Rodolfo Morales-Avalos

Age- and gender-related variations in morphometric characteristics of thoracic spine pedicle: A study of 4,800 pedicles.

Transpedicular spinal fusion is the most commonly used fixation technique for the surgical treatment of vertebral disorders. However, the instrumentation of the thoracic spine using this technique continues to be controversial. The objective of the present study was to determine the morphometric characteristics of the thoracic pedicle and to establish how these characteristics vary with gender and age. Two hundred thoracic spines (4800 thoracic pedicles) from individuals of known gender and age were analyzed (in accordance with the order of vertebrae). The spines were divided into six groups according to age and gender. The horizontal and vertical diameters of the thoracic pedicle were determined for each piece. The mean and standard deviation of each variable were determined, and differences between age groups for each gender were evaluated using parametric correlation tests. The pedicle diameters of men and women differed significantly for most groups (P < 0.05). The horizontal diameters decreased from T1 to T5 and increased up to T12. The vertical diameter followed a cephalocaudal pattern of development from T1‐T12. The pedicle diameters decreased with increasing age in women, while the opposite trend was observed in men. In men, the dimensions of the thoracic spine pedicle increase with increasing age; in women, they decrease. These differences should be taken into account when selecting the appropriate pedicle screw. Clin. Anat. 27:441–450, 2014.

A new Morphological Classification of the Anterior Inferior Iliac Spine: Relevance in Subspine Hip Impingement

El Sindrome de Pinzamiento Femoroacetabular (PFA) es una entidad clinica reconocida en los ultimos anos como una causa de dolor y desarrollo de artrosis temprana de cadera. El pinzamiento subespinoso de la cadera se caracteriza por una espina iliaca anteroinferior (EIAI) prominente o con una morfologia anormal, lo que contribuye al desarrollo de un cuadro clinico similar al PFA. El objetivo fue proponer una nueva clasificacion morfologica de la EIAI y determinar las prevalencias de las distintas morfologias de la EIAI en base a la misma y correlacionarla con los distintos sexos y grupos de edad. La muestra consistio en un total de 458 hemipelvis, de sexo y edad conocidos (264 hombres y 194 mujeres). Cada pieza fue analizada para determinar la prevalencia de variaciones morfologicas de la EIAI en base a la clasificacion propuesta. Tipo 1: presencia de una superficie concava entre la EIAI y reborde acetabular, Tipo 2A: presencia de una superficie plana entre la EIAI y el reborde acetabular, Tipo 2B: presencia de una superficie convexa entre la EIAI y el reborde acetabular y Tipo 3: la EIAI protruye hacia el acetabulo anterior o inferiormente. Se determino una prevalencia de 69,87% para la EIAI Tipo 1 (320/458). En cuanto a las morfologias anormales, se determino una prevalencia de 17,90% (82/458), 3,71% (17/458) y 8,52% (39/459) para los Tipos 2A, 2B y 3, respectivamente. La prevalencia de una morfologia anormal en las EIAI de especimenes del sexo masculino fue de 30,30% (80/264) y en el sexo femenino 29,90% (58/194). Se evidencia la prevalencia de las diferentes morfologias que puede tener la EIAI; esta informacion sera de ayuda para determinar el papel de la EIAI en la aparicion del pinzamiento subespinoso de la cadera.

Safe Areas for the Placement of Standard Shoulder Arthroscopy Portals: An Anatomical Study

The abundant vascular structures that surround the shoulder joint are complex and variable, complicating arthroscopy approaches. The aim of this study is to determine safe and risky areas around standard posterior and standard anterior portals, and accounting for the distribution of neurovascular structures of small and medium diameters that can lead to intra-articular bleeding during surgery. The standard posterior portal, and standard anterior portal were placed as described in the literature, and punch dissection was performed 2.5 cm around the trocar in situ. The arrangement of each identified structure was photographically documented and digitalized for each anatomic plane; the distance to the trocar and the diameter of each structure were measured. Based on each digitalized anatomic plane, safe and risky tissue areas were determined, and a clock face coordinate system was used to represent these areas. The safe area around the standard posterior portal was located between 11 and 1 o´clock for the left shoulder and 11 and 2 o´clock for the right shoulder. For the standard anterior portal, the safe area was located between 2 and 3 o´clock for the left shoulder and between 9 and 12 o´clock for the right shoulder. However, we did document a risk of injuring the cephalic vein 5 times, the axillary artery 3 times and the deltoid branch of the thoracoacromial artery once. This study reports quantitatively the total number of small diameter structures present in the two shoulder arthroscopic portals evaluated. The safe areas proposed in this study must be evaluated to propose new access points for performing arthroscopic procedures on the shoulder.

Morphological Analysis of Major Segments of Coronary Artery Occlusion: Importance in Myocardial Revascularization Surgery

En la cirugia de revascularizacion miocardica se debe asegurar la similitud morfologica entre la arteria coronaria y el injerto. Esto es un factor importante en su duracion y permeabilidad. El objetivo fue analizar las caracteristicas morfologicas y morfometricas de los segmentos de mayor oclusion de las arterias coronarias. Estudio observacional, transversal y descriptivo que consto de dos fases. Una macroscopica en la que se extrajeron 11 corazones de cadaveres y se determino la dominancia coronaria y longitud de la arteria interventricular anterior (AIA), la arteria coronaria derecha (ACD) y la arteria circunfleja (ACX). En la fase microscopica se obtuvo un total de 77 segmentos de estas arterias y se determino el diametro luminal, grosor de pared, cantidad de fibras elasticas y presencia y tamano de ateroma. La dominancia coronaria derecha fue la mas frecuente. La longitud total de los vasos fue de 15,65±1,17 cm para la AIA, de 12,67±2,02 cm para la ACD y 8,79±2,5 cm para la ACX. Los diametros oscilaron entre los 2,3 mm en los segmentos proximales y entre 1,1 mm a 1,8 mm en los segmentos distales. Los grosores de pared en los segmentos proximales se presentaron entre 354 µm y 396 µm y en los segmentos distales oscilaron entre 120 µm a 305 µm. La cantidad de fibras elasticas demostro que son arterias musculares. El 35% de los ateromas se presento en la ACX y el 32,5% en la AIA al igual que en la ACD. Los de mayor tamano se encontraron en los segmentos proximales. Este estudio analizo la morfologia y la morfometria de los segmentos de las arterias coronarias que se ocluyen con mayor frecuencia. Los resultados encontrados aporta informacion sobre los parametros mas significativos que se deben considerar para la eleccion del injerto vascular en la cirugia de revascularizacion miocardica.

Neurovascular structures at risk during anterolateral and medial arthroscopic approaches of the hip

El objetivo fue describir las areas de seguridad para la colocacion de 5 portales estandar (portal anterior, anterolateral, posterolateral, portal anterior proximal medial y portal anterior distal medial) y 3 portales mediales emergentes (antero medial, portal posteromedial y posteromedial distal) para proporcionar una descripcion topografica de la seguridad de cada portal. Se realizo un estudio descriptivo, observacional y transversal, en la que se diseco el triangulo femoral de 12 caderas. Se colocaron los 5 portales laterales y los 3 portales mediales. Se documento la medicion de cada estructura neurovascular de relevancia clinica en relacion a cada uno de los portales evaluados. En cuanto al portal de mayor riesgo entre los laterales, se encontro el portal anterior con mayor cercania al nervio cutaneo femoral lateral (1,42±0,85 cm), ubicado lateral al portal. En los portales mediales el portal anterior medial tiene el margen mas estrecho respecto a la arteria femoral (2,14±0,35 cm) lateral al portal, y medial el nervio obturador (0,87±0,62 cm). Los portales laterales tienen un amplio margen de seguridad, el portal con el margen mas reducido es el portal anterior en relacion al nervio cutaneo femoral lateral, presentando un elevado riesgo de lesionarlo, los portales mediales tienen un alto riesgo de lesionar las estructuras neurovasculares femorales y el nervio obturador.

Anthropometric Landmarks for Posterior Cruciate Ligament Reconstruction in Anatomical Position

El proposito del estudio fue determinar referencias anatomicas viables para la correcta colocacion de los tuneles femorales y tibiales en posicion anatomica durante la reconstruccion del ligamento cruzado posterior (LCP). Se utilizaron 10 rodillas, las cuales fueron disecadas para analizar las mediciones de la insercion femoral y tibial del LCP, sus fasciculos y estructuras adyacentes. Se utilizo el sistema de las manecillas del reloj para la medicion de las inserciones femorales. Los meniscos y el ligamento cruzado anterior (LCA) fueron utilizados como referencias para la medicion de las inserciones tibiales. El LCP y las caracteristicas de sus fasciculos correspondientes fueron determinados por su insercion femoral, porcion central e insercion tibial. La media de la longitud entre la porcion central de la huella dejada por el LCP y el margen anterior del cartilago femoral a las 12:00 h fue de (±3.94) y 17,73 mm (±4,11) para la rodilla derecha e izquierda, respectivamente. La longitudes del LCP fueron de 11,94 mm (±5,08) entre el margen posterior del LCP y el margen anterior del LCP. La media fue de 33,52 mm (±3,49) desde el margen medial del menisco lateral al margen lateral del LCP y de 32,24 mm (±2,28) del margen medial del menisco medial al margen medial del LCP. Desde el punto de vision anteroposterior, el fasciculo anterolateral es mayor que el posteromedial tanto en su insercion femoral como en el punto central e insercion tibial. Se analizo una coleccion cuantitativa de bases de datos con distintas variables del LCP, asi como de sus fasciculos y sus inserciones femorales y tibiales. Se obtuvieron varias medidas, indicando la alta funcionalidad compartida por los fasciculos del LCP. Las inserciones reportadas son referencias practicas para la localizacion de los tuneles tibiales y femorales durante la plastia del ligamento cruzado posterior.

Direct withdrawal of a knife in the lumbar spinal canal in a patient without neurological deficit: case report and review of the literature

IntroductionStab-wound injuries to the spinal cord are rare and currently, do not have a well-established management in the literature despite its strong association with neurological injury.Case presentationWe report a case of a patient with a stab-wound injury with a knife in the lumbar region, who underwent direct removal in the operating room without surgical exploration. Upon admission, the patient had no neurological deficit. The X-rays and CT scan before removal showed the involvement of >50% of the intramedullary canal at L2. The removal was performed in the operating room with a surgical team available and ready in case there was neurological deterioration during the procedure.DiscussionWe concluded that any neurologic deficit in a patient with a stab-wound injury in the spine must mandate surgical exploration and in patients without neurological deficit, direct removal of the stabbing object is a safe and effective method without adding the risks of a surgical exploration.

Results of External Fixation and Metatarsophalangeal Joint Fixation With K-Wire in Brachymetatarsia:

Background: Brachymetatarsia is a rare foot deformity caused by the premature closure of the metatarsal physis. It may result in functional as well as cosmetic alterations, which may require operative management. Methods: A prospective study examining outcomes of 48 cases of brachymetatarsia with gradual bone lengthening at a rate of 1 mm/d using an external fixator and metatarsophalangeal joint fixation was performed. The difference between the length before treatment and after external fixator removal was measured. The patients were assessed at 2, 4, 6, and 8 weeks postoperatively; at the end of the period of distraction; and 1 year after surgery. The total number of patients was 26, and surgery was performed in 48 metatarsals. The mean age was 17.0 ± 4.1 (range, 11-24) years, and all were female. Results: The fourth metatarsal was the most frequently affected, representing 98% of the cases; the third metatarsal represented the other 2%. The average length gained was 18.6 ± 6.7 mm, and the average length gained as a proportion of the original metatarsal length was 38.2% ± 3.1% (range, 13%-24%). The mean healing time was 71.0 (range, 64-104) days, and the mean healing index (healing time divided by centimeters of length gained [d/cm]) was 38.4 (range, 38.2-50.1) d/cm. Conclusion: Gradual bone lengthening at a rate of 1 mm/d using an external fixator and intramedullary nailing was a safe and efficient method, representing a minimally invasive procedure with a low incidence of complications and satisfactory results for the patient. Level of Evidence: Level IV, retrospective case series.

Clinical, biomechanical and morphological assessment of anterior cruciate ligament Kevlar®-based artificial prosthesis in rabbit model

Background The aim of this study was to evaluate the clinical, biomechanical and morphological characteristics of a Kevlar®-based prosthetic ligament as a synthetic graft of the anterior cruciate ligament (ACL) in an experimental animal model in rabbits. Methods A total of 27 knees of rabbits randomly divided into 3 groups (control, ACL excision and ACL replacement with a Kevlar® prosthesis) were analyzed using clinical, biomechanical and morphological tests at 6, 12 and 18 weeks postprocedure. Results The mean displacement in mechanical testing was 0.73 ± 0.06 mm, 1.58 ± 0.19 mm and 0.94 ± 0.20 mm for the control, ACL excision and ACL replacement with synthetic prosthesis groups, respectively. The results showed an improvement in the stability of the knee with the use of the Kevlar® synthetic prosthesis in the biomechanical testing (p<0.05) compared with rabbits that underwent ACL excision, in addition to displacements that were larger but comparable to that in the control group (p>0.05), between the replacement group and the control group. The histological study revealed a good morphological adaptation of the synthetic material to the knee. Conclusions This study proposes a new animal model for the placement and evaluation of Kevlar®-based synthetic ACL implants. The studied prosthesis showed promising behavior in the clinical and biomechanical tests and in the histological analysis. This study lays the foundation for further basic and clinical studies of artificial ACL prostheses using this material.

Perineural spread-susceptible structures: a non-pathological evaluation of the skull base

Perineural spread adenoid cystic carcinoma can alter the dimension of foramina and canals of the skull base. The objective of this study was to determine the range of normal variation of the foramina and canals of both hemicranium. We analyzed 200 individuals with no alterations of the skull base in a retrospective manner using high-resolution computed tomography. We measured the short and long axis diameters of the foramen rotundum (FR), foramen ovale (FO), stylomastoid foramen (SMF), pterygoid canal (PTC), internal auditory canal (IAC), and the facial nerve canal in its labyrinthine portion (LPFC) to calculate the area in each hemicranium, compare them and obtain the normal range of asymmetry. Parametric and non-parametric comparison tests were realized. The structures that had the lowest range of asymmetry were the LPFC (0.00–0.79 mm2) and the FR (0.00–2.12 mm2). The one that had the highest asymmetry range was the FO (0.00–9.16 mm2). Significant differences were found in the FO (p = 0.01) and the IAC (p = 0.00) in the gender comparison. We determined a normal asymmetry range of the susceptible foramina and canals of the skull base. This study reports a useful and objective measure to differentiate anatomical from pathological variations of the foramina and canals of the skull base by age and gender. Our results establish a basis for future studies that evaluate this range as a diagnostic tool of metastasis in the skull base as a complement of other imaging techniques.