Example surgical systems include end-effector assembly, arm assembly, and elbow joint assembly. Arm assembly includes proximal and distal ends. Elbow joint assembly secures proximal end of arm assembly to distal end of second arm assembly. Elbow joint assembly includes first and second elbow joint portions. First elbow joint portion includes first end section secured to proximal end of arm assembly, second end section, and first joint joining first and second end sections of first elbow joint portion. Second elbow joint portion includes first end section secured to second end section of first elbow joint portion, second end section secured to distal end of second arm assembly, and second joint joining first and second end sections of second elbow joint portion. First end section of first and second elbow joint portion are pivotable relative to first and second axes, respectively, formed by center line drawn through first and second joints, respectively.