Re-formation of the coracoacromial ligament after open resection or arthroscopic release.

In 21 (91%) of 23 shoulder revisions after primary surgery involving resection or release of the coracoacromial ligament, there was evidence of a reattached or re-formed coracoacromial ligament. In 9 cases there was no other obvious explanation for symptom recurrence, and in 7 cases the coracoacromial ligament might have influenced progression of rotator cuff pathosis. Electron micrographs of a re-formed ligament showed a substantially large amount of large-diameter (> 100 microns) collagen fibrils resembling those of a normal ligament. We conclude that the coracoacromial ligament has an ability to re-form or reattach, whether primarily resected or released, and that this might account for recurrent symptoms.