Langer’s axillary arch (axillopectoral muscle): a variation of latissimus dorsi muscle

Best-known variant structure of the axillary components of men is a muscular or fibro-muscular slip extending from the latissimus dorsi muscle to the tendons, muscles or fasciae of the superior part of the humerus. This variation had first described by Ramsay in 1795 and confirmed by Langer in 1864 and named as axillary arch of Langer. Although different frequencies have been reported from cadaver investigations and clinical studies, among different populations this variation occurs unilaterally up to 7%; its bilateral incidence is unknown. Among the variety of terminology that describes this variant structure as “Achselbogen”, “axillopectoral muscle”, “axillary arch”, “Langer’s axillary arch” or “muscular axillary arch” [1–3], we prefer the term “axillary arch” (“arcus axillaris” in Latin) in this report. The latissimus dorsi muscle originates from sacrum, iliac crest and along the five lumbar and lower six thoracic vertebrae. It is a flat triangular muscle which covers lumbar regions and is gradually contracted into a narrow fasciculus before its insertion. The quadrilateral tendon of latissimus dorsi muscle, which is about 7 cm long, lies in front of the tendon of the teres major muscle and is inserted into the intertubercular groove of the humerus. Variations of latissimus dorsi can be seen at its origins where the number of dorsal vertebrae to which it attached, vary from four to seven or eight, as well as the varying number of costal attachments and muscle fibers that may or may not be reaching to the crest of the Sinan BAKIRCI Ilker Mustafa KAFA Murat UYSAL Erdogan SENDEMIR