The operation of spondylodesis
In principle, a stiffening operation/spondylodesis of the lumbar spine can be performed from the front, abdomen, back, back or both sides simultaneously or in two separate operations. In the area of the cervical spine, the most common procedure is a stiffening operation from the front. There are various techniques and materials available with which a spondylodesis operation can be performed.
This cannot be discussed in detail here. Such detailed knowledge is also of no interest to the layperson. For some time now, so-called dynamic spondylodesis implants have also been available, to which one topic is dedicated.
Using various surgical techniques and materials (implants), a section of the spine that has been determined before the spondylodesis operation is stabilized. The actual stiffening, in the sense of a bony fusion of a spinal segment, is the task of the body and takes place in the months following a spondylodesis operation, when the stabilized spinal segments fuse together in a bony fashion. In spondylodesis, the stabilization of a spinal segment is usually achieved by inserting screws and rods from behind.
Displaced vertebral bodies can be set up beforehand, while spinal canal narrowings and narrowings in the area of the nerve exit holes (neuroforamas) are removed beforehand (decompression). The screws are inserted through a part of the vertebra (pedicle) into the vertebral body. Two screws are inserted per vertebral body.
These screws are then connected to each other by rods in the longitudinal and sometimes transverse direction. This procedure alone is usually not sufficient for spondylodesis surgery, because the vertebral bodies are not able to fuse together in this way. For this purpose, it is necessary to remove and replace the intervertebral discs on the stiffening section.
Bone blocks that can be removed from the patient’s pelvic bone (iliac crest) are a suitable replacement. They are inserted into the previously cleared intervertebral disc spaces and can grow together with the adjacent vertebral bodies. Alternatively, metal cages can be inserted into the intervertebral disc spaces, which have previously been filled with growth bone (spongiosa). Smaller cages can be inserted from the back during the operation, larger ones must be inserted from the abdomen. If a complete vertebral body replacement is necessary, e.g. in the context of a destructive infection or a serious tumor disease, special implants (vertebral body replacement implants) are available.
