title: Thoracic Outlet Syndrome in the Overhead Athlete: A Report of 2 Cases of Subclavius Posticus Muscle.
abstract: Subclavius posticus muscle is a supernumerary anatomical variation of the subclavius muscle. The aim of this study was to show the possible contribution of the posticus muscle in the development of unilateral thoracic outlet syndrome (TOS) in overhead athletes, presenting hypertrophy of the dominant arm due to their sport activity. Reported here are 2 young overhead athletes complaining pain, paresthesia, weakness in the dominant upper limb, although presenting none of the main shoulder and neurological disorders. After developing subclavian vein thrombosis, TOS was suspected and finally diagnosed by dynamic magnetic resonance angiography, which also showed bilateral subclavius posticus muscle in both patients. Despite bilateral subclavius posticus, TOS was only evident in the dominant limb in which the association of hypertrophy of lateral cervical muscles, resulting from the overhead sport activity, to the subclavius posticus likely led to a significant reduction of the upper thoracic outlet space.
authors.affiliation: *Regenerative and Reconstructive Orthopaedic Surgery Unit, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy; †Residency Program in Orthopaedic Surgery, University of Milan, Italy; ‡Department of Radiology, San Raffaele Scientific Institute, Milan, Italy; §Department of Biomedical Sciences for Health, University of Milan, Milan, Italy; and ¶Department of Orthopaedics and Traumatology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Ciampi
authors.forename: Marco
authors.initials: M
authors.lastname: Agnoletto
authors.forename: Celeste
authors.initials: C
authors.lastname: Scotti
authors.forename: Rosa
authors.initials: R
authors.lastname: Ballis
authors.forename: Simonetta
authors.initials: S
authors.lastname: Gerevini
authors.forename: Giuseppe M
authors.initials: GM
authors.lastname: Peretti
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Fraschini
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D010146:Pain; D010369:Pectoralis Muscles / Q000473:pathology*; D013901:Thoracic Outlet Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult