and affects the spines ability to support loads. Stability can be achieved if the applied force follows the curvature of the spine, passing close to the vertebral centroids. Previously we showed that calculated muscle forces required for stability in an idealised model increased with increasing and more evenly distributed lumbar curvatures. The purpose of this study was to calculate the muscle forces required for stability in standing in a group of healthy adults. Methods. Positional MRI was used to acquire sagittal images of the lumbar spine in a standing posture in 30 healthy adults. Sacral inclination was measured and active shape modelling used to characterise lumbar spine shape. A two-dimensional model of the lumbar spine was constructed using vertebral centroid positions and a simplified representation of the lumbar extensor muscles. The muscle forces required at each level to produce a follower load were calculated using a force polygon. Results. Sacral angle was positively correlated with the amount of overall curvature in the lumbar spine (P<0.001) but not the distribution of curvature. Muscle forces increased with increasing curvature at all lumbar levels (P<0.02). The distribution of curvature affected the muscle forces only at L3 (P<0.03). Conclusion. In a sample of healthy adults, muscle forces required to maintain stability are determined by the overall curviness of the lumbar spine and, to a lesser extent, the distribution of curvature. Variations in spinal shape should be considered when modelling lumbar spine loading. 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. An NHS Endowment grant provided further funding