A shoulder dislocation is when the ball of the shoulder pops out of the socket. Emergently, the ball needs to be replaced in the socket, which might require a trip to the emergency room. The risk of repeat dislocation is based on age, which may indicate a simple course of rehabilitation or possibly surgery.
In general, X-rays are the only imaging study needed to confirm a dislocation. However, an MRI or an MRI arthrogram (an MRI with contrast injected into the shoulder) may be recommended to see if surgery would be recommended.