Surgical table top accessory with sacral offloading attachment

A riser system for mounting on a surgical table, the surgical table having a support surface, the riser system comprising:

• one or more riser panels having a patient support surface, the riser panels mounted above and an in spaced apart relation to the support surface of the surgical table,
• a receiver block disposed on one of the one or more riser panels;
• a sacral loading attachment disposed adjacent one of the one or more riser panels, the sacral loading attachment removably attached to the receiver block, the sacral loading attachment having a body defined in part by a plurality of elongate members extending downward along a midportion of the length of the sacral loading attachment, the plurality of elongate members having openings defined between adjacent elongate members, the openings configured to provide space for deformation of the sacral loading attachment under a load along a curve from a proximal end of the top surface of the sacral loading attachment to a distal end of the top surface, the sacral loading attachment configured to deform outwardly and downwardly along a curve with respect to the patient support surface.