The invention provides an orthopedic external fixation system for treatment of lower and upper extremities fractures. The system comprises an elongate base rail supported by a stand structure and a plurality of open rings slidably and removably coupled to the base rail along the base rail length. The ring members are connected to struts that support flag members, which support wires and pins that interact with the fractured bones for fixation of their positions relative to the rings during treatment. The system has means for combining the rings into separate modules that can be moved relative to each other. Through the use of the struts the rings can be bound into an integral system that can be disconnected from the base and the stand structure, while remains in a working position on the injured limb of the patient.