System IV is an implant system, which relies on the pedicular fixation. The pedicular fixation (introduced by Prof. Raymond Roy-Camille in the 1960ties) nowadays belongs to the standard procedures in the spine surgery.
In this operative-technique only those steps are mentioned, which specifically refer to the System IV. Regarding the approaches, two widely spread standard techniques are known, namely the medial and the lateral approach. The medial approach is normally used when the spinal canal must be simultaneously opened, e.g. for treating a disc prolapse. The lateral approaches (acc. to Wiltse) are in so far advantageous as the pedicles can be accessed along their lateral axis and that muscular scars are thus minimized.
System IV is basically suitable for the entire lumbar spine, i.e. from L1 to S1 (sacrum). For patients with small vertebral bodies it should previously be verified whether the upper vertebrae (e.g. L2, L1) allow accommodation of the provided pedicle screws and connection rods.