Gross Anatomical, Morphometric, Histological, and Ultrasonographic Examination of a Deltoid‐Associated Fibrous Band and Its Continuity With the Lacertus Fibrosus in the Domestic Goat

ABSTRACT

The connective tissues of the proximal thoracic limb form complex anatomical relationships with muscles, tendons, and fasciae that may contribute to coordinated limb function. This study aimed to characterize a distinct fibrous band in the craniolateral brachial and antebrachial region of the domestic goat, with emphasis on its anatomical relationships, morphometric features, histological organization, and ultrasonographic appearance. Bilateral gross anatomical examination was performed in eleven adult Iranian native goats. The course and anatomical relationships of the fibrous band were documented, and its dimensions and those of the associated lacertus fibrosus were measured. Histological examination and ultrasonographic evaluation were performed to further characterize the structure. The fibrous band originated from the tuberositas deltoidea and extended distally along the craniolateral aspect of the brachium and proximal antebrachium, where it became continuous with the lacertus fibrosus and the tendon of the extensor carpi radialis. Fibres of the mm. deltoideus and cleidobrachialis were continuous with the structure, while the m. brachialis was closely associated with its deep aspect. The structure measured 115.36 ± 9.45 mm in length and 0.56 ± 0.10 mm in thickness, with no significant differences between right and left thoracic limbs. Histological examination demonstrated its organized collagenous architecture. On ultrasonography, the structure appeared as a well‐defined echogenic band with a fibrillar pattern in the longitudinal plane and a distinct echogenic appearance in transverse sections, allowing its continuity and anatomical course to be followed. The findings provide a detailed morphological characterization of a specialized fibrous component of the goat proximal thoracic limb and demonstrate its continuity with multiple musculofascial and musculotendinous structures. This anatomical organization may suggest a potential role in force transmission across the limb, although its mechanical function remains to be established.