A surgical distance adjusting assembly for a distractor has a base having a first connecting portion configured to hold a first bone attachment member and a carrier having a second connecting portion configured to hold a second bone attachment member. The base and the carrier are movable relative to each other, wherein the first and second connecting portions provide a releasable mechanical coupling to the first and second bone attachment members. The releasable mechanical coupling comprises a hook member at one or both of the first and second connecting portions and configured to engage the respective bone attachment member. Alternatively, the releasable mechanical coupling comprises an opening at one or both of the first and second connecting portions. The opening has a thread for a fixation screw configured to releasable couple the respective bone attachment member to the respective connecting portion.