A surgical distance adjusting assembly (10 130) for a bone distractor (128 156) is described. The assembly (10 130) comprises a base (12 132) having a first connecting portion (16 136) configured to hold a first bone attachment member (102 148) and a carrier (14 134) having a second connecting portion (18 138) configured to hold a second bone attachment member (120 154). The base (12 132) and the carrier (14 134) are movable relative to each other, wherein the first and second connecting portions (16, 18 136, 138) provide a releasable mechanical coupling to the first and second bone attachment members (102, 120 148, 154). The releasable mechanical coupling comprises a hook member (94) at one or both of the first and second connecting portions (16, 18 136, 138) and configured to engage the respective bone attachment member (102, 120). Alternatively, the releasable mechanical coupling comprises an opening (144) at one or both of the first and second connecting portions (16, 18 136, 138). The opening (144) has a thread for a fixation screw (158) configured to releasable couple the respective bone attachment member (148, 154) to the respective connecting portion (136, 138).
