The present invention relates to a medical implant for reducing pain in diseased joints such as synovial joints, in particular ball and socket joints such as the hip joint and the shoulder joint. One embodiment relates to a medical implant for attachment to and at least partly covering the femoral head, said medical implant comprising a dome shaped shell with an orifice, said shell having a height h1, an equatorial shell radius rs and an orifice radius ro wherein the shell radius rs>ro, and h1>rs, and the orifice is defined by a circumferential rounded edge.