Biomechanical and radiographic analysis of partial coracoclavicular ligament injuries.

Background: A spectrum of acromioclavicular joint injuries may exist between type II acromioclavicular joint disruption (coracoclavicular strain) and type III acromioclavicular joint injuries (coracoclavicular disruption). This may help explain the variability in outcomes seen in patients with type II acromioclavicular injuries.

Hypothesis: Injury to either the conoid or trapezoid ligaments would lead to instability of the acromioclavicular joint after complete acromioclavicular joint injury.