Horizontal Gaze Assessment: An Extensive Narrative Review.

OBJECTIVE: Bipedalism was a significant milestone in the evolutionary development of Homo sapiens sapiens, influencing neocortical evolution and subsequent behavioral changes. Coordinated visual and sensory inputs are crucial for posture, environmental interaction, and surgical planning, with horizontal gaze being a pivotal parameter. This narrative review aims to explore various geometric measures used to assess horizontal gaze in patients, highlighting their applications in surgical planning. METHODS: A literature review was conducted in indexed databases using Mesh terms like "Cervical Vertebrae" and "Visual Fields" along with keywords such as "horizontal gaze" and "sagittal spine parameters." Among 477 initially identified articles, 41 were selected for inclusion after rigorous filtering. RESULTS: The most recognized method for assessing horizontal gaze is the Chin Brow Vertical Angle (CBVA), initially described in patients with ankylosing spondylitis. Clinical photography is employed as a tool for CBVA calculation, while other measures like McGregor slope and Slope of the Line of Sight have been considered as alternatives to CBVA. Each method presents its unique advantages and limitations. CONCLUSIONS: This review highlights the need for further research into horizontal gaze measurement methods. Developing novel approaches to determine horizontal gaze can significantly enhance surgical planning and, consequently, improve patient outcomes. The ongoing exploration of these geometric measures offers promising prospects for advancing the field and optimizing patient care.

Mecanismos neurológicos involucrados en la escoliosis idiopática. Revisión sistemática de la literatura / Neurological mechanisms involved in idiopathic scoliosis. Systematic review of the literature

La literatura que explica los mecanismos neurológicos que subyacen al desarrollo o a la compensación de la escoliosis idiopática es limitada. El objetivo del presente artículo es describir e integrar los mecanismos y las vías nerviosas por medio de las cuales se compensa y/o se desarrolla la escoliosis idiopática. Se realizó una revisión sistemática narrativa en diferentes bases de datos sobre los estudios publicados entre el 1 de enero 1967 y el 1 de abril de 2021, empleando los siguientes términos: «scoliosis», «vision», «ocular», «vestibule», «labyrinth», «posture», «balance», «eye movements», «cerebellum», «proprioception» y «physiological adaptation». En la búsqueda se identificaron 1.112 referencias, de las cuales al final se incluyeron 50: 46 estudios clínicos observacionales analítico-descriptivos (entre cohortes, reporte y serie de casos) y 4 estudios experimentales. En la respuesta neurológica a la escoliosis idiopática, la integración sensitivo-cortical de las aferencias visual-oculomotor-vestibular-propioceptiva permite realizar modificaciones a nivel postural con el fin de lograr una compensación inicial sobre el balance sagital y el centro de masa; sin embargo, con el tiempo dicho mecanismo de compensación puede agotarse y causar progresión de la deformidad inicial. (AU)

The literature that explains the neurological mechanisms underlying the development or compensation of idiopathic scoliosis is limited. The objective of the article is to describe and integrate the mechanisms and nerve pathways through which idiopathic scoliosis is compensated and/or developed. A narrative systematic review in different databases of the studies published between January 1, 1967 and April 1, 2021 was performed, using the following terms: «scoliosis», «vision», «eye», «vestibule», «labyrinth», «posture», «balance», «eye movements», «cerebellum», «proprioception», and «physiological adaptation». In the search, 1112 references were identified, of which 50 were finally included: 46 observational analytical clinical studies-descriptive (between cohorts, report and series of cases) and 4 experimental studies. In the neurological response to idiopathic scoliosis, the sensory-cortical integration of the afferences in the visual-oculomotor-vestibular-proprioceptive systems, allows modifications at the postural level in order to achieve an initial compensation on the sagittal balance and the centre of body mass; however, over time these compensation mechanisms may be exhausted causing progression of the initial deformity. (AU)

Neurological mechanisms involved in idiopathic scoliosis. Systematic review of the literature.

The literature that explains the neurological mechanisms underlying the development or compensation of idiopathic scoliosis is limited. The objective of the article is to describe and integrate the mechanisms and nerve pathways through which idiopathic scoliosis is compensated and/or developed. A narrative systematic review in different databases of the studies published between January 1, 1967 and April 1, 2021 was performed, using the following terms: "scoliosis", "vision", "eye", "vestibule", "labyrinth" "posture", "balance", "eye movements", "cerebellum", "proprioception", and "physiological adaptation". In the search, 1112 references were identified, of which 50 were finally included: 46 observational analytical clinical studies-descriptive (between cohorts, report and series of cases) and 4 experimental studies. In the neurological response to idiopathic scoliosis, the sensory-cortical integration of the afferences in the visual-oculomotor-vestibular-proprioceptive systems, allows modifications at the postural level in order to achieve an initial compensation on the sagittal balance and the centre of body mass; however, over time these compensation mechanisms may be exhausted causing progression of the initial deformity.

Venous anatomy of the lumbar region applied to anterior lumbar interbody fusion (ALIF): Proposal of a new classification.

BACKGROUND: Anterior lumbar interbody fusion (ALIF) is a good alternative for the surgical treatment of lumbar degenerative disc disease. The primary vascular complications regarding this intervention involve the common iliac vein bifurcation complex (CIVC). Currently, no classification system allows defining which patients are more prone to these complications. We aimed to perform a retrospective study evaluating the anatomy of the common iliac CIVC at the L5-S1 disc proposing a novel classification system as it relates to the ALIF difficulty. METHODS: 91 consecutive patients who underwent ALIF at the L5-S1 level were included. We categorize the CIVC at the L5-S1 disc space into four types according to the veins position along the disc space. The patient records were reviewed for demographic information, surgical characteristics, and complications. The surgical difficulty was rated at the end of the procedure. RESULTS: 54% of the patients were women. The mean age was 52.5 ± 14.8 years. Mean surgical bleeding was 152 ml (range 20ml -3000 ml), and mean surgical time was 79 ± 13.3 minutes. Berbeo-Diaz-Vargas (BDV) classification type 4 was found in 43.9% of the patients. The surgical complexity was associated with the bleeding magnitude and surgical time spent (p<0.01), not being related to the corporal mass index or sacral slope. Bleeding magnitude, surgical time, and surgical complexity were significantly related to the BDV classification system (p<0.01). Weighted Cohen´s kappa index for the BDV scale was 0.89 (95% IC 0.822 - 0.974). CONCLUSIONS: BDV scale is a reliable and reproducible tool for the classification of CIVC significantly related to a higher incidence of bleeding, prolonged operating time, and increased perceived difficulty by the surgeon.

Articulación facetaria lumbar: correlación anatómica, clínica e imagenológica / Lumbar facet joint: anatomical, clinical and imaging correlation

El dolor facetario lumbar es una de las principales causas de dolor lumbar; representa alrededor del 15-56%. La articulación facetaria estabiliza la columna vertebral, tiene un rol fundamental en el soporte, distribución del peso y regulación de los movimientos rotacionales de la columna. Por ello, el conocimiento de la anatomía y de la biomecánica de esta articulación ayuda a tener una mejor comprensión de su participación en la fisiopatología del dolor lumbar y, por ende, mejora su abordaje diagnóstico y terapéutico. Nosotros revisamos aquí los conceptos actuales de embriología, anatomía, biomecánica y la correlación clínica/imagenológica de los cambios asociados a la enfermedad degenerativa facetaria de la columna lumbar.

Low back pain is a very common reason for emergency room consultation, it is found in approximately 60% of adults, and, within it, facet lumbar pain is one of the main causes, accounting for about 15-56% of low back pain cases. The facet joint stabilizes the spine, helps to distribute loads and has a fundamental role in support, weight distribution, and rotational movements regulation of the spine. Consequently, knowledge of the anatomy and biomechanics of this joint is helpful to have a better understanding of their contribution to the low back pain pathophysiology and, therefore, improving diagnostic and therapeutic approaches. This paper aims to review the current concepts of embryology, anatomy, biomechanics, and clinical/imaging correlation of the changes associated with lumbar degenerative facet disease

Avances fisiopatológicos para el entendimiento de la lesión medular traumática: revisión bibliográfica / Advances in understanding physiology of traumatic spine injury: [review]

El trauma raquimedular es una de las patologías que genera la mayor cantidad de consecuencias no solamente médicas sino sociales y laborales. Las secuelas neurológicas producidas por la lesión traumática de la médula y sus raíces son frecuentes y acompañadas de síntomas y signos neurológicos mayores que afectan la integridad física, los aspectos sociales, profesionales y de calidad de vida del paciente. El grado de lesión traumática determina el compromiso neurológico y sus secuelas, pero el adecuado tratamiento inicial puede modificar en algún grado la severidad de las lesiones. La base de este tratamiento se fundamenta en el conocimiento fisiopatológico de la cascada de eventos que aparecen una vez se genera la lesión. Aunque el arsenal terapéutico disponible para el manejo de estos pacientes no es amplio, son muchos los avances que se están realizando para desarrollar nuevas alternativas terapéuticas. Una vez se produce el evento traumático aparecen los mecanismos de lesión primaria (compresión persistente, compresión transitoria, distracción, laceración, transección) y los de lesión secundaria (choque neurogénico, lesión vascular, excitotoxicidad, lesiones secundarias mediadas por calcio, alteraciones hidroelectrolíticas e inmunológicas, apoptosis, alteración mitocondrial). El blanco terapéutico debe ir dirigido a ambos procesos, pero es el secundario en el que se está trabajando de forma más extensa. En este artículo se evalúa la utilidad de los esteroides en el manejo de las lesiones traumáticas de la médula espinal y se presentan aquellos avances terapéuticos en desarrollo.

Cómo seleccionar basado en conceptos biomecánicos un disco artificial cervical / Selecting based on biomechanical concepts cervical artificial disc

La artroplastía cervical con reemplazo total de disco por una prótesis artificial dinámica es en la actualidad una importante opción de tratamiento de la enfermedad degenerativa de la columna cervical; permite conservar el movimiento, generando estabilidad y evitando degeneración del segmento adyacente. Son múltiples las opciones de discos artificiales disponibles actualmente en el mercado. Aplicamos los principales conceptos biomecánicos y estudio de materiales para analizar cinco de los más utilizados discos cervicales artificiales ( PCM®, Bryan Disc®, Cervidisc®, Prodisc C® y Prestige I ®); damos una puntuación y unas conclusiones para que el cirujano de columna tenga herramientas a la hora de escoger un disco artificial.