CORACOACROMIAL LIGAMENT - IN-SITU LOAD AND VISCOELASTIC PROPERTIES INROTATOR CUFF DISEASE

The coracoacromial ligament plays a role in rotator cuff disease, The changes in the in situ load and viscoelastic properties of the coracoa cromial ligament in shoulders with rotator cuff tears were evaluated, Coracoacromial ligaments from 16 cadaveric shoulders (8 with rotator c uff tears, 8 without tears) were evaluated via biomechanical testing o f bone ligament bone specimens, An in situ load existed in the coracoa cromial ligaments of 19.6 +/- 15.4 N (rotator cuff tear) and 18.3 +/- 9.8 N (no rotator cuff tear), This difference was not statistically si gnificant. Cyclic loading of the ligaments demonstrated a greater drop in peak stress in rotator cuff tear shoulders than in normal shoulder s, whereas the stress relaxation response was not different, These cha nges in the coracoacromial ligament in shoulders with cuff tears may b e attributable to ultrastructural changes within the ligament as a res ult of an altered loading environment, It remains unknown whether they occur as a result of a rotator cuff tear or if they contribute to the pathogenesis of cuff disease.