A sterile adaptor is provided. The adaptor includes a housing, a retractor plate assembling, and a disc. The retractor plate assembly is coupled to the housing and includes a spring plate between upper and lower retractor plates. The spring plate includes an aperture with leaves. The disc is movably coupled to the spring plate of the retractor plate assembly, with a first side of the disc couplable to a surgical instrument and a second side of the disc couplable to a manipulator arm of a robotic surgical system. The disc is capable of transmitting torque from the manipulator arm to the surgical instrument.