The Acromioclavicular Joint: The Sporting Shoulder Injury
Injuries to the Acromioclavicular joint or the AC jt as it is frequently referred to as makes up almost half of all sporting shoulder injuries. An acromioclavicular joint injury typically is caused by direct impact to the shoulder from a fall which may occur for example when coming off a push bike or in contact sports like rugby where you get “dumped” on your shoulder during a tackle.
What’s Damaged With An AC Joint Sprain?
An injury to the AC joint involves failure of the acromioclavicular ligaments and the joint capsule which are the supportive structures directly holding the collar bone to the part of your shoulder blade known as the acromium. More significant AC joint injuries will include damage to the above structures followed by failure of the coraco-clavicular ligaments (which are the ligaments going from the front of shoulder blade to the collar bone) as well as damage to some of the adjacent soft tissues (fascia of the shoulder muscles).
Grading Injury To The Acromioclavicular Joint
Outcomes following AC joint injury correlate well with the grade (or severity) of injury so it is important to know the grade of injury as this dictates treatment and prognosis. An X ray of the AC joint is useful for diagnosis and helping establish the grade of injury.
Classifications Of AC Joint Injury And Treatment
The classification of AC joint injury and their management for the varied grades of acromioclavicular joint injuries:
- Type I- AC ligament sprain with the AC joint not dislocated.
Type II- AC ligament tear, and coracoclavicular ligaments intact.
For these AC joint sprain grades 1 and 2 they are generally treated non-operatively. Patients wear a sling for 1-2 weeks with or without supportive taping as guided by pain and physiotherapy rehabilitation starts once pain subsides with most patients returning to sport after a couple of months.
- The treatment for Type three injuries is less clear cut. Type III- AC and coracoclavicular ligaments torn with 100% AC joint dislocation.
These injuries can be managed surgically or non surgically and most patients recover adequate strength and endurance when treated non-surgically. Management of this type of AC joint injury is more controversial than that of lower grade injuries and some patients will be suggested surgical intervention by their surgeon. Most likely surgery is an option when an individuals work or sports require repetitive overhead activities, if surgery is to be performed then it is best done within six weeks of the injury before healing is complete.
- The more significant AC joint injuries, type IV to VI are surgically managed with the intention of positioning the acromioclavicular joint back in its anatomic position. Type IV to VI AC joint injuries are complete dislocation variations where the collar bone displaces through the muscle behind, above and below respectively and are obviously more severe injuries requiring surgery and a more drawn out physiotherapy rehabilitation.
Disclaimer: Sydney Physio Clinic does not endorse any treatments, procedures, products mentioned. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific advice or assistance regarding Acromioclavicular Joint Injury And Management should consult his or her orthopaedic surgeon, general practitioner, sports medicine specialist or physiotherapist.