There are many difficulties a student or educator can present in the anatomy course. Technological advances and availability of new tools have provided alternatives to improve the learning method.
A ...3D model of an orbit and ocular globe (OG) was designed and 3D printed. It consisted of a roof, floor, medial and lateral walls, and a posterior wall. The superior and inferior orbital fissures were represented, as well as the common tendinous ring (Zinn's) and the optic canal from which a cylindrical axis extends in a 45° angle, representing the optic nerve (ON). At the end of this axis, a sphere an enarthrosis sphere simulates the OG. The medial wall is parallel to the OG’s axis, while the lateral wall is almost parallel to the ON’s axis. The OG was formed with polygons to allow better perception of the movements. The center of the sphere attached to the ON matches the center of the OG, resulting in the OG rotating without moving within the orbit.
Six holes were made in the OG, in which elastic threads were placed. In the anterior half of the OG, a hole for the superior, inferior, medial and lateral surfaces was made, corresponding to the insertions of the superior rectus (SR), inferior rectus (IR), medial rectus (MR), and lateral recti muscles (LR) respectively. On the lateral surface of the posterior half of the OG, a hole in the superior region was made for the insertion of the superior oblique (SO) and another in the inferior region for the insertion of the inferior oblique (IO). The four rectus muscles originate from the annulus of Zinn, and represented with holes that cross the posterior wall of the orbit in the common tendinous ring at the four points of insertion.
In the medial wall of the orbit, at the superior anterior corner, a trochlea was made, through which the thread representing the SO passes and is anchored to the posterior wall through a hole that is superior to the hole for the SR. On the same wall, but in the interior anterior corner of the orbit, we designed a hole to anchor the thread that represents the IO. The angles between the axes of the oblique muscles, recti muscles, and the axis of the OG were kept as close to reality as possible. In the model, the axis between the recti muscles and the OG’s is 20° (human orbit is 23°) and between the oblique muscles and the OG’s is 70° (human orbit is 51°).
The design allows an internal rotation when tightening the threads that are inserted in the superior half of the OG (SR, SO); if the inferior half are tightened (IR, IO), it causes an external rotation; if the recti are tightened, adduction occurs (except for the LR); if those representing the obliques and the LR are tightened, an abduction occurs; if those inserted in the anterior half of the OG (SR, IR, MR, LR) are tightened, the movement corresponding to its name is produced, and if those inserted in the posterior half are tightened, the movement occurs opposite to what their names indicate (SO, IO).
The model is effective and makes learning easier. Student perception has not been surveyed yet. Future version may improve the angle between the oblique’s and the OG’s axis. Pathological finding can also be exemplified.
Introducción y objetivos: La introducción de plantas exóticas para uso ornamental representa un riesgo de invasión para los ecosistemas. Cenchrus advena, C. longisetus y C. setaceus son gramíneas ...introducidas como ornamentales y altamente cultivadas en el centro-norte de Argentina, aunque se desconoce su estado en el proceso de invasión. En este trabajo se registra la presencia de estas tres especies, se actualiza su taxonomía, nomenclatura y morfología. Además, se presentan mapas de presencia y una clave para diferenciarlas de sus congéneres, tanto nativas como exóticas. Se analiza el estado de invasión y se discuten recomendaciones de manejo.
M&M: Se estudiaron ejemplares de herbario, nuevas poblaciones de plantas cultivadas y naturalizadas y se recopiló información de bases de datos digitales de acceso abierto.
Resultados: Se encontraron 158 registros de las tres especies distribuidos en 11 provincias, que permitieron citar por primera vez a C. setaceus para la Flora Argentina. Se halló una alta proporción de registros naturalizados de C. setaceus y C. longisetus. Ambas especies presentaron individuos establecidos en ambientes naturales disturbados de Córdoba, iniciando su propagación como invasoras. Cenchrus advena fue únicamente hallada bajo cultivo.
Conclusiones: El comportamiento invasor de los pastos C. longisetus y C. setaceus hallado en Córdoba podría estar replicándose en otras provincias debido al elevado nivel de cultivo y a la susceptibilidad ambiental. Por ende, es urgente frenar su cultivo, monitorear las poblaciones naturalizadas e invasoras y reemplazar su cultivo por especies nativas en el marco de objetivos sustentables y reglamentaciones vigentes.
Acquisition of Basic Surgical Skills (BSS) are essential for medical students. The objective was to determine it's fidelity impact.
Using four suturing models (SM) (pigskin, sponge, commercial pad, ...and orange), SM-quality and student-SM interaction were evaluated. After a 1-h class, participants were divided into groups and randomly assigned exercises in SM in 15-min intervals. The experiment included completing three individual simple stitches and a 3-stitch continuous suture in each SM.
Eighty-two medical students participated. Suturing quality was better in pigskin and sponge, which were also the preferred models (p < 0.001). Significant differences in quality between the insertion and exit point, and firmness of knots (p < 0.05) in both simple and continuous sutures, as well as between length and distance in continuous ones (p < 0.001) were identified.
Acquisition and quality of BSS are influenced by the intrinsic characteristics of SM. An adequate degree of resistance, consistency, and elasticity are necessary.
Purpose
To identify, describe, and compare the prevalence of sacroiliac joint anatomical variants.
Methods
A retrospective study was performed on computed tomography scans. Joint space was measured, ...and variants were classified as accessory joint, ileosacral complex, bipartite bony plate, semicircular defect, iliac bony plate, and ossification centers.
Results
400 scans were analyzed. Mean age was 49 years, 180 men (45%), and 220 women (55%). 209 (52.2%) patients presented an anatomical variant with higher prevalence in women (65.4% vs 36.2%), and those older than 40 years of age (60% vs 40%). Mean joint space was similar bilaterally (right 2.41 ± 0.65 mm vs. left 2.37 ± 0.65 mm). Prevalence was: 19.8% accessory joint, 6.5% ileosacral complex, 12.3% bipartite bony plate, 8% semicircular defect, 5% iliac bony plate, and 0.8% for ossification centers.
Conclusion
Prevalence of anatomical variants of the SIJ is higher in the Hispanic population, women, and those older than 40 years.
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).
Purpose
The rotator cuff transverse force couple (RCTFC) is fundamental in the shoulder biomechanics, as the balance of its muscle components (the subscapularis relative to the infraspinatus and ...teres minor) provides stability to the joint. The chronic progression of rotator cuff tears usually present alterations in muscle volume, along with atrophy and compensatory hypertrophy, which can be determined using imaging techniques. The aim of this study was to quantify RCTFC muscle volume in a large sample taking into account the age and gender of the participants involved.
Methods
An observational, retrospective, cross-sectional, descriptive and comparative study was conducted, evaluating thoracic computed tomography scans from 152 patients (304 shoulders) of indistinct gender, with ages ranging between 18 and 85 years. The RCTFC muscle volume was quantified with an oblique/multiplanar segmentation technique. Measuring time was also documented.
Results
We observed that muscle volume decreases among the different age (
p
< 0.04) and gender (
p
< 0.001) groups. However, the RCTFC volume ratio remained constant at 1.02 ± 0.18 without significant differences throughout all age and gender groups evaluated (
p
> 0.298).
Conclusion
The decrease in the RCTFC muscle volume is proportional during the different stages of life, maintaining a constant ratio between its components (physiological RCTFC muscle atrophy). The time-saving segmentation method and volume ratio formula proposed in this study contribute to the management and understanding of rotator cuff tear/pathology.
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