Abstract: The invention relates to the medical field, particularly to traumatology and orthopedics, and may be utilized for the treating of patients with the bone injuries and diseases of extremities, specifically for the reducing of its deformities and shortenings. It comprises supports (1, 2) in the form of sectional, coaxially disposed relatively to each other rings (3, 4), one of them (3) is inner with a ring gear (21) on the external butt, another (4)—external with lugs (23) having holes (24), and also connecting supports (1, 2), threaded rods (25, 26, 27, 28), reposition units (29, 30), bone fixators (69) and locking element (63).