Background: Acromioclavicular joint separations are very common lesions, with the majority falling into Rockwood classification type I and II. It is generally agreed that conservative treatment of these injuries leads to good functional results, although there are some studies that suggest these injuries are associated with a high incidence of persistent symptoms.
Hypothesis: Type I and II acromioclavicular joint disruption significantly impairs long-term shoulder function.
Study Design: Case series; Level of evidence, 4.
Methods: The shoulder function of 23 patients who were treated for type I or II acromioclavicular joint disruption was evaluated at a mean of 10.2 years after injury. The objective and subjective measures of the injured shoulder were assessed using Constant, University of California–Los Angeles Shoulder Scale, and Simple Shoulder Test scores and were compared with results of the uninjured shoulder.
Results: At an average follow-up of 10.2 years, 12 of 23 patients (52%) reported at least occasional acromioclavicular joint symptoms. The average Constant score for the injured shoulder was 70.5 and 86.8 for the uninjured shoulder (P < .001). The average University of California–Los Angeles Shoulder Scale score for the injured shoulder was 24.1 and 29.2 for the uninjured shoulder (P < .001). The average Simple Shoulder Test value for the injured shoulder was 9.7 and 10.9 for the uninjured shoulder (P < .002). The extent of acromioclavicular joint disruption and acromioclavicular joint width did not have any statistically significant influence on the shoulder functional scores.
Conclusion: Type I and II acromioclavicular joint disruptions impair long-term shoulder function in about half of patients 10 years after injury.