Estudio morfométrico del radio proximal en una población chilena / Morphometric study of the proximal radius in a Chilean population

RESUMEN: El objetivo de esta investigación fue determinar la morfometría del extremo proximal del radio, mediante mediciones efectuadas en la cabeza, cuello y tuberosidad del radio, en una población chilena y compararlas según sexo. Se efectuó un estudio transversal analizando exámenes de Tomografía Computarizada (TC) de codo, realizados entre enero de 2014 y diciembre de 2018. Se incluyó 32 TC, correspondientes a 16 hombres y 16 mujeres. Se transfirió las imágenes formateadas al software RadiAnt, para efectuar las mediciones en el radio proximal. El análisis estadístico de los resultados se realizó mediante el software SPSS 22. El diámetro de la cabeza del radio en hombres osciló entre 22,8±1,3 y 25,0±1,7 mm; en mujeres osciló entre 19,4±1,4 y 20,7±1,4 mm. El diámetro del cuello del radio proximal en hombres osciló entre 14,0±0,8 y 15,6±0,7 mm; en mujeres osciló entre 11,7±0,8 y 13,3±1,3 mm. El diámetro del cuello del radio distal en hombres osciló entre 14,4±1,0 y 16,0±1,2 mm; en mujeres osciló entre 12,5±1,0 y 13,8±1,5 mm. El diámetro de la tuberosidad radial en hombres osciló entre 15,1±1,5 y 17,7±1,8 mm; en mujeres osciló entre 13,2±1,1 y 15,5±1,8 mm. El promedio de altura de la cabeza del radio fue de 11,2±1,2 mm en hombres y de 9,5+0,8 mm en mujeres. El análisis comparativo entre sexos mostró diferencias estadísticamente significativas en todas las mediciones precedentes. El promedio de altura del cuello del radio fue de 11,2±1,2 mm en hombres y 10,1±1,6 mm en mujeres, sin diferencia significativa (p= 0,15). Los valores promedios de la morfometría del radio proximal de la población chilena difieren de los descritos para la población europea y presentan algunas similitudes con la población china. Nuestros resultados pueden ser de utilidad para el diseño de implantes y prótesis para el extremo proximal del radio y para una correcta planificación quirúrgica en ortopedia y traumatología.

SUMMARY: The aim of this research was to determine the morphometry of the proximal radius in a Chilean population, by means of measurements made in head of radius, neck of radius and radial tuberosity, and to compare them according to sex. A cross-sectional study was conducted analyzing Computed Tomography scans (CT) of elbows, performed between January 2014 and December 2018. Thirty-two CT corresponding to 16 men and 16 women were included. The formatted images were transferred to the RadiAnt software in order to perform measurements in the proximal radius. The statistical analysis of the results was performed using the SPSS 22 software. The diameter of the head of radius in men ranged between 22.8±1.3 and 25.0±1.7 mm; in women it ranged between 19.4±1.4 and 20.7±1.4 mm. The diameter of the proximal neck of radius in men ranged between 14.0±0.8 and 15.6±0.7 mm; in women, it ranged between 11.7±0.8 and 13.3±1.3 mm. The diameter of the distal neck of radius in men ranged between 14.4±1.0 and 16.0±1.2 mm; in women, it ranged between 12.5±1.0 and 13.8±1.5 mm. The diameter of radial tuberosty in men ranged between 15.1±1.5 and 17.7±1.8 mm; in women, it ranged between 13.2±1.1 and 15.5±1.8 mm. The mean height of the head of radius was 11.2±1.2 mm in men and 9.5±0.8 mm in women. Statistically significant sex differences were revealed in all the preceding measurements. The mean height of the neck of radius was 11.2±1.2 mm in men and 10.1±1.6 mm in women, with no significant difference (p= 0.15). The average values of morphometry of the proximal radius of the Chilean population differ from those describing the European population, and show some similarities with the Chinese population. Our results may be useful to design of implants and prostheses for the proximal radius, and to correct surgical planning in orthopedics and traumatology.

Incidence of Third Head of Biceps Brachii in Indian Population.

Background: The biceps brachii is one of the muscles of the anterior compartment of the upper arm. It is characteristically described as a two-headed muscle that originates proximally by a long head and a short head. The present study was carried out to find the occurrence of a third head of biceps brachii among a sample Indian population. Materials and Methods: The arms of 35 adult cadavers were dissected and observed for variations in the origin and insertion of biceps brachii muscle bilaterally. Results: Among the 70 arms studied, three had 3-headed biceps brachii, 2 on the left and 1 on the right side. All the third heads were of humeral origin, which inserted into the radial tuberosity by a common tendon with the long and short heads. Conclusion: Knowledge of the existence of the third head of biceps brachii may enhance pre-operative evaluation, facilitate surgical intervention within the arm and improve postoperative outcomes.

Morphology of Brachialis Muscle: Variations and Clinical Significance.

Background: Though rare but variations of brachialis muscle insertion have been reported. Material and Methods: The study was conducted on 115 upper limbs over a period of 4 years. The dissection of arm and forearm was done carefully to preserve all minute details ,observing the morphology of insertion pattern and nerve supply. Observation: Out of 115 specimens, 2 specimens showed insertion of brachialis into bicipital aponeuroses. Accessory slips were seen in 4 specimens which are mixed with main fibers at insertion point. Rarest of all was insertion of an accessory brachialis muscle on radial tuberosity in 2 specimens. The muscle originated from lateral border of shaft of humerus and shared a few fibers with main Brachialis muscle. The muscle was inserted into radius just below the radial tuberosity. Conclusion: The identification of an inter-nervous plane may allow for improvement in the current anterior and anterolateral surgical approaches to the humerus. This could be one of a possible etiology of Radial tunnel syndrome.