Thoracic Vertebrae

Degenerative scoliosis is a prevalent issue among the aging population. Controversy remains over the role of surgical intervention in patients with this disease. The authors discuss a suitable approach to help guide surgical treatment, including decompression, instrumented posterior spinal fusion, anterior spinal fusion, and osteotomy. These treatment options are based on clinical analysis, radiographic analysis of the mechanical stability of the deformity, given pain generators, and necessary sagittal balance. The high potential complication rates appear to be outweighed by the eventual successful clinical outcomes in patients suitable for operative intervention. This approach has had favorable outcomes and could help resolve the controversy.

-Thoracic Spinal Cord Compression by Ligamentum Flavum Ossifications. Ossification of the ligamentum flavum is common in Japan but rare in Western countries. Myelopathy of variable severity is a possible complication. Extension of the lesions over several levels at the thoracic spine is exceedingly rare. We report a new case in a 50-year-old man who had slowly progressive spinal cord compression with a sensory level at the navel. Computed tomography (CT) and magnetic resonance imaging (MRI) of the thoracic spine showed calcium-density masses that were in contact with the neural arches and bulged into the spinal canal at T5/T6, T7/T8, T9/T10, and T10/T11. Laboratory test findings were unremarkable. Surgical decompression by laminectomy and foraminotomy was followed by a favorable outcome. Histology showed extensive areas of bone metaplasia associated with calcific deposits. The diagnosis, treatment, and possible etiologies of this rare condition are discussed based on a literature review.

Objectives: The lumbar kyphosis in patients with myelomeningocele is a complex deformity whose treatment is mainly surgical. The objective of this study is to summarize the results and complications obtained by the group in 2012 with respect to this group of patients. Method: Performed a retrospective analysis of the medical records and radiographs of patients consecutively operated in 2012. The technique was originally described by Dunn-McCarthy and consists of kyphectomy and posterior fixation using S-shaped Luque rods through the foramina of S1 associated with pedicle screws in the thoracic spine. Results: Six patients were included in the study. The age at surgery was 11 years and 7±22 months and the weight was 29.1±11.9 kg. The procedure lasted 271±87 minutes, with the removal of one or two (mean 1.5) vertebrae from the apex of the kyphosis. Hospitalization time was 10±9 days. The lumbar kyphosis measuring 116.3±37 degrees preoperatively was reduced to 62.5±21 degrees. All patients began to sit without support and to lie in the supine position. Four patients developed postoperative infection and required surgical debridement at the follow-up. One patient had the implant removed after a year due to loosening of the rod in the sacrum. Conclusion: The surgical technique allows excellent functional results in the correction of lumbar kyphosis in patients with myelomeningocele despite high complication rates. It is necessary to conduct studies with a larger number of patients and duration of follow-up to assess whether the use of pedicle screws will decrease the rate of loosening and pseudoarthrosis.

We have studied the human thoracolumbar fascia by sulated mechanoreceptors (Ruffini's and Vater-Pacini using antiserum against neurofilament protein (NFP) corpuscles) were identified. These findings support and S-1 00 protein to identify sensory nerve fibers and the hypothesis that the thoracolumbar fascia may their endings. Seven surgical specimens from 7 play a neurosensory role in the lumbar spine patients were studied with light microscopy. In mechanism. addition to free nerve endings, two types of encap-

We report the clinical and MRI findings of two patients with familial spinal arachnoiditis. Although their initial symptoms were various, they both showed spastic paraparesis and sensory disturbance below the thoracic level. Cytokines and WBC in the CSF were studied, but they were not elevated at all. The spinal magnetic resonance images of each showed extensive arachnoiditis and a cystic structure. The other impressive features included: (i) an enhancement within the thickened arachnoid and an adhesion between the spinal cord and the dura mater, (ii) deformation of the thoracic cord where the arachnoid adhered, and (iii) secondary syrinx formation. Laminectomy may have an adverse outcome for such patients.

Diagnostic testing. The goal of this study is to measure the accuracy and reliability of the Orthoscan (Orthoscan Technologies, Inc.) and to determine whether it can be substituted for radiographs in the surveillance of adolescent idiopathic scoliosis (AIS). AIS is usually followed using scoliosis radiographs, which offer the most reliable way to quantify the curve, but carry the risk of exposure to ionizing radiation. The Orthoscan is a nonradiographic topographic method for measuring spinal curves. There were 5 phases of this study that measured: the accuracy and reliability of the machine when used with a plastic model; the variability with a real patient; the intraobserver variability; the correlation between the measurements of the machine and that of the radiograph; and the correlation between the change in radiograph measurement over time and the change in Orthoscan measurement over time. In measurement of a static plastic model, the machine measured curves with a standard de...

The vertebral heart size (VHS) is used to objectively assess cardiac dimensions on thoracic radiographs. A high VHS suggest the presence of cardiac pathology, such as dilated cardiomyopathy, degenerative atrioventricular valvular disease, pericardial effusion, pericardioperitoneal diaphragmatic hernia, tricuspid dysplasia, ventricular septal defect, or patent ductus arteriosus, among others. However, breed or body conformation can influence the VHS. Because Greyhounds have a high prevalence of physiologic systolic murmurs associated with high aortic velocity, and large cardiac dimensions when compared with dogs of similar size, they are frequently suspected of having heart disease. The purpose of this study was to compare the VHS in normal Greyhounds with those in Rottweilers, and a group of dogs from various other breeds using both analog and digital radiology. The VHS was significantly higher in Greyhounds (Po0.0001), when compared with Rottweilers and to other dog breeds. The mean VHS on lateral radiographs for Greyhounds was 10.5 AE 0.1, for Rottweilers it was 9.8 AE 0.1, and for mixed breed dogs it was 10.1 AE 0.2. This study confirms that the relative cardiomegaly reported in necropsy and echocardiographic studies in Greyhounds is easily detected using plain radiography and the VHS.

Postmortem aortography was performed in 38 adults, aged 17 to 29 years, to elucidate the normal anatomy of the arteries supplying the lower thoracic and lumbosacral regions. The lowest 3 thoracic segmental arteries, examined in 32 cases, ran symmetrically in 27 cases. In 5 cases (16%) their course was asymmetric; on one side every segment was fed by an artery of its own, whereas on the other side a segmental artery fed 2 or more segments. The course, distribution and size of the 1st to 4th lumbar arteries were constant in every case except one, while the middle sacral artery and its branches, the 5th lumbar arteries, varied in size, being frequently compensated for, partly or wholly, by the iliolumbar arteries derived from the internal iliac arteries. In their course around the vertebral bodies, lumbar arteries frequently passed beiween and beneath fibrous attachments of the crura of the diaphragm and the psoas muscle.

Pyogenic spondylodiscitis associated with epidural abscess is a rare but serious problem in spinal surgery, because it may cause a severe morbidity or mortality, if the diagnosis is established late and the treatment is inadequate. A case of pyogenic thoracic spondylodiscitis associated with epidural abscess whose symptoms progressed over two months from back pain to acute paraplegia was presented. Magnetic resonance imaging of the spine suggested the presence of T9–10 spondylodiscitis with partial destruction of the T9 and T10 vertebral bodies and concomitant epidural abscess. Treatment consisting of surgical debridement of infected vertebrae and disc material, fusion and anterior spinal instrumentation was performed. Microbiological culture of the material revealed infection with Staphylococcus aureus and after 3 months of antibiotic treatment, recovery was almost complete. Based on a thorough review of the literature and the case presented in this report, it is concluded that accurate and prompt diagnosis requires high index of suspicion followed by a combination of adequate surgical and conservative treatment prevents severe morbidity in cases of nonspecific pyogenic spondylodiscitis associated with epidural abscess.

We report a rare complication of autopsy-proven fat and bone marrow embolization following percutaneous vertebroplasty in a patient who had no evidence of cement leakage. Cement injection was done during one patient encounter, covering 3 vertebral levels by using a unipedicular approach. Patients may have complications even without polymethylmethacrylate leakage.

A total 71 male athletes (weight lifters, wrestlers, orienteers, and ice-hockey players) and 21 nonathletes were randomly selected, for a baseline MRI study. After 15 years all the participants at baseline were invited to take part in a follow-up examination, including a questionnaire on back pain and a follow-up MRI examination. Thirty-two athletes and all non-athletes had disc height reduction at one or several disc levels. Disc degeneration was found in more than 90% of the athletes and deterioration had occurred in 88% of the athletes, with the highest frequency in weight lifters and ice-hockey players. 78% of the athletes and 38% of the non-athletes reported previous or present history of back pain at baseline and 71 and 75%, respectively at follow-up. There was no statistically significant correlation between back pain and MRI changes. In conclusion, athletes in sports with severe or moderate demands on the back run a high risk of developing disc degeneration and other abnormalities of the spine on MRI and they report high frequency of back pain. The study confirmed our hypothesis, i.e. that most of the spinal abnormalities in athletes seem to occur during the growth spurt, since the majority of the abnormalities demonstrated at follow-up MRI after the sports career were present already at baseline. The abnormalities found at young age deteriorated to a varying degree during the 15-year followup, probably due to a combination of continued high load sporting activities and normal ageing. Preventive measures should be considered to avoid the development of these injuries in young athletes.

We reviewed retrospectively our patients with thoracic lordoscoliosis and conducted a conceptual analysis of the patients with airway compression and atelectasia due to anterior protrusion of the vertebral bodies in order to describe the pathological conditions involved and the management methods used. Our goal was to develop a new concept for quantifying thoracic deformation. The individual cases discussed here have been reported earlier, but this is the first series analysis to date. Eighteen patients, aged 7.3 to 18 years, with thoracic lordoscoliosis due to a variety of causes, mostly neuromuscular disorders (12 cases), are described. Most patients were treated by anterior subtotal periosteal resection of the vertebral body followed by posterior instrumentation and arthrodesis. Atelectasia disappeared with a normalization of blood gases but the effect was variable on vital capacity. The analysis of the CT studies led to the concept of spinal deformity as an endothoracic deformat...

Preparation for surgery for thoracic intraspinal lesions commonly involves rather difficult X-ray procedures in the operating room. The object of this report is to inform neurosurgeons about a modified technique for preoperative surface localization of intraspinal thoracic pathology. Adhesive, disposable radiographic skin markers placed at the presumed level of an intraspinal lesion are visualized along with the lesion on sagittal magnetic resonance scans of the thoracic spine. The lesion and the skin markers were clearly identified within the same field of view. The lesion itself rather than the vertebral body becomes the reference point for localization. Preoperative imaging with adhesive skin markers facilitates positioning and draping for surgery for thoracic intraspinal lesions. It may even replace intra-operative X-ray procedures in selected cases.

Introduction Compression fractures at the thoracolumbar junction are frequently treated by reconstruction with vertebral body replacement systems. Modern cage implants have been developed which respect the anatomy and angulation of the adjacent bony endplates. The objective of this study was to investigate the biomechanical performance of anatomic endplate design and variable endplate angulation. Materials and methods Three cage systems [Hydrolift (HYL), Aesculap; Synex II (SYN), Synthes; Obelisc (OBC), Ulrich] were compared employing a composite bone substitute material at two levels of endplate angulation (0°, 3°). Their load-bearing capacity was assessed in a physiologic test with human vertebral specimens in a misalignment situation (3°). The HYL and SYN offered anatomically shaped endplates. The endplates of the HYL had variable angulation during insertion and were then mechanically fixated. The OBC had fixed and circular endplates. The load to failure and system stiffness were evaluated by an axial compression test. The bone mineral density (BMD) and the area of the bony endplates were measured via CT.

There is signiWcant paucity in the literature regarding vertebral aponeurosis. We were able to Wnd only a few descriptions of this speciWc fascia in the extant medical literature. To elucidate further the anatomy of this structure, forty adult human cadavers were dissected. Both quantitation and anatomical observations were made of the vertebral aponeurosis. The vertebral aponeurosis was iden-tiWed in 100% of specimens. This fascia was identiWed as a thin Wbrous layer consisting of longitudinal and transverse connective tissue Wbers blended together deep to the latissimus dorsi muscle. It attached medially to the spinous processes of the of the thoracic vertebrae; laterally to the angles of ribs; inferiorly to the fascia covering the serratus posterior inferior muscle (superWcial lamina of the posterior layer of thoracolumbar fascia); superiorly it ran deep to the serratus posterior superior and splenius capitis muscles to blend with the deep fascia of the neck. At the level of the serratus posterior inferior muscle, the vertebral aponeurosis fused to form a continuous layer descending toward the sacrotuberous ligament covering the erector spinae muscle. Morphometrically, the mean length of the vertebral aponeurosis was 38 cm and the mean width was 24 cm. The mean thickness was three mm. There was no signiWcant diVerence between left and right sides, gender or age with regard to vertebral aponeurosis length, width, or thickness (P > 0.05). During manual tension of the vertebral aponeurosis, the tensile force necessary for failure had a mean of 38.7 N. In all specimens, the vertebral aponeurosis was capable of holding sutures placed through its substance. We hope that these data will be of use for descriptive purposes and may potentially add to our understanding of the biomechanics involved in movements of the back. As back pain is perhaps the most common reason patients visit their physicians, additional knowledge of this anatomical region is important.

Validity of a clinical test can be defined as the extent to which the test actually assesses what it is intended to assess. In order to investigate the validity of manual physical assessment of the spine, it is therefore essential to establish what physical therapists intend to assess when they are applying these tests.

We report 2 cases of right pulmonary aplasia with left pulmonary artery sling responsible for severe respiratory symptoms. Repositioning of the left pulmonary artery without tracheal surgery was successful in both patients. The postoperative course was simple, and the outcome was favorable at last follow-up (after 2 years and 3 months, respectively). Computed tomography provided an accurate diagnostic evaluation that helped to choose the best surgical technique.

To describe a technique for thoracolumbar lateral corpectomy and to evaluate its use for treatment of chronic thoracolumbar disk disease in dogs. Retrospective study. Fifteen dogs with signs of chronic thoracolumbar disk herniation. After a dorsal or lateral approach to the spine, a lateral slot was created in 2 adjacent vertebral bodies on either side of the herniated disk and extruded/protruded material was removed. Data collected included history, duration of clinical signs, presurgical assessment of neurologic status, postsurgical neurologic status, complications, and outcome. Ambulatory capacity was maintained or regained, and neurologic status improved by 1 grade (3 dogs), 2 grades (8), 3 grades (2), or 4 grades (2). Eleven dogs were considered free of disease. A seroma in 1 dog was the sole complication observed. Lateral corpectomy permits relatively easy removal of protruded-extruded disk material from within the vertebral canal in chronic disk disease without further iatrogenic injury to the spinal cord. Lateral corpectomy is an alternative to dorsal decompression for treatment of ventral and lateroventral thoracolumbar chronic disk disease in dogs.

Objectives. To review the various radiographic parameters currently used to assess traumatic thoracolumbar injuries, emphasizing the validity and technique behind each one, to formulate evidence-based guidelines for a standardized radiographic method of assessment of these fractures.

To summarize the current knowledge relating to diagnosing and treating Scheuermann's disease. Scheuermann's disease is the most common cause of structural kyphosis in adolescence. A literature-based narrative review of English language medical literature. Recent studies have revealed a major genetic contribution (a dominant autosomal inheritance pattern with high penetrance and variable expressivity) to the etiology of Scheuermann kyphosis with a smaller environmental component (most probably mechanical factors). The natural history of Scheuermann kyphosis remains controversial, with conflicting reports as to the severity of pain and physical disability. Since we cannot predict which kyphotic curves will progress, we are unable to determine effectiveness of brace treatment. Physical therapy is scarcely mentioned in the literature as an effective treatment for Scheuermann kyphosis. Although there is little evidence that physical therapy alone can alter the natural history of ...

We present the case of a 14-year-old male with Scheuermann's disease and significant neurological deficit due to thoracic disk herniation at the apex of kyphosis. He was treated with an anterior decompression, anterior and posterior fusion in the same setting using plate, cage and a segmental instrumentation system. The patient had an excellent outcome with complete neurological recovery.

In order to reduce the observer variability in radiographic scoliosis assessment, a computer-aided system was developed. The system semi-automatically measured the Cobb angle and vertebral rotation on posteroanterior radiographs based on Hough transform and snake model, respectively. Both algorithms were integrated with the shape priors to improve the performance. The system was tested twice by each of three observers. The intraobserver and interobserver reliability analyses resulted in the intraclass correlation coefficients higher than 0.9 and 0.8 for Cobb measurement on 70 radiographs and rotation measurement on 156 vertebrae, respectively. Both the Cobb and rotation measurements resulted in the average intraobserver and interobserver errors less than 2°and 3°, respectively. There were no significant differences in the measurement variability between groups of curve location, curve magnitude, observer experience, and vertebra location. Compared with the documented results, measurement variability is reduced by using the developed system. This system can help orthopedic surgeons assess scoliosis more reliably.

The assessment of vertebral fracture by conventional radiography has been refined and improved using either semiquantitative or quantitative criteria. The inter- and intraobserver variability was determined for a semiquantitative visual approach that we routinely use in clinical studies for assessing prevalent and incident vertebral fractures. In addition, the semiquantitative approach was compared with a quantitative morpho-metric approach. The incidence and prevalence of vertebral fractures were determined in 57 postmenopausal women (age 65–75 years) by three independent observers. The radiographic basis for fracture definitions and the source of interpretative errors are illustrated. The results show excellent intraobserver agreement and good interobserver agreement for the semiquantitative technique. We conclude that the semiquantitative approach can be applied reliably in vertebral fracture assessment when performed using well-defined criteria.

Union of the vertebral centra or ''ring'' epiphyses occurs during adolescence and early adulthood, providing valuable age at death information. We present a system for estimating age based on the timing and pattern of vertebral ring union. Data from 57 known individuals aged 14-27 years were used to establish age ranges for various patterns of union in females and males. Female age ranges were more well defined with less overlap in patterns of union than male age ranges. The age ranges are accompanied by descriptions of the stages of union observed that aid in applying this method. A test of interobserver error in scoring stages of union demonstrated strong consistency among three observers (r = 0.91-0.97). Estimating age by observing all stages documented resulted in 78%, 88%, and 100% accuracies using vertebral data alone. We encourage the continued use of this method, in conjunction with other age indicators.

A follow-up of disc herniation (herniated nucleus pulposus [HNP]) resorption on magnetic resonance imaging (MRI). To assess the determinants of resorption of HNP. Neovascularization in the outermost areas of HNP, presenting as an enhancing rim in gadolinium diethylenetriamine pentaacetic acid MR images, is thought to be a major determinant of spontaneous resorption of HNP. Patients with HNP-induced sciatica at baseline were rescanned at 2 months (N = 74) and after 12 months (N = 53). The volume of HNP (mm), thickness (mm) and extent (%) of enhancement, and the degree of HNP migration (Komori classification) were analyzed. Repeated measures analysis of covariance was used in statistical analysis. Significant resorption of HNP occurred from baseline to 2 months, although the resorption rate was more pronounced over the whole 1-year follow-up. Higher baseline scores of rim enhancement thickness, higher degree of HNP displacement in the Komori classification, and age category 41-50 year...

Introduction The current authors have developed a modular system of reference array Wxation which is tailored spe-ciWcally to the spinal level being operated upon. They believe that this system may further increase the precision and accuracy of pedicle screw placement. Materials and methods Two formalin-Wxed whole body cadavers were used for this study. For cervical spine evaluation of the reference clamp, four odontoid screws (two per cadaver) for C1/C2-fusion and four lateral mass screws (two per cadaver) were implanted. Following navigated screw placement with 2D and 3D Xuoroscopic veriWcation, insertion of two lateral mass screws was performed. In the same way, lumbar and thoracic pedicle screws were implanted. Two pedicle screws were placed at two levels of the lumbar and two levels of the thoracic areas giving an overall of 16 screws implanted (8 cervical, 4 thoracic, and 4 lumbar). Postoperative evaluation involved comparison of postoperative 3D scans and preoperative planning images. A simple classiWcation system was used for evaluation of any deviation from the planned trajectory. Results All pedicle screw placements were performed as planned without any technical problems. The reference array clamps remained in position at all the spinal levels at which they were employed with no loosening or displacement and no secondary damage to any of the spinous processes. Manual manipulation was performed but no displacement or slippage was observed. Image artefacts caused by the reference clamp were not signiWcant as to obscure the area of interest. Both imaging modalities (Iso-C 3D and Vario 3D) generated suYciently precise 3D images. There was no substantial diVerence in quality when those two systems were compared. Discussion InsuYcient Wxation of the reference clamp can lead to failure and complications. To date, no reference clamp systems have been developed speciWcally for navigated spine surgery. Conclusions Stable reference array Wxation is a critical step in navigated surgery. To date, the same reference clamps have been applied to the spinal anatomy as have been developed originally for the appendicular skeleton. The current investigators have developed a novel modular clamp and have demonstrated its eYcacy in a cadaveric model.

In this letter to the Editor, an additional radiological thoracic deformity parameter is described, which was not included in the review, namely the rib index (RI). The index and its usefulness of its application are described, both in the clinical praxis and in the aetiology of idiopathic scoliosis. The pertinent literature is also sited.

Objective-To describe outcome after an alternative unilateral approach to the thoracolumbar spine for dorsal laminectomy. Study Design-Retrospective clinical study. Animals-Dogs (n ¼ 14) with thoracolumbar spinal cord compression. Methods-Thoracolumbar spinal cord compression was lateral (6 dogs), dorsal (4), and dorsolateral (4) caused by subarachnoid (7) and synovial cysts (2) and intradural-extramedullary neoplasia (5). All dogs were treated by dorsal laminectomy with osteotomy of the spinous process using a unilateral paramedian approach. The contralateral paraspinal muscles were not stripped from the spinous process and the osteoligamentous complexes were preserved. Retraction of the spinous process and muscles to the contralateral side resulted in complete visualization of the dorsal vertebral arch thereby allowing dorsal laminectomy to be performed. Results-No technique complications occurred. Approximately 75% exposure of the spinal cord (dorsal and lateral compartments) was achieved providing adequate visualization and treatment of the lesions. Transient deterioration of neurologic state occurred in 5 dogs because of extensive spinal cord manipulation. At long-term follow-up, 6 dogs were normal, 6 had clinical improvement, and 2 were unchanged. Conclusion-Dorsal laminectomy after osteotomy and retraction of the spinous process may be considered in canine patients with dorsal, dorsolateral, or lateral compression to facilitate adequate decompression of the spinal cord. Clinical Significance-This surgical technique offers an alternative approach to the thoracolumbar spine and spinal cord by a modified dorsal laminectomy that preserves the paraspinal muscle integrity on the contralateral side.

Object. Spinal osteochondromas (OCs) are rare and can originate as solitary lesions or in the context of hereditary multiple exostoses. Concurrent spinal cord compression is a very rare entity. The purpose of this study was to evaluate the authors' 10-year experience with the imaging characteristics and surgical outcome in patients with symptomatic spinal OC.