US Patent 11033398 Shoulder implant for simulating a bursa

A shoulder implant for simulating a naturally occurring bursa proximal to or in lieu of a subacromial bursa, the shoulder implant comprising: an expandable member expandable to a size and/or a shape sufficient to fill a space beneath an acromion and/or a coracoid process of the shoulder, the space defines a filled volume less than a maximal volume occupied by the expandable member if fully expanded; and an amount of filler for filling the expandable member to the filled volume, such that, when implanted, the expandable member is configured to cushion and facilitate motion between a tendon and/or ligament of a rotator cuff, and a bone part in the shoulder.