A shoulder separation occurs when the ligaments that connect the end of the collarbone (clavicle) to the corner of the shoulder blade (acromion) are injured. Depending on the degree of damage to the ligaments the clavicle may show no outward sign of deformity or may become displaced and appear raised relative to the acromion. A shoulder separation, or acromioclavicular (AC) separation, is a distinct injury unrelated to shoulder dislocation where the ball and socket become dissociated.
Most AC joint separations can be managed without surgery, even those in which there is considerable deformity from the clavicle displacing and resting higher than the acromion. This is because in many cases overall shoulder function is minimally affected by the change once the symptoms from the acute injury subside. Moreover, extensive research over recent years has not demonstrated that surgical correction of a AC joint separation reliably improves patients’ perception of their shoulder function. Therefore surgery is reserved for generally the most severe cases of separation in the most high demand patients.