The Displacement of the Clavicle is a Better Predictor of Surgical Intervention in the Non-Operatively Treated Acromioclavicular Dislocation than the Increase in Coracoclavicular Distance

OBJECTIVES: Acromioclavicular (AC) joint injuries are common and constitute approximately 3.2% of all shoulder injuries. Traditionally Rockwood Types I and II are treated conservatively, Type III dislocations are controversial, and Types IV, V, and VI AC dislocations are indicated for surgery. Little is known about nonoperative treatment of Type V AC dislocations especially in active populations. The purpose of this study was to compare the outcomes between Type V AC dislocations treated initially with acute surgical intervention versus those treated conservatively and to identify potential risk factors associated with failure of non-operative treatment. METHODS: A retrospective review was conducted using an automated search of electronic patient medical records from January 2007 through December 2012 for patients diagnosed with an AC dislocation in the Tripler Army Medical Center Department of Orthopedics. A Type V injury was defined as greater than 100% increase in the coracoclavicular (CC) distance compared to the contralateral side. Patients were excluded if there were no bilateral radiographs, who did not present acutely or who were tertiary referrals. RESULTS: 25 patients were identified as having acute Type V dislocations. Acute surgical AC reconstruction was selected in 8 patients and initial conservative therapy 17. In the conservative group: 8 patients (57%) returned to duty without surgery (average 90.3 days); 4 patients had delayed surgery and returned to full duty (average 238.75 days from initial injury); 2 refused surgery and changed careers; and 3 patients were lost to follow up. In the acute surgical group: 6 patients (75%) returned to full duty in an average of 207 days with 3 of those requiring revision surgery; 1 patient was lost to follow up, and 1 patient failed to return to full duty. There was no significant difference in time to return to duty between the acute surgical group and those who underwent delayed surgical reconstruction (p=0.62). In the conservatively treated group, patients who failed conservative treatment and elected for surgery had a mean increase in CC distance of 144% (range 118%-166%) with a mean 22.5mm displacement of the clavicle above the acromion (19.3- 25.1 mm). In conservative group that did not undergo surgery there was an average 141% increase in CC distance (range 102% - 217%) with a mean 17.3mm displacement (12.5-24.22 mm). There was a significant difference in mm of displacement of the clavicle above the acromion in conservatively treated patients who underwent surgical correction and those who did not (p=.035) while there was no significant difference between the CC distance in this same group (p=0.9). CONCLUSION: No study has compared initial conservative vs. operative management in type V AC joint dislocations. This study demonstrates that initial nonoperative treatment returns a majority of active patients to full duty faster than acute surgical reconstruction. Patients who undergo early operative management do not return at a higher rate, experience a similar rate of revision surgery, and time to return to duty is not significantly shorter than their initial conservative counterparts. Thus, we recommend that type 5 AC joint injuries, even in an active population, should be managed initially conservatively, as it is effective in the majority of patients, and initial surgery offers no advantage.