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Emerg Radiol (2010) 17:317320 DOI 10.1007/s10140-010-0862-2
ORIGINAL ARTICLE
The Mouzopoulos sign: a radiographic sign of posterior shoulder dislocation
George Mouzopoulos
Received: 15 November 2009 /Accepted: 3 February 2010 /Published online: 25 February 2010 # Am Soc Emergency Radiol 2010
Abstract Posterior shoulder dislocation is a rare injury and often overlooked. This report describes the composition of the Mouzopoulos sign seen in anteroposterior X-ray views of the shoulder and underlines the importance of this sign in the recognition of posterior shoulder dislocation.
Keywords Posterior . Shoulder . Dislocation .
Mouzopoulos sign
Introduction
Even under optimum conditions, the radiographic detection of posterior shoulder dislocation is frequently difficult. When it is impossible to obtain an axillary or scapular Y view, recognition of posterior shoulder dislocation becomes even more difficult, since the abnormal posterior relationship of humeral head to the glenoid fossa is not clearly demonstrated. So the rare posterior dislocation goes unrecognized on initial evaluation in over 50% of cases [1]. This is why McLaughlin called it a diagnostic trap [2].
This report describes the composition of the Mouzopoulos sign seen in anteroposterior X-ray views of the shoulder and underlines the importance of this sign in the recognition of posterior shoulder dislocation.
Methods
Anteroposterior X-ray views in neutral position of the shoulder, of 14 patients who sustained posterior shoulder dislocation, were evaluated by two independent orthopedic surgeons for detecting possible radiographic signs of posterior shoulder dislocation such as: light bulb sign, rim sign, trough line sign, absence of normal half-moon overlap, and the Mouzopoulos sign.
The last sign is the Mouzopoulos sign from the capital letter M of the Greek alphabet, which is the first letter of the authors name and is produced by the projections of greater and lesser tuberosity borders, seen on AP view of humeral head. As a matter of fact, in the Greek alphabet, the capital letter obviously consists of the union of the two capital letters . Each capital letter represents the posterior and anterior borders of greater tuberosity (the lateral part) and the posterior and anterior borders of lesser tuberosity (the medial part) in AP view. So the capital letter M represents the borders of greater and lesser tuberosities seen en face because of the internal rotation of the humeral head...