A modular prosthetic implant is provided, including a support cleat unit having a circular seat portion and a shape delimited by an imaginary dome. The support cleat unit includes a cylindrical body portion having a central axis and a hole concentric with the central axis, the hole having a least a first section whose diameter defines a female Morse taper adapted to receive a male member having a corresponding Morse taper. The support cleat unit also includes a plurality of arched appendages integral with the cylindrical body portion. The arched appendages are radially spaced apart from one another and extend outwardly from a base portion thereof at an outer circumferential surface of the cylindrical body portion so that lower/outer surfaces of the arched appendages define the overall domed shape of the support cleat unit.