A robotic surgical system comprises a manipulator arm including a spring loaded input and a spring loaded plunger. The system also comprises a sterile adaptor. The sterile adaptor includes a housing, an electrical contact coupled to the housing, and a retractor plate assembly including a top retractor plate and a bottom retractor plate. The retractor plate assembly is movably disposed relative to the housing and adapted to engage the spring loaded plunger. The sterile adaptor also includes a disc captured between and rotatable relative to the top retractor plate and the bottom retractor plate. The disc has a first surface adapted to engage the spring loaded input and a second rotatable surface adapted to engage a surgical instrument in a sterile field.