A reverse shoulder orthopaedic implant includes a metaglene component having a platform with a number of screw holes extending through it, and an elongated stem extending outwardly from a medial surface thereof, the elongated stem being configured to be implanted into the scapula of a patient and having a bore formed therein. A glenosphere component has a bore formed therein, with a retaining ring secured within the bore in the glenosphere component. A screw cap has a shaft positioned in the bore of the metaglene component, and a locking flange extending outwardly from the shaft so as to cover each of the number of screw holes of the metaglene component at least partially, the screw cap being retained in the glenosphere component by means of the retaining ring.L'implant orthopédique d'épaule inversée ci-décrit comprend un composant de glénosphère ayant une surface d'appui latérale conçue pour s'articuler avec la cupule humérale d'une prothèse humérale. Le composant de métaglène comprend une plateforme conçue pour recevoir le composant de glénosphère.