Man With Right Shoulder Pain

Abstract

A 61-year-old man fell from his scooter resulting in right shoulder pain. The patient required first aid in a local hospital where plain film radiography showed no apparent abnormalities. He then presented to our emergency department due to persistent pain and an inability to move his right shoulder, with his right arm in a supportive sling. Radiography revealed rounding of the humeral head (Figure 1), which was confirmed by point-of-care ultrasound (Figure 2A ).Figure 2Point-of-care ultrasound, using a curvilinear probe in the transverse orientation behind the scapular spine. A, Before the procedure, the humeral head was protruding from the glenoid toward the posterior aspect of the shoulder, indicating a posterior dislocation. B, After the procedure, the humeral head was immediately adjacent to the glenoid, confirming a successful reduction. Ant, anterior side; Post, posterior side; Med, medial side; Lat, lateral side; D, deltoid muscle; G, glenoid; H, humeral head; I, infraspinatus muscle; S, scapula spine.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Posterior dislocation of the right shoulder. Point-of-care ultrasound showed that the humeral head protruded from the glenoid toward the posterior side. A closed reduction of the right shoulder was performed, and point-of-care ultrasound confirmed a successful reduction (Figure 2B). The patient was discharged and was followed up in an outpatient clinic. Posterior shoulder dislocations are rare. Missed diagnoses are frequent because the humeral head appears aligned within the glenoid fossa on plain film radiograph.1Hatzis N. Kaar T.K. Wirth M.A. et al.The often overlooked posterior dislocation of the shoulder.Tex Med. 2001; 97: 62-67PubMed Google Scholar,2Magnussen A.P. Watura C. Torr N. et al.Missed posterior shoulder fracture dislocations: a new protocol from a London major trauma centre.BMJ Open Quality. 2020; 9e000550Crossref Scopus (1) Google Scholar Additionally, patients with shoulder trauma usually have the shoulder immobilized with a sling at the time of imaging, causing the anteroposterior radiographs obtained to be imprecise with the expected rounding of the humeral head. This makes the characteristic “light bulb” sign on a radiograph unreliable.2Magnussen A.P. Watura C. Torr N. et al.Missed posterior shoulder fracture dislocations: a new protocol from a London major trauma centre.BMJ Open Quality. 2020; 9e000550Crossref Scopus (1) Google Scholar Ultrasonography is highly sensitive and specific for the identification of shoulder dislocation.3Gottlieb M. Holladay D. Peksa G.D. Point-of-care ultrasound for the diagnosis of shoulder dislocation: A systematic review and meta-analysis.Am J Emerg Med. 2019; 37: 757-761Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar Normally, the humeral head appears as a hyperechoic, semicircular line with an acoustic shadow immediately lateral to the glenoid. The humeral head will not be congruent to the glenoid in shoulder dislocations, appearing deeper with an anterior dislocation and more superficial with a posterior dislocation.