A comparison of three techniques for the osteosynthesis after minimal invasive osteotomies for hallux valgus.

PURPOSE: Third and fourth-generation minimal invasive osteotomies (MIO) for the treatment of hallux valgus (HV) have become popular procedures worldwide with promising results due to the improvement in the fixation method. The tricortical cannulated screw placement remains a complex procedure that is technically challenging and requires a long skill learning curve with high radiation exposure mainly in the form of intensifier shots (IS) required for the MIO fixation. This study aims to compare the number of X-ray IS required using three different techniques for the cannulated guide placement. METHODS: A retrospective cross-sectional observational and comparative study was conducted to assess the number of X-rays IS required for correct cannulated screw guide placement using three different techniques: traditional perforator, the drill and joystick, and K-wire first techniques. RESULTS: A total of 53 MIS procedures from thirty-one patients in two different hospitals were included. IS X-rays were 155.1 ± 29.7 in the traditional technique (n = 14), 143.0 ± 43.2 in the drill and joystick technique (n = 22), and 85 ± 18.7 in the K-wires first technique (n = 17), p = < 0.001 using one-way ANOVA. CONCLUSIONS: The K-wire first technique statistically significantly decreases X-ray IS numbers p ≤ 0.001. There were no statistically significant differences between the traditional (after osteotomy K-wire placement) and the drill and joystick techniques (p = 0.36).

Gallstone Ileus in a Young Patient: A Clinical Case Report and Literature Review.

Gallstone ileus is a rare presentation of gallbladder disease. It is mostly encountered in female and elderly patients. It occurs when a stone causes a fistula between the gallbladder and the intestinal lumen. More than half of the patients do not have a history of biliary disease. Surgical intervention is still considered the best treatment option; however, the best choice between one-stage and two-stage surgery is still unknown. We present a gallstone Ileus case in a patient with uncommon epidemiological characteristics: a 28-year-old male Hispanic patient without a gallbladder disease history.

Copper induces damage, oxidative stress and cell death in endothelium of chronic intoxicated Wistar rats / El cobre induce daño, estrés oxidativo y muerte celular en el endotelio de ratas Wistar intoxicadas

SUMMARY: Reactive Oxygen Species (ROS) are part of the functional balance of various systems, they can generate cellular damage by oxidative stress associated with disease processes such as atherosclerosis, cardiovascular disease, diabetes, and aging. Some studies report that copper induces damage to the endothelium, which could be associated with cardiovascular pathologies. This study was an experimental comparative, prospective, longitudinal, and controlled clinical trial in a murine animal model. Twenty-four male Wistar rats were included, the distribution of the groups was time-depending chronic exposition to copper, and a control group. Results show gradual alterations in the groups treated with copper: areas with loss of the endothelium, signs of disorganization of smooth muscle fibers in the tunica media, as well as areas with the fragmentation of the elastic sheets. A significant statistical difference was observed in the active- Caspase-3 analysis expression in the aortic endothelium and endothelium of the capillaries and arterioles of the lung between the control group vs 300 ppm of copper. Expression of eNOS was detected in the endothelium of the aorta and vessels of the lung. Our study shows histological changes in the walls of the great vessels of intoxicated rats with copper, and the increment of inflammatory cells in the alveoli of the study model, mainly at a high dose of copper exposition. These results will be useful to understand more about the mediators involved in the effect of copper over endothelium and cardiovascular diseases in chronic intoxication in humans.

RESUMEN: Las Especies Reactivas de Oxígeno (ROS) son parte del equilibrio funcional de varios sistemas, pueden generar daño celular por estrés oxidativo asociado a procesos patológicos como aterosclerosis, enfermedades cardiovasculares, diabetes y envejecimiento. Algunos estudios informan que el cobre induce daños en el endotelio, lo que podría estar asociado a patologías cardiovasculares. Este estudio fue un ensayo clínico experimental comparativo, prospectivo, longitudinal y controlado en un modelo animal murino. Se incluyeron veinticuatro ratas Wistar macho, la distribución de los grupos fue la exposición crónica al cobre en función del tiempo y un grupo de control. Los resultados muestran alteraciones graduales en los grupos tratados con cobre: áreas con pérdida del endotelio, signos de desorganización de las fibras musculares lisas en la túnica media, así como áreas con la fragmentación de las láminas elásticas. Se observó una diferencia estadística significativa en la expresión del análisis de caspasa-3 activa en el endotelio aórtico y el endotelio de los capilares y arteriolas del pulmón entre el grupo de control frente a 300 ppm de cobre. Se detectó expresión de eNOS en el endotelio de la aorta y los vasos del pulmón. Nuestro estudio muestra cambios histológicos en las paredes de los grandes vasos de ratas intoxicadas con cobre, y el incremento de células inflamatorias en los alvéolos del modelo de estudio, principalmente a una alta dosis de exposición de cobre. Estos resultados serán útiles para comprender más sobre los mediadores involucrados en el efecto del cobre sobre el endotelio y las enfermedades cardiovasculares en la intoxicación crónica en humanos.

Relationship of Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratio With Visual Acuity After Surgical Repair of Open Globe Injury.

Purpose: To assess the relationship and prognostic value of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) with poor final best-corrected visual acuity (BCVA) after surgical repair of open globe injuries (OGI) in adults. Design: Retrospective analysis of data from an ongoing prospective cohort of consecutive patients. Methods: In a tertiary university hospital, 197 eyes of 197 patients were included between 2013 and 2017. NLR and PLR were obtained from pre-operative blood tests to analyze its relationship with poor final BCVA. Results: Severe visual impairment (SVI) was defined as ≤20/200, and was observed in 96 (48.7%) patients after surgical repair of OGI. SVI patients had higher NLR (7.4 ± 6.6 vs. 4.0 ± 3.2, p < 0.001), and PLR (167 ± 92 vs. 139 ± 64; p = 0.021) than non-SVI. NLR ≥ 3.47 and PLR ≥ 112.2 were the best cut-off values for SVI, were univariate risk factors for SVI, and had sensitivity: 69.0, 71.4, and specificity: 63.6, 44.8, respectively. In multivariate analysis, only OTS, athalamia, and hyphema remained as risk factors. NLR had significant correlation with ocular trauma score (OTS) (r = -0.389, p < 0.001) and final BCVA (r = 0.345, p < 0.001). Limitations: Simultaneous trauma in other parts of the body that could influence the laboratory findings. Conclusion: Patients with SVI after a repaired OGI had increased pre-operative NLR and PLR levels. High NLR and PLR are risk factors for SVI in univariate analysis. It is confirmed that low OTS is a risk factor for SVI. High NLR and PLR could be used as a prognostic tool to identify patients at higher risk for SVI after repair of OGI.

Hyaluronic Acid Embolism Treated with Subcutaneous High and Low Hyaluronidase Doses: Efficacy and Surrounding Tissue Effect.

BACKGROUND: The use of hyaluronidase in hyaluronic acid vascular occlusion has been evaluated; however, the models used do not accurately assimilate the facial morphologic characteristics or study the effects on adjacent tissues. The purpose of this study was to determine an effective concentration of subcutaneous hyaluronidase to dissolve a hyaluronic acid embolism and its effect on surrounding tissue. METHODS: Fifteen rabbits were divided into six groups. An inguinal incision was performed on the femoral artery to create a hyaluronic acid embolism in the control and treatment groups (low-, medium-, and high-hyaluronidase groups). Hyaluronidase was injected subcutaneously. Photographic follow-up, histologic analysis, and quantification of hyaluronic acid were performed. Kruskal-Wallis test and post hoc with Bonferroni correction (p < 0.05) was used to compare the presence of hyaluronic acid in the arterial lumen between groups. RESULTS: Despite the persistence of intravascular hyaluronic acid, macroscopic and microscopic differences were found between the embolism control group and embolism hyaluronidase high-dose group. Histologic analysis demonstrated thrombosis throughout groups. Skeletal muscle was least affected in the embolism hyaluronidase 500 IU group with less lysis and inflammatory infiltrate. CONCLUSIONS: A 500 IU hyaluronidase dose partially prevents the damage caused by the embolism, and does not affect the surrounding tissue. The use of thrombolytic therapy combined with higher doses of hyaluronidase subcutaneously in this model is proposed.

Anatomical and positional variants of the brachiocephalic trunk in a Mexican population.

BACKGROUND: Brachiocephalic trunk (BCT) variants may have a clinical impact during surgical procedures, some of which could be fatal. The objective of this study was to classify height positions of the BCT and report their prevalence in a Mexican population. METHODS: Patients: A retrospective, descriptive, observational, and cross-sectional was performed using computed tomography angiography (CTA) of adult (> 18 years of age) patients, without gender distinction, of Mexican origin. Measuring techniques were standardized using the suprasternal notch to analyze linear and maximum heights, linear and curved lengths, and the vertebral origin and bifurcation levels of the BCT. RESULTS: A total of 270 CTA were obtained (66.7% men and 33.3% women). A high position of BCT was present in 64.81% (n 175/270). The mean linear medial height was 0.58 ± 1.91 cm, the maximum height of the free edge was 3.85 ± 2.04 cm, side length of the midline at the maximum height of the free edge was 1.46 ± 2.59, linear length 3.72 ± 0.70, and a curve length 3.99 ± 0.79. The BCT origin was most predominant at the T3 (57.9%) and T4 (27.0%) vertebral levels, with the bifurcation at T2 (57.9%) and T1 (36.2%). CONCLUSIONS: There is a high prevalence of high position BCT in our population. Patients should be assessed before any procedures in the area, due to the potential risk of complications.

Localized gallbladder perforation: a systematic review of treatment and prognosis.

BACKGROUND: The optimal management of localized gallbladder perforation (Neimeier type II) has yet to be defined. The aim of this systematic review was to identify factors associated with improved patient outcomes. METHODS: Systematic review of studies that described the management of Neimeier type II perforation, reported complications of the first intervention, necessity of added interventions, resolution of the pathology, and days of hospital stay were included. The search strategy was conducted in EMBASE, Mayo Journals, MEDLINE, SCOPUS, and Web of Science (December 2020) RESULTS: A total of 122 patients (53% male) from case reports, series, and cohorts were included for analysis. In total 56 (46%) and 44 (36%)patients were treated with open and laparoscopic cholecystectomy respectively. Overall risk of bias was moderate. The need for another intervention was higher in the laparoscopic group (5 vs 17, p=<0.001) as well as prevalence of complications (4 vs 16, p=<0.001), but lower for days of hospital stay (median days 5. vs 15, p = 0.008) against open cholecystectomy. Preoperative percutaneous catheter drainage did not influence outcome. CONCLUSION: Open cholecystectomy has a lower need for further surgical procedures and postoperative complications, but a longer hospital stay. These outcomes did not vary with preoperative percutaneous drainage. The effect of timing of cholecystectomy did not influence the outcomes.

Prevalence of Morphological Variations Associated With Femoroacetabular Impingement According to Age and Sex: A Study of 1878 Asymptomatic Hips in Nonprofessional Athletes.

BACKGROUND: Radiographic findings related to the cam and pincer variants of femoroacetabular impingement (FAI) include measurements of the alpha angle and lateral center-edge angle (LCEA). The function of these radiographic findings has been put into question because of high heterogeneity in reported studies. PURPOSE: The aim of this study was 3-fold: (1) to determine the prevalence of cam and pincer variants according to sex and age on anteroposterior (AP) pelvic radiographs from an asymptomatic nonathletic population, (2) to identify the most common radiographic signs of cam- and pincer-type variants, and (3) to determine if there are variations in the prevalence of these radiographic signs according to sex and age. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: There were 3 independent observers who retrospectively analyzed the 939 AP pelvic radiographs (1878 hips) of patients aged 18 to 50 years who did not have hip symptoms and who were not professional athletes. The prevalence of the cam and pincer variants according to the alpha angle and LCEA, respectively, and the presence of other radiographic signs commonly associated with these variables were determined in the overall population and by subgroup according to sex and age group (18-30, 31-40, and 41-50 years). Descriptive and inferential statistics were used to analyze the study sample. RESULTS: The mean age of the included population was 31.0 ± 9.2 years, and 68.2% were male. The prevalence of the cam-type variant was 29.7% (558/1878), and that of the pincer-type variant was 24.3% (456/1878). The radiographic signs that were most associated with the cam and pincer variants were a pistol-grip deformity and the crossover sign, respectively. Significant differences (P < .001) in the prevalence of these variants were identified between men and women in both variants. No differences were observed in the alpha angle or LCEA according to sex or age. CONCLUSION: Radiographic findings suggestive of FAI had significant variations with respect to sex and age in this study sample. This study provides information to determine the prevalence of these anatomic variants in the general population.

The morphology of the tibial footprint of the anterior cruciate ligament changes with ageing from oval/elliptical to C-shaped.

PURPOSE: To further the current understanding of the modifications of the morphology of the ACL tibial footprint in healthy knees during the ageing process. The hypothesis is that there are differences in the morphology of the ACL tibial footprint between the cadavers of the young and elderly due to a degenerative physiological process that occurs over time. METHODS: The tibial footprint of the ACL was dissected in 64 knee specimens of known gender and age. They were divided into four groups by age and gender, setting 50 years of age as the cut-off point. Three observers analyzed the tibial footprint dissections and the shape was described and classified. RESULTS: The knees from the cadavers of males older than 50 years of age presented a "C" morphology in 85% of the cases. In the group of males aged less than 50 years, an oval/elliptical morphology was found in 85.7% of the cases. In the group of women over 50 years-old, the "C" morphology was observed in 82.3% of the cases. In women under the age of 50, the oval/elliptical morphology was found in 84.6% of the cases. A significant difference was observed between the prevalence rates of the morphologies of the younger and older groups (p < 0.001 for both genders). However, no differences were observed between males and females of the same age group (n.s.). CONCLUSIONS: The morphology of the tibial footprint of the ACL presents significant variations with ageing. It can go from an oval/elliptical shape to a "C" shaped morphology. The results of this work make for an advance in the individualization of ACL reconstruction based on the age and the specific morphology of the tibial footprint.

Modifications to the delivery of a gross anatomy course during the COVID-19 pandemic at a Mexican medical school

The Coronavirus disease was declared a pandemic this year, causing an impact on medical education. Following the World Health Organization's (WHO) recommendations, Universities around the world implemented social distancing and the use of online platforms. Anatomists lead medical students, most of which are part of Generation Z. Different technological tools have been used in the gross anatomy course in combination with face-to-face classes, but now are forced to move exclusively online. The Human Anatomy Department in the Medical School of the Universidad Autonoma de Nuevo León (UANL) implemented asynchronous sessions as a short-term resolution, transformed to synchronous sessions as the pandemic progressed. It is important to consider the adaptability of the student, the near-peer teacher, and academic staff, with the creation of innovative ideas to facilitate the learning for the student and to maintain the quality of the course. Their role in this modality should be assessed, as it may change medical education and the way to teach in the future for the new generation of medical students. Professors' roles are changing and it is necessary to adapt to new situations

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Avoiding iatrogenic injuries to the vertebral artery: A morphometric study of the vertebral artery-free dissection area.

OBJECTIVE: To determine the area of a safety window that excludes the vertebral artery for the safe access of the occipital condyle screws during occipitocervical fixation. METHODS: This study included 138 cervical computed tomography angiograms. Six measurements per side were made in each imaging study. These measurements are from the vertebral artery to (A) the mastoid process, (B) the mastoid incisura, (C) the posterior condylar fossa, (D) the occipital condyle in its midline, and (E) the medial border of the condyle. We also measured from the tip of the mastoid process to the lower border of the occipital condyle on its lateral side (F). RESULTS: A total of 276 areas from 138 individuals were included, of which 51.4 % were men. The mean age was 54.2 ±â€¯18.63 years. The mean variable measurements (mm) for all the population were 21 ±â€¯4, 16 ±â€¯3, 6 ±â€¯2, 3 ±â€¯2, 2 ±â€¯1 and 35 ±â€¯4 for variables A-F, respectively. We found significant differences between sex when we compared measurements A (p = 0.003), C (p = 0.001), D (p = 0.000) and F (p = 0.000). The incidence rate of dominance for the vertebral artery was 18.8 % and 30.4 % for right and left respectively. CONCLUSION: Women had significantly smaller measures than men. This could indicate a higher risk of iatrogenic injury secondary to a smaller vertebral artery-free area. Results may guide surgeons in the pre-surgical planning aiming to reduce the risk of iatrogenic injuries to the vertebral artery.

Anatomical variations of the acromial and coracoid process: clinical relevance.

PURPOSE: The acromial and coracoid process morphology is of clinical relevance due to associations with functional limitations and shoulder pathology. Our objective was to describe the anatomical characteristics of the acromial and coracoid process using computed tomography (CT). METHODS: Descriptive, observational, transversal and retrospective study. A total of 155 CT of patients without shoulder pathology, of both genders, and indistinct age were evaluated and grouped by age: Group 1 < 25 years; group 2 25-40 years; group 3 > 40 years. The following parameters were evaluated: Acromial type (AcT), vertical coracoid distance (VCD), acromial tilt (AT), acromial projection (AP), critical shoulder angle (CSA), type of the subcoracoid outlet (TSO), and the area of the subcoracoid outlet (ASO). RESULTS: Statistically significant differences were found between men and women for VCD (14.44 ± 4.79 vs. 11.76 ± 4.00 mm; p < 0.001) and AP (3.66 ± 4.71 vs. 1.62 ± 4.99 mm; p < 0.05) as well as between age groups 1 and 3 for AT (35.08 ± 11.53 vs. 28.41 ± 6.60; p < 0.05) and ASO (398.99 ± 153.91 vs. 255.56 ± 124.58 mm2; p < 0.001). An unexpected high ASO variation was identified with 11% of S-shaped acromion and 1.3% clock-shaped TSO. CONCLUSION: The age group between 25-40 years had the most uniform distribution of data. There is a high morphological variability present in an asymptomatic population, which should be considered in the clinical assessment such as shoulder impingement syndrome.

Polymorphic eruption of pregnancy in Mexico.

BACKGROUND: Currently, the exact incidence of Polymorphic Eruption of Pregnancy (PEP) in the Mexican population is unknown. PEP tends to manifest in the abdomen, primarily in the stretch marks caused by distension. It is characterized by severely pruritic urticarial-like papules that converge in plaques, extending to the buttocks and proximal thighs. Our study determined its incidence, along with other common dermatoses in pregnancy. METHODS: Patients between 14 and 45 years of age were evaluated. In each patient, a complete medical history and physical examination was performed with emphasis on skin and adnexa. Patients were followed until the end of their pregnancy. RESULTS: A total of 217 women were included. PEP was identified in three patients (1.38%), all primigravida, with single fetus pregnancy, and all concluded their pregnancy by vaginal delivery. The neonates were 2 females and 1 male. No other gestational pathologies were identified. CONCLUSIONS: We identified a higher incidence of PEP than reported, without association to complications or need for medical management. There may be an association between high maternal weight and the presence of PEP, however a larger sample is needed.

Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials.

PURPOSE: Osteoarthritis (OA) is one of the most common causes of disability and a prevalent chronic disease. The use of collagen is growing due to the satisfactory results in the treatment of OA. However, the possible beneficial effects of collagen for the treatment of OA are currently controversial. The aim of the present meta-analysis was to evaluate the effect of collagen-based supplements on OA symptoms. METHODS: PubMed-Medline, Scopus, and Google Scholar databases were searched for randomized placebo-controlled trials evaluating the effect of orally administered collagen on OA symptoms using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale and/or the Visual Analog Scale (VAS). Meta-analysis was conducted using a random-effects model and a generic inverse variance method. Heterogeneity was tested using the I2 statistic index. RESULTS: Collagen treatment showed a significant reduction in the score of total WOMAC index (WMD - 8.00; 95% CI - 13.04, - 2.95; p = 0.002). After subgroup analysis of the WOMAC subscores, the collagen supplementation revealed a significant decrease in the stiffness subscore (WMD - 0.41; 95% CI - 0.74, - 0.08; p = 0.01), whereas the pain (WMD - 0.22; 95% CI - 1.58, 1.13; p = 0.75) and functional limitation (WMD - 0.62; 95% CI - 5.77, 4.52; p = 0.81) subscores did not have significant differences. Finally, a significant reduction was found in the VAS score after collagen administration (WMD - 16.57; 95% CI - 26.24, - 6.89; p < 0.001). CONCLUSION: The results of this meta-analysis showed that collagen is effective in improving OA symptoms by the decrease of both total WOMAC index and VAS score.

Anatomía morfométrica de importancia clínica del atlas en relación a la estabilización del complejo atlantoaxial y occipitocervical / Morphometric anatomy of clinical importance of the atlas in relation to the stabilization of the atlantoaxial and occipitocervical complex

RESUMEN: Evaluar de manera integral los parámetros morfométricos de la vértebra atlas (C1) en la población mexicana de relevancia en la realización de procedimientos quirúrgicos de la unión craneocervical con el fin de proveer datos cuantitativos indispensables para su realización. Para este estudio se utilizaron un total de 576 vértebras C1 secas de población mexicana contemporánea. Se realizaron 11 mediciones respecto a la morfología de C1. Las mediciones se efectuaron bilateralmente utilizando un vernier digital milimétrico con una precisión de 0,01 milímetros y se aplicó un análisis estadístico. Un total de 576 vértebras atlas (C1), fueron medidas de manera bilateral, todas nuestras mediciones se reportaron en milímetros. El promedio del ancho de las masas lateral fue de 14,87 mm ± 1,38 mm. El promedio de la altura de las masas laterales fue de 4,05 mm ± 0,93 mm. El promedio del ancho del foramen transverso fue de 5,93 mm ± 0,98 mm. El promedio del largo del foramen transverso fue de 6,96 mm ± 0,98 mm. El promedio de la altura del foramen transverso fue de 5,76 mm ± 1,31 mm. El promedio del ancho del surco de la arteria vertebral fue de 18,87 mm ± 1,3 mm. El promedio de la distancia entre la línea media y el margen medial del surco de la arteria vertebral sobre la superficie anterior del arco posterior de C1 en su cara superior fue de 12,47 mm ± 3,14 mm. El promedio de la distancia entre la línea media y el margen medial del surco de la arteria vertebral sobre la superficie posterior del arco posterior de C1 en su cara superior fue de 18,75 mm ± 3,94 mm. El promedio de la distancia entre la línea media y el margen lateral del surco de la arteria vertebral sobre la superficie anterior del arco posterior de C1 en su cara superior fue de 19,7 mm ± 2,52 mm. El promedio de la distancia entre la línea media y el margen lateral del surco de la arteria vertebral sobre la superficie posterior del arco posterior de C1 en su cara superior fue de 29,52 mm ± 3,23. Nuestro estudio demuestra que las mediciones realizadas en nuestra población presentan diferencias significativas respecto a lo reportado actualmente en la literatura. Es necesario contar con un conocimiento de la morfología vertebral en nuestra población para disminuir la ventana de error al realizar procedimientos quirúrgicos que involucren este segmento.

SUMMARY: To evaluate in an integral way the morphometric parameters of the atlas (C1) vertebra in the Mexican population of relevance in performing surgical procedures of the craniocervical junction in order to provide quantitative and essential data for its realization. For this study, a total of 576 dry C1 vertebrae of contemporary Mexican population were used. Eleven measurements were carried out regarding the morphology of C1. The measurements were made bilaterally using a millimeter digital vernier with an accuracy of 0.01 millimeters and a statistical analysis was applied. A total of 576 atlas vertebrae (C1) were measured bilaterally, all our measurements were reported in millimeters. The average width of the lateral masses was 14.87 mm ± 1.38 mm. The average height of the lateral masses was 4.05 mm ± 0.93 mm. The average width of the transverse foramen was 5.93 mm ± 0.98 mm. The average length of the transverse foramen was 6.96 mm ± 0.98 mm. The average height of the transverse foramen was 5.76 mm ± 1.31 mm. The average width of the groove of the vertebral artery was 18.87 mm ± 1.3 mm. The average distance between the midline and the medial edge of the vertebral artery groove on the anterior surface of the posterior arch of C1 on its superior surface was 12.47 mm ± 3.14 mm. The average distance between the midline and the medial border of the vertebral artery groove on the posterior surface of the posterior arch of C1 on its upper face was 18.75 mm ± 3.94 mm. The average distance between the midline and the lateral border of the vertebral artery groove on the anterior surface of the posterior arch of C1 on its superior surface was 19.7 mm ± 2.52 mm. The average distance between the midline and the lateral border of the vertebral artery groove on the posterior surface of the posterior arch of C1 on its superior surface was 29.52 mm ± 3.23. Our study shows that the measurements made in our population present differences with respect to what is currently reported in the literature. It is necessary to have knowledge of vertebral morphology in our population to reduce the error window when performing surgical procedures involving this segment.

Análisis morfométrico del axis para la fijación atlantoaxial / Morphometric analysis of the axis for atlantoaxial fixation

El objetivo de este estudio fue evaluar de manera integral los parámetros morfométricos de la vértebra axis (C2) en la población mexicana involucrados en la realización de procedimientos quirúrgicos con el fin de proveer datos cuantitativos indispensables en su abordaje quirúrgico. Para este estudio se utilizaron un total de 576 vértebras axis (C2) de población mexicana contemporánea. Las mediciones de las vértebras se efectuaron bilateralmente utilizando un vernier digital milimétrico con una precisión de 0.01 mm (Mitutoyo Digimatic w/Absolute Encoders- Series 500). Un total de 576 vértebras axis (C2), fueron medidas de manera bilateral, todas nuestras mediciones se reportaron en mm. El promedio del ancho del pedículo fue de 8,96 mm con una DE ± 2,11 mm. El promedio de la altura del pedículo fue de 10,82 mm con una DE de ± 1,89 mm. El promedio de la altura del proceso odontoideo fue de 16,90 mm con una DE de ± 2,99 mm. El promedio del ancho del proceso odontoideo fue de 9,99 mm con una de DE de ± 0,80 mm. El promedio del diámetro de la faceta articular fue de 8,44 mm con una DE de ± 1,04 mm. El promedio del diámetro AP del cuerpo vertebral fue de 15,11 mm con una DE de ± 1,88 mm. El promedio del diámetro trasverso del cuerpo vertebral fue de 17,93 mm con una DE de ± 2,22 mm. El promedio de la altura del cuerpo vertebral fue de 18,54 mm con una DE de 2,38 mm. El promedio de la altura de las láminas fue de 11,53 mm con una DE de ± 1,39 mm. El promedio del ancho de las láminas fue de 6,10 mm con una DE de ± 1,44 mm. Los resultados obtenidos en nuestras mediciones demuestran una variación con los resultados de otros autores en diferentes estudios de piezas osteológicas y de estudios de imagen del axis (C2), lo que sugiere, con el fin de reducir los riesgo de daño a estructuras neurovasculares, utilizar técnicas y medidas especiales para la estabilización atlantoaxial de la población mexicana.

The aim of the study was to evaluate the morphometric parameters of the axis vértebra (C2) in the Mexican population involved in the performance of surgical procedures in order to provide essential quantitative data in their surgical approach. A total of 576 axis vertebrae (C2) of contemporary Mexican population were used for this study. The measurements of the vertebrae were made bilaterally using a millimeter digital vernier with an accuracy of 0.01 millimeters (Mitutoyo Digimatic w / Absolute Encoders - Series 500). A total of 576 axis vertebrae (C2) were measured bilaterally, all our measurements were reported in millimeters. The average width of the pedicle was 8.96 mm with a SD ± 2.11 mm. The average height of the pedicle was 10.82 mm with a SD of ± 1.89 mm. The average height of the odontoid process was 16.90 mm with a SD of ± 2.99 mm. The average width of the odontoid process was 9.99 mm with a SD of ± 0.80 mm. The average diameter of the articular facet was 8.44 mm with a SD of ± 1.04 mm. The average diameter of the AP of the vertebral body was 15.11 mm with a SD of ± 1.88 mm. The average transverse diameter of the vertebral body was 17.93 mm with a SD of ± 2.22 mm. The average height of the vertebral body was 18.54 mm with a SD of 2.38 mm. The average height of the lamina was 11.53 mm with a SD of ± 1.39 mm. The average width of the lamina was 6.10 mm with a SD of ± 1.44 mm. The results obtained in our measurements show a variation with the results of other authors in different studies of osteological pieces and studies of the axis image (C2), which suggests the use of techniques and special measures for the atlantoaxial stabilization of the Mexican population in order to reduce the risk of damage to neurovascular structures.

Variations in the Torg-Pavlov cervical ratio with regard to age and sex: a comprehensive anatomical and morphometric study on contemporary cadaveric specimens / Variaciones en el índice de Torg-Pavlov cervical respecto a edad y sexo: un exhaustivo estudio anatómico en una población contemporánea

The Torg-Pavlov ratio is a method used to detect cervical stenosis. A Torg-Pavlov ratio ≤0.80 suggests significant stenosis. This ratio is obtained by dividing the anteroposterior diameter of the cervical canal by the anteroposterior diameter of the vertebral body. The aim of this study was to evaluate these parameters and determine if there are significant differences with respect to sex and age. This is an anatomical and comparative study in which 1020 cervical vertebrae from C2-C7 from an osteological collection were evaluated. We determined the anteroposterior diameter from the vertebral body, the anteroposterior diameter from the vertebral canal and the Torg-Pavlov ratio. The pieces studied were divided into groups according to sex and age, resulting in six groups of study. A statistical analysis was made to determine the significance of the differences between sex and age groups. The size of the vertebral body diminished form C2-C3 and increased from C4-C7. The canal diminished form C2-C4 and increased from C5-C7. The Torg-Pavlov ratio decreased from C2-C7. The body and the canal were higher in men, while the Torg-Pavlov ratio was higher in women. With age, in men, the size of the body increased, the canal maintained its size, and the Torg-Pavlov ratio diminished significantly. In the group of women ≥60 years, the size of the body decreased, and the canal and the Torg-Pavlov ratio increased. In men, the Torg-Pavlov ratio is determined by the vertebral body and canal, because these did not show differences in most of the age groups. While in women, it is determined mostly by the spinal canal because it presented more variability between the age groups.

El Índice de Torg-Pavlov se utiliza para la detección de estenosis del canal cervical. Un resultado ≤0.80 indica estenosis significativa. Se obtiene dividiendo el diámetro anteroposterior del canal cervical entre el diámetro anteroposterior del cuerpo. El objetivo de este estudio fue evaluar estos parámetros y determinar si existen diferencias significativas en relación con el sexo y la edad. Se realizó un estudio anatómico y comparativo, en el que se incluyeron 1020 vértebras cervicales de C2-C7 tomadas de una colección osteológica. Se determinó el diámetro anteroposterior del cuerpo vertebral, el diámetro anteroposterior del canal vertebral y el Índice de Torg-Pavlov. Las piezas evaluadas se dividieron en grupos de acuerdo al sexo y la edad, resultando en seis grupos de estudio. Se realizó un análisis estadístico para determinar si existían diferencias significativas entre estos grupos. El tamaño del cuerpo vertebral disminuyó de C2-C3 y aumentó de C4-C7. El canal disminuyó de C2-C4 y aumentó de C5-C7. El Índice de Torg-Pavlov disminuyó de C2-C7. El cuerpo y el canal vertebral fueron mayores en los hombres, mientras que el Índice de Torg-Pavlov fue mayor en las mujeres. Con la edad, en los hombres, el tamaño del cuerpo vertebral aumentó, el canal mantuvo su tamaño y el Índice de Torg-Pavlov disminuyo significativamente. En el grupo de mujeres ≥60 años, el tamaño del cuerpo disminuyó y el canal y el Índice de Torg-Pavlov aumentaron. En los hombres, el tamaño del cuerpo y el canal vertebral determinan el Índice de Torg-Pavlov, ya que estos no mostraron diferencias en la mayoría de los grupos de edad. Mientras que, en las mujeres, este está determinado principalmente, por el canal vertebral, porque este parámetro presento más variabilidad entre los grupos de edad.