Abstract: An external fixation system may have a first bone anchoring body configured to be secured to a first bone, a second bone anchoring body configured to be secured to a second bone, and a first strut assembly. The first strut assembly may have a first end configured to be removably coupled to the first bone anchoring body, a second end configured to be removably coupled to the second bone anchoring body, an intermediate portion that extends between the first end and the second end, the intermediate portion having a length that is adjustable, and a clutch mechanism. The clutch mechanism may be movable between an unlocked position in which the clutch mechanism allows both increase and reduction in the length, and a restricted position in which the clutch mechanism allows one of increase and reduction in the length while restricting the other of increase and reduction in the length.