An apparatus suggested by the author for extrafocal transosseous osteosynthesis consists of cross pins, pin holders, sectional base square frames, arms with a clamp, shafts, screwed connection and guides. The apparatus was utilized in treatment of 17 patients with closed (in 13 patients) and open (in 3 patients) fractures of crural bones. The technic of applying this device is described. According to the author's data the use of this apparatus for extrafocal transosseous osteosynthesis has enabled to gain a greater efficacy of fixation and facilitated a reposition of bone fragments, also it shortened the period of the apparatus application, its management being much easier than otherwise.