Skoliose. Operative Therapies
Traction (stretching of the spine) in preparation for scoliosis surgery.
If scoliosis is diagnosed early enough and progression checked and treated according to its stage, spinal traction before or during scoliosis treatment is fortunately relatively rarely necessary today. In the case of very severe or inflexible types of scoliosis or for excessive anterior curvatures of the spine (known as hyperkyphosis), traction of the spinal deformity is however sometimes necessary. The traction procedure (Latin: tractio - pull, pulling force) such as the Halo traction procedure achieves traction/stretching of the body through a continuously acting lengthwise pulling action by means of a ring fixed to the patient's head. The aim is to slowly stretch out stiff curvatures and shortened soft tissue parts (e.g. musculature) in order to achieve a better and in particular from the neurological perspective also a safer surgical outcome.
Surgical procedure: Posterior or anterior access.
With operative procedures it is important to differentiate between anterior and posterior access to the spine. The vast majority of scoliosis cases can be operated on from one point of access. It is only in severe cases that a combined procedure is needed, i.e. using an anterior and posterior approach and if need be on different days. The choice of operative procedure depends on many factors such as the kind, extent and shape of the scoliosis and a separate decision must be made for each patient.
Surgical procedure: The posterior approach.
With the posterior approach, the spinous process and vertebral arches are exposed in the first instance during surgery in order to lodge anchor screws firmly on both sides of the pedicles in the vertebrae (called pedicle screws). These are then linked by metal rods. Using the screw/rod system, correction of the relevant segments of the spine can then take place. Finally bone or bone substitute material is placed on the debrided posterior vertebral structures in order to allow adhesion of the vertebrae with each other, a process known as stiffening or fusion. In the first year after surgery, the implant keeps the spine in the correct place until fusion (stiffening) occurs, i.e. bony fusion of the vertebrae involved in the former scoliotic arch, has taken place. Thereafter, in theory only, the metal implant could be removed again, something which is almost never advisable however because this would involve another intervention requiring major surgery.
Surgical procedure: The anterior approach.
With the anterior approach the anterior segments of the spine i.e. the vertebrae and intervertebral discs are exposed using a lateral incision i.e. from the thorax and / or abdominal cavity. This means the surgical channel of access is from the side towards which the curvature requiring surgery is directed, i.e. from the convex side. The intervertebral discs in the operative area are removed in order to be able to mobilise the spine in the first instance. After introducing bone chips between the vertebrae for purposes of subsequent spinal stiffening/fusion, the implant system is then firmly attached with screws and one or two rods to the vertebrae so that correction of the spinal segment can then take place. In the case of access to the thoracic spine the insertion of a thorax drain is necessary for a few days following surgery to remove wound fluids from the chest.
Special surgical method: The Halm-Zielke instrumentation method
Halm-Zielke instrumentation is a modern implantation system with which correction of scoliosis is possible using an anterior approach. After mobilising the spinal segment, which is to undergo surgery, a flat iron plate is then attached to the sides of the vertebrae by means of 2 screws, providing very stable fixation. 2 rods are then attached to these in succession. Three-dimensional correction of the spinal segment is then implemented by means of this stable screw-rod plate connection. This procedure achieves the best possible correction in all three dimensions and especially good correction of rib hump and lumbar prominence. In addition the very stable connection makes a corset unnecessary following surgery.