Purpose. To question the reliability of Thoracic Spine pain as a red flag and symptoms of a possible cause of Serious Spinal Pathology (SSP). Methods. The clinical notes and Magnetic Resonance Imaging (MRI) results of patients presenting to the Sheffield Spinal Service with Thoracic spine symptoms but no signs were retrospectively reviewed over the period of 2 year (September 2008-August 2010). The clinical reason for request of Thoracic MRIs were noted and the patient notes were reviewed to determine their presentation, length of time of symptoms, age and also it was noted whether any other recognized red flag symptoms were present. Exclusion criteria consisted of patients referred with known SSP or myelopathic symptoms. Results. 57 thoracic spine MRI requests were made in total by the orthopaedic spinal teams for patients presenting with thoracic spine pain in the time period. 8 patients were excluded as per criteria as they were referred with known SSP as were 4 other patients with a history of previous cancer. 45 patients presented with thoracic spine pain but no other red flag signs or symptoms of these none had MRI evidence of serious spinal pathology or indeed anything pathological indicating the cause of their symptoms. Conclusion. The majority of those presenting to orthopaedic spinal clinic with thoracic spine pain alone with no other red flag signs have no pathological cause. Thoracic pain is a widely accepted indicator (red flag) of potential serious spinal pathology. The findings from this review would not support thoracic pain alone as an indicator of SSP

Observation of sub-clinical neurological abnormalities has led to the proposal of a neuro-developmental etiologic model for AIS. Our research group have demonstrated longer latency in somatosensory–evoked potential (SSEP) and impaired balance control in AIS subjects. A previous pilot study compared the regional brain volume between right thoracic AIS subjects and normal controls. Significant regional brain differences were found relating to corpus callosum, premotor cortex, proprioceptive and visual centers. Most of these regions involved the brain unilaterally, indicating there might be abnormal asymmetrical development in the brain in right thoracic AIS. In this pilot study, we investigated whether similar changes are present in left thoracic AIS patients who differ from matched control subjects. Nine AIS female patients with atypical left thoracic AIS (mean age 14.8, mean Cobb angle 19°) and 11 matched controls as well as 20 right thoracic AIS (mean Cobb angle 33.8°) and 17 matched controls, underwent three-dimensional isotropic magnetization prepared rapid acquisition gradient echo (3D_MPRAGE) magnetic resonance (MR) imaging of the brain. Fully automatic morphometric analysis was used to analyse the MR images; it included brain-tissue classification into grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF). and non-linear registration to a template brain. Tissue densities were compared between AIS subjects and controls. There was no significant difference between AIS subjects and normal controls when comparing absolute and relative (i.e. brain-size adjusted) volumes of grey and white matter. Using voxel-based morphometry, significant group differences (controls > left AIS) were found in the density of WM in the genu of the corpus callosum, the left internal capsule (anterior arm) and WM underlying the orbitofrontal cortex of the left hemisphere. The above differences were not observed in the right AIS group. This first controlled study of regional tissue density showed that corpus callosum, which is the major commissural fiber tract, was different in the atypical left thoracic scoliosis while significant regional brain changes have not yet been found in those with typical right thoracic scoliosis. Further investigation is warranted to see whether the above discrepancy is related to laterality of the scoliotic curves and infratentorial neuroanatomical abnormalities. A larger sample and a longitudinal study is required to establish whether the brain abnormalities are predictive of curve progression

Inßuence of scoliosis surgery on pulmonary changes and even upon thoracic deformity changes are still controversial. The purpose of the study was to determine thoracic volume (TV) changes in patients operated on by means of posterior and anterior surgery because of severe thoracic AIS. 50 patients, operated by þrst author randomly chosen from the period 1993–97 were selected. In 25 patients (21 girls, 4 boys) anterior instrumentation was used (group 1), and posterior instrumentation in other 25 patients (20 girls, 5 boys; group 2). TV calculation was performed basing on preoperative and postoperative plain x-rays, using a well known equation (second and third, independent author). The curves were 73û ± 12.4 pre op, and 19û ± 15 post op (group 1), and 75û ±13 pre op., 37û± 10 post op. (group2). Calculated TV for group 1 increased from 5234 ml to 6043 ml postoperatively (17% ± 16). In group 2, TV increased from 5155 to 5489 to 4,371 (6% ± 7). The correlation between the Cobb angle change and the thoracic volume change was poor (+0.2 for group 1, -0.4 for group 2). To determine the role of frontal, sagital and vertical thoracic diameters in TV increase, further correlation tests were performed. The best correlation was found between the frontal and vertical diameter increase in anterior instrumentation (r=0.62; 0.71), whereas the best correlation was found between TV and sagital parameters in posterior instrumentation (r=0.74). It is concluded that anterior instrumentation can increase TV more than posterior instrumentation

Introduction. Children with early-onset scoliosis (EOS) with rib hump chest-wall distortion or fused/absent ribs have thoracic insufficiency syndrome (TIS). Commonly, respiration is adversely affected by loss of lung volume from chest-wall constriction and clinical loss of active rib cage expansion. The dynamic thoracic components of diaphragm or rib cage lung expansion during respiration is poorly characterised by radiograph or CT scan. Pulmonary function tests indicate only hemithorax performance. Dynamic lung MRI, however, can visualise both chest-wall and diaphragm motion, allowing assessment of each individual hemithorax performance, so that a dynamic classification system of the thoracic function can be developed. Methods. Ten patients with TIS underwent dynamic lung MRI testing as part of the routine clinical preoperative work-up. Each hemithorax was graded: 1=intact motion of both chest wall and diaphragm; 2=primarily loss of chest-wall motion with minimal diaphragm abnormality; 3=substantial loss of diaphragm excursion with minimal loss or compensatory hyperkinesis of chest wall; and 4=substantial loss of both diaphragm and chest-wall motion. The grades for each hemithorax were added and averaged to form the thoracic function score. Ranges of scores were grouped into levels of clinical thoracic performance: level I (score 1–1·5); level II (>1·5–2·5); level III (>2·5–3·5); and level IV(>3·5–4·0). Results. Of nine patients with EOS, two were level I, three were level II, and four were level III. In four patients there was marked posterior obstruction of diaphragmatic excursion by soft-tissue organs. One patient with hypoplastic thorax without scoliosis was level II. Conclusions. Thoracic function index is a new thoracic performance approach based on dynamic lung MRI that has potential to identify biomechanical abnormalities of the thorax in EOS that cause restrictive lung disease. This index could provide insight into how to reverse the abnormality with new types of surgeries. Posterior obstructive blockade of the diaphragm is identified as a new cause for restrictive lung disease in EOS

Introduction. Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional deformity of the spine with unclear etiology. Due to the asymmetry of lateral curves, there are differences in the muscle activation between the convex and concave sides. This study utilized a comprehensive thoracic spine and ribcage musculoskeletal model to improve the biomechanical understanding of the development of AIS deformity and approach an explanation of the condition. Methods. In this study, we implemented a motion capture model using a generic rigid-body thoracic spine and ribcage model, which is kinematically determinate and controlled by spine posture obtained, for instance, from radiographs. This model is publicly accessible via a GitHub repository. We simulated gait and standing models of two AIS (averaging 15 years old, both with left lumbar curve and right thoracic curve averaging 25 degrees) and one control subject. The marker set included extra markers on the sternum and the thoracic and lumbar spine. The study was approved by the regional Research Ethics Committee (Journal number: H17034237). Results. We investigated the difference between the muscle activation on the right and left sides including erector spinae (ES), psoas major (PS), and multifidus (MF). Results of the AIS simulations indicated that, on average throughout the gait cycle, the right ES, left PS and left MF had 46%, 44%, and 23% higher activities compared to the other side, respectively. In standing, the ratios were 28%, 40%, and 19%, respectively. However, for the control subject, the differences were under 7%, except ES throughout the gait, which was 17%. Conclusion. The musculoskeletal model revealed distinct differences in force patterns of the right and left sides of the spine, indicating an instability phenomenon, where larger curves lead to higher muscle activations for stabilization. Acknowledgement. The project is funded by the European Union's Horizon 2020 program through Marie Skłodowska-Curie grant No. [764644]

Thoracic hyperkyphosis (TH – Cobb angle >40°) is correlated with rotator cuff arthropathy and associated with anterior tilting and protraction of scapula, impacting the glenoid orientation and the surrounding musculature. Reverse total shoulder arthroplasty (RTSA) is a reliable surgical treatment for patients with rotator cuff arthropathy and recent literature suggests that patients with TH may have comparable range of motion after RTSA. However, there exists no study reporting the possible link between patient-reported outcomes, humeral retroversion and TH after RTSA. While the risk of post-operative complications such as instability, hardware loosening, scapular notching, and prosthetic infection are low, we hypothesize that it is critical to optimize the biomechanical parameters through proper implant positioning and understanding patient-specific scapular and thoracic anatomy to improve surgical outcomes in this subset of patients with TH. Patients treated with primary RTSA at an academic hospital in 2018 were reviewed for a two-year follow-up. Exclusion criteria were as follows: no pre-existing chest radiographs for Cobb angle measurement, change in post-operative functional status as a result of trauma or medical comorbidities, and missing component placement and parameter information in the operative note. As most patients did not have a pre-operative chest radiograph, only seven patients with a Cobb angle equal to or greater than 40° were eligible. Chart reviews were completed to determine indications for RTSA, hardware positioning parameters such as inferior tilting, humeral stem retroversion, glenosphere size/location, and baseplate size. Clinical data following surgery included review of radiographs and complications. Follow-up in all patients were to a period of two years. The American Shoulder and Elbow Surgeons (ASES) Shoulder Score was used for patient-reported functional and pain outcomes. The average age of the patients at the time of RTSA was 71 years old, with six female patients and one male patient. The indication for RTSA was primarily rotator cuff arthropathy. Possible correlation between Cobb angle and humeral retroversion was noted, whereby, Cobb angle greater than 40° matched with humeral retroversion greater than 30°, and resulted in significantly higher ASES scores. Two patients with mean Cobb angle of 50° and mean humeral retroversion 37.5° had mean ASES scores of 92.5. Five patients who received mean humeral retroversion of 30° had mean lower ASES scores of 63.7 (p < 0 .05). There was no significant correlation with glenosphere size or position, baseplate size, degree of inferior tilting or lateralization. Patient-reported outcomes have not been reported in RTSA patients with TH. In this case series, we observed that humeral stem retroversion greater than 30° may be correlated with less post-operative pain and greater patient satisfaction in patients with TH. Further clinical studies are needed to understanding the biomechanical relationship between RTSA, humeral retroversion and TH to optimize patient outcomes

Purpose of the study: Fixing the pedicles can be difficult to achieve during surgical treatment of scoliosis involving the thoracic spine because of the vertebral rotation raising the risk of neurological and vascular disorders. Use of extrapedicular thoracic screws has been proposed for more adapted and safe fixation. No clinical data has been published concerning the safety of these screws. Material and methods: This multicentric retrospective clinical and radiological study included 467 thoracic screws in 34 patients operated for scoliosis. Neurophysiological monitoring was used for all procedures. Screws were positioned free hand without radioscopic control. Pedicular screws were inserted in T10, T11, T12. Extra-pedicular screws were inserted for thoracic vertebrae above T10 to T4. Correction was achieved with rods bent in situ. The purpose of this study was to evaluate the position of the thoracic screws within the vertebral body and in relation to the great vessels and the cord. The position of the screws in the thoracic spine was studied by two independent observers reading multiple thin-slice CT images. The observers noted malposition as: 1) penetration into the canal more than 2 mm, 2) less than 1 cm hold in the vertebral body, 3) screw protrusion more than 2 mm beyond the vertebral cortical. Results: Screw malposition was observed for 9 of 161 pedicular screws (5.4%) and for 21 of 306 (6.8%) thoracic screws. None of the screw malpositions had a clinical expression. There was one episode of thoracic effusion associated with thoracoplasty. Two patients required revision (one for poor indication and one for disincarceration). There were no postoperative deep infections. Three cases of intercostals neuralgia subsided within three months. Conclusion: Insertion of thoracic screws for fixation and correction is a useful technique with few complications. It enables better 3D correction and better control of the deformation. Screw malposition in this series was similar to that observed with classical pedicular techniques. There was no major complication associated with thoracic screws

The objective of this study was to assess the reliability and appropriateness of statistical shape modelling for capturing variation in thoracic vertebral anatomy for future use in assessing scoliotic vertebral morphology. Magnetic resonance (MR) images of the thoracic vertebrae were acquired from 20 healthy adults (12 female, 8 male) using a 1.5 T MR scanner (Intera, Philips). A T1 weighted spin-echo sequence (repetition time = 294 ms, echo time = 8 ms, number of signal averages = 3) was used. A set of slices (number = 27, thickness = 1.9 mm, gap = 1.63 mm, pixel size = 0.5 mm) were acquired for each vertebrae, parallel to the mid-transverse plane of the vertebral body. Repeated imaging, including participant repositioning, was performed for T4, T8 and T12 to assess reliability. Landmark points were placed on the images to define anatomical features consisting of the vertebral body and foramen, pedicles, transverse and spinous processes, inferior and superior facets. A statistical shape model was created using software tools developed in MATLAB (R2013a, The MathWorks Inc.). The model was used to determine the mean vertebral shape and ‘modes of variation’ describing patterns in vertebral shape. Analysis of variance was used to test for differences between vertebral levels and subjects and reliability was assessed by determining the within-subject standard deviation from the repeated measurements. The first three modes of variation, shown below (green = mean, red and blue = ±2 standard deviations about the mean), accounted for 70% of the variation in thoracic vertebral shape (Mode 1 = 44%, Mode 2 = 19%, Mode 3 = 4%). Visual inspection indicated that these modes described variation in anatomical features such as the aspect ratio of the vertebral bodies, width and orientation of the pedicles, and position and orientation of the processes and facet points. Variation in shape along the thoracic spine, characterised by these modes of variation, was consistent with that reported in the literature. Significant differences (p< 0.05) between vertebral levels and between some subjects were found. The reliability of the method was good with low relative error (Mode 1 = 5%, Mode 2 = 8%, Mode 3 = 19%). Statistical shape modelling provides a reliable method for characterizing many anatomical features of the thoracic vertebrae in a compact number of variables. This is useful for robustly assessing morphological differences between scoliotic and non-scoliotic vertebrae and in assessing entry points and trajectories for pedicle screws

Object. Giant thoracic discs (occupying more than 40% of the spinal canal) are a difficult surgical pathology. They are increasingly being recognized as or particular subset of thoracic disc pathology. It has been recommended that an aggressive surgical approach of open 2 level verteberectomy and instruments should be utilized.21 However Retropleural thoracotomy provides the shortest direct route to the anterior thoracic spine and avoids pleural cavity entry making it an ideal if infrequently used approach to access ventral thoracic and thoracolumbar spine abnormalities. We present a detailed description of our experience utilising this approach, for the treatment of Giant Thoracic discs without the need for vertebrectomy or instrumentation. Methods. A prospective cohort of patients with Giant thoracic discs operated on utilizing the mini open retropleural thoracotomy technique was used, intra-operative and post-operative complications and length of post-op stay. Functional outcome and pain scores, were also prospectively recorded using SF-36, Oswestry Disability Index (ODI), and visual analogue pain scores (VAS). Results. 17 patients underwent a retropleural thoracotomy for Giant thoracic disc between 2001 and 2010. There were 8 male and 9 female patients with a median age of 50 years (range 35 – 70). The surgical level was T8/9 (58%) followed by T10/11 (33%) and finally T11/12 (8%). 1 patient had redo surgery following a failed primary discectomy at another institution. The mean post-operative length of stay was 12.8 days Intra-operative complications included 5 pleural tears during the approach. Chest drain was placed post-op in one patient. The tears were primarily repaired and the approach did not have to be abandoned. 2 patients had an intra-operative CSF leak (1 had intradural disc erosion). Post-operative complications included 1 pleural effusion, 1 patient had pneumonia and a PE, 1 patient died from an unrelated respiratory tract infection of the lung (opposite to the side of the approach) 40 days after surgery. Conclusion. Large calcified thoracic disc herniations can be a very challenging pathology. The retropleural transthoracic approach can be employed safely in this setting with acceptable morbidity for the patient

In multilevel posterior cervical instrumented fusions, extending the fusion across the cervico-thoracic junction at T1 or T2 (CTJ) has been associated with decreased rate of re-operation and pseudarthrosis but with longer surgical time and increased blood loss. The impact on patient reported outcomes (PROs) remains unclear. The primary objective was to determine whether extending the fusion through the CTJ influenced PROs at 3 and 12 months after surgery. Secondary objectives were to compare the number of patients reaching the minimally clinically important difference (MCID) for the PROs and mJOA, operative time duration, intra-operative blood loss (IOBL), length of stay (LOS), discharge disposition, adverse events (AEs), re-operation within 12 months of the surgery, and patient satisfaction. This is a retrospective analysis of prospectively collected data from a multicenter observational cohort study of patients with degenerative cervical myelopathy. Patients who underwent a posterior instrumented fusion of 4 levels of greater (between C2-T2) between January 2015 and October 2020 with 12 months follow-up were included. PROS (NDI, EQ5D, SF-12 PCS and MCS, NRS arm and neck pain) and mJOA were compared using ANCOVA, adjusted for baseline differences. Patient demographics, comorbidities and surgical details were abstracted. Percentafe of patient reaching MCID for these outcomes was compared using chi-square test. Operative duration, IOBL, AEs, re-operation, discharge disposittion, LOS and satisfaction were compared using chi-square test for categorical variables and independent samples t-tests for continuous variables. A total of 206 patients were included in this study (105 patients not crossing the CTJ and 101 crossing the CTJ). Patients who underwent a construct extending through the CTJ were more likely to be female and had worse baseline EQ5D and NDI scores (p> 0.05). When adjusted for baseline difference, there was no statistically significant difference between the two groups for the PROs and mJOA at 3 and 12 months. Surgical duration was longer (p 0.05). Satisfaction with the surgery was high in both groups but significantly different at 12 months (80% versus 72%, p= 0.042 for the group not crossing the CTJ and the group crossing the CTJ, respectively). The percentage of patients reaching MCID for the NDI score was 55% in the non-crossing group versus 69% in the group extending through the CTJ (p= 0.06). Up to 12 months after the surgery, there was no statistically significant differences in PROs between posterior construct extended to or not extended to the upper thoracic spine. The adverse event profile did not differ significantly, but longer surgical time and blood loss were associated with construct extending across the CTJ

Introduction and Aims: The anterior approach to dealing with complex spinal deformities around the cervical thoracic junction presents a surgical challenge. With the help of a cardiothoracic surgeon, a sternal splitting technique was utilised in five paediatric patients to resolve this difficulty and gain access to spinal deformities around the cervical thoracic junction. Method: A longitudinal incision is made parallel to the sternocleido muscle and extended across the sternum for a median sternotomy. The sternocleido muscles are retracted to the lateral aspect of the incision. The carotid and jugular vein are dissected out. To continue with the dissection and exposure of the upper thoracic spine, a full sternotomy is done. The sternum is opened. The dissection of the right carotid is extended over the innominate artery, including the bifurcation of the right subclavian artery. The jugular vein is dissected out coming down to the superior vena cava. The innominate vein is isolated. The lower end of the anterior scalenus muscle is divided up. Results: This technique was employed in five paediatric patients, aged three to 15 years, at the authors’ institution. Diagnoses included Klippel-Feil Syndrome, Proteus Syndrome, Larsen Syndrome and, Neurofibromatosis (two patients). All patients had severe cervical thoracic kyphosis requiring surgical instrumentation. This technique resulted in a range of access from C5 to T6 being granted. In one patient, a separate thorocotemy was performed in order to gain access to the lower thoracic spine. Conclusion: This approach was invaluable in gaining access to the cervical thoracic junction to address complex spinal deformities. Access to the lower cervical and the upper thoracic spine is granted. No significant complications occurred. The aid of a cardiothoracic surgeon is advised

Introduction Symptomatic Thoracic disc prolapse (TDH) is a rare condition, with approximately 1 case per million population presenting per year. There are not many Spinal surgeons with a significant experience in the management of these lesions which necessitate a familiarity with the anatomy of the thorax and thoracic spinal cord. TDH is often diagnosed on modern imaging, but the indications for surgery in asymptomatic cases or in patients with spinal pain only, remain undefined. The natural history of TDH is not known and there is a poor correlation between the radiological and clinical presentation. The advent of newer minimally invasive endoscopic techniques for TDH may have reduced the incidence of open procedures for this condition, but may lead to an increase in operations performed for TDH, especially in cases where the surgical indications remain uncertain. In a small country like New Zealand it is especially difficult to build up a large series and to become very familiar with what remains a difficult operation. Methods The Neurosurgical experience with this condition in Auckland over the last ten years was reviewed. Clinical presentation, diagnostic imaging, surgical management and patient outcome were analyzed. Results Twenty-one patients were treated over the last 10 years. All had symptomatic TDH. Most operations were performed by the senior author. Patient age varied between 30 and 80, with mean age 50.8 years. There was a slight female preponderance (n=14). Most patients were of European ethnicity. Most patients had spinal cord or nerve root dysfunction, but local pain and sensation change were also noted. MRI was the mainstay in diagnosis, and CT scan was often also used. Surgical exposure was aimed at avoiding spinal cord manipulation and will be discussed. The surgical approach was via thoracotomy in most cases, costotransversectomy, pediculectomy and laminectomy. One case was treated conservatively. There was one case of postoperative paraplegia which will be discussed. There were no other permanent major neurological complications. Patient outcomes will be discussed in detail. Patients with motor weakness showed post operative improvement or full recovery. Pain and sensory loss symptoms were less likely to resolve. Complications that warrant discussion included temporary cranial nerve palsy, thoracic empyema, and long-term opioid addiction for pain. Discussion Over the past 10 years, a reasonable number of patients with TDH have been treated surgically without major incident. The surgical management of this condition remains a challenge. Younger spinal surgeons may not have the training to deal with these cases, which should be addressed. Endoscopic treatment has a steep learning curve, and may not be well suited to larger symptomatic TDH

Thoracic Outlet Syndrome (TOS) is a complex of symptoms representing neurovascular compression in the supraclavicular area and shoulder girdle. Arterial thoracic outlet syndrome represents only 1% of all TOS's. We present two cases of arterial TOS's following internal fixation of clavicular fractures. Two cases of clavicular fractures managed with internal fixation and subsequently diagnosed with symptomatic, position dependent arterial occlusion are presented. The first case of a 16-year-old male treated with an intramedullary compression screw. He developed symptoms and was diagnosed with TOS using dynamic duplex examination performed by a vascular surgeon. Revision surgery was planned to decompress the subclavian artery from the hypertrophic callus at the fracture site. Before this could be performed the patient re-fractured his clavicle and bent the intramedullary screw. This resulted in resolution of the TOS symptoms. Following this second injury the patient went on to unite the fracture. The second case was of a 48-year-old male. He was initially treated non- operatively until the patient reported sensory and motor disturbances involving the hand and forearm. Excess callus was excised and the fracture was fixed using a locking plate. The symptoms improved, but worsened again eight weeks post operatively. Angiogram revealed vascular occlusion on arm abduction. Repeat surgery was performed in conjunction with a vascular surgeon. The plate was removed, vascular structures were released from fibrous tissue in the region of the fracture, and the posterior edge of the clavicle was debrided with a burr to reduce future impingement on vascular structures. Post operatively the TOS symptoms did not recur. Arterial thoracic outlet syndrome is an uncommon complication of trauma involving the clavicle. It can present in the presence or absence of surgical intervention, but can require surgical intervention to resolve

Purpose & Background: The spinal muscles are increasingly being linked to spinal complaints. However, little is known regarding the corticospinal control of these muscles. Corticospinal pathways can be activated using transcranial magnetic stimulation (TMS) applied over the motor cortex. This study uses TMS to assess corticospinal input to the paraspinal muscles in the thoracic region. Methods: Ten individuals (mean [± SD] age 33 ± 10 yrs; mean height 166 ± 10 cm; two left-handed; five male, five female) with no history of neurological disorder were recruited into this study and written informed consent obtained. Subjects lay prone in a relaxed position with the head unsupported. Surface electromyographic (EMG) recording electrodes were positioned bilaterally over the paraspinal muscles adjacent to thoracic spinal processes T1 and T2. TMS was applied using a MagStim 200 stimulator connected to a double cone coil with its cross-over positioned over the vertex so that the maximum induced current flowed in a posterior to anterior direction. The stimulus intensity was adjusted in steps of 5% of the maximum stimulator output (MSO), and ten stimuli were delivered at each strength. Threshold for a motor evoked potential (MEP) in each muscle was determined as the minimum intensity that would evoke MEPs to 50% of stimulus presentations. Latency of MEPs was determined by measuring the time between the stimulus and the start of the first deflection in the MEP. The procedure was repeated for the other pairs of thoracic segments between T3 and T12. Results: In all subjects, it was possible to evoke MEPs in relaxed paraspinal muscles at all thoracic levels. Mean (±SEM) threshold for evoking a MEP on the left side increased from 47 ± 2.5 %MSO at level T1 to 55 ± 2.5 %MSO at T12 (Pearson correlation, P< 0.05) but remained more constant (P> 0.05) on the right side (T1, 55 ± 3.9 %MSO; T12, 57 ± 3.3 %MSO). Over all levels tested, mean threshold for MEPs was 3.9 ± 0.6 %MSO higher on the right than the left side (Student’s paired t-test, P< 0.05). Mean latency of MEPs on the left increased from 11.9 ± 0.7 ms at level T1 to 15.5 ± 0.6 ms at T12 and on the right from 12.3 ± 0.5 ms at level T1 to 16 ± 0.7 ms at T12 (Pearson correlation, P< 0.05). Throughout the thoracic region, latency of MEPs was 0.8 ± 0.2 ms longer on the right than the left side (Student’s paired t-test, P< 0.05). Conclusion: The latency of MEPs increased as recordings were made from muscles innervated more caudally. Threshold for MEPs varied between subjects and at different spinal levels but our results indicate that it was higher at more caudal levels, perhaps suggesting weaker corticospinal innervation. Threshold was lower and latency shorter for muscles on the left side raising the interesting possibility that paraspinal muscles have some asymmetry in their corticospinal innervation. This study has provided us with baseline electrophysiological data allowing us to investigate the voluntary control pathways to muscles stabilising the thoracic spinal cord following trauma or disease

Summary Statement. Pedicle screws provide robust fixation and rigid immobilization. There has been no attempt to correlate the anatomic dimensions of thoracic and lumbar pedicles with the accuracy of navigated insertion. This study demonstrates that comparable accuracy using this technique. Introduction. Pedicle screws provide robust mechanical fixation, which makes their use attractive; their use enables fixation of the three spinal columns. There remains concern about the potential both for misplacement; various investigators have studied the accuracy of pedicle screw insertions, comparing different techniques. What is not clear, however, is whether there is any relation between the variables of pedicles’ anatomic dimensions, screw dimensions and accuracy. This study aims to elucidate the relationship between these variables. Patients & Methods. We conducted a retrospective review of consecutive pedicle screws that were inserted in the thoracic and lumbar spine at our institution. Screws were inserted using the navigated method (Stealth Station® TREON™, Medtronic, Louisville, CO). The accuracy of the screw insertion was measured using the classification system developed by Gertzbein and Robbins; pedicle dimensions were measured from post-operative computed tomography scans. The corresponding pre-operative scans were then used to measure the pedicle dimensions at the other levels. The magnitude of a cortical breach in the pedicle was represented by a letter: A (no breach), B (<2mm), C (>2mm, <4mm), D (>4mm, <6mm) and E (>6mm). In addition, measurements were made of the anatomic dimensions of the pedicles. The combination of these two measures allowed for direct correlation to be made between the accuracy of screw insertion, screw dimensions and pedicle anatomy. We then computed the proportion of each pedicle (width) occupied by a screw. Results. A total of 765 screws were reviewed, 493 were in the thoracic spine and 272 in the lumbar spine. Of the screws in the thoracic spine, 472 (96%) were either fully in the pedicle or less than 2mm beyond the cortex (within the A+B classification); when considered separately, 323 (66%) were completely within the pedicle (A) and 149 (30%) were less than 2mm beyond the cortex. A total of 21 (4%) screws were beyond 2mm but within 6mm (C+D). In the lumbar spine, 270 (99%) were either completely within the cortex or less than 2mm exposed (classified as A or B). The nadir of pedicle width was at T4. From L1 to L5, measured pedicle width also rose. This pattern was followed, although it was less profound, when screw diameter was measured in the lumbar spine (and even less so in the thoracic vertebrae). The height of pedicles was noted to progressively increase, peaking at the thoraco-lumbar junction. The mid thoracic region was associated with screws occupying the greatest proportion of pedicle diameter. Discussion/Conclusion. The use of pedicle screws in the thoracic and lumbar spine remains relatively safe. The accuracy of navigated insertion was found to compare well to previous series’. Although there is some association between the anatomical dimensions of pedicles and the dimensions of screws, this doesn't seem to be a strong association. Based on the findings in this series, future studies that relate the long term outcome (e.g. failure or screw loosening) with proportion of pedicle diameter taken up by a screw may be warranted

A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. The purpose of this study was to determine the accuracy of placement and safety of pedicle screws in open reduction of unstable thoracic spine fractures. The surgeries were performed by one of five fellowship trained spinal surgeons. CT scans were formed on twenty-three patients totaling two hundred screws using 3mm cuts. Three independent reviewers assessed and categorized the screw position as within the pedicle or as a violation of the pedicle wall. 98% of the screws were accurate and we recommend the use of pedicle screws in thoracic fractures . A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. This study is to determine the accuracy of placement, safety of pedicle screws in open reduction of unstable thoracic spine fracture. Surgery was performed by one of five fellowship trained spine surgeons. CT scans were performed on twenty-three patients using 3mm cuts in both sagittal and transverse planes. Pedicle screw position was assessed by three independent reviewers. Screw position was categorized as within the wall of the pedicle or in violation of the wall. Further sub-classification of pedicle wall violation reviewed the direction and distance of perforation. Independent perioperative and postoperative surveillance for complications was done. Twenty-three unstable thoracic spine fractures treated with two hundred posterior pedicle screws were analyzed. The pedicle screws spanned from T1-T12 with the majority of screws in the mid-thoracic region. Of the two hundred thoracic pedicle screws placed, 70% were fully contained within the pedicle wall. The remaining screws were deemed “out” with cortical perforation (30%). Of these, 20% were lateral perforations, 5% were medial perforations and 5% were anterolateral perforations. No superior, inferior, or anteromedial perforations were found. There was no regional area variation in incidence of perforations. 10% of all perforations were directly related to pedicle diameter to screw diameter mismatch. There were no adverse neurological, vascular, or visceral injuries detected intraoperatively or postoperatively. Surgical management of unstable thoracic spine fractures with posterior pedicle screw fixation is safe. 98% of screws had satisfactory accuracy. Although very minor misplacement of pedicle screws occurred, there were no complications and we recommend the use of pedicle screws in thoracic fractures

Purpose & Relevance: To examine the prevalence of degenerative findings in the thoracic spine in a population sample of adult men. Normative data on thoracic degenerative findings provide an essential reference for related observations in patients. Methods & Results: Qualitative and quantitative assessments of thoracic disc degeneration were obtained from MRI (levels T6-L1) for general population sample of 532 men aged 25–70 years. Qualitative assessments of disc degeneration were performed by an experienced spine surgeon and custom-made software was used to acquire quantitative assessments. Descriptive statistics were acquired using SPSS. Moderate or severe disc bulging was present in at least one disc in 7.9% of subjects, with bulging most common at the two lowest levels. The prevalence of disc herniations was 0.8%. Moderate or severe disc height narrowing was present in 2.7% to 9.7% by disc level with 22.4% of subjects having at least one narrowed disc. Four or more wedged vertebrae (≥ 5°) were present in 68 subjects and 13 (2.4%) had coexisting Schmorl’s nodes. Seven subjects (1.3%) met more stringent criteria for Scheuermann’s disease, with three or more wedged vertebrae, endplate changes, sclerosis and disc height narrowing. Of the variables examined, disc signal intensity correlated highest with age (r= 0.31–0.40, depending on disc level). Conclusion: The prevalence of disc degeneration appears lower in the thoracic spine than previously reported in the lumbar spine. However, one-fifth of the subjects have markedly narrowed discs, which have been associated with symptom history in the lumbar spine. Disc signal intensity is the finding most highly associated with age

Summary Statement. Using abdominal CT scans to evaluate bone mineral density following acute fractures of the thoracic and lumbar spine demonstrates significant levels of osteoporosis in older patients; this approach may help save on time and resources, and reduce unnecessary radiation exposure. Introduction. While a reduction in bone mineral density (BMD) is associated with aging, relatively few patients have formal dual-energy X-ray absorptiometry (DXA) to quantify the magnitude of bone loss, as they age. This loss of bone may predispose to fractures. Recent data, which correlates mean Hounsfield units (HU) in an area of the L1 vertebra with BMD, now makes it possible to screen for osteoporosis using incidental abdominal Computed Tomography (CT) scans to measure bone density. This innovation has the potential to reduce both cost and radiation exposure, and also make it easier to identify patients who may be at risk. The aims of this study were to evaluate the utility of this approach in patients with acute thoracic and lumbar spine fractures and to evaluate the impact of aging on BMD, using CT screening. Patients & Methods. Following institutional review board approval, we performed a retrospective study of patients who presented to a level I trauma center with acute fractures of the thoracic and lumbar spine between 2010 and 2013; patients also had to have had an abdominal (or L1) CT scan either during the admission or in the 6 months before or after their injury. Using a picture archiving and communication (PACS) system, we generated regions of interest (ROI) of similar size in the body of L1 (excluding the cortex) and computed mean values for HU. Values derived were compared against threshold values which differentiate between osteoporosis and osteopenia - for specificity of 90%, a threshold of 110 was set; for balanced sensitivity and specificity, a threshold of <135 HU was set and for 90% sensitivity a threshold of <160 HU was set. A student's t test was used to compare the age stratified mean HU (younger than 65yrs; 65yrs and older), while Fisher's exact test was used to perform aged stratified comparisons between the proportions of patients above and below the thresholds outlined (in each of the three threshold groups). Results. A total of 124 patients were evaluated, with 74 having thoracic and 50 having lumbar fractures. Among those with thoracic fractures, there were 33patients in the younger cohort, who also had a mean BMD of 196.51HU and 41 in the older cohort, who had mean BMD of 105.90HU (p<0.001). In patients with lumbar fractures, 27 patients were in the younger cohort, with mean BMD of 192.26HU and 23 patients in the older cohort with mean BMD of 114.31HU (p<0.001). At the threshold of 110 HU, set for specificity, the magnitude of difference between the age stratified cohorts was greater in the thoracic spine (p<0.001 vs. p=0.003). At the other thresholds: 135HU (balanced for sensitivity and specificity) and 160 HU (90% sensitivity), age of 65 years or older was significantly associated with reduction in CT derived measure of BMD (p<0.001 in all cases). Discussion. This study demonstrates the relative frequency of osteoporosis in acute fractures of the thoracic and lumbar spine, and how this changes with age; it is also the first study to do this using opportunistic CT scans. There seems to be a strong association between a reduction in bone mineral density and advanced age, in patients presenting with acute fractures of the spine. This approach may save on the extra cost and additional radiation exposure that may be associated with DXA scanning; in addition, it may help provide clinicians and patients with an approach to monitor developing problems with BMD before it becomes clinically apparent, especially in younger patients

Classic management of large and stiff thoracic scoliotic curves in the adolescent comprise of anterior release followed by posterior instrumentation. However third generation segmental spinal instrumentations have shown increased correction of thoracic curves. Therefore, the indication for an anterior release may no longer be required. We reviewed our database for cases with thoracic curves with Cobb angle between 70 and 90° that we had only done posterior surgery. We found that with adequate posterior release, and the use of third generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range. Large and stiff thoracic scoliotic curves in the adolescent represent a classic indication of anterior release before posterior spinal instrumentation. To assess if third generation segmental posterior instrumentation can omit the need of anterior surgery in large and stiff thoracic curves. An independent observer, reviewed in a retrospective fashion our electronic database of adolescent scoliosis surgery (Scolisoft) with the following query: Thoracic curves, Cobb angle between 70 and 90° degrees and posterior surgery only. There was nineteen patients who fit the criteria. Out of these, four were judged to flexible (bends < than 45°) and were not included. Fifteen patients (mean age 13.6) with thoracic scoliosis with average Cobb 78.5° with a flexibility index of 32.5% were analyzed. (mean f/u: twenty-eight months). Postoperatively the thoracic Cobb angle measured on average 34.8° (25° −45°), which represents a correction rate of 54 % (range, 40.0–67.1%) and remained unchanged at the last follow-up (35°). Sagittal alignment improved from an average 11° to 18°. There were two complications (one excessive bleeding and one infection). Coronal balance was improved, as was shoulder balance. All patients reported satisfactory results except the patient with an adding-on phenomena. In the literature most of the results of anterior thora-coscopic release and posterior surgery give a percentage of Cobb angle correction similar or inferior (averaging 50%) to our series for an average initial Cobb angle of less magnitude. With adequate posterior release, and the use of third generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range

Introduction:. Trauma is endemic in South Africa. The upper thoracic spine is extremely difficult to image and assess clearly with frontline x-rays resulting in up to 22% of proximal fractures being missed. Aim:. To review a series of patients with proximal thoracic fractures. Methods:. Thirty-three patients with proximal thoracic fractures in the T1–T4 area managed in a spinal unit were identified. A retrospective review of medical records and radiology was undertaken. Demographic data, mechanism of injury, diagnostic modalities, level and type of fracture, neurological status, associated injuries, hospital stay, management, complications and outcome was recorded. Results:. There were 21 males and 12 females, with a median age of 31.8 years. Aetiology was 21 MVA passengers, 8 drivers, 1 pedestrian, 1 assault, 1 bicycle and 1 hanglider accident. Delay in diagnosis was 1 day in 8, 2–5 days in 2 and greater than 2 weeks in 5. The fractures were A1 in 7, A3 in 14, B1 in 7, C1 in 2 and C2 in 2. Twenty three patients had neurological compromise, 13 being complete. Twenty-three had associated chest and head injuries. Hospital stay was a mean of 27 days (maximum 246) and ICU stay median 14 (maximum 115) days. Twenty-six patients underwent surgery, posterior instrumented fusion being the commonest procedure. Although the surgery did not change the median kyphosis (25° preop to 20°at 1 year and 21°at 2 years), the most kyphotic patients were improved (55°to 45°). Conclusion:. A high index of suspicion for proximal thoracic fractures needs to be maintained in high energy injuries, especially MVA passengers, where there is chest injury. Prompt exclusion by appropriate special investigations is mandatory. Once recognized, they can be adequately managed with posterior instrumented fusion, although these patients are resource intensive due to the associated neurological impairment and chest injuries