An instrument system for reducing displacement between adjacent vertebrae, comprising:an inserter (24) engageable to a connecting element (90) andat least one anchor extension (100) mountable with an anchor (80) secured to a vertebra, wherein said inserter is movably mountable to said at least one anchor extension to move said connecting element along an insertion axis to a position adjacent said anchor, wherein said at least one anchor extension includes a first member (120) and a second member (160), said second member being mountable to said anchor and said first member and said second member being movable relative to one another to contact said connecting element with said first member and move said anchor and said connecting element toward one another in a direction transverse to said insertion axiswherein said first member is an outer sleeve with a passage and said second member is movably mounted in said passage of said first member andwherein said anchor extension includes a locking mechanism to releasably secure said first and second members in position relative to one another.
