Snapping Shoulder Secondary to Subluxation of an Accessory Coracobrachialis

Hardi Madani; Sarim Ather; Roxanne Giggens; Hira Hasan; David McKean

doi:10.7759/cureus.7967

Snapping Shoulder Secondary to Subluxation of an Accessory Coracobrachialis

Cureus. 2020 May 5;12(5):e7967. doi: 10.7759/cureus.7967.

Authors

Hardi Madani¹, Sarim Ather², Roxanne Giggens², Hira Hasan³, David McKean⁴

Affiliations

¹ Radiology, East and North Hertfordshire NHS Trust, Stevenage, GBR.
² Radiology, Oxford University Hospitals NHS Foundation Trust, Oxford, GBR.
³ Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, GBR.
⁴ Radiology, Buckinghamshire Healthcare NHS Trust, Aylesbury, GBR.

Abstract

Numerous snapping syndromes have been reported in the musculoskeletal system. Identifying the cause of these symptoms can often be challenging as the underlying abnormality may not be appreciable on routine static examinations. We report a 30-year-old female who presented with an unusual snapping sensation in her right anterior shoulder. This was readily reproducible during shoulder abduction with a palpable clicking evident on clinical examination. Dynamic ultrasound revealed this to be secondary to an accessory coracobrachialis muscle, which subluxed suddenly over the anterior subscapularis tendon during abduction. An accessory coracobrachialis muscle is a rare normal variant that is often asymptomatic. Extra-articular causes of shoulder snapping have been rarely reported, and this is the first case report of an accessory coracobrachialis muscle causing a snapping shoulder phenomenon.

Keywords: accessory; anatomy; coracobrachialis; mri; muscle; shoulder; us.

Publication types

Case Reports