A surgical instrument for fixing bone fragments is provided. The surgical instrument comprises a positioning member with two pad holding portions, two pad members each having a bone contacting surface and each configured to be releasably held at one of the pad holding portions of the positioning member so that the bone contacting surfaces of the two pad members face each other, and two guiding channels configured to receive a flexible elongated member, each guiding channel being formed in a region between the bone contacting surface of one of the pad members and the associated pad holding portion.