Abstract: This invention relates to apparatus for use in surgery. More specifically, it relates to a spinal fixation device which is adapted to engage a spinal body (e.g. vertebra, or sacrum) and to grip an elongate part, which may be a rod, bar, wire or the like. for convenience. Two or more such devices may engage respective vertebrae and grip a common rod, which may act to improve a spinal defect, such as ankylosing spondylitis, lumbar scoliosis or spondylolisthesis. The invention also relates to surgical instrumentation for use with such a spinal fixation device.