Biometría de las conexiones intertendinosas del dorso de la mano humana / Biometry of the intertendinous connection of the dorsum of the human hand

RESUMEN: Las conexiones intertendinosas (CIT) son bandas estrechas de tejido conectivo que unen tendones adyacentes del músculo extensor de los dedos. Dichas bandas se ubican de manera superficial en el dorso del segundo, tercer y cuarto espacios intermetacarpianos (EIMC) presentando funciones importantes como colaborar en la estabilización de la articulación metacarpofalángica y permitir la redistribución de fuerzas extensoras sobre esta articulación. El objetivo del presente estudio fue establecer la biometría de las CIT. Para ello se utilizaron 24 miembros superiores formolizados, pertenecientes al laboratorio de Anatomía, de la Universidad Andrés Bello, sede Viña del Mar, Chile. Se registraron las longitudes de inserción lateral y medial, el ancho y la longitud total de cada CIT. Siguiendo dos criterios, las CIT se clasificaron según morfología y además se localizaron según tercios del dorso de la mano. De las 69 CIT encontradas, el 39 % presentó una disposición transversa y 61 % una oblicua. En relación a la clasificación morfológica de la CIT se identificó un 29 % del tipo 1; 39 % del tipo 2. Para el caso del tipo 3, un 20 % presentó la forma "r" y en un 12 % la forma "y". Respecto a su localización se estableció que en el segundo EIMC el 18 % de las CIT se ubicaron el tercio distal del dorso y el 82 % en el tercio medio. En el tercer EIMC el 96 % de las CIT se localizó en el tercio distal y 4 % en el tercio medio. En el cuarto EIMC el 96 % se ubicó en el tercio distal y el 4 % en el tercio medio. Considerando como referencia la línea biestiloidea, las CIT en el segundo EIMC presentaron un promedio de ancho de 8,16 ± 1,94 mm y una longitud total promedio de 13,71 ± 4,70 mm. En el tercer EIMC, un promedio de 10,94 ± 4,39 mm para el ancho y 6,29 ± 3,26 mm de longitud total promedio. En el cuarto EIMC el promedio de ancho fue de 7,00 ± 3,06 mm y la longitud total promedio 7,08 ± 4,42 mm. Estos hallazgos aportan datos respecto de la biometría y localización de las CIT, lo que resulta de utilidad en procedimientos de reparación quirúrgica del dorso de la mano humana.

SUMMARY: Intertendinous connections (IC) are narrow connective tissue bands extending between the extensor digitorum (ED) tendons. These bands are located superficially on the dorsum of the second, third and fourth intermetacarpal (IMC) space, presenting important functions such as collaborating in the stabilization of the metacarpophalangeal joint (MCP) and allowing the redistribution of extensor forces on this joint. The objective of the present study was to establish the biometric characteristics of IC. To do this, 24 formalized upper limbs are used, belonging to the Anatomy laboratory of the Universidad Andrés Bello, Viña del Mar, Chile. Lateral and medial insertion lengths, width and total length of each IC were recorded. Following two criteria, IC were classified according to morphology and were also located according to thirds of the back of the hand. 69 IC were found, 39% presented a transverse arrangement and 61 % an oblique arrangement. In relation to the morphological classification of IC, 29 % of type 1 were identified, 39 % of type 2. In the case of type 3, 20 % presented the form "r" and 12 % the form "y". Regarding its location, it was established that in the second IMC space, 18 % of the IC were located in the distal third of the back and 82 % in the middle third. In the third IMC space, 96 % of the IC was located in the distal third and 4 % in the middle third. In the fourth IMC space, 96 % were located in the distal third and 4 % in the middle third. Considering the biestiloid line as a reference, the IC in the second IMC space considers an average width of 8.16 + 1.94 mm and an average total length of 13.71 + 4.70 mm. In the third IMC space, an average of 10.94 + 4.39 mm for the width and 6.29 + 3.26 mm of average total length. In the fourth IMC space the average total width of 7.00 + 3.06 mm and the average total length of 7.08 + 4.42 mm. These findings provide data regarding the biometrics and location of IC, which is useful in surgical repair procedures on the back of the human hand.

A Morphological Study of the Extensor Tendons and Juncturae Tendinum on the Dorsum of the Hand / 대한정형외과학회잡지

PURPOSE: To clarify the morphological patterns of the extensor tendon and juncturae tendinum on the dorsum of the hand. MATERIALS AND METHODS: Fifty eight hands of cadavers were dissected to evaluate the morphological patterns of the extensor tendon and juncturae tendinum. RESULTS: The tendon of extensor indicis proprius and extensor digitorum communis (EDC) to the index finger arose and terminated at a single tendon. The EDC to the long finger arose as a single tendon, divided into two slips and then converged again to form a single tendon. The EDC to the ring finger arose as double tendons, divided into three or four slips and converged again into double tendons. The EDC to the little finger was usually absent (72%). The extensor digiti minimi arose and terminated as double tendons. The juncturae tendinum (JT) between the EDC tendons to the index finger and those to the long finger were of type I (thin filamentous type). The JT between EDC tendon to the long finger and those to the ring finger consisted of 16% in type I, 31% in type II (thick filamentous type) and 53% in type III (tendinous type). There were 14% of type II JT and 86% of type III JT between the ring and small fingers. CONCLUSION: A knowledge of both the usual and possible variations of the extensor tendon and the juncturae tendinum is useful in the identification and repair of these structures.