Comparative Computed Tomographic Measurements of the Synsacrum in Some Birds / Mediciones Tomográficas Computarizadas Comparativas del Sinsacro en Algunas Aves

SUMMARY: The Synsacrum is constructed of pelvic bones, sacral, lumbar vertebrae and some thoracic vertebrae, and it takes the form of a thin sheet of bone which is curled downwards at the sides. This study is designed to assess the morphometric specialization of the lumbosacral portion of the vertebral section in flying and non-flying winged creatures. Several parameters (ratio of cranial/caudal parts and diameter/length) of the lumbosacral vertebral column were calculated in computed tomography (CT). The ratio of diameter/length of the synsacrum was the narrowest in ostrich while the widest was in pigeon. While the cranial/caudal ratio was the smallest in ostrich and the largest in pigeon. The parameters of penguin were closed to that of pigeon. It is supposed that this ratio is related to the bird locomotion, flying, swimming or/and strolling.

El sinsacro está formado por huesos pélvicos, sacros, vértebras lumbares y algunas vértebras torácicas, y toma la forma de una fina lámina de hueso curvada a los lados hacia abajo. Este estudio está diseñado para evaluar la especialización morfométrica de la porción lumbosacra de la sección vertebral en criaturas aladas voladoras y no voladoras. Se calcularon varios parámetros (relación de partes craneal/caudal y diámetro/longitud) de la columna vertebral lumbosacra en tomografía computarizada (TC). La relación diámetro/longitud del sinsacro fue la más estrecha en avestruz mientras que la más ancha fue en paloma. Mientras que la relación craneal/caudal fue la más pequeña en avestruz y la más grande en la paloma. Los parámetros del pingüino estaban cerrados en relación a los de la paloma. Se supone que esta relación está relacionada con la locomoción de las aves, volando, nadando y/o caminando.

Unraveling sauropod diversity in the Portezuelo Formation of Patagonia through a comprehensive analysis of new and existing material.

The Portezuelo Formation preserves an outstanding record of the upper Turonian - lower Coniacian. Despite the discovery of a significant quantity of sauropod fossil material from the formation, only two species have been formally described to date: Malarguesaurus florenciae and Futalognkosaurus dukei. Here we present new sauropod material mostly composed of non-articulated caudal vertebrae (MCF-PVPH 916 and 917) that belong to two titanosauriforms on the basis of the following features: anterior caudal vertebrae with procoelous-opisthoplatyan articulations, transverse processes that reach the posterior articular face of the centrum and neural spines with a transverse width of around 50% of their anteroposterior length; anterior and middle caudal vertebrae with the neural arch restricted to the anterior half of the centrum; middle caudal centra with circular cross-section. Phylogenetic analysis recovers the new material in close relation to Malarguesaurus within a monophyletic clade at the base of Somphospondyli. This clade shares large pedicel height with a vertical anterior border on the middle caudal vertebrae, a vertical orientation of the neural spines on the distalmost middle caudal vertebrae and proximalmost posterior caudal vertebrae, and subequal relative lengths of the proximal ulnar condylar processes. The specimens presented here are distinct not only from Futalognkosaurus, but also from other indeterminate titanosaurian remains from the same formation. However, there are no significant differences between the specimen MCF-PVPH 917 and Malarguesaurus, but there are differences between the posterior caudal vertebrae of MCF-PVPH 916 and Malarguesaurus, so they could be considered different species. Whilst we err on the side of caution in not naming new taxa here, the two specimens significantly expand what we know about sauropods in the Turonian-Coniacian ecosystems of Patagonia, which will continue to do so as more material is discovered.

Morphological Design and Study of a 3D Printed Integrated Fusion Device Based on CT Measurement Data Assisted Anterior Lumbosacral Spine / Diseño Morfológico y Estudio de un Dispositivo de Fusión Integrado Impreso en 3D Basado en Datos de Medición de TC Asistida de Columna Lumbosacra Anterior

SUMMARY: To measure and study the anatomical morphological data of the lumbar 5 to sacral 1 intervertebral space with the aid of CT and design an anatomical anterior lumbosacral 3D printed integrated interbody fusion for the treatment of degenerative lumbosacral spine diseases. 100 adults (50 of each sex) who underwent CT examination of the lumbar spine in our hospital were selected, and their lumbar 5 to sacral 1 intervertebral space anatomical data were measured, including the anterior lumbar convexity angle, different sagittal and coronal heights, and the sagittal and coronal diameters of the superior and inferior endplates. The measured data were also statistically analyzed, and morphological design and study of the 3D printed integrated fusion device in the anterior lumbosacral spine was performed by applying computer software. When comparing the coronal and sagittal diameters of the superior and inferior endplates from lumbar 5 to sacral 1, the differences were statistically greater in men than in women (P0.001). When comparing the height at different positions in the median sagittal plane, both males and females showed an anterior high and posterior low pattern. In the coronal plane, both males and females showed the highest height in the middle position (P0.001). CT can measure the anatomical data of the lumbosacral spinal hiatus more accurately. The 3D-printed anterior integrated fusion device of the lumbosacral spine designed according to the analysis of the data results is more in line with the anatomical structure of the lumbosacral spine, fits well with the superior and inferior endplates, and effectively restores the height and anterior convexity angle of the lumbosacral space.

El objetivo de este trabajo fue medir y estudiar los datos morfológicos anatómicos del espacio intervertebral lumbar 5 a sacro 1 con la ayuda de TC y diseñar una fusión intersomática integrada anatómica lumbosacra anterior impresa en 3D para el tratamiento de enfermedades degenerativas de la columna lumbosacra. Se seleccionaron en nuestro hospital 100 adultos (50 de cada sexo) que se sometieron a un examen de TC de la columna lumbar y se midieron los datos anatómicos del espacio intervertebral lumbar 5 al sacro 1, incluyendo el ángulo de la convexidad lumbar anterior, diferentes alturas sagital y coronal, y los diámetros sagital y coronal de las placas terminales superior e inferior. Los datos medidos también se analizaron estadísticamente y se realizó el diseño morfológico y el estudio del dispositivo de fusión integrado impreso en 3D en la columna lumbosacra anterior mediante la aplicación de software informático. Al comparar los diámetros coronal y sagital de las placas terminales superior e inferior desde lumbar 5 hasta sacro 1, las diferencias fueron estadísticamente mayores en hombres que en mujeres (P 0,001). Al comparar la altura en diferentes posiciones en el plano mediano, tanto hombres como mujeres mostraron un patrón anterior alto y posterior bajo. En el plano coronal, tanto hombres como mujeres mostraron la altura más alta en la posición media (P0,001). La TC puede medir los datos anatómicos del hiato espinal lumbosacro con mayor precisión. El dispositivo de fusión anterior integrado impreso en 3D de la columna lumbosacra diseñado de acuerdo con el análisis de los resultados de los datos está más en línea con la estructura anatómica de la columna lumbosacra, se adapta bien a las placas terminales superior e inferior y restaura eficazmente la altura y la parte anterior del ángulo de convexidad del espacio lumbosacro.

[Evaluation of spino-pelvic mobility; its importance in preventing total hip replacement dislocation]. / Evaluación de la movilidad espino-pélvica; su importancia para prevenir la luxación de prótesis total de cadera.

Recently, it has been recognized that changes in sagittal alignment and spinopelvic mobility due to alterations of the lumbosacral spine can influence the dislocation of a hip replacement. The biggest difficulties for this problem are: a) the bibliography related to this topic has been written in English and there is confusion in its terminology; b) there is no consensus on what parameters should be used to identify, measure, and estimate the risks of dislocation occurring; c) the basic concepts that interrelate spinal disorders and prosthetic dislocation are not clearly understood; and d) spine and hip surgeons pursue different goals. The objective of this narrative review is to overcome the aforementioned difficulties by using a strategy to answer some questions: Is hip dislocation really a problem? What is the interrelationship between alterations in the pelvic spinal balance and the dislocation of a prosthesis? How is sagittal balance and lumbosacral mobility defined and how can their alterations be measured? What are their compensatory mechanisms to achieve a good functioning and how these mechanisms can be used to correctly orient the acetabulum? To document this review, we consulted the databases of PubMed, Scopus, SciELO and Google Scholar with the keywords: Spinopelvic, Total Hip Arthroplasty, Hip Dislocation, Spine-Pelvis-hip Arthroplasty. The articles that, in the author's opinion, were the most objective and/or relevant for the study of this topic were selected.

Recientemente se ha reconocido que los cambios en alineación sagital y la movilidad espino-pélvica por alteraciones de la columna lumbosacra pueden ejercer influencia en la luxación de una prótesis de cadera. Las mayores dificultades para este problema son: a) que la bibliografía relacionada con este tema se ha escrito en idioma inglés y hay confusiones en su terminología; b) no hay consenso de cuáles son los parámetros que deben utilizarse para identificarla, medirla y para estimar los riesgos de que ocurra una luxación; c) no se conocen con claridad los conceptos básicos que interrelacionen los trastornos de la columna y la luxación protésica; y d) que los cirujanos de columna y artroplásticos de cadera persiguen diferentes objetivos. Esta revisión narrativa persigue como objetivo allanar las dificultades antes mencionadas, utilizando como estrategia contestar algunas preguntas: ¿la luxación de cadera es realmente un problema?; ¿cuál es la interrelación entre las alteraciones en el balance espino-pélvico y la luxación de una prótesis?; ¿cómo se define el balance sagital y la movilidad lumbosacra y cómo se pueden medir sus alteraciones?; ¿cuáles son sus mecanismos compensatorios para lograr un buen funcionamiento, y cómo se pueden aprovechar estos mecanismos para orientar correctamente el acetábulo? Para documentar esta revisión se consultaron las bases de datos de PubMed, Scopus, SciELO y Google Académico con las palabras clave: Spinopelvic, Total Hip Arthroplasty, Hip Dislocation, Spine-Pelvis-hip Arthroplasty. Se seleccionaron los artículos que a juicio del autor fueron los más objetivos y/o relevantes para el estudio de este tema.

[Frequency of spinopelvic alterations in postoperative total hip arthroplasty patients and their association with functional outcomes]. / Frecuencia de alteraciones espinopélvicas en pacientes postoperados de artroplastía total de cadera y su asociación con resultados funcionales.

INTRODUCTION: the analysis of spinopelvic imbalance in patients undergoing total hip arthroplasty has gained significance in recent years, being recognized as a risk factor for instability. Few reports exist regarding the prevalence of spinopelvic alterations in Latin American literature. The aim of this study is to determine the frequency of spinopelvic imbalance in our patients and to associate them with functional outcomes. MATERIAL AND METHODS: 29 patients who underwent total hip arthroplasty using a lateral approach (32 arthroplasties) were included. All patients completed clinical outcome questionnaires preoperatively. Twelve months after surgery, they underwent anteroposterior pelvic and lateral pelvic X-rays, both standing and sitting, and clinical outcome questionnaires were completed. The radiographic parameters examined were: pelvic incidence, lumbar lordosis, sacral slope, anterior pelvic plane and pelvic femoral angle. Functional outcome was assessed with the Harris Hip Score and WOMAC scales. Patients were classified according to their spinopelvic alteration and statistical analysis was performed to identify significant differences between the groups and the correlation with functional outcomes. RESULTS: there was a high frequency of spinopelvic balance alterations (46.8%); 6.2% (n = 2/32) presented isolated spinal stiffness (group 1B), 37.5% (n = 12/29) spinal deformity without spinal stiffness (group 2A) and 3.1% (n = 1/29) spinal deformity associated with stiffness (group 2B). We found no improvement in HHS and WOMAC scores in the groups with spinal stiffness (1B and 2B) (p = 0.98 y 0.15). There is association between spinal stiffness (SS < 10°) and poor functional outcomes (p = 0.02). CONCLUSIONS: the frequency of spinopelvic balance alterations was high. While there was no observed rise in prosthetic dislocations, the existence of spinal stiffness, defined by a SS of less than 10°, was associated to poor outcomes on functional scales.

INTRODUCCIÓN: el análisis de las alteraciones del balance espinopélvico en pacientes sometidos a artroplastía total de cadera ha adquirido importancia en años recientes, siendo reconocido como un factor de riesgo para inestabilidad. Existen pocos reportes de la prevalencia de alteraciones espinopélvicas en literatura latinoamericana. El objetivo de esta investigación es determinar la frecuencia de alteraciones del balance espinopélvico en nuestros pacientes y su asociación con los resultados funcionales. MATERIAL Y MÉTODOS: se incluyeron 29 pacientes intervenidos de artroplastía total de cadera mediante abordaje lateral (32 artroplastías). Todos los pacientes completaron escalas funcionales preoperatoriamente. A los 12 meses de la intervención, se valoró el balance espinopélvico mediante radiografías anteroposterior de pelvis y laterales de pelvis tanto de pie como en sedestación y completaron escalas funcionales. Los parámetros radiográficos valorados fueron: incidencia pélvica, lordosis lumbar, inclinación del sacro (sacral slope), plano pélvico anterior y ángulo pélvico femoral. El estado funcional se valoró con las escalas Harris Hip Score (HHS) y WOMAC. Se clasificó a los pacientes de acuerdo a su alteración espinopélvica y se realizó análisis estadístico para identificar diferencias significativas entre los grupos y la asociación con resultados funcionales. RESULTADOS: encontramos una elevada frecuencia de alteraciones del balance espinopélvico (46.8%); 6.3% (n = 2/32) presentaron rigidez espinal aislada (grupo 1B), 37.5% (n = 12/29) deformidad espinal sin rigidez espinal (grupo 2A) y 3.1% (n = 1/29) deformidad espinal asociada a rigidez (grupo 2B). En los grupos con rigidez espinal (1B y 2B) no hubo mejoría significativa en HHS y WOMAC (p = 0.98 y 0.15). Encontramos asociación entre la presencia de rigidez espinal (SS < 10°) y resultados funcionales subóptimos con valor de p = 0.02. CONCLUSIONES: la frecuencia de alteraciones en el balance espinopélvico fue elevada. A pesar de no verse reflejado en un aumento en la incidencia de luxaciones protésicas, la presencia de rigidez espinal caracterizada por un SS menor a 10° se asoció con resultados subóptimos en las escalas funcionales.

Bovine Aortic Arch with an Aberrant Left Vertebral Artery in a 3-Year-Old Boy with VACTERL Association: A Case Report.

BACKGROUND The VACTEREL association is an acronym that includes vertebral malformations (V), anal atresia (A), cardiac defects (C), tracheoesophageal fistula (TE), renal defects (R), and limb malformations (L). The aortic arch is the section between the ascending aorta and the descending aorta, where some variants have been described, such as the right aortic arch and bovine aortic arch, among others. A rare presentation in the Natsis classification is the "type X" where a bovine aortic arch and anomalous origin of the left vertebral artery are present. Several structural cardiac malformations have been described in the VACTEREL association. Still, there is no bovine arch or an anomalous left vertebral artery. CASE REPORT Our patient was a 3-year-old boy with a diagnosis of VACTEREL association (type III esophageal atresia, congenital hip dislocation, scoliosis, bilateral clubfoot, and grade IV biliary ureteral reflux). Echocardiographic findings showed changes in the aortic arch, and angiotomography and magnetic resonance angiography showed a bovine aortic arch and an anomalous left vertebral artery. At the time of diagnosis, there were no clinical manifestations or complications due to the anomalous origin of the left vertebral artery. CONCLUSIONS This is the first description of a bovine type X arch according to the Natsis classification in a VACTEREL association. In general, knowledge of the anatomical variants of the aortic arch and the origin and course of the vertebral arteries is of great clinical and interventional importance, mainly because of the risk of cerebral ischemia.

Arthrological reconstructions of the pterosaur neck and their implications for the cervical position at rest.

The lack of any pterosaur living descendants creates gaps in the knowledge of the biology of this group, including its cervical biomechanics, which makes it difficult to understand their posture and life habits. To mitigate part of this issue, we reconstructed the cervical osteology and arthrology of three pterosaurs, allowing us to make inferences about the position of the neck of these animals at rest. We used scans of three-dimensionally preserved cervical series of Anhanguera piscator, Azhdarcho lancicollis and Rhamphorhynchus muensteri for the reconstructions, thus representing different lineages. For the recognition of ligaments, joint cartilages, and levels of overlapping of the zygapophyses, we applied the Extant Phylogenetic Bracket method, based on various extant birds and on Caiman latirostris. We inferred that pterosaur intervertebral joints were probably covered by a thin layer of synovial cartilage whose thickness varied along the neck, being thicker in the posterior region. Ignoring this cartilage can affect reconstructions. According to the vertebral angulation, their neck was slightly sinuous when in rest position. Our analyses also indicate that pterosaurs had segmented and supra-segmented articular cervical ligaments, which could confer stabilization, execute passive forces on the neck and store elastic energy.

Relationship between spinal structural damage and sagittal balance in axial spondyloarthritis: Is the thoracic spine the starting point?

OBJECTIVES: To assess the relationship between spinal structural damage, sagittal balance parameters and spine curvatures in patients with axial spondyloarthritis (axSpA). MATERIAL AND METHODS: In this cross-sectional study, the pelvic and sagittal balance parameters were obtained through EOS® (Biospace, Paris, France). Patients were divided into three groups according to the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) tertiles (G1 ≤6, n = 36; G2: 6.1-31, n = 36; G3 >31, n = 35) and pelvic and sagittal parameters were compared across them. Multivariable regression analysis was performed to analyze the impact of spinal structural damage and of other factors on sagittal vertical axis (SVA), an important sagittal balance parameter. RESULTS: A total of 107 patients was included. G2 and 3 exhibited higher mean values of thoracic kyphosis T1-T12 when compared to G1 (10.5°(12.3) vs. 22.3°(17.3) vs. 35.2°(14.6), p < 0.001), and G3 demonstrated lumbar L1-S1 straightening compared to the other groups (55.7°(9) and 50.7°(19.8), G1 and G2, respectively, vs. 35.7°(13.2), p < 0.001). Mean SVA values showed an increasing gradient from G1 to G3 (21.6(25.1) vs. 41(44.3) vs. 84.3(47.2)mm, p < 0.001). In the multivariable regression, a one-unit increase in total mSASSS was associated with an average 0.8 mm higher SVA. CONCLUSIONS: Our data showed that more spinal structural damage is associated with a higher SVA, reflecting poorer sagittal balance. Patients with increasing spinal damage have an important increase in thoracic kyphosis suggesting that postural modifications in patients with axSpA might have their origin in the thoracic spine.

Characterizing Negative Online Reviews of Spine Surgeons.

DESIGN: Retrospective review. OBJECTIVE: Characterize negative reviews of spine surgeons in the United States. SUMMARY: Physician rating websites significantly influence the selection of doctors by other patients. Negative experiences are impacted by various factors, both clinical and nonclinical, geography, and practice structure. The purpose of this study was to evaluate and categorize negative reviews of spine surgeons in the United States, with a focus on surgical versus nonsurgical reviewers. METHODS: Spine surgeons were selected from available online professional society membership directories. A search for reviews was performed on Healthgrades.com, Vitals.com, and RateMDs.com for the past 10 years. Free response reviews were coded by complaint, and qualitative analysis was performed. χ 2 and Fisher exact tests were used to compare categorical variables, and multiple comparisons were adjusted with Benjamini-Hochberg correction. A binary logistic regression model was performed for the top three most mentioned nonclinical and clinical complaint labels. A P -value <0.05 was considered statistically significant. RESULTS: A total of 16,695 online reviews were evaluated, including 1690 one-star reviews (10.1%). Among one-star reviews, 64.7% were written by nonsurgical patients and 35.3% by surgical patients. Nonclinical and clinical comments constituted 54.9% and 45.1% of reviews, respectively. Surgeons in the South had more "bedside manner" comments (43.3%, P <0.0001), while Northeast surgeons had more "poor surgical outcome" remarks compared with all other geographic regions (14.4%, P <0.001). Practicing in the South and Northeast were independent predictors of having complaints about "bedside manner" and "poor surgical outcome," respectively. CONCLUSION: Most one-star reviews of spine surgeons were attributed to nonsurgical patients, who tended to be unsatisfied with nonclinical factors, especially "bedside manner." However, there was substantial geographic variation. These results suggest that spine surgeons could benefit from focusing on nonclinical factors (bedside manner), especially among nonoperative patients, and that regional nuances should be considered in delivering spine care. LEVEL OF EVIDENCE: Level- 5.

Formal Radiologist Interpretations of Intraoperative Spine Radiographs Have Low Clinical Value.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To evaluate the clinical relevance, usefulness, and financial implications of intraoperative radiograph interpretation by radiologists in spine surgery. SUMMARY OF BACKGROUND DATA: Due to rising health care costs, spine surgery is under scrutiny to maximize value-based care. Formal radiographic analysis remains a potential source of unnecessary health care costs, especially for intraoperative radiographs. MATERIALS AND METHODS: A retrospective cohort analysis was performed on all adult elective spine surgeries at a single institution between July 2020 and July 2021. Demographic and radiographic data were collected, including intraoperative localization and post-instrumentation radiographs. Financial data were obtained through the institution's price estimator. Radiographic characteristics included time from radiographic imaging to completion of radiologist interpretation report, completion of radiologist interpretation report before the conclusion of surgical procedure, clinical relevance, and clinical usefulness. Reports were considered clinically relevant if the spinal level of the procedure was described and clinically useful if completed before the conclusion of the procedure and deemed clinically relevant. RESULTS: Four hundred eighty-one intraoperative localization and post-instrumentation radiographs from 360 patients revealed a median delay of 128 minutes between imaging and completion of the interpretive report. Only 38.9% of reports were completed before the conclusion of surgery. There were 79.4% deemed clinically relevant and only 33.5% were clinically useful. Localization reports were completed more frequently before the conclusion of surgery (67.2% vs. 34.4%) but with lower clinical relevance (90.1% vs. 98.5%) and clinical usefulness (60.3% vs. 33.6%) than post-instrumentation reports. Each patient was charged $32 to $34 for the interpretation fee, cumulating a minimum total cost of $15,392. CONCLUSIONS: Formal radiographic interpretation of intraoperative spine radiographs was of low clinical utility for spine surgeons. Institutions should consider optimizing radiology workflows to improve timeliness and clinical relevance or evaluate the necessity of reflexive consultation to radiology for intraoperative imaging interpretation to ensure that value-based care is maximized during spine surgeries. LEVEL OF EVIDENCE: 3.

Hox genes control homocercal caudal fin development and evolution.

Ancient bony fishes had heterocercal tails, like modern sharks and sturgeons, with asymmetric caudal fins and a vertebral column extending into an elongated upper lobe. Teleost fishes, in contrast, developed a homocercal tail characterized by two separate equal-sized fin lobes and the body axis not extending into the caudal fin. A similar heterocercal-to-homocercal transition occurs during teleost ontogeny, although the underlying genetic and developmental mechanisms for either transition remain unresolved. Here, we investigated the role of hox13 genes in caudal fin formation as these genes control posterior identity in animals. Analysis of expression profiles of zebrafish hox13 paralogs and phenotypes of CRISPR/Cas9-induced mutants showed that double hoxb13a and hoxc13a mutants fail to form a caudal fin. Furthermore, single mutants display heterocercal-like morphologies not seen since Mesozoic fossil teleosteomorphs. Relaxation of functional constraints after the teleost genome duplication may have allowed hox13 duplicates to neo- or subfunctionalize, ultimately contributing to the evolution of a homocercal tail in teleost fishes.

New information on paleopathologies in non-avian theropod dinosaurs: a case study on South American abelisaurids.

Studies on pathological fossil bones have allowed improving the knowledge of physiology and ecology, and consequently the life history of extinct organisms. Among extinct vertebrates, non-avian dinosaurs have drawn attention in terms of pathological evidence, since a wide array of fossilized lesions and diseases were noticed in these ancient organisms. Here, we evaluate the pathological conditions observed in individuals of different brachyrostran (Theropoda, Abelisauridae) taxa, including Aucasaurus garridoi, Elemgasem nubilus, and Quilmesaurus curriei. For this, we use multiple methodological approaches such as histology and computed tomography, in addition to the macroscopic evaluation. The holotype of Aucasaurus shows several pathognomonic traits of a failure of the vertebral segmentation during development, causing the presence of two fused caudal vertebrae. The occurrence of this condition in Aucasaurus is the first case to be documented so far in non-tetanuran theropods. Regarding the holotype of Elemgasem, the histology of two fused vertebrae shows an intervertebral space between the centra, thus the fusion is limited to the distal rim of the articular surfaces. This pathology is here considered as spondyloarthropathy, the first evidence for a non-tetanuran theropod. The microstructural arrangement of the right tibia of Quilmesaurus shows a marked variation in a portion of the outer cortex, probably due to the presence of the radial fibrolamellar bone tissue. Although similar bone tissue is present in other extinct vertebrates and the cause of its formation is still debated, it could be a response to some kind of pathology. Among non-avian theropods, traumatic injuries are better represented than other maladies (e.g., infection, congenital or metabolic diseases, etc.). These pathologies are recovered mainly among large-sized theropods such as Abelisauridae, Allosauridae, Carcharodontosauridae, and Tyrannosauridae, and distributed principally among axial elements. Statistical tests on the distribution of injuries in these theropod clades show a strong association between taxa-pathologies, body regions-pathologies, and taxa-body regions, suggesting different life styles and behaviours may underlie the frequency of different injuries among theropod taxa.

Long-Term Follow-up of Untreated Adult Patients with Spondylothoracic Dysostosis (Jarcho-Levin Syndrome).

BACKGROUND: Spondylothoracic dysostosis (STD), also known as Jarcho-Levin syndrome (JLS), is a rare autosomal recessive disorder affecting the formation of the spine, characterized by a complete bilateral fusion of the ribs at the costovertebral junction, producing a "crablike" appearance of the thorax. Despite being declared a core indication for a V-osteotomy vertical expandable prosthetic titanium rib (VEPTR) expansion thoracoplasty of the posterior thorax, the natural history of STD in untreated subjects remains poorly documented. In this study, we report radiographic and pulmonary function findings and Patient-Reported Outcomes Measurement Information System (PROMIS) and 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24) scores for untreated adult subjects with STD to gain insights into the natural history. METHODS: We identified 11 skeletally mature, untreated subjects with STD. Findings on medical evaluation, demographics, radiographic parameters, pulmonary function, genetic testing results, PROMIS measures, and EOSQ-24 scores were assessed. RESULTS: Five male and 6 female subjects (mean age, 32.3 years [range, 15 to 70 years]) with a confirmed STD diagnosis based on radiographs and genetic testing were evaluated. Mean body mass index (BMI) was 24.4 kg/m 2 (range, 18 to 38.9 kg/m 2 ), and mean thoracic height was 16 cm (range, 12 to 17 cm). Pulmonary function tests (PFTs) showed a mean forced vital capacity (FVC) of 22% of predicted, mean forced expiratory volume in 1 second (FEV1) of 24% of predicted, and FEV1/FVC ratio of 107% of predicted. The mean PROMIS dyspnea score was 40 ± 8 points (range, 27.7 to 52.1 points). The mean total EOSQ-24 score was 77.3 ± 18 points (range, 43.9 to 93.2 points). CONCLUSIONS: Our study characterizes the natural history of STD in untreated subjects. We confirmed the expected restrictive pattern in pulmonary function, but interestingly, our subjects exhibited better EOSQ scores compared with those reported in neuromuscular populations. PFT results and thoracic height did not correspond to PROMIS and EOSQ scores, questioning the use of those parameters as a surgical indication. We therefore suggest that the STD diagnosis as an absolute indication for VEPTR expansion thoracoplasty surgery be reconsidered. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Antagonistic regulation of homeologous uncx.L and uncx.S genes orchestrates myotome and sclerotome differentiation in the evolutionarily divergent vertebral column of Xenopus laevis.

In anurans, the vertebral column diverges widely from that of other tetrapods; yet the molecular mechanisms underlying its morphogenesis remain largely unexplored. In this study, we investigate the role of the homeologous uncx.L and uncx.S genes in the vertebral column morphogenesis of the allotetraploid frog Xenopus laevis. We initiated our study by cloning the uncx orthologous genes in the anuran Xenopus and determining their spatial expression patterns using in situ hybridization. Additionally, we employed gain-of-function and loss-of-function approaches through dexamethasone-inducible uncx constructs and antisense morpholino oligonucleotides, respectively. Comparative analysis of the messenger RNA sequences of homeologous uncx genes revealed that the uncx.L variant lacks the eh1-like repressor domain. Our spatial expression analysis indicated that in the presomitic mesoderm and somites, the transcripts of uncx.L and uncx.S are located in overlapping domains. Alterations in the function of uncx genes significantly impact the development and differentiation of the sclerotome and myotome, resulting in axial skeleton malformations. Our findings suggest a scenario where the homeologous genes uncx.L and uncx.S exhibit antagonistic functions during somitogenesis. Specifically, uncx.S appears to be crucial for sclerotome development and differentiation, while uncx.L primarily influences myotome development. Postallotetraploidization, the uncx.L gene in X. laevis evolved to lose its eh1-like repressor domain, transforming into a "native dominant negative" variant that potentially competes with uncx.S for the same target genes. Finally, the histological analysis revealed that uncx.S expression is necessary for the correct formation of pedicles and neural arch of the vertebrae, and uncx.L is required for trunk muscle development.

Access to the Lumbosacral Spine: A Current View / Acesso à coluna lombossacral: Visão atual

Abstract The surgical approach to the lumbosacral spine has been the subject of experimental and scientific anatomical studies since the Hippocratic era. However, it was in the 20th century that, with the evolution of asepsis and antibiotic therapy, spine surgery began to evolve at breakneck speed, and the various possibilities of access roads became objects of development and discussion. As a result, pathologies of the lumbosacral spine can be accessed in different ways and positions, from the traditional posterior approach in the prone position to the anterior, oblique, lateral, and endoscopic approaches. The current article brings state-of-the-art access routes to the lumbosacral spine. This article objective is to elucidate the possibilities of accesses the lumbar spine for any purposes, as decompression, fusion, tumour resections, reconstruction or deformity correction, despites type of implants or implants positioning.

Resumo A abordagem cirúrgica da coluna lombossacral tem sido objeto de estudos anatômicos experimentais e científicos desde a era hipocrática. Contudo, foi no século XX que, com a evolução da assepsia e da antibioticoterapia, a cirurgia da coluna começou a evoluir em velocidade vertiginosa e as diversas possibilidades de vias de acesso tornaram-se objetos de desenvolvimento e discussão. Desta forma, as doenças da coluna lombossacral podem ser acessadas de diferentes maneiras e posições, desde a abordagem posterior tradicional em decúbito ventral até as abordagens anterior, oblíqua, lateral e endoscópica. O presente artigo traz vias de acesso de última geração para a coluna lombossacral. O objetivo deste artigo é elucidar as possibilidades de acesso à coluna lombar para quaisquer finalidades, como descompressão, fusão, ressecções tumorais, reconstrução ou correção de deformidades, independentemente do tipo de implante ou seu posicionamento.

Translation and Cross-cultural Adaptation of the SOSG-OQ 2.0 Questionnaire into Brazilian Portuguese / Tradução e adaptação transcultural do questionário SOSG-OQ 2.0 para o português brasileiro

Abstract Objective: To perform the cross-cultural adaptation and translation into Brazilian Portuguese of the Spine Oncology Study Group - Outcomes Questionnaire 2.0 (SOSG-OQ 2.0) to enable its application to Brazilian patients and to allow Brazilian researchers to use a questionnaire that is on trend in the scientific literature. Materials and Methods: The present is a basic, non-randomized, non-comparative study. The translation followed the proposal by Reichenheime and Moraes, mainly for the semantic equivalence and measurement equivalence sessions, as well as the recommendations by Coster and Mancini mainly in the translation stage. The stages were as follows: first - translation into Brazilian Portuguese; second - back-translation; third - semantic comparison; fourth - validation of the final construct. Results: The translations of the SOSG-OQ 2.0 made by three translators presented a high degree of similarity for most questions. The translators kept all question titles and subtitles, as well as their internal and external orders. Two sworn translators, with native proficiency in English, performed the back-translation of the amalgamated text. Both back-translations were quite similar, and any differences were solved through consensus between the main author and the sworn translators, and the translated text was considered the final version. Conclusion: The present study shows a translated version of the SOSG-OQ 2.0 with semantic validity with the original version published in English. As such, researchers can apply the questionnaire to the Brazilian population, adding another tool for spine surgeons to improve the monitoring of this complex group of patients.

Resumo Objetivo: Realizar a adaptação transcultural e a tradução para o português brasileiro da versão 2.0 do Questionário de Desfechos do Spine Oncology Study Group (Spine Oncology Study Group - Outcomes Questionnaire 2.0, SOSG-OQ 2.0, em inglês) para viabilizar sua aplicação em pacientes brasileiros e permitir a utilização deste questionário que está em voga na literatura científica por pesquisadores brasileiros. Materiais e Métodos: Trata-se de uma pesquisa básica, não randomizada, não comparativa. As etapas de tradução foram realizadas conforme propostas por Reichenheime e Moraes, principalmente as sessões de equivalência semântica e equivalência de mensuração, e também foram seguidas as recomendações de Coster e Mancini, principalmente na etapa de tradução. As etapas foram as seguintes: primeira - tradução do questionário para o português brasileiro; segunda - retroversão; terceira - comparação semântica; e quarta - validação final do constructo. Resultados: As traduções do SOSG-OQ 2.0 feitas por três tradutores apresentaram grande similaridade na maioria das questões. Todos os títulos e subtítulos de perguntas foram mantidos pelos tradutores, assim como as ordens interna e externa das perguntas. A retroversão da tradução conciliada foi realizada por dois tradutores juramentados, com fluência nativa na língua inglesa. Ambas as retroversões foram bastante similares, as divergências foram sanadas por consenso entre o autor principal e os tradutores juramentados, e a versão traduzida foi considerada a versão final. Conclusão: Neste estudo, apresenta-se uma versão traduzida do SOSG-OQ 2.0 que tem validade semântica com a versão original publicada em inglês, o que permite a sua aplicação na população brasileira, e acrescenta mais uma ferramenta para que os cirurgiões de coluna possam acompanhar de forma melhor este complexo grupo de pacientes.

Efficacy of Dynamic Magnetic Resonance Imaging in the Diagnosis of Degenerative Cervical Myelopathy: Systematic Review Protocol / Eficácia da ressonância magnética dinâmica no diagnóstico da mielopatia cervical degenerativa: Protocolo de revisão sistemática

Abstract Cervical degenerative myelopathy (CDM) is a cervical spine condition resulting in clinical manifestations of spinal cord compression related to the chronic, non-traumatic, and progressive narrowing of the cervical spinal canal. Conventional magnetic resonance imaging (MRI) is the gold standard test to diagnose and assess the severity of CDM. However, the patient is in a neutral and static position during the MRI scan, which may devalue the dynamic factors of CDM, underestimating the risk of spinal cord injury related to cervical spine flexion and extension movements. Dynamic MRI is a promising technique to change this scenario. Therefore, the present review aims to answer the following question: "Is dynamic MRI of the cervical spine more accurate in diagnosing CDM than conventional MRI?". We will search for studies in the MEDLINE (via PubMed), Embase, Scopus, Web of Science, LILACS, and SciELO databases. The search strategy will contain a combination of terms related to cervical myelopathy and magnetic resonance imaging. Two independent reviewers will select studies, extract data, and assess the risk of bias. The synthesis of results will be descriptive, considering the main findings of the studies about the outcomes of interest.

Resumo A mielopatia cervical degenerativa (MCD) é uma doença da coluna cervical com manifestações clínicas de compressão da medula espinal relacionadas ao estreitamento crônico, não traumático e progressivo do canal vertebral cervical. A ressonância magnética (RM) convencional é o exame padrão-ouro para o diagnóstico e a avaliação da gravidade da MCD. Contudo, o paciente encontra-se em posição neutra e estática durante a realização deste exame, o que pode desvalorizar os fatores dinâmicos da MCD, subestimando o risco de lesão medular relacionados aos movimentos de flexão e extensão da coluna cervical. A RM dinâmica é uma técnica promissora para modificar esse panorama. Portanto, a presente revisão tem o objetivo de responder a seguinte pergunta: "A RM dinâmica da coluna cervical é mais precisa no diagnóstico de MCD em comparação à RM convencional?" As buscas por estudos serão realizadas nas bases de dados MEDLINE (via PubMed), Embase, Scopus, Web of Science, LILACS e SciELO. A estratégia de busca conterá combinação de termos relacionados à mielopatia cervical e à ressonância magnética. Dois avaliadores independentes irão realizar a seleção dos estudos, a extração dos dados e a avaliação dos riscos de viés. A síntese dos resultados será realizada de maneira descritiva, considerando os principais achados dos estudos relacionados aos desfechos de interesse.