Posterior AcromioclavicularDislocation with Clavicular Fracture and TrapeziusEntrapment

AbstractBackground: Posterior acromioclavicular dislocation is rare.Dislocation associated with fracture of the clavicle andsimultaneous entrapment of the lateral end of the clavicle bytrapezius muscle has not been reported. Posterior dislocationoccurs frequently owing to forceful move of the scapulaanteriorly and superiorly or from direct force applied to thelateral end of the clavicle and this may be associated withclavicular fracture. In acute dislocations, open reduction,internal joint stabilization and soft tissues reconstructionhave been recommended.Case Study: Acute posterior dislocation occurred in a 32-year-old man.The lateral end of the clavicle was displaced posteriorly andinferiorly, and firmly entrapped in trapezius muscle. Theclavicular fracture was undisplaced. The coracoclavicularligaments were stretched but intact. Open reduction was securedwith two smooth Kirschner wires. The disrupted soft tissues wererepaired. The clavicular fracture was not explored. Shouldermovement started at 6 weeks. Wires were removed. 10 years laterhe had pain-free, unrestricted shoulder movement, and theradiographs showed wellreduced, essentially normalacromioclavicular joint.Conclusion: Open reduction, internal joint stabilization and softtissue reconstruction will result in return and long lastingunrestricted pain-free function of the shoulder.