Treatment of advanced rotator cuff dysfunction with reverse shoulder arthroplasty

In the last 25 years our understanding and ability to treat shoulders with significant rotator cuff dysfunction has undergone rapid growth. once the sequelae of the cuff deficient shoulder was recognized by Neer, a push to discover a more satisfactory and reliable treatment to restore shoulder function was undertaken. Succeeding where others had failed, Grammont emerged with an idea for a "reversed prosthesis" that would be functional and stable while relying solely on the deltoid. The early clinical success of Grammont's device encouraged the investigation of the biomechanical and anatomical principles behind the improvements which were beyond the "limited-goals" of the past. Treating the rotator cuff dysfunctional shoulder has required the synthesis of scientific and clinical knowledge. The challenge of understanding the effects of implant design with respect to center of rotation and neck-shaft angle, along with techniques such as inferior tilt, and applying them appropriately has proved to be of utmost importance in treating this difficult clinical entity. optimal synthesis of this information will allow the orthopedic surgeon to successfully treat a spectrum of disease from the primary case of an arthritic rotator cuff deficient shoulder, to the more complex cases of revision and massive bone loss with the expectation of reliable patient improvement. The following review encompasses the brief history which spurned the development of reverse shoulder arthroplasty as well as an over-view of the subsequent biomechanical research that has helped improve prosthetic design. Clinical data utilizing various reverse designs is presented along with the underlying biomechanical principles that distinguish them from one another in both design and function.