Dynamic sonographic evaluation of posterior shoulder dislocation secondary to brachial plexus birth palsy injury.

onographic evaluation of hip dysplasia has been used since the early 1980s and is now a well-established procedure for the assessment and monitoring of neonatal and infantile hip stability. This same technology can be applied to glenohumeral joint evaluation. Computed tomography (CT) was the first radiographic modality to be used to describe shoulder instability in children with Erb palsy 25 years ago, 1 followed by magnetic resonance imaging