A shoulder joint repair prosthesis (12, 14) comprises a support structure which comprises anchorage points (24) which are in the installed configuration positioned adjacent positions of the anatomical tendinous insertion points of the tendons related to the joint. A securing clamp (30) arrangement connects to the anchorage points with direct rigid connection devices (32), the securing clamp arrangement having a surface area larger than the direct connection devices, the securing clamp arrangement being arranged to clamp the tendons between the securing clamp arrangement and the underlying surface area and providing a fixed gap between clamp and underlying connecting areas to trap any attached bony fragments.