Aims

To determine whether side-bending films in scoliosis are assessed for adequacy in clinical practice; and to introduce a novel method for doing so.

Introduction. Genetic predisposition is a key causal factor in adolescent idiopathic scoliosis (AIS), which is the most common form of spinal deformity. However, common quantitative genetic effect estimates such as hereditability have not been fully evaluated and reported for this disorder. We aimed to determine the sibling recurrent risk and hereditability of AIS in first-degree relatives of 513 Chinese patients with this disorder. Methods. Family members of 513 Chinese patients with AIS attending a scoliosis clinic were assessed. A diagnosis of AIS was made with the criteria of Cobb angle greater than 20°. The evaluation included clinical assessment and physical examination in a health screening centre by medical doctors with use of forward bending test. Any positive screening cases were referred to a scoliosis clinic for follow-up spinal radiograph. All radiographs were assessed by an orthopaedic surgeon in the scoliosis clinic. A population prevalence of scoliosis was obtained from the data of a territory-wide screening campaign. The prevalence of AIS among siblings of probands was measured both overall and divided by sex of siblings. The sibling recurrent risk (λs) was calculated for male and female siblings separately with reported population incidence of AIS. Results. The 513 probands had 640 siblings, and 110 affected siblings were identified (17·2%, 95% CI 14·3–20·1), which was significantly higher than the disease prevalence in the general population (1·39%, p<0·0001). The prevalence of AIS was 11·3% (7·6–14·9) in male siblings and 22·2% (17·8–26·6) in female siblings. The prevalence of AIS in female siblings was significantly higher than that in male siblings (p<0·001). The average sibling recurrent risk ratio (λs) was 12·4. Overall, heritability was estimated to be 87·5%. Conclusions. The results confirmed the prevailing impression of a strong genetic effect on risk of AIS. We provided these standard genetic aggregation estimates and hereditability of AIS for the first time. The estimates allow comparison with other complex diseases such as diabetes mellitus in term of genetic predisposition. Our findings suggest that AIS has a moderate to strong genetic predisposition and it is comparable with other complex traits

Aims

Precise implant positioning, tailored to individual spinopelvic biomechanics and phenotype, is paramount for stability in total hip arthroplasty (THA). Despite a few studies on instability prediction, there is a notable gap in research utilizing artificial intelligence (AI). The objective of our pilot study was to evaluate the feasibility of developing an AI algorithm tailored to individual spinopelvic mechanics and patient phenotype for predicting impingement.

Aims

Scoliosis is a lateral curvature of the spine with associated rotation, often causing distress due to appearance. For some curves, there is good evidence to support the use of a spinal brace, worn for 20 to 24 hours a day to minimize the curve, making it as straight as possible during growth, preventing progression. Compliance can be poor due to appearance and comfort. A night-time brace, worn for eight to 12 hours, can achieve higher levels of curve correction while patients are supine, and could be preferable for patients, but evidence of efficacy is limited. This is the protocol for a randomized controlled trial of ‘full-time bracing’ versus ‘night-time bracing’ in adolescent idiopathic scoliosis (AIS).

The purpose of this study was to establish the a)feasibility, b) reproducibility of spinal Quantec scans (a non-intrusive surface topography system) and c) the validity of the Quantec Q-angle against Cobb angles from spinal radiographs, in non-ambulant children with cerebral palsy (CP). Eighteen non-ambulant children (aged 5–11 years) with CP had successful clinical, radiological and Quantec assessment of their spine while seated in a supportive seating system. Scoliosis incidence was 72%, Cobb angles ranged from 1–73° (mean 18.2°). Quantec scanning was feasible with appropriate postural support. Mean interobserver differences were 0.5 ± 5.8° (median 1.3°, 5 / 95th percentiles lying at −7.3 / 8.5° respectively). Mean differences between Cobb and Q-angle were 0.02 ± 6.2° (median 1.0°, with 5 / 95th percentiles lying at −8.2 / 7.7° respectively). Surface topography may be used to safely monitor the spine for non-ambulant CP children. Results show similar or improved trends to previous comparisons with idiopathic scoliosis. Ovadia (2007) showed an interobserver mean difference of 6.3 ± 4.9° using an Ortelius800TM system. Thometz (2000) showed mean differences between Cobb and Q-angle ranging from 1.1–12.6 ± 4.9–10.2°. Further research is needed for the user group described in this study with larger spinal curves. Ethics approval: Ethics approval granted by Leeds (West) Research Ethics Committee. COREC number: 08/H1307/22. Interest Statement: None

In the past measurement of deformity correction in spinal surgery has been done using measurements made directly from radiographs using a pencil, ruler and goniometer The aim of this paper is to describe a reproducible, accurate and partially automated system that has been developed for measuring x-rays of patients with spinal disorders. Computer assisted measurement of polyethylene wear in patients with THJR is now well established. Many of the image processing algorithms have been modified to allow identification of the outline of both thoracic and lumbar vertebral bodies on digital images of radiographs made from patients with spinal disorders. The Genetic Algorithm (GA), a branch of Artificial Intelligence, has been adapted to allow the modelling of a four sided figure to each vertebral body, with minimal user input. The accurate identification of each vertebral body within a spinal radiograph allows measurement of multiple parameters, including Cobb angles, vertebral width, vertebral height and cross sectional area, as well as measurement of average disc height and cross sectional area. The method is 100% reproducible for each digital image. An attempt to measure accuracy has not been made because these are two dimensional measurements of a three-dimensional structure. Comparison of these measurements between pre and post-operative radiographs for a patient allows accurate and reproducible measurement of reconstructive surgery for scoliosis and other spinal disorders. It may aid in development of a classification system for scoliosis

Over 5 years we gave 84 patients epidural cortisone (80 mg depomedrol and local anaesthesia) for back and/or leg pain due to degenerative disease of the spine. The mean age of the 35 men and 49 women was 65.2 years (37 to 86). All patients had back pain and 77% had neurogenic leg pain. Spinal radiographs demonstrated degenerative changes, including intervertebral disc space narrowing and/or facet joint arthritis, in 84%. MRI, performed in 80 patients (95%), confirmed degenerative disease of the lumbar spine and demonstrated neural compression in 78 of the 80 (97%). Five patients received a second epidural injection and one a third. Complete resolution of back and/or leg pain occurred in 32 patients (38%), and 34 (40%) had relief for between 1 and 12 months. There was no change in the symptoms of 18 patients (21%). Surgery was undertaken in 17 patients (20%), with seven undergoing spinal decompression alone and 10 decompression and a fusion. After surgery, four of the seven patients who did not have a fusion still had back pain. All 10 of the patients who underwent decompression and fusion had a good outcome. One patient developed an epidural haematoma following the epidural injection. Epidural steroid injection had a favourable outcome in 78% of our patients, with a low incidence of complications. Patients who failed to respond to the epidural injection did poorly with spinal decompression alone

Study Design: This is a retrospective study evaluating the use of BoneSave (Stryker, UK) in posterolateral inter-transverse spinal fusion. Objectives. To evaluate the clinical outcomes and fusion success rates associated with the use of BoneSave in posterolateral spinal fusion. Summary of Background Data: Achieving spinal fusion is the guiding principle behind surgical treatment for a range of pathologies of the spine. The use of a substantial amount of bonegraft is often required and autograft, commonly harvested from the iliac crest, represents the gold standard. Morbidities associated with graft harvest and a limited supply of graft material have led to the development of alternatives. BoneSave, a porous tricalcium phosphate-hydroxyapatite ceramic, is one such alternative which has been employed in spinal fusion over the past few years. Despite this the outcomes associated with its use lack research. Methods: Clinical data was collected retrospectively from the case notes of all patients who underwent posterolateral inter-transverse spinal fusion at any level, involving the application of BoneSave, between June 2003 and January 2005 at Frenchay hospital, Bristol, UK. A postal questionnaire was used to collect the latest follow-up information, with an average follow-up of 46 months. Validated outcome instruments employed included the Short Form 36 and Oswestry Low Back Pain Disability Index. In addition visual analogue scales for both back and leg pain, Patient Global Impression of Change data, work status, persisting symptoms, and patient satisfaction data was collected. Radiological evaluation of fusion was carried out from the most recent spinal radiographs available for each patient. Results: There were 45 patients in the study group. Qualitative post-operative data was available in 96% and response rate to the follow-up questionnaire was 68.4%. Radiographical evaluation was possible in 67%. Significant post-operative improvements were seen across all outcome measures in the large majority of cases. Successful fusion was achieved in 56.7% of cases. Conclusion: The clinical outcomes associated with the use of BoneSave are comparable to those available in the literature for more conventional techniques of spinal fusion. The fusion rate was not significantly lower than achieved with other techniques

Background: It is commonly observed that a good correction of the Cobb angle at scoliosis surgery is accompanied by an acute asymmetry of shoulder height. Kuklo et al in 2002 described (. Spine. . 26. (18):. 1966. –1975. ) spontaneous reversal of this, using radiographic measures and patient questionnaires. Objective: To determine the incidence and extent of shoulder-imbalance before posterior spinal surgery and to ascertain its outcome, using radiographic and topographic measures. Methods: Patients with right thoracic adolescent idiopathic scoliosis who had undergone corrective posterior spinal fusion by one surgeon were identified. Pre- and all postoperative spinal radiographs and surface topography were evaluated and correlated. Any effect from concomitant anterior release procedures was sought. Results: Sixty six patients were identified, 56 girls and 10 boys. Their pre-operative major Cobb angle was 73°±14.0 and mean correction was 38.8°±12.333 (56%). Before surgery, surface topography showed the mid-point of the right shoulder to be at a mean or 18.3mm.±10.9 higher than the equivalent left point; eight days later, the difference was −6.7 mm. ±9.68, a mean change of 25.9mm±11.8. At six months, it was −5.1 ±6.86, statistically unchanged. At two years, it was −2.16 (p=0.051) and at three years, 1.76± 6.53 and indistinguishable from zero or perfect balance. The difference between pre-operative and final shoulder level difference was 19.54mm.±9.09. The Cobb angle of the compensatory upper thoracic curve was not significantly changed throughout. There was no statistically significant difference in shoulder height between patients undergoing single or two-stage surgery, either before or at any stage after. Discussion and conclusion: Correction of post-operative shoulder imbalance does occur spontaneously, as reported by Kuklo et al. and is not a function of spinal accommodation to the new anatomy

Summary of Background Data: The craniofacial malformations described by Goldenhar can be associated with congenital anomalies of the vertebrae. This non-random association of abnormalities represents unilateral errors in the morphogenesis of the spine, as well as the first and second branchial arches. Purpose of the study: The aim of the present study was to determine the prevalence of Goldenhar related conditions in patients with congenital deformities of the spine and to describe the types of vertebral abnormalities and the necessity for treatment. Material-Methods: We performed a retrospective study of 668 consecutive patients with congenital deformities of the spine. The medical records and spinal radiographs were reviewed and patients with a Goldenhar associated condition were identified. The vertebral anomalies causing the spine deformity were detected on antero-posterior and lateral spine radiographs. The type and site of the craniofacial abnormalities, as well as other musculoskeletal deformities and systemic anomalies were recorded. Results: Fourteen patients had Goldenhar associated conditions (7 males and 7 females). A thoracic scoliosis was the most common type of deformity occurring in ten patients (71.5%). Eight of these patients had an isolated hemivertebra and the remaining two had a unilateral unsegmented bar with contralateral hemivertebra at the same level. There was only one patient with a lumbar scoliosis and this was due to a hemivertebra. The side of the vertebral anomaly correlated with that of the hemifacial microsomia in five of the eleven patients who had a scoliosis or kyphoscoliosis. A thoracolumbar kyphosis occurred in four patients; two had posterior hemivertebrae, one had wedge vertebrae, and the remaining patient had an anterior unsegmented bar. A thoracolum-bar kyphoscoliosis occurred in only one patient and was due to a posterolateral quadrant vertebra. Klippel-Feil syndrome occurred in six patients (42.8%). Eight patients (57%) underwent surgical treatment at a mean age of 9.8 years (range: 2.9–19). Four patients had a combined anterior-posterior spine arthrodesis. The remaining four patients had a posterior spinal arthrodesis. Conclusions. The prevalence of Goldenhar associated conditions in patients with congenital deformities of the spine was 2%. Failures of vertebral segmentation were the most frequent abnormality in the cervical spine, whereas failures of vertebral formation most commonly occurred in the thoracic or thoracolumbar spine

To present the results of surgical correction in patients with double or triple thoracic/lumbar AIS (Lenke types 2,3,4) with the use of a novel convex/convex unilateral segmental screw correction technique in a single surgeon's prospective series. We reviewed the medical records and spinal radiographs of 92 consecutive patients (72 female-20 male). We measured scoliosis, thoracic kyphosis, lumbar lordosis, scoliosis flexibility and correction index, coronal and sagittal balance before and after surgery, as well as at minimum 2-year follow-up. SRS-22 data was available preoperatively, 6-month, 12-month and 2-year postoperatively for all patients. Surgical technique. All patients underwent posterior spinal fusion using pedicle screw constructs. Unilateral screws were placed across the convexity of each individual thoracic or lumbar curve to allow for segmental correction. ‘Corrective rod’ was the one attached to the convexity of each curve with the correction performed across the main thoracic scoliosis always before the lumbar. Maximum correction of main thoracic curves was always performed, whereas the lumbar scoliosis was corrected to the degree required to achieve a balanced effect across the thoracic and lumbar segments and adequate global coronal spinal balance. Concave screws were not placed across any deformity levels. Bilateral screws across 2 levels caudally and 1–2 levels cephalad provided proximal/distal stability of the construct. Mean age at surgery was 14.9 years with mean Risser grade 2.8. The distribution of scoliosis was: Lenke type 2–26 patients; type 3–43 patients; type 4–23 patients. Mean preoperative Cobb angle for upper thoracic curves was 45°. This was corrected by 62% to mean 17° (p<0.001). Mean preoperative Cobb angle for main thoracic curves was 70°. This was corrected by 69% to mean 22° (p<0.001). Mean preoperative Cobb angle for lumbar curves was 56°. This was corrected by 68% to mean 18° (p<0.001). No patient lost >2° correction at follow-up. Mean preoperative thoracic kyphosis was 34° and lumbar lordosis 46°. Mean postoperative thoracic kyphosis was 45° (p<0.001) and lumbar lordosis 46.5° (p=0.69). Mean preoperative coronal imbalance was 1.2 cm. This corrected to mean 0.02 cm at follow-up (p<0.001). Mean preoperative sagittal imbalance was −2 cm. This corrected to mean −0.1 cm at follow-up (p<0.001). Mean theatre time was 187 minutes, hospital stay 6.8 days and intraoperative blood loss 0.29 blood volumes (1100 ml). Intraoperative spinal cord monitoring was performed recording cortical and cervical SSEPs and transcranial upper/lower limb MEPs and there were no problems. None of the patients developed neurological complications, infection or detected non-union and none required revision surgery to address residual or recurrent deformity. Mean preoperative SRS-22 score was 3.6; this improved to 4.6 at follow-up (p<0.001). All individual parameters also demonstrated significant improvement (p<0.001) with mean satisfaction rate at 2-year follow-up 4.9. The convex-convex unilateral pedicle screw technique can reduce the risk of neurological injury during major deformity surgery as it does not require placement of screws across the deformed apical concave pedicles which are in close proximity to the spinal cord. Despite the use of a lesser number of pedicle fixation points compared to the bilateral segmental screw techniques, in our series it has achieved satisfactory scoliosis correction and restoration of global coronal and sagittal balance with improved thoracic kyphosis and preserved lumbar lordosis. These results have been associated with excellent patient satisfaction and functional outcomes as demonstrated through the SRS-22 scores

Purpose: The purpose of this study was to detect any possible prognostic factors which may affect the spinal deformity progression and their relationships in idiopathic scoliosis. Methods: The stereo-radiograph of whole spine at each visit was reconstructed with two spinal x-ray images in PA 0° and 20° using DLT techniques. Sequential data sets with 3, 4 or 5 successive values of prognostic factors were extracted from 111 consecutive patients (12.3±2.3 yrs, Cobb angle 30.2±12.4°) and separated into the stable and the progressed groups, based on a progression threshold of Cobb angle 5° and 10°. The prognostic factors included gender, curve pattern, age, curve magnitude, apex location, lateral deviation and spinal growth. Effects of those factors were conducted by comparing them between two groups (statistical significances p< 0.05) and the relationships were determined using Pearson’s correlation coefficient (r). Results: The progressed subjects were predominantly females (50–79%) with double curves. Double curves progressed on both curves RT and LL at the same times and alternatively. There were no significant differences of initial ages and ages with maximum curve magnitudes between two groups. Initial and maximum curve magnitudes were significantly large in the progressed group, but no significantly different between maximum curve magnitudes in the stable group and initial curve magnitude in the progressed group. High curve apex locations were observed in the progressed group. Initial and maximum apex lateral deviations were clearly different in two groups and correlated with curve magnitudes from well to excellent (r = 0.43–0.98). The relationships between the spinal growth and the curve progressing were not consistent (r = −0.6 – +0.6). There were no evidences to show the significant differences of spinal growths between groups and genders. Conclusions: Scoliosis progression is case dependent. Double curves dynamically progress between curve regions. Initial curve magnitudes have more significant effect on the progression than initial ages. A great progression can be expected from curves with high apex location. Apex lateral deviations are changing with curve magnitudes and spinal growths and, however, the curve magnitudes are not always increased with spinal growths. Funding: 2 Funding Parties: Alberta Provincial CIHR Training Program in Bone and Joint Health

Objective: Axially loaded MRI simulates imaging of the lumbar spine in the standing position and is useful in the assessment of spinal stenosis[. 1. ]. This study determines the ability of axially loaded spinal MRI to assess Cobb angle in patients with idiopathic scoliosis. Design: Prospective study. Newly diagnosed patients with idiopathic scoliosis were referred for MRI of the whole spine. Cobb angle measurements were made from erect AP spinal radiographs prior to MRI. Coronal MR images of the thoracic and/or lumbar spine were obtained prior to and following loading of the spine in an MR compatible compression device (Dynawell). Cobb angle measurements were made on unloaded and loaded MRI studies using the same reference points as on radiographs. Radiographic and MRI Cobb angle measurements were compared. Informed consent was obtained from all patients and the study was approved by the local Ethics Committee. Subjects: Five patients, all females with mean age 14 years (range 12–16 years) were included in the study. Outcome Measures: Six curves were compared on pre-referral erect radiographs, unloaded and loaded MRI studies, 2 in the thoracic region and 4 in the thoracolumbar region. Results: Curve characteristics and Cobb angle measurement on radiographs vs. axial unloaded and loaded MRI were as follows: Curve 1; T4-T12, 45°, 36° and 41°. Curve 2; T10-L4, 52°, 22° and 30°. Curve 3; T10-L4, 45°, 36° and 38°. Curve 4; T6-T10, 42°, 22° and 22°. Curve 5; T11-L3, 43°, 32° and 43°. Curve 6; T11-L3, 34°, 11° and 31°. Conclusions: Axial loading increases MRI Cobb angle measurements compared to unloaded studies. Initial results suggest that axial loaded MRI using the Dynawell Compression device may allow comparative measurement of Cobb angle to erect radiographs in the thoracolumbar region, but not in the thoracic region. This is likely related to the loading characteristics of the compression device, which is designed to concentrate loading in the lumbar region. Modification to include loading of the thoracic spine may improve results. The technique has the potential to replace radiography and thus reduce radiation burden to young adolescents with some types of idiopathic scoliosis

Background: A sharp, localised, thoracolumbar gibbus is pathognomonic of the mucopolysaccharidosis (MPS) group of disorders, the most common of which is Hurlers syndrome (MPS I). Untreated patients with this disease run an inevitable course of neurological and physical degeneration until death within the first decade. Haemopoietic stem cell transplantation (HSCT) has resulted in considerable improvement in survival with amelioration of many of the symptoms and signs which characterise this disease. Data, however, is disappointing in relation to the impact of HSCT on skeletal dysplasia. This study reviews the natural history of spinal deformity in Hurler’s syndrome after HSCT in infancy. Methods: Twenty three patients (12 male and 11 female), transplanted at a mean age of 0.9 years ± 0.47, (range 0.27 – 1.8yrs) were investigated, of whom 19 were at least two years post-HSCT and were included. HLA identical donor sources included unaffected or heterozygote family members, unrelated adults or cord blood. Mean age at review was 9.4 years ± 4.57, (range 2.5 – 18.4yrs). Serial measurements of the thoracolumbar spines incorporated clinical records, radiographs and surface topography. The thoracolumbar gibbus was measured on lateral spinal radiograph using the standard adaptation of the Cobb method. Two segments of the spine were documented: the gibbus itself and the thoracic profile above it. Clinical assessment and surface topography were contrasted with this. Results: At presentation, all showed the characteristic gibbus at the thoracolumbar junction, with a flat and stiff thoracic spine above. Three patients underwent surgery to correct or maintain the gibbus, which was unsuccessful in two; the third is stable, but still young. Two patients have developed scoliosis: one in the juvenile period and one in infancy. Three female patients are now post-menarchal and have shown no progression of their gibbus. One male patient, now aged 19 years, had significant progression of his gibbus at puberty, but is now stable, untreated and cosmetically acceptable. The remainder are still pre-pubertal but their deformities are not currently progressive. Conclusion: The fate of the spinal deformity in untreated MPS-I has been poorly documented, as the condition was invariably fatal from cardiorespiratory failure during the first decade. These interim results suggest that, while the deformity persists and may become more pronounced during growth and adolescence, it does not significantly impact on quality of life. The considerations which usually dictate intervention in other spinal deformities of childhood may not necessarily apply and should be approached with caution. The more recent availability of recombinant human -L- iduronidase adds further interest to the management of these patients and warrants cautious expectation , in the context of experience gained in these groups of patients. In conclusion atients with MPS I have complex multisystem disorders, independent of their orthopaedic status. While monitoring their spinal deformity is indicated, over-intrusive investigation and treatment may be counterproductive

Background: In lumbar scoliosis curves of school screening referrals were evaluated (1) for the possible relation of pathomechanisms to standard and non-standard vertebral rotation (NSVR) [. 1. ], and (. 2. ) the relation between apical lumbar axial vertebral rotation and the frontal plane spinal offset angle (FPTA) [. 2. ]. Methods: Consecutive patients referred to hospital during routine school screening using the Scoliometer were examined in 1996–9. None had surgery for their scoliosis. There are 40 subjects with either pelvic tilt scoliosis (11), idiopathic lumbar scoliosis (19), or double curves (10)(girls 31, postmenarcheal 25, boys 9, mean age 15.3 years). One observer (RGB) measured: 1) in AP spinal radiographs Cobb angles (CAs), apical vertebral rotations (Perdriolle AVRs), and trigonometrically sacral alar tilt angle (SATA), and FPTA as the tilt of the T1–S1 line to the vertical; and 2) total leg lengths (tape). Results: Excluding the double curves there are 16 left and 14 right lumbar curves mean CA 11 degrees (range 4–24 degrees), mean AVR 9 degrees (concordant to CA in 18/30, discordant in 7/30), SATA 2.8 degrees (range 0.2–7.7 degrees associated with CA side and severity, p=0.0003), and leg-length inequality 0.7 cm (significantly shorter on left, p< 0.0001 and associated with SATA (p=0.02) but not CA). Neither CA nor AVR in each of the laterality concordant and discordant lumbar or thoracic curves is significantly different. Twenty-six subjects have thoracic curves (16 right) 22 with AVR (mean CA 11 degrees, range 4–17 degrees, AVR 9 degrees, n=22) the CA being associated with each of lumbar CA and SATA (respectively p< 0.0001, p=0.003, n=26). Thoracic curve laterality of CA and AVR is concordant in 12/26 curves and discordant in 10/26 and for concordance/discordance neither is significantly different; thoracic AVR sides with laterality of lumbar curve AVR shown by thoracic AVR (but not CA) being greater in lumbar discordant than in lumbar concordant curves (14 & 7 degrees respectively, p=0.03, n=18 & 7). Both for lumbar curves alone and for lumbar with double curves, AVR by side is significantly associated with FPTA by side (r= −0.568, p=0.001, n=30; r=−0.560, p=0.0002, n=40). Conclusion: (1) It is hypothesized that different pathomechanisms may separately affect the frontal (CA) and transverse (AVR) planes: in discordant curves these mechanisms may neutralize each other and limit curve progression; concordant curves require these biplanar mechanisms to summate and facilitate curve progression. (2) The association of frontal plane spinal tilt angle and lumbar AVR may result from balance mechanisms affecting trunk muscles – mechanisms that may underlie the complication of post-operative frontal plane spinal imbalance or decompensation [. 2. ]

To determine the range of in-vivo magnification error in lateral spinal digital radiographs, and determine the effect of BMI on this error. An analysis of two hundred and fifty patients with digital radiographs and CT/MRIs was performed. Digital imaging software was used to measure the antero-posterior vertebral body dimensions (VBD) at C2, C5, L1, and L4. Magnification values were determined in comparison to CT/MRI. CT measurements were also compared to MRI. BMI for each patient was obtained by chart review. The difference between the mean VBD as measured on CT and MRI was < 0.1mm (n=130, p< 0.2514, paired t-test). Mean magnification at the cervical spine was 21% (1.21 ± 0.01; range = 1.06–1.57 (n=177)) and 31% at the lumbar spine (1.31 ± 0.01; range = 1.09–1.63 (n=284)). Linear regression showed a significant positive correlation between BMI and magnification at both the cervical and lumbar spine (Cervical: n=96; p=0.0019; Lumbar: n=144; p< 0.0001). There was a significant difference in magnification between non-obese and obese patients at both the cervical and lumbar levels. Cervical: 1.19 ± 0.01 magnification for non-obese (n=136), versus 1.26 ± 0.01 for obese (n=39) (p< 0.0001). Lumbar: 1.28 ± 0.01 (n=207), versus 1.38 ± 0.01 (n=71) (p< 0.0001), respectively. Linear in-vivo measurements obtained on digital radiographs are subject to magnification errors at both cervical and lumbar spine. This error correlates to the patient’s BMI. Consequently, clinical-decision making, regardless of the anatomical area, that is based on linear measurements obtained from radiographs that do not account for this error are invalid. In the scenario that this measurement is crucial (e.g. dynamic radiographs), this error can be corrected by comparison to morphometric data from CT/MRI

The October 2013 Spine Roundup³⁶⁰ looks at: Standing straighter may reduce falls; Operative management of congenital kyphosis; Athletic discectomy; Lumbar spine stenosis worsens with time; Flexible stabilisation?: spinal stenosis revisited; Do epidural steroids cause spinal fractures?; Who does well with cervical myelopathy?; Secretly adverse to BMP-2?

The August 2012 Spine Roundup³⁶⁰ looks at: neural tissue and polymerising bone cement; a new prognostic score for spinal metastases from prostatic tumours; recovery after spinal decompression; spinal tuberculosis; unintended durotomy at spinal surgery; how carrying a load on your head can damage the cervical spine; and how age changes your lumbar spine.