A robotic surgical assembly includes a slave manipulator connected to a surgical instrument. A jointed subassembly includes at least a first, second and third links. The first and second links are associated in a first joint providing a degree of freedom between the first link and the second link. The second and third links are associated in a second joint providing a degree of freedom between the second link and the third link. The surgical instrument includes a tendon for moving a degree of freedom; the tendon including a tendon distal portion secured to the third link. The first link and/or the second link includes a tendon contact surface on which the tendon slides remaining in contact with the tendon contact surface, defining one or more sliding paths on the tendon contact surface. The sum of all sliding paths defines a total winding angle of at least 120°.