Interposition Graft Repair of Irreparable Rotator Cuff Tears: A Review of Biomechanics and Clinical Outcomes.

Managing massive irreparable rotator cuff tears is a challenge. Interposition graft repairs to bridge the torn defect are a promising solution. Many graft materials are available for interposition repairs including the following: allografts, autografts, extracellular matrix, and synthetic grafts. Currently, it is unknown how these materials compare biomechanically or in their clinical outcomes when used for interposition graft repairs of massive irreparable rotator cuff tears. Most allografts and autografts are similar, in maximal load and stiffness, to intact rotator cuff tendons. Synthetic grafts have similar maximal load but lower stiffness, whereas extracellular matrix grafts are lower in maximal load and stiffness compared with intact rotator cuff tendons. Overall interposition graft repairs have shown some promising 2-year outcomes in patient and physician-reported functional outcomes, regardless of graft type. Few reported complications or repair failure associated with interposition graft repairs of massive irreparable rotator cuff tears at 2 years postsurgery have been noted.