The present disclosure relates to cannula assemblies for use with robotic surgical systems. According to an aspect of the present disclosure, a surgical cannula assembly for use with a mounting structure of a robotic arm, is provided. The surgical cannula assembly includes a cannula configured for reception of a surgical instrument at least partially therethrough； an attachment mechanism configured to releasably engage the cannula； and a barrier configured to extend through a channel of the mounting structure. The barrier includes a proximal ring for positioning adjacent a proximal face of the mounting structure, a distal ring for positioning adjacent a distal face of the mounting structure, and a cylindrical section defining a lumen therein and extending between the proximal ring and the distal ring, the cannula configured for insertion within the lumen in a distal-to-proximal direction.
