The reverse coracoacromial ligament transfer for "horizontal" acromioclavicular joint instability.

Background: Acromioclavicular (AC) horizontal instability is a problem affecting not only young athletic patients after a trauma to the AC joint but also older patients who have undergone distal clavicle resection. It may cause pain and poor functional outcomes unless the reconstruction technique specifically addresses the horizontal instability of the clavicle, in addition to the well-known superior instability.

Methods: Three cadaveric specimens underwent dissection of the AC joint capsule to determine the superior attachments of the AC joint capsule.