Parameters of nuclear magnetic resonance in patients with congenital narrowing of the lumbar spinal canal / Parâmetros de ressonância magnética em pacientes com estreitamento congênito do canal vertebral lombar / Parámetros de resonancia magnética en pacientes con estrechamiento congénito del conducto lumbar

ABSTRACT Objective: To compare the morphological parameters of magnetic resonance in patients with congenital narrowing of the lumbar spinal canal with patients with low back pain. Methods: A descriptive, retrospective, observational study was conducted with measurements in the axial and sagittal magnetic resonance sections of the vertebral body and canal of the lumbar spine of 64 patients with diagnosis of low back pain, which were compared with resonance images taken from 31 Mexican patients with congenital narrowing of the lumbar spinal canal. Results: The results show that patients with congenital narrowing of the lumbar spinal canal in the axial sections have a difference in diameters, being L2<13.9 mm, L3<13.3 mm, L4<12.9 mm, L5<13.1 mm, compared with controls L2<20.5 mm, L3<20.5 mm, L4<19.3 mm, L5<18.1 mm with p = 0.000. Conclusions: We found different measurements in the Mexican population compared to those found by similar studies. With the parameters obtained, it would be possible to make the proper diagnosis, surgical planning, and treatment.

RESUMO Objetivo: Comparar os parâmetros morfológicos de ressonância magnética de pacientes com estreitamento congênito do canal lombar com os pacientes com lombalgia. Métodos: Foi realizado um estudo descritivo, retrospectivo, observacional, com medições nos cortes axiais e sagitais de ressonância magnética do corpo e do canal vertebral da coluna lombar de 64 pacientes com diagnóstico de lombalgia, os quais foram comparados com ressonâncias feitas em 31 pacientes com diagnóstico de estreitamento congênito de canal vertebral lombar na população mexicana. Resultados: Os resultados obtidos mostram que os pacientes com estreitamento congênito do canal vertebral lombar apresentam, nos cortes axiais, uma diferença com relação aos diâmetros, sendo em L2 < 13,9 mm, L3 < 13,3 mm, L4 < 12,9 mm, L5 < 13,1 mm, em comparação com os controles L2 < 20,5 mm, L3 < 20,5 mm, L4 < 19,3 mm, L5 < 18,1 mm com p = 0,000. Conclusões: Foram encontradas distintas medições na população mexicana em comparação com outros estudos similares. Com os parâmetros obtidos será possível realizar o diagnóstico adequado, planejamento cirúrgico e tratamento.

RESUMEN Objetivo: Comparar parámetros morfológicos en resonancia magnética nuclear de pacientes con estrechamiento congénito del conducto lumbar con pacientes con lumbalgia. Métodos: Se realizó un estudio descriptivo, retrospectivo, observacional, con mediciones en cortes axiales y sagitales del cuerpo y conducto vertebral en resonancias magnéticas de columna lumbar de 64 pacientes con diagnóstico de lumbalgia y se comparó con resonancias magnéticas de 31 pacientes diagnosticados con estrechamiento congénito del conducto lumbar en población mexicana. Resultados: Los resultados obtenidos demuestran que los pacientes con estenosis lumbar congénita presentan, en cortes axiales, una diferencia en cuanto a los diámetros, siendo en L2 < 13,9 mm, L3 < 13,3 mm, L4 < 12,9 mm, L5 < 13,1 mm en comparación a los controles L2 < 20,5 mm, L3 < 20,5 mm, L4 < 19,3 mm, L5 < 18,1 mm con una p = 0,000. Conclusiones: Encontramos distintas mediciones en población mexicana comparado a otros estudios similares. Con estos parámetros obtenidos se podrá realizar un adecuado diagnóstico, planeación quirúrgica y tratamiento.

Evaluation of the diameter of the lumbar vertebral canal using computed tomography in mexican population / Avaliação do diâmetro do canal vertebral lombar por tomografia computadorizada na população mexicana / Evaluación del diámetro del conducto lumbar por tomografía computarizada en población mexicana

ABSTRACT Objective: To conduct a descriptive study to find measures of central tendency in the vertebral bodies L3, L4, and L5 in the Mexican population. Methods: Fifty patients were considered, 33 male and 17 female, aged between 30 and 55 years. Measurements were performed at the levels L3, L4 and L5 taking the interpedicular distance (A), mid-sagittal diameter (B), anteroposterior distance (AP) and the depth of lateral recess (R) in axial 2-mm sections of CT scans (Somaton Emotion, SIEMENS, 2 sections) in a Mexican population with healthy vertebral bodies, with no history of lumbar pathology. Results: Overall, the measures obtained were mean interpedicular distance of 22.80 in L3, range of 16.34/28.72. In L4, mean of 23.83, range of 17.62/27.92. In L5, mean of 25.28, range of 21.88/31.29. Conclusions: This study managed to make a database that did not exist in Mexico, using measures of central tendency. Therefore, it opens the way for it to be possible, in future studies, to identify predictive factors or even developing implants.

RESUMO Objetivo: Realizar um estudo descritivo para encontrar medidas de tendência central nos corpos vertebrais L3, L4 e L5 na população mexicana. Métodos: Foram considerados 50 pacientes, 33 homens e 17 mulheres, com idades entre 30 e 55 anos. Foram realizadas medidas no nível de L3, L4 e L5, tomando-se a distância interpedicular (A), o diâmetro mediossagital (B), a distância anteroposterior (AP) e a profundidade do recesso lateral (R) em cortes axiais de tomografia computadorizada (tomógrafo Somaton Emotion, SIEMENS, 2 cortes) em uma população mexicana com corpos vertebrais saudáveis, sem história prévia de patologia lombar. Resultados: Obteve-se, no geral, distância interpedicular média de 22,80 em L3, com faixa de 16,34/28,72. Em L4, média de 23,83, faixa de 17,62/27,92. Em L5, média de 25,28, faixa de 21,88/31,29. Conclusões: O presente estudo conseguiu fazer um banco de dados que não existia no país usando medidas de tendência central. Desse modo, abre-se o caminho para que, em estudos posteriores, seja possível identificar fatores preditivos ou até mesmo o desenvolvimento de implantes.

RESUMEN Objetivo: Realizar un estudio descriptivo para buscar medidas de tendencia central en los cuerpos vertebrales L3, L4 y L5 en población mexicana Métodos: Fueron considerados 50 pacientes, 33 hombres y 17 mujeres, con edades entre 30 y 55 años. Se realizaron mediciones a nivel de L3, L4, L5, tomando la distancia interpedicular (A), el diámetro mediosagital (B), la distancia anteroposterior (AP) y profundidad de receso lateral (R) en cortes axiales de tomografía axial computarizada de 2 mm (tomógrafo Somaton Emotion, SIEMENS, 2 cortes) en una población mexicana con cuerpos vertebrales sanos, sin antecedente previo de patología lumbar. Resultados: Se obtuvo en general una distancia interpedicular media de 22,80 en L3, con un rango de 16,34/28,72. En L4, media de 23,83, rango de 17,62/27,92. En L5, media de 25,28, rango de 21,88/31,29. Conclusiones: El presente estudio logró realizar una base de datos no existente en el país utilizando medidas de tendencia central. De este modo, se abre camino para que en estudios posteriores se logre determinar factores predictivos o inclusive el desarrollo de implantes.

Reevaluation of the Pavlov Ratio in Patients with Cervical Myelopathy

BACKGROUND: This study was designed to reevaluate the effectiveness of the Pavlov ratio in patients with cervical myelopathy. METHODS: We studied 107 patients who underwent open door laminoplasty for the treatment of cervical myelopathy between the C3 to C7 levels. We determined the Pavlov ratio on preoperative and postoperative cervical spine lateral radiographs, the vertebral body-to-canal ratio on sagittal reconstruction CT scans, and the vertebral body-to-cerebrospinal fluid (CSF) column ratio on T2-weighted sagittal MR images from C3 to C6. The severity of myelopathy was determined using the JOA score on both preoperative and postoperative images. The recovery rate was also calculated. The Pavlov ratio in plain radiographs from patients with myelopathy was compared with the ratio of the vertebral body to the spinal canal on CT and MRI. RESULTS: The average Pavlov ratio between C3 and C6 ranged from 0.71 to 0.76. On CT scan, the average vertebral body-to-canal ratio between C3 and C6 ranged from 0.62 to 0.66. On MRI, the vertebral body-to-CSF column ratio between C3 and C6 ranged between 0.53 and 0.57. A positive correlation was noted between the Pavlov ratio and the vertebral body-to-canal ratio on sagittal-reconstruction CT (correlation coefficient = 0.497-0.627, p = 0.000) and between the Pavlov ratio and the vertebral body-to-CSF column ratio on MRI (correlation coefficient = 0.511-0.649, p = 0.000). CONCLUSIONS: We demonstrated a good correlation between the Pavlov ratio and both the vertebral body-to-canal ratio on CT and the vertebral body-to-CSF column ratio on MRI. Therefore, the Pavlov ratio can be relied upon to predict narrowing of the cervical spinal canal in the sagittal plane.

Estudio Ultrasonográfico de las Estructuras Nerviosas del Canal Vertebral a Nivel de la Articulación Atlantooccipital en Caninos Adultos / Ultrasonographic Study of the Nervous Structures of the Vertebral Canal at the Atlantooccipital Joint Level in Adult Dogs

Los objetivos de este estudio fueron describir y comparar, mediante el ultrasonido, las estructuras nerviosas que se encuentran en el canal vertebral a nivel de la articulación atlanto-occipital en caninos adultos de talla corporal pequeña y grande. Se utilizaron 20 caninos adultos clínicamente sanos: 10 caninos de talla corporal pequeña (peso < a 10 kg) y 10 a caninos de talla corporal grande (peso > a 20 kg). Se realizó el examen ultrasonográfico con un transductor de 7,5 MHz, utilizando para ello el espacio atlantooccipital como ventana ecográfica. Se midieron diámetros verticales y horizontales del saco dural y médula espinal, y áreas del saco dural, médula espinal y espacio subaracnoídeo. Se calcularon razones entre algunas mediciones. Las estructuras estudiadas se observaron ecográficamente de modo similar en los caninos de ambos grupos. La duramadre se observó como una línea hiperecoica continua, adherida al borde óseo del canal vertebral. La médula espinal se observó como una estructura ovalada hipoecoica, con un parénquima homogéneo. Los diámetros verticales y horizontales del saco dural, médula espinal y las áreas del saco dural, médula espinal y espacio subaracnoídeo fueron significativamente menores (p<0,05) en los caninos de talla corporal pequeña. Las diferencias entre las áreas de médula espinal entre los grupos fue menor a 0,1 cm² y entre las áreas de saco dural y espacio subaracnoídeo fue de aproximadamente 1 cm². Se concluye que el ultrasonido permite visualizar adecuadamente la médula espinal y estructuras asociadas en la región de la articulación atlanto-occipital en caninos adultos. Finalmente, existieron diferencias mínimas en los valores de áreas de médula espinal y notoriamente mayores en los valores de áreas del saco dural y espacio subaracnoídeo entre ambos grupos de animales.

The goals of this study were to describe and compare by ultrasound the nervous structures in the vertebral canal at the atlanto-occipital joint region in small and large size adult dogs. A total of 20 healthy adult dogs were selected for the study. They were 10 small dogs (< 10 kg) and 10 large dogs (> 20 kg). Ultrasonographic examination was performed with a 7,5 MHz transducer and using the atlanto-occipital space as an echographic window. In transverse images, vertical and horizontal diameters of the dural sac and spinal cord and areas of the dural sac, spinal cord and subarachnoid space were measured. Some ratios between measurements were also calculated. Analysed structures were observed in a similar way in both groups of dogs. The dura mater was observed as an echogenic continuous line and attached to the bony border. The subarachnoid space has an anechoic appearance. The pia mater was observed as a thin echogenic line covering the spinal cord surface. The spinal cord was observed as an oval hypoechogenic structure inside the vertebral canal and with a homogeneous parenchyma without differentiation between gray and white matter. Vertical and horizontal diameters of the dural sac and spinal cord and areas of the dural sac, spinal cord and subarachnoid space were significantly different (P<0,05) in both group of dogs. Differences of spinal cord areas between small and large dogs were minimal (<0,1 cm²), compared with differences between dural sac and subarachnoid space areas (around 1 cm x). In conclusion, ultrasound allows an adequate examination of spinal cord and associated structures at the atlanto-occipital joint region in adult dogs. Differences between groups are minor in areas of spinal cord and larger in areas of dural sac and subarachnoid space.

C3-4 level cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) is uncommon at the C3-4 level. Fourteen patients with C3-4 CSM were treated over a period of 3 years. The radiological factors contributing to CSM at the C3-4 level were studied. These factors included the assessment of static and dynamic canal diameters, retrolisthesis, posterior osteophytes and degenerative spinal segmental fusion on plain X-rays; and, the antero-posterior cord compression ratio (APCR) on magnetic resonance imaging (MRI). The clinical status of the patients was assessed by the modified Japanese orthopedic association scale (mJOAS). The mean difference between the static and dynamic canal diameters was statistically significant at C3-4 (p < 0.01). The APCR obtained at different levels showed a significant compression at the C3-4 level in comparison to the lower level. There was a correlation between the APCR and the preop mJOAS, r=0.6 (p< 0.05). The mean mJOAS improved from 9.35 to 14.35 at follo-up. The recovery rate calculated using the modified Hirabayashi rate was 66.9%. Degenerative changes at lower cervical segments predispose to increased mobility and spondylotic changes at the C3-4 level. The patients in this study were young as compared to those reported in the international literature.

Morphology of the Lumbar Spinal Canal in Normal Adult Turks

Pathological changes can occur in the diameters of the lumbar spinal canal. Therefore, assessing the canal size an important diagnostic procedure. Two hundred plain anterioposterior radiographs of the lumbar spine were examined. The sample consisted of 100 males and 100 females. The transverse diameter of the bony spinal canal (interpedicular distance), which was measured as the minimum distance between the medial surfaces of the pedicles of a given vertebra, was measured. In addition, the transverse diameter of the vertebral body, which was measured as the minimum distance across the waist of the vertebra, was measured. The distances were measured to the nearest one tenth of a millimetere using a Vernier caliper. At all levels (L1 - L5) the transverse diameters of the lumbar spinal canal were approximately 1 - 1.5 mm higher in males than in females. The intersegmental differences increased proximodistally, in both sexes. The ratio of the transverse diameter canal to the width of the vertebra ranged from 0.55 to 0.60 mm in both sexes. The distribution of the different lumbar canal types were 47% A, 42% B, 11% C. Additionally, subtypes were determined and classified.

Diagnostic value of plain radiography and myelography in lumbar canal stenosis

The records of seventy six patients with surgically proven lumbar canal stenosis were analysed. Clinical features, plain radiography and myelography of the lumbar spine were studied. Plain x-ray abnormalities suggesting spinal canal stenosis were positive in 66 cases [78.9%]. Myelography was correct in 67 eases [88.2%]

Injury of the stenotic cervical canal

Twenty-two patients of injured cervical spine having radiological evidences of cervical canal stenosis and 14 with wide canals taken as control group were submitted to clinical, radiological and follow up assessment. It was found that there were basic differences in the pathological pattern, the mode of recovery, and the basic management principles between both groups; the wide and stenotic canals