A shoulder prosthesis includes a vault-filling component defining a bearing-facing surface (38) and having a first coupling component (40), the vault-filling component including (i) a vault-filling first portion (42) defining a first part (46) of the bearing-facing surface, and (ii) a projecting second portion (44) projecting from the vault-filling first portion so as to define a second part (48) of the bearing-facing surface. The vault-filling first portion and the projecting second portion define a bone space (50) between them. The shoulder prosthesis includes a bearing component (34) having a bearing surface (35), and a second coupling component (39) which cooperates with the first coupling component to couple the bearing component to the vault-filling component. At least one bone attachment member (36) is positioned in the bone space. The projecting second portion of the vault-filling component further defines a scapula-facing surface (58). The vault-filling first portion of the vault-filling component further defines (i) a first lateral surface (54) extending from the scapula-facing surface, and (ii) a second lateral surface (56) extending from the first part of the bearing-facing surface. The first lateral surface and the second lateral surface taper towards each other in a direction extending away from the bearing-facing surface.
