Search

Byline: Bao Quan Qi (1), Spencer W. Beasley (1), Dejan Arsic (1) Keywords: Anorectum; Imperforate anus; Vertebral; Rachischisis; Ethylenethiourea Abstract: Lumbosacral vertebral abnormalities are a common association of anorectal malformations (ARMs) and are one of the determinants of the eventual level of fecal continence that can be achieved. This study used a fetal rat model to investigate the spectrum of axial skeletal maldevelopment that may occur with ARMs. Time-mated pregnant rats received 125 mg/kg of 1% ethylenethiourea (ETU) (experimental group) or vehicle only (control). Their fetuses were examined for external malformations and prepared for staining of their skeletons using Alcian blue and Alizarin red S. ARMs developed in 67/68 (98%) of ETU-exposed fetuses, of which 28 (42%) also developed rachischisis, mainly involving the lumbosacral vertebrae. No skeletal abnormality was found in control fetuses. ETU-exposed fetuses with ARMs and rachischisis had abnormal ossification of the vertebral centrum, abnormal fusion between the neural arches of vertebrae, localized narrow or interrupted thoracic vertebral canal, a widely open vertebral canal in the lumbosacral area (rachischisis), and absence of the lower two sacral and coccygeal vertebrae. Rib abnormalities included absence of two to three floating ribs, abnormal fusion of adjacent proximal segments, and abnormal ramification, irregularity, and angulation of their distal segments. The vertebral and rib abnormalities found in ETU-exposed fetuses with ARMs but no rachischisis were much less severe. In addition to the lumbosacral anomalies that are common with ARMs, severe abnormalities of the thoracic vertebrae and their corresponding ribs may occur also. Fetuses with both ARM and rachischisis tend to have more extensive and severe vertebral and rib anomalies. These observations imply a possible common aetiology for ARMs and vertebral anomalies and are consistent with our understanding of the perceived role of the notochord in axial development. Author Affiliation: (1) Department of Paediatric Surgery, Christchurch Hospital, Private Bag 4710, Christchurch, New Zealand Article History: Registration Date: 29/04/2004 Accepted Date: 02/02/2004 Online Date: 16/06/2004

Byline: R. Hasserius (1), M.K. Karlsson (1), B.E. Nilsson (1), I. (1), O. Johnell (2) Keywords: KeywordsaFractures; Fragility fractures; Mortality; Osteoporosis; Prediction; Vertebral deformity Abstract: aThe aim of this study was to evaluate whether a prevalent vertebral deformity predicts mortality and fractures in both men and women. In the city of Malmo, 598 individuals (298 men, 300 women age 50--80 years) were selected from the city's population and were included in the Swedish part of the European Vertebral Osteoporosis Study (EVOS). At baseline the participants answered a questionnaire and lateral spine radiographs were performed. The prevalence of subjects with vertebral deformity was assessed using a morphometric method. The mortality during a 10-year follow-up period was determined through the register of the National Swedish Board of Health and Welfare. Eighty-five men and 43 women died during the study period. The subsequent fracture incidence during the follow-up period was ascertained by postal questionnaires, telephone interviews and by a survey of the archives of the Department of Radiology in the city hospital. Thirty-seven men and 69 women sustained a fracture during the study period. Data are presented as hazard ratios (HR) with 95% confidence interval (95% CI) within brackets. Prevalent vertebral deformity, defined as a reduction by more than 3 standard deviations (SD) in vertebral height ratio, predicted mortality during the forthcoming decade in both men [age-adjusted HR 2.4 (95% CI 1.6--3.9)] and women [age-adjusted HR 2.3 (95% CI 1.3--4.3)]. In men there was an increased mortality due to cardiovascular and pulmonary diseases and in women due to cancer. Prevalent vertebral deformity predicted an increased risk of any fracture during the forthcoming decade in both men [age-adjusted HR 2.7 (95% CI 1.4--5.3)] and women [age-adjusted HR 1.8 (95% CI 1.1--2.9)]. Prevalent vertebral deformity predicted an increased risk of any subsequent fragility fracture in women [age-adjusted HR 2.0 (95% CI 1.1--3.5)] however, in men the increased risk was nonsignificant [age-adjusted HR 1.9 (95% CI 0.7--5.1)]. In summary, a prevalent vertebral deformity can predict both increased mortality and increased fracture incidence during the following decade in both men and women. We conclude that prevalent vertebral deformity could be used as a risk factor in both genders for mortality and future fracture. Author Affiliation: (1) Department of Orthopaedics, Malmo University Hospital, SE-205 02 Malmo, Sweden Tel: +46 40 331000 Fax: +46 40 336200 e-mail: Ralph.Hasserius@skane.se, SE (2) Department of Diagnostic Radiology, Malmo University Hospital, SE-205 02 Malmo, Sweden, SE Article note: Received: 22 March 2002 / Accepted: 27 August 2002 AcknowledgementaFinancial support was received from the Swedish Medical Research Council K2001-73GX-14080-01 and K2001-73P-14088-01A, the Swedish Society of Medicine, the Swedish Society of Medical Research and the Greta and Johan Kock Foundation.

While the etiology and pathogenesis of adolescent idiopathic scoliosis are still not well understood, it is generally recognized that it progresses within a biomechanical process involving asymmetrical loading of the spine and vertebral growth modulation. This study intends to develop a finite element model incorporating vertebral growth and growth modulation in order to represent the progression of scoliotic deformities. The biomechanical model was based on experimental and clinical observations, and was formulated with variables integrating a biomechanical stimulus of growth modulation along directions perpendicular (x) and parallel (y, z) to the growth plates, a sensitivity factor [beta] to that stimulus and time. It was integrated into a finite element model of the thoracic and lumbar spine, which was personalized to the geometry of a female subject without spinal deformity. An imbalance of 2 mm in the right direction at the 8th thoracic vertebra was imposed and two simulations were performed: one with only growth modulation perpendicular to growth plates (Sim1), and the other one with additional components in the transverse plane (Sim2). Semi-quantitative characterization of the scoliotic deformities at each growth cycle was made using regional scoliotic descriptors (thoracic Cobb angle and kyphosis) and local scoliotic descriptors (wedging angle and axial rotation of the thoracic apical vertebra). In all simulations, spinal profiles corresponded to clinically observable configurations. The Cobb angle increased nonlinearly from 0.3[degrees] to 34[degrees] (Sim1) and 20[degrees] (Sim2) from the first to last growth cycle, adequately reproducing the amplifying thoracic scoliotic curve. The sagittal thoracic profile (kyphosis) remained quite constant. Similarly to clinical and experimental observations, vertebral wedging angle of the thoracic apex progressed from 2.6[degrees] to 10.7[degrees] (Sim1) and 7.8[degrees] (Sim2) with curve progression. Concomitantly, vertebral rotation of the thoracic apex increased of 10[degrees] (Sim1) and 6[degrees] (Sim2) clockwise, adequately reproducing the evolution of axial rotation reported in several studies. Similar trends but of lesser magnitude (Sim2) suggests that growth modulation parallel to growth plates tend to counteract the growth modulation effects in longitudinal direction. Overall, the developed model adequately represents the self-sustaining progression of vertebral and spinal scoliotic deformities. This study demonstrates the feasibility of the modeling approach, and compared to other biomechanical studies of scoliosis it achieves a more complete representation of the scoliotic spine. [DOI: 10.1115/1.1516198] Keywords: Idiopathic Scoliosis, Biomechanical Modeling, Growth Modulation, Spine, Vertebra

Byline: M. Lunt (1), A. A. Ismail (1), D. Felsenberg (2), C. Cooper (3), J. A. Kanis (4), J. Reeve (5), A. J. Silman (1), T. W. O'Neillthe EPOS Study Group* (1) Keywords: Key words:Comparison of morphometric methods -- Incident vertebral deformity -- Population study -- Vertebral morphometry Abstract: Various morphometric criteria have been used to define incident vertebral deformity. The aim of this analysis was to compare the relative validity of two established criteria and a novel method in which these criteria were combined. Men and women aged 50 years and over were recruited from population registers across Europe and had lateral spinal radiographs performed using a standard protocol. A subsample of individuals had bone mineral density (BMD) at the spine or femoral neck. Subjects were followed prospectively and a subsample had repeat spinal radiographs a median of 3.8 years after the baseline survey. All radiographs were evaluated morphometrically in the radiology coordinating center in Berlin. Anterior, middle and posterior height were recorded in all vertebrae from T4 to L4. On the basis of these morphometric measurements incident vertebral deformity was defined using one of three methods: (i) the change method -- a change in any vertebral height of 20% or more between films, plus the additional requirement that a vertebral body have changed in absolute vertebral height by 4 mm or more (ii) the point prevalence method, where a vertebra satisfies criteria for a prevalent deformity (McCloskey--Kanis) on the follow-up, though not the baseline film (iii) a combination of the height reduction and the point prevalence criteria. Paired films were also evaluated qualitatively by an experienced radiologist for the presence of incident vertebral deformity. Logistic regression was used to compare the three morphometric methods using known risk factors for vertebral deformity including age, baseline vertebral deformity and BMD, and the qualitative evaluation. Computer simulation was used to determine the potential degree of bias and loss of statistical efficiency due to misclassification for each of the three methods, using the radiologist's assessment of incident deformity as the reference. Six thousand eight hundred subjects were included in this analysis. Of these 450 had sustained an incident vertebral deformity according to at least one of the three morphometric methods. The distribution of risk factors was similar in the subjects who satisfied only one morphometric criterion and those who satisfied neither. However, the subjects who satisfied both criteria had a very different distribution of risk factors: they were older, more likely to be female, more likely to have had a previous vertebral deformity and more likely to have an incident fracture in the opinion of an experienced radiologist. Using computer simulation, at low incidence levels, combining the criteria led to greater statistical efficiency and less bias in estimating associations with risk factors. Thus in this analysis the combination of the point prevalence and 20% change in height criterion for defining incident vertebral deformity showed a stronger relationship with clinical risk factors than either single criterion. Its application in population-based studies would increase the likelihood of detecting risk factors for incident vertebral deformity for a given sample size. Author Affiliation: (1) ARC Epidemiology Unit, University of Manchester, Manchester, UK, GB (2) Department of Radiology and Nuclear Medicine, Free University, Berlin, Germany, DE (3) MRC Environmental Epidemiology Unit, University of Southampton, Southampton, UK, GB (4) WHO Collaborating Centre for Bone Disease, University of Sheffield, Sheffield, UK , GB (5) Strangeways Research Laboratory, Wort's Causeway, Cambridge, UK, GB Article note: Received: 6 November 2001 / Accepted: 7 May 2002

Byline: H. Jinbayashi (1), K. Aoyagi (2), P. D. Ross (3), M. Ito (4), H. Shindo (1), T. Takemoto (2) Keywords: Key words:Japanese -- Osteoporosis -- Physical impairment -- Vertebral deformity Abstract: Vertebral fractures are a hallmark of postmenopausal osteoporosis and an important end point in trials of osteoporosis treatment, but the clinical significance of vertebral deformities remains uncertain. We examined the prevalence of vertebral deformity and associations of vertebral deformities and other characteristics with physical functioning among 584 Japanese women ages 40 to 89 years. Lateral spine radiographs were obtained and radiographic vertebral deformities were assessed by quantitative morphometry, defined as vertebral heights more than 3 SD below the normal mean. A self-administered questionnaire was used to survey participants about difficulty in performing selected basic and instrumental activities of daily living (ADL). Overall, 15% of women had at least one vertebral deformity, and 8% had 2 or more. The prevalence of vertebral deformities increased progressively with age. Half of women ages 80 and over had vertebral deformities. Impaired function was defined as difficulty performing 3 or more ADLs. After adjusting for age, the odds of impaired function were increased by 1.4 times (95% CI: 0.7, 2.9) in women with a single vertebral deformity, and 3.1 times (1.4, 6.8) in those with two or more deformities. Additional adjustment for number of painful joints, number of comorbidities, body mass index, and back pain did not materially alter these findings. In conclusion, women with multiple vertebral deformities had significantly greater impaired function. The association was independent of age, back pain and the number of painful joints, suggesting that deformities may impair function even when back pain is not present. Author Affiliation: (1) Department of Orthopedic Surgery, JP (2) Department of Public Health, JP (4) Department of Radiology, Nagasaki University School of Medicine, Sakamoto, Nagasaki, Japan, JP (3) Merck and Co. Inc., Rahway, New Jersey, USA, US Article note: Received: 29 October 2001 / Accepted: 11 April 2002

Genetic influences on lordosis, a mammalian social behavior, are amenable for study because of the relative simplicity of both stimuli and response. The neural circuit for lordosis involves a supraspinal loop, which is controlled by an estrogen- and progesterone-dependent signal from the medial hypothalamus and results in heightened sexual motivation. In turn, this involves elevated states of arousal, defined by increased sensory alertness, motor activity and emotional reactivity. Mice in which the gene encoding the [alpha] form of the estrogen receptor (ER[alpha]) has been knocked out show that ER[alpha] is crucial for lordosis behavior. Comparing ER[alpha]-, ER[beta]- and double knockouts reveals that different patterns of sexual behaviors in mice require different patterns of ER activity. Understanding how hormonal and genetic effects on deep motivational and arousal processes contribute to their effects on specific sexual and aggressive behaviors pose significant challenges for mouse functional genomics.

This paper presents a technique for automating human scoliosis detection by computer based on moire topographic images of human backs. Scoliosis is a serious disease often suffered by teenagers. For prevention, screening is performed at schools in Japan employing a moire method in which doctors inspect moire images of subjects' backs visually. The inspection of a large number of moire images collected by the school screening causes exhaustion of doctors and leads to misjudgment. Computer-aided diagnosis of scoliosis has, therefore, been requested eagerly by orthopedists. To automate the inspection process, unlike existent three-dimensional techniques, displacement of local centroids is evaluated two-dimensionally between the left-hand side and the right-hand side of the moire images in the present technique. The technique was applied to real moire images to draw a distinction between normal and abnormal cases. According to the leave-out method, the entire 120 image data (60 normal and 60 abnormal) were separated into three data sets. The linear discriminant function based on Mahalanobis distance was defined on the two-dimensional feature space employing one of the data sets containing 40 moire images and classified 80 images in the remaining two sets. The technique finally achieved the average classification rate of 88.3%. Index Terms--Linear discriminant functions, moire images, potential symmetry, scoliosis, spinal deformity.

Byline: T. Illes (1), V. Halmai (1), T. de Jonge (1), J. Dubousset (2) Keywords: Key words:Bone mineral density -- Bone mineral turnover -- Dual-energy X-ray absorptiometry -- Neurofibromatosis-1 -- Spinal deformities Abstract: A cross-sectional study was carried out to obtain data on the bone mineral density status of a group of neurofibromatosis-1 patients with spinal deformities, and to search for possible accompanying changes in the bone mineral turnover. Neurofibromatosis-1 is a heredofamiliar disorder that is associated with a variety of skeletal anomalies (mostly spinal deformities) in 10--50% of patients. Intraoperatively, a poor vertebral bone quality has been observed. Efforts have been made to identify factors preventing curve progression, to optimize operational planning and to explain the pathomechanism. As part of the preoperative evaluation, dual-energy X-ray absorptiometry was used to assess the bone mineral density of the lumbar spine in 12 patients with neurofibromatosis-1, supplemented by laboratory blood/urine investigations. A significant decrease in bone mineral density of the lumbar spine was measured. An inverse relation was suggested between the severity of scoliosis and the lumbar spine Z-scores. No pivotal alterations were identified in the laboratory measurements. The bony tissue abnormality observed intraoperatively in neurofibromatosis-1 patients may be described as a diminution of the axial bone mineral density. The biochemical parameters do not support the presence of hyperparathyroidism, renal disorders or other associated diseases influencing the bone mineral turnover. The evaluation of bone mineral density in the course of the preoperative planning is proposed in neurofibromatosis-1 the exact background and the role of a possible osteoporosis in the prognosis remain to be elucidated. Author Affiliation: (1) Department of Orthopaedics, Medical and Health Sciences Center, University of Pecs, Hungary , HU (2) Service de Chirurgie Infantile, Hopital Saint-Vincent-de-Paul, Universite Rene Descartes, Paris, France, FR Article note: Received: 12 January 2001 / Accepted: 21 March 2001

A gene for autosomal recessive spondylocostal dysostosis (SD), a disorder in which vertebral-segmentation defects and rib anomalies are associated, maps to 19q13.1-q13.3. Short trunk and stature result as do other problems. The disorder can be familial and has been reported with both autosomal and dominant and autosomal recessive (AR) inheritance. Genomewide scanning was carried out in a large consanguineous ARSD Arab Israeli family which has six definitely affected members, and confirmation involved a second family, one of Pakistani descent, with three affected members.

Ossification of the posterior longitudinal ligament of the spine (OPLL) has been mapped to a predisposing locus on chromosome 6p close to the HLA complex. A genetic-linkage study has been carried out in 91 affected sib pairs from 53 Japanese families. OPPLL is a common disorder among Japanese people and all over Asia.

A method based on biomechanical analysis of video-recordings assesses the influence of physical loads and support on the lumbar spine and identifies biomechanical risk of back disorders in industrial work. The method considers body postures and occurrence of support and external load. The compression of the L5-S1 intervertebral disc and strain on the lumbodorsal fascia is calculated after every five seconds during each task. However, task by task analysis of the load fails to provide an accurate picture of continuous load over the complete workday.

Three-dimensional configuration of the scoliotic spine was mathematically expressed by a spatial curve passing through each vertebral centroid ('vertebral body line'). Three-dimensional location of the vertebral centroid was determined from digitization on the frontal and sagittal roentgenograms. Cobb angle, which is clinically used for measuring scoliosis curvature, was calculated in space to evaluate scoliosis deformity three-dimensionally. In forty-five scoliotic spines, regardless of curvature and curve patterns, the spinal configurations were excellently approximated by vertebral body lines. Vertebral body lines swerved from the sagittal plane at the end vertebrae, but aligned on a certain plane within the scoliosis region. Three-dimensional Cobb angle, which was larger than that in the frontal plane, can be utilized to evaluate the scoliosis deformity.

A backrest stabilizes the lumbar spine by providing support to the lower back, which facilitates kyphosis, contrary to the belief that it facilitates lumbar lordosis. Seats with vertical or anteriorly curved backrests also facilitate kyphosis, which may be the result of pushing the lumbar spine backwards against the backrest to enhance stability. However, the reason behind the production of lordosis while using anteriorly curved backrest, and kyphosis while using traditional backrests in active sitting, remains unclear.

Spondylolysis refers to a separation in a vertebral arch between the body and the spinous process. Most spondylolysis seen in humans occurs in the lower lumbar region and is due to stress (fatigue) fracturing, usually through the isthmus between the superior and inferior articular processes. Referred to here as 'typical' spondylolysis, it is related to erect posture and bipedal locomotion, and, as such, it is a uniquely hominid condition. It develops only after a child has begun to walk, and a developing lesion may heal or progress to complete separation. Seen more often in males than females, frequencies among populations vary widely. Certain activities have been suggested to put individuals performing them at greater risk to develop the condition. Although often approached as a pathological condition requiring corrective treatment, spondylolysis usually produces relatively mild symptoms if any at all, and may even provide the advantages of greater lower back flexibility. Complete bilateral spondylolysis separates the inferior articular processes from the body, thus allowing the body to slip forward relative to the vertebra below (spondylolisthesis). Another form of the condition, referred to as degenerative spondylolisthesis, allows a slow forward migration of one vertebra over another due to osteoarthritic remodeling of the posterior vertebral joints without any spondylolysis. KEY WORDS Separate neural arch, Erect posture, Lumbar curve, Stress fracture, Congenital, Degenerative, Osteoarthritis

A 25-year-old man was diagnosed with tethered-cord syndrome with myelomeningocele, a protrusion of membrane and the spinal cord through a defect in the spinal column. Tethered-cord syndrome is a disorder characterized by incomplete closure of the spinal column before birth. The patient was admitted to the hospital with intermittent lower back pain. He had had a history of this type of pain throughout his life but it had become worse after surgery one year before admission to the hospital. A large tumor had been found during the surgery but it had not been removed. A magnetic resonance image (MRI) scan of his spine revealed an oval mass inside the spinal canal and abnormalities in the spine and the spinal column. Urodynamic studies showed some abnormalities in bladder function. During surgery to remove the spinal mass, it was revealed that the patient was suffering from tethered cord syndrome.

This study was designed to investigate the natural history of atlantoaxial instability in individuals with Down syndrome and to determine whether significant changes in C1-C2 relationship are taking place over time. Although more than 400 patients with Down syndrome who are presently followed at the Child Development Center had cervical spine radiographic examinations in the past, only 141 patients who had serial radiological examinations and whose radiographs were available for reevaluation participated in this study. The results of our investigations revealed that there were only minor changes (1 to 1.5 mm) of atlanto-dens interval measurements over time in 130 (92%) patients with Down syndrome. Eleven patients (8%) had changes of atlantodens interval measurements between 2 and 4 mm over time; however, none of these patients had any clinical symptoms. The analyses of data obtained from several subgroups (males and females, various age groups, and patients with and without atlantoaxial instability) did not show any significant changes of atlanto-dens interval measurements of successively obtained radiographs. Our recommendations for and rationale of routine screening for atlantoaxial instability and follow-up examinations are discussed in detail.

To learn more about the nature of spinal cord injury in rugby players, a review was carried out of the clinical and X-ray records of nine patients who had sustained temporary paralysis injuries while playing. No evidence was seen on X-rays of a spinal cord injury, such as fracture or dislocation. The patients' injuries were to the cervical (neck) segments of the spinal cord. Based on the results, four categories were identified: five players had developmental stenosis (narrowing of the spinal canal, in which the cord lies); two players had intervertebral disk disease (disease of the connective tissue disks that separate the vertebrae); one player had congenital abnormalities; and two players had no abnormalities. (One player had both developmental stenosis and intervertebral disk disease.) A discussion is presented of these conditions and the effects of trauma on them. It is likely that spinal cord concussion in rugby players is associated with narrowing of the spinal canal or congenital anatomic abnormalities. Players with spinal stenosis or vertebral fusion who sustain such an injury should consider choosing a less risky sport. (Consumer Summary produced by Reliance Medical Information, Inc.)

A case-control study was undertaken to generate some hypotheses concerning the etiology of sacroiliac fusion in a group of skeletons dating from the 18th and 19th centuries. Forty-one skeletons with fusion of the sacroiliac joint were compared with eighty-two adult skeletons without the condition. The sacroiliac joints were most frequently fused with bridging osteophytes and no preference for site or side of fusion could be detected. Except where there were other features in the skeleton suggestive of a sero-negative arthropathy, radiography demonstrated that there was no intra-articular ankylosis. We were able to confirm earlier observations that the condition is more prevalent in males and in older age-groups. The study also showed a significant association between sacroiliac fusion and the presence of diffuse idiopathic skeletal hyperostosis (DISH) and osteoarthritis of the spine but not for osteoarthritis at any other site. There was a highly significant association between sacroiliac fusion and the phenomenon that we refer to as 'bone forming.' We devised a series of bone-former scores and were able to show a significant excess of cases with high scores compared with the controls. This association persisted when allowance had been made for potential confounding factors such as DISH, osteoarthritis of the spine, and age.