Shoulder joint prosthesis (1) comprising a humeral axis (6) and a proximal element 5 (7) capable of being mounted on said humeral axis (6) by mounting means (8-12), said mounting means (8-12) comprise cavities (10) formed on a proximal end surface of the humeral axis (6), partially intersected with each other, and a pin (11) secured to said proximal element (7)； characterized in that: - said cavities (10) are two conical cavities (10), and at least one wedge surface (9) extends to the immediate vicinity of the openings of said cavities (10)； - said pin (11) is conical and has an axis displaced in relation to the center of said proximal element (7), said pin (11) being able to be fitted and trapped in one of said conical cavities (10), and - in at the base of said pin (11), there is a polygonal part (12) centered on the axis of said pin, forming at least two locking facets capable of alternately approaching, depending on the angular position of the proximal element (7) in in relation to the humeral axis (6), in the immediate vicinity of said wedge surface (9) comprised by said humeral axis (6).Prótesis de la articulación del hombro (1) que comprende un eje humeral (6) y un elemento 5 proximal (7) capaz de ser montado en dicho eje humeral (6) por medios de montaje (8-12), dichos medios de montaje (8-12) comprenden cavidades (10) formadas en una superficie extrema proximal del eje humeral (6), parcialmente intersectadas una con otra, y un tetón (11) asegurado a dicho elemento proximal (7)； caracterizado porque: - dichas cavidades (10) son dos cavidades cónicas (10), y cuando menos una superficie de cuña (9) se extiende a la vecindad inmediata de las aberturas de dichas cavidades (10)； - dicho tetón (11) es cónico y tiene un eje desplazado en relación al centro de dicho elemento proximal (7), dicho tetón (11) siendo capaz de ser encajado y atrapado en una de dichas cavidades cónicas (10), y - en la base de dicho tetón (11), hay una parte poligonal (12) centrada en el ej
