The ratio of the sagittal diameter of the cervical canal to the corresponding diameter of the vertebral body has been described as a reliable means for assessing stenosis of the canal and detecting those at risk of cervical neuropraxia. The use of ratio techniques has the advantage of avoiding variation in magnification when direct measurements are made from plain radiographs. We examined the reliability of this method using plain lateral radiographs of unknown magnification and CT scans. We also assessed other possible ratios of anatomical measurements as a guide to the diameter of the canal.

Our findings showed a poor correlation between the true diameter of the canal and the ratio of its sagittal diameter to that of the vertebral body. No other more reliable ratio was identified. The variability in anatomical morphology means that the use of ratios from anatomical measurements within the cervical spine is not reliable in determining the true diameter of the cervical canal.

Aims. The aim of this study was to determine the differences in spinal imaging characteristics between subjects with or without lumbar developmental spinal stenosis (DSS) in a population-based cohort. Methods. This was a radiological analysis of 2,387 participants who underwent L1-S1 MRI. Means and ranges were calculated for age, sex, BMI, and MRI measurements. Anteroposterior (AP) vertebral canal diameters were used to differentiate those with DSS from controls. Other imaging parameters included vertebral body dimensions, spinal canal dimensions, disc degeneration scores, and facet joint orientation. Mann-Whitney U and chi-squared tests were conducted to search for measurement differences between those with DSS and controls. In order to identify possible associations between DSS and MRI parameters, those who were statistically significant in the univariate binary logistic regression were included in a multivariate stepwise logistic regression after adjusting for demographics. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported where appropriate. Results. Axial AP vertebral canal diameter (p < 0.001), interpedicular distance (p < 0.001), AP dural sac diameter (p < 0.001), lamina angle (p < 0.001), and sagittal mid-vertebral body height (p < 0.001) were significantly different between those identified as having DSS and controls. Narrower interpedicular distance (OR 0.745 (95% CI 0.618 to 0.900); p = 0.002) and AP dural sac diameter (OR 0.506 (95% CI 0.400 to 0.641); p < 0.001) were associated with DSS. Lamina angle (OR 1.127 (95% CI 1.045 to 1.214); p = 0.002) and right facet joint angulation (OR 0.022 (95% CI 0.002 to 0.247); p = 0.002) were also associated with DSS. No association was observed between disc parameters and DSS. Conclusion. From this large-scale cohort, the canal size is found to be independent of body stature. Other than spinal canal dimensions, abnormal orientations of lamina angle and facet joint angulation may also be a result of developmental variations, leading to increased likelihood of DSS. Other skeletal parameters are spared. There was no relationship between DSS and soft tissue changes of the spinal column, which suggests that DSS is a unique result of bony maldevelopment. These findings require validation in other ethnicities and populations. Level of Evidence: I (diagnostic study). Cite this article: Bone Joint J 2021;103-B(4):725–733

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

Surgical site infections following spinal surgery profoundly influence continued treatment, significantly impacting psychological and economic dimensions and clinical outcomes. Its reported incidence varies up to 20%, with the highest incidence amongst neuromuscular scoliosis and metastatic cord compression patients. We describe the first reported biphasic osteoconductive scaffold (Cerament G) with a logarithmic elution profile as a cumulative strategic treatment modality for adjacent spinal surgery infections. All patients who developed surgical site infections following instrumented fusion (May 2021-December 2021) had their demographics (age, sex), type and number of procedures, isolated organism, antibiotics given, comorbidities, and WHO performance status analysed. The infected wound was debrided to healthy planes, samples taken, and Cerament g applied. Thirteen patients were treated for deep SSI following spinal instrumentation and fusion procedures with intraoperative Cerament G application. There were four males and nine females with an average age of 40 ranging between 12 and 87. Nine patients underwent initial surgery for spinal deformity, and four were treated for fractures as index procedure. 77% of infections were attributable to MSSA and Cutibacteriousm acnes; others included Klebsiella, Pseudomonas and Streptococcus and targeted with multimodal cumulative therapy. A WHO performance score improved in 11 patients. In addition, there was no wound leak, and infection was eradicated successfully in 12/13 with a single procedure. This series shows the successful eradication of the infection and improved functional outcomes with Cerament G. However, the low numbers of patients in our series are an essential consideration for the broader applicability of this device

Purpose and background. Identifying features in nonspecific low back pain (NSLBP) subjects that distinguish them from controls, or for elucidating subgroups, has proved elusive. Yet these would be helpful to monitor progress, improve management, and understand the nature of the condition. Previous work using quantitative videofluoroscopy (QF) has indicated that the distribution of motion between lumbar intervertebral joints is more uneven in those with a history of NSLBP. However, there maybe other features of these complex motion patterns yet to be revealed. A multivariate analysis was therefore carried out to explore other possible differences. Methods and results. Intervertebral motion data of L2/3 to L4/5, from a previously published study was used. This examined 40 patients with NSLBP and 40 healthy controls, matched for gender, age and body mass index, who underwent passive recumbent QF in the coronal and sagittal planes. For each motion direction, principal components analysis was carried out and salient dimensions selected. Using a lower dimensional principal components (PC) representation, groups were compared using Hoteling's T test. Linear and quadratic discriminant analysis (LDA and QDA) was carried out using PC representations to examine group differences. The features most clearly distinguishing groups from the LDA was examined graphically. An analysis of the sensitivity of the results to the number of PC dimensions was carried out. The performance of the LDA and QDA classifiers were examined using leave-one-out cross-validation. Conclusions. Hotelling tests revealed significant differences between groups for right and left side-bending. This was confirmed by LDA and QDA. There was no clear difference in the performance of these classifiers and performance did not improve by including more than 4 PC dimensions. Visualisation of the LDA indicated that patients had relatively lower amplitude motion at L4/5, compensated by higher amplitude at L2/3/4. These results point to additional features of lumbar motion that differentiates NSLBP. No conflicts of interest. No funding obtained (however, the original study was funded by NIHR - CATCDRF09)

School of Mechanical Engineering, University of Birmingham, Birmingham, UK. This study investigated the effects on friction of changing the dimensions of a ball-and-socket Total Disc Arthroplasty (TDA). A generic ball-and-socket model was designed and manufactured based on the dimensions and geometry of a metal-on-metal Maverick (Medtronic, Minneapolis, USA) device. Keeping the radial clearance similar to the Maverick, the ball and socket dimensions varied between 10 to 16 mm and 10.015 to 16.015 mm, respectively, in order to enable the comparison between different dimensions. The implants were made out of Cobalt Chrome Molybdenum alloy, with a surface roughness of 0.05 μm. A Bose spine simulator (Bose Corporation, ElectroForce Systems Group, Minnesota, USA) was used to apply an axial compressive force to the TDA. Axial rotation of ±2° was then applied at various frequencies and the resulting frictional torque measured. The tests were performed under an axial load of 50, 600 and 1200 N and frequencies of 0.5, 1.0, 1.5 and 2.0 Hz, for four different samples of radii 10, 12, 14 and 16 mm (48 combinations in total). The results showed variation of frictional torque in different frequencies for all four samples under constant axial load. It was observed that the frictional torque had the lowest value for the implant with ball radius of 16mm. It might be concluded that the implant with larger ball radius may create less friction and hence offer a longer life

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

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

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

Aims

Repeated lumbar spine surgery has been associated with inferior clinical outcomes. This study aimed to examine and quantify the impact of this association in a national clinical register cohort.

Aims. There is little information about the optimum number of implants to be used in the surgical treatment of idiopathic scoliosis. Retrospective analysis of prospectively collected data from the Swedish spine register was undertaken to discover whether more implants per operated vertebra (implant density) leads to a better outcome in the treatment of idiopathic scoliosis. The hypothesis was that implant density is not associated with patient-reported outcomes, the correction of the curve or the rate of reoperation. Patients and Methods. A total of 328 patients with idiopathic scoliosis, aged between ten and 20 years at the time of surgery, were identified in the Swedish spine register (Swespine) and had patient reported outcomes including the Scoliosis Research Society 22r instrument (SRS-22r) score, EuroQol 5 dimensions quality of life, 3 level (EQ-5D-3L) score and a Viual Analogue Score (VAS) for back pain, at a mean follow-up of 3.1 years and reoperation data at a mean follow-up of 5.5 years. Implant data and the correction of the curve were assessed from radiographs, preoperatively and a mean of 1.9 years postoperatively. The patients were divided into tertiles based on implant density. Data were analyzed with analysis of variance, logistic regression or log-rank test. Some analyses were adjusted for gender, age at the time of surgery, the flexibility of the major curve and follow-up. Results. The mean number of implants per operated vertebra in the low, medium and high-density groups were 1.36 (1.00 to 1.54), 1.65 (1.55 to 1.75) and 1.91 (1.77 to 2.00), respectively. There were no statistically significant differences in the correction of the curve, the SRS-22r total score, EQ-5D-3L index or number of reoperations between the groups (all p > 0.34). In the SRS-22r domains, self-image was marginally higher in the medium implant density group (p = 0.029) and satisfaction marginally higher in the high implant density group (p = 0.034). Conclusion. These findings suggest that there is no clear advantage in using a high number of implants per operated vertebra in the surgical treatment of patients with idiopathic scoliosis. Cite this article: Bone Joint J 2018;100-B:1080–6

We investigated the pre-operative and one-year post-operative health-related quality of life (HRQOL) outcome by using a Euroqol (EQ-5D) questionnaire in 263 patients who had undergone surgery for herniation of a lumbar disc. Data from the National Swedish Register for lumbar spinal surgery between 2001 and 2002 were used and, in addition, a comparison between our cohort and a Swedish EQ-5D population survey was performed. We analysed the pre- and post-operative quality of life data, age, gender, smoking habits, pain and walking capacity. The mean age of the patients was 42 years (20 to 66); 155 (59%) were men and 69 (26%) smoked. Pre-operatively, 72 (17%) could walk at least 1 km compared with 200 (76%) postoperatively. The mean EQ-5D score improved from 0.29 to 0.70, and the HRQOL improved in 195 (74%) of the patients. The pre-operative score did not influence the post-operative score. In most patients, all five EQ-5D dimensions improved, but did not reach the level reported by an age- and gender-matched population sample (mean difference 0.17). Predictors for poor outcome were smoking, a short pre-operative walking distance, and a long history of back pain

Aims

To determine the value of scoliosis surgery, it is necessary to evaluate outcomes in domains that matter to patients. Since randomized trials on adolescent idiopathic scoliosis (AIS) are scarce, prospective cohort studies with comparable outcome measures are important. To enhance comparison, a core set of patient-related outcome measures is available. The aim of this study was to evaluate the outcomes of AIS fusion surgery at two-year follow-up using the core outcomes set.

Aims

This study addressed two questions: first, does surgical correction of an idiopathic scoliosis increase the volume of the rib cage, and second, is it possible to evaluate the change in lung function after corrective surgery for adolescent idiopathic scoliosis (AIS) using biplanar radiographs of the ribcage with 3D reconstruction?

The purpose of this study was to determine whether it would be feasible to use oblique lumbar interbody fixation for patients with degenerative lumbar disease who required a fusion but did not have a spondylolisthesis. A series of CT digital images from 60 patients with abdominal disease were reconstructed in three dimensions (3D) using Mimics v10.01: a digital cylinder was superimposed on the reconstructed image to simulate the position of an interbody screw. The optimal entry point of the screw and measurements of its trajectory were recorded. Next, 26 cadaveric specimens were subjected to oblique lumbar interbody fixation on the basis of the measurements derived from the imaging studies. These were then compared with measurements derived directly from the cadaveric vertebrae. Our study suggested that it is easy to insert the screws for L1/2, L2/3 and L3/4 fixation: there was no significant difference in measurements between those of the 3-D digital images and the cadaveric specimens. For L4/5 fixation, part of L5 inferior articular process had to be removed to achieve the optimal trajectory of the screw. For L5/S1 fixation, the screw heads were blocked by iliac bone: consequently, the interior oblique angle of the cadaveric specimens was less than that seen in the 3D digital images. . We suggest that CT scans should be carried out pre-operatively if this procedure is to be adopted in clinical practice. This will assist in determining the feasibility of the procedure and will provide accurate information to assist introduction of the screws. Cite this article: Bone Joint J 2013;95-B:977–82

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

Lumbar spine foraminal stenosis has previously been defined by the foraminal and posterior disc height. We performed a study to determine whether residual clinically significant foraminal stenosis correlates with foraminal dimensions and peri-neural fat signal loss in a group of patients with leg pain undergoing surgery for lateral recess stenosis. We retrospectively studied the pre-operative para-sagittal MRI slices of 57 patients undergoing lumbar decompression and measured pre- and post-operative VAS as a primary outcome measure to evaluate surgical success. We performed a linear regression analysis comparing change in VAS score, 1 year VAS and percentage change in VAS with foraminal height and width and found no significant correlation (R. 2. <0.2 for all correlations). We identified a sub-group of 16 patients with absent perineural foraminal fat signal with a significantly increased probability of post-operative VAS>2 compared to patients with present fat signal (p=0.0001) who all had foraminal height <10mm. In conclusion, we were unable to define dimensional foraminal parameters for clinically significant foraminal stenosis on para-sagittal MRI. Obliteration of perineural fat was associated with worse outcome and post-operative leg pain. The aetiology of foraminal stenosis is multi-factorial and more detailed imaging of the foramen is required. We recommend that coronal and fine para-sagittal MRI slices are analysed to evaluate patients with central and lateral recess stenosis for co-existing foraminal stenosis

To determine if there is a safe osseous corridor for trans-sacroiliac screw fixation of U-type sacral fractures using fluoroscopic landmarks. We reviewed the sacral anatomy of patients who underwent Computed Tomography (CT) investigations between October and December 2009. Agfa-IPMAX Version 5.2 software was used to determine if there was a trans-sacroiliac osseous corridor in the S1 and S2 vertebrae from one ilium to the other. 76 patients were in the study, 38 male and 38 female. Exclusion criteria were patients under 18 years old; patients with degenerate lumbar spine and lumbo-sacral junction; CT imaging slices greater than 2.5mm. We measured various parameters including the dimensions of the S1 and S2 mid-sagittal vertebral body; cross-sectional areas of the S1 and S2 corridor; location of the centre of the S1 and S2 corridor. The mean cross-sectional area for S1 and S2 corridors in males and females are 21mm. 2. and 15mm. 2 . respectively. The mean cross-sectional area for the S2 corridor in males and females were 15mm. 2 . and 11mm. 2 . respectively. The centre of the S1 and S2 corridor is located in the centre of both S1 and S2 vertebrae. Two-thirds of males and females have a complete osseous corridor to pass a trans-sacroiliac S1 screw. The S2 corridor was present in all males but only in 87% of females. Before placement of trans-sacroiliac screws, the surgeon should review the CT sacral anatomy to determine if the trans-sacroiliac osseous corridor is present. Ethics Approval: None – Audit Interest Statement: None

Purpose and background. Although low back pain (LBP) with leg pain, is considered by most a poor prognostic indicator, it is at the same time believed to have a favourable natural resolution, and is often treated along similar lines to non-specific LBP, in line with current guidelines. It is unclear whether patients with LBP and leg pain are a distinct subgroup that might benefit from early identification and targeted interventions. We set out to investigate the impact of LBP with leg pain on health outcomes and health resources compared with that of LBP alone, and to explore which factors contribute to the observed disability outcomes. Methods. A systematic literature search of all English language peer reviewed publications was conducted using Medline, EMBASE, and CINAHL for the years 1994 to 2009. Results. Of the 89 papers retrieved, 9 were included in the review. The heterogeneity of data allowed only for narrative analysis of findings. All studies reported worsening baseline health status in terms of poorer self-assessment and increasing use of health care the further the radiation of leg pain. Differences in quality of life measures were higher for physical than for mental health dimensions. Pain and disability outcome at follow up assessment appeared to be less favourable in this group than for individuals with LBP alone. Conclusion. LBP with leg pain is associated with poorer health outcomes and increased use of health resources. These findings argue for early identification of these cases by health care professionals and for pursuing effective treatments rather than simply treating similarly to non-specific LBP

To define how pre-operative evaluation guides surgical planning in patients with atlanto-axial subluxation secondary to rheumatoid arthritis and to measure clinical outcome for the same group. Prospective evaluation of a consecutive cohort of 26 patients undergoing C1/2 fusion over 5 years (2004-2009). Pre-operative evaluation of posterior atlanto-dens interval (PADI), C1 lateral mass and C2 pedicle dimensions. Pre- and post-op Ranawat scores and visual analogue scores for neck and C2 pain. C1/2 instability resulted from rheumatoid arthritis (21), trauma (4) and infection (1). C1 lateral mass mean height 4.4mm, C2 pedicle mean height 5.1mm and mean width 3.4mm (30% width <3mm). Ranawat scale improved Grade II to Grade I (p=0.07). Neck pain (pre-op mean 5.5, s.d. 2.8; post-op mean 1.6, s.d. 2.1, t<0.05) and C2 pain (pre-op mean 2.1, s.d. 3.3; post-op mean 0.5, s.d. 1.2, t<0.05) improved. No instrumentation failure. In the rheumatoid group, 17/21 patients had C1 lateral mass and C1/2 transarticular screws. 1 patient had a cranio-cervical fusion and 3 patients had other constructs. 3 patients had C2 numbness. No other neurological deficit. In a rheumatoid population, pre-operative evaluation often precludes the use of C2 pedicle screws. Rigid fixation with a C1 lateral mass and C1/2 transarticular polyaxial screw-rod system is associated with good clinical outcomes