BackgroundThe medial coracoclavicular ligament (MCCL), is a structure that shows defined morphologic and histologic features. However, little attention has been paid to the MCCL to date. This study was conducted to (1) determine whether the MCCL is a constant structure, (2) analyze its mechanical properties, and (3) determine its possible role in acromioclavicular (AC) stability.MethodsAC joints, lateral coracoclavicular ligaments (LCCLs; conoid and trapezoid), and MCCLs were dissected in 30 fresh frozen upper limbs. In 6 of these specimens, we performed a sequential sectioning following the aforementioned order. A 20-N cephalad force was applied to the lateral clavicle at each step, recording the AC distance and coracoclavicular space and their variation. In 6 other specimens, we evaluated the anteroposterior motion of the clavicle following the MCCL section. Biomechanical testing was performed in 8 specimens, comparing the resistance of the MCCL to the LCCLs.ResultsThe MCCL in all of the specimens featured a sharp-edge bundle stretching from the coracoid process to the clavicle and subclavius sheath. It showed ligament-like mechanical properties although less tensile resistance than the LCCLs. Once the AC and LCCLs were sectioned, transection of the MCCL determined a significant increase in both cephalad and posterior displacement.ConclusionThe MCCL is a constant structure with the mechanical behavior of a ligament. It may act as the last container of the coracoclavicular space both in cephalad and posterior directions, precluding additional displacement in the absence of the LCCLs.

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Background: The distal half of the hypothenar eminence (HE) skin vascularization has been extensively investigated. Different flaps have been described based on these arteries. Similarly, the vascularization of the proximal half of HE has also been investigated, although to a lesser extent. The aim of this paper is to determine, in a cadaver sample, the anatomy of the hypothenar cutaneous branches in their proximal half. Methods: In all, 20 adult, red-colored-latex-injected hands were studied. Dissections were performed with a 4X to 10X magnification. Cutaneous branches in the proximal half of the HE were found. Their variants were studied, and they were classified into different types according to their relationships. Results: A cutaneous branch of the deep palmar artery (CBDPA) was identified. It was located in the subcutaneous cellular tissue thickness in the proximal half of the HE. Moreover, it presented 3 anatomical variants, classified according to its relationships with the superficial ulnar nerve branch (SUN). Type 1 variant: the CBDPA and the PDA ran in front of the SUN (60% of cases). Type 2: the CBDPA and the DPA ran behind the SUN (30% of cases). Type 3: the CBDPA ran in front of the SUN while the DPA ran behind it (10% of cases). Conclusion: There is a CBDPA which is the HE proximal half main cutaneous branch. Although it presented several variants, its existence is constant, making it possible to use it as pedicle for proximal hypothenar flaps.

<p><strong>Objetivo</strong></p><p>El ligamento de Caldani o córacoclavicular medial (LCCM) ha sido estudiado anatómicamente pero no hemos hallado mención alguna sobre su identificación imagenológica. El objetivo del presente trabajo es presentar una técnica original de resonancia magnética que hemos desarrollado para identificarlo, y describir las imágenes correspondientes.</p><p><strong>Materiales y Métodos</strong></p><p> Se incluyeron en el protocolo de investigación a 7 voluntarios sin patología de hombro conocida. Se utilizó un Resonador Magnético PHILLIPS INGENIA de una intensidad de campo magnético de 1.5 Tesla Versión 4.1, diámetro de Gantry (túnel del resonador) de 70 cm, bobina Sense específica para Hombro de 8 canales con imágenes de alta resolución. Se realizaron las secuencias de búsqueda del ligamento en tres planos.</p><p><strong>Resultados</strong></p><p>El LCCM fue identificado en todos los casos, extendiéndose oblicuamente desde la apófisis coracoides a la clavícula coincidiendo con las descripciones de la bibliografía anatómica consultada. Presentó una señal hipointensa en todas las secuencias, indicando el poco espacio entre fibras y correspondiendo a tejido colágeno compacto. Su longitud promedio fue de 41,15mm (entre 34mm y 47mm, desvío standard de 4,40). El espesor promedio fue de 2,11mm (entre 1,3mm y 3,2mm, desvío standard de 0,66).</p><p><strong>Conclusión</strong></p><p>El LCCM puede ser observado en imágenes de resonancia magnética mediante la técnica original que describimos. La posibilidad de localizar y observar el LCCM mediante resonancia magnética abre las puertas al estudio del mismo en futuras investigaciones, no sólo de compresiones neurovasculares sino también en lesiones traumáticas acromioclaviculares, especialmente en las tipo V de la clasificación de Rockwood.</p>

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