AC joint dislocation

The Acromio-clavicular Joint (ACJ) is made up of the outer end of the collar bone articulating with the shoulder blade at the front of the shoulder. The ACJ assists in daily routine activities through coordinated movements of the shoulder. Any abnormality affecting the ACJ can have a huge impact on the quality of life. An ACJ dislocation is not a minor injury, and if left untreated can lead to stiffness, pain, disruption of the alignment of the whole shoulder and interference with specialised functions such as reaching overhead for objects. ACJ dislocation commonly occurs during contact sports activities such as football, rugby etc or when you break a fall while cycling.


The diagnosis of ACJ dislocation is based on a history predisposing to injury, physical examination of pain localized to the joint and X-ray imaging to determine the direction and severity of the dislocation. Comparative weight bearing X-rays of both AC joints are the most widely used diagnostic tool. Sometimes the dislocation is associated with a fracture of the outer end of the collar bone or of the coracoid process of the shoulder blade and may need concomitant treatment. A CT scan is mandatory to rule out these associated injuries. An MRI may show tearing of associated soft tissue in this region.

Non operative treatment

The objective of early dislocation management is to provide pain relief and splint the affected shoulder. In partial dislocations just strapping the outer end of the collar bone down (for ACJ dislocations) and supporting the arm with an arm sling will help the ligaments to heal.


Arthroscopic or open reduction of the ACJ dislocation may be required if the dislocation is complete and the collar bone has either moved up, back or down, or fails to maintain due to an associated fracture. This may involve general anaesthesia. The associated fracture may need concomitant fixation with plates and screws. The maintenance of a reduced joint may need stabilisation with an internal splint. Dr Bala prefers to use devices for ACJ reconstruction where an artificial ligament is used to replace the torn ligaments. This ligament prevents the upward and backward displacement of the collar bone and has few complications such as stretching out of the reconstruction.




It is important to ensure that the involved part of the shoulder returns to its function after the joint is reduced by early controlled mobilisation and involvement of a dedicated physiotherapist. Rehabilitation program involves exercises and gradual increase in activity levels to strengthen the muscles and improve range of movement.

Dr Bala specialises in the treatment of failed surgery for AC joint dislocation