Hip prosthesis (P； 100) comprising: - a prosthetic head (4； 104) basically in the form of a hemispherical dome that has an external sliding surface adapted to articulate with an acetabular dome (5) that is inserted into the acetabulum and which has a concavity on its inner surface, - a first prosthetic component (2； 102) that basically has the shape of a hemispherical dome with concavity towards the concavity of the prosthetic head, - a second prosthetic component (3； 103) connected to the prosthetic head and disposed within the first prosthetic component, wherein - the second prosthetic component (3； 103) is a sphere having a circular section with a center (O), and - the center of the radius of curvature of the first prosthetic component (2； 102) coincides with the center of the radius of curvature of the prosthetic head (4； 104) that coincides with the center (O) of said sphere (3； 103), characterized in that the hip prosthesis comprises or n stem (1； 101) adapted to be inserted into the neck (60) of the femur (6) and a first prosthetic component that is connected to the stem (1； 101), the sphere (3； 103) comprises a hole (3a； 103a) into which a rod (4a； 104a) is inserted, projecting radially inwards from the prosthetic head (4； 104), and the prosthetic head (104) comprises a thicker central part (140) arranged around the stem (104a) and a peripheral part (141) with a lower thickness, such that it generates a stop surface (142)； the central part with a greater thickness (140) is placed on the external surface of the sphere (103) such that it generates an air gap (150) between the external surface of the sphere (103) and the internal surface of said peripheral portion part of a lower thickness (141), such that the edge (122) of the first component (102) can enter the interior of the air gap (150) until it stops when stuck against the abutment surface ( 142).Prótesis de cadera (P； 100) que comprende: - una cabeza protésica (4； 104) en forma básicamente de cúpula sem
