The acromioclavicular joint is the junction between the clavicle (collar bone) and the scapula (shoulder blade). Together with the clavicle, the joint is important in stabilising the upper limb so that power lifting using the rest of the arm and forearm is possible.
The dislocation occurs almost always with a fall or a high impact force onto the side of the shoulder. The patient will complain of severe pain with swelling over the joint. Depending on the severity of the dislocation, the end of the clavicle becomes prominent and tends to “tent” the skin over the joint.
The treatment of these injuries depends generally on the severity of the dislocation. For the low grade dislocation, the injured shoulder is supported in a sling for pain relief and gentle exercises may be started as soon as the pain resolves.
For the high grade dislocations, these injuries signify severe tears of the ligaments connecting the clavicle and scapula. Non-operative treatment has been shown to lead to poor function and strength of the upper limb.
It is recommended that these injuries be treated early with surgical reduction using a special plate and/or wires with repair of the torn ligaments. Once stabilised, shoulder exercises can be started early to reduce shoulder stiffness.