Acromio-clavicular joint dislocation is one of the most common shoulder injuries orthopedic surgeons treat. Severe dislocations are often treated with surgery, but patients who opt for non-surgical treatment typically experience fewer complications and return to work sooner, according to new research published today in the Journal of Orthopaedic Trauma.

The AC joint is located at the top of the shoulder, between the collarbone and top of the shoulder blade. The AC joint is most commonly injured during sports, but can also be caused by motor vehicle accidents or falls.

For minor AC joint dislocations, surgeons often suggest patients wear a sling for a few weeks and undergo physiotherapy, rather than undergo surgery using a plate and screws.

"For severe AC joint dislocations, surgery is the common practice but there's not much evidence to suggest this is actually the best treatment," said Dr. Michael McKee, an orthopedic surgeon with St. Michael's Hospital.

Eighty-three patients with moderate to severe AC joint dislocations were assigned to receive either plate-and-screws surgery followed by rehabilitation or receive non-surgical treatment with sling and rehabilitation. Researchers followed the patients at regular intervals for two years, tracking complications, level of disability and patient satisfaction with how their shoulders looked after injury.

Non-surgical patients showed greater mobility than the surgical patients at follow-up sessions six weeks and three months after their injury. There were no significant differences between the groups at six months, one year or two years after their injury.

"Three months after the initial injury, more than 75 per cent of the patients who did not have AC joint surgical repair were able to return to work, whereas only 43 per cent of those who underwent surgery were back at work," said Dr. McKee.

Of the 40 patients who received surgery, seven experienced major complications such as a loose plate or a deep wound infections. Seven surgical patients experienced minor complications such as a minor infection or numbness at the point of the incision.

There were only two major complications among the 43 patients who did not receive surgery. Both complications were a result of repeat falls that further injured the AC joint.

"The main advantages of surgery are that the joint is put back in place and the shoulder appears more symmetrical and pleasing to the eye," said Dr. McKee. "The long-term implications of surgery for AC joint dislocation remain unclear when compared to non-operative treatment."

Because the non-operative patients did not have the dislocation put back into place with surgery, they were more likely to be dissatisfied with the appearance of their shoulder compared to the group who'd received surgery.

After one year, five per cent of the surgical patients reported dissatisfaction with the appearance of their shoulder compared to 16 per cent of the non-surgical patients. That gap widened after the second year, when more than 21 per cent of non-surgical patients had issues, compared to four per cent of those who'd received surgical repair

"While satisfaction with appearance of the shoulder should be a consideration, I believe surgeons should think twice before recommending surgery for an AC joint dislocation--regardless of the severity," said Dr. McKee. "Patients who forgo surgery return to work sooner, experience less disability during the first months after injury and have fewer complications."