Idiopathic Scoliosis Osteotomies Posterior Spinal Fusion Traction

Severe Idiopathic Scoliosis, Treated with Preoperative Halo-Gravity Traction and then Posterior Spinal Fusion

The patient presented with the below scoliosis, no prior treatment.

The proximal thoracic curve measured 57 degrees, and the main thoracic 91 degrees in skeletally mature patient.

The patient has developed daily back pain, which is interfering with school and sporting activities.

Not only does scoliosis cause chest asymmetry and back pain, but it can also decrease lung volume and function. In the slide below the patient’s two pulmonary function measures, FVC and FEV1, were 1.61 l and FEV1 1.44 l (see below).

FVC stands for “Forced Vital Capacity”. It is the amount of air exhaled forcefully after inhaling as much as possible.

FEV1 stands for “Forced Expiratory Volume, 1 second”. It is the amount of air a person can force out of their lungs in 1 second.

These are two common measures obtained at routine pulmonary function tests.

The absolute values of FVC and FEV1 are not very helpful, so we calculated the measured volume relative to what is expected for a patient with similar arm span. We do not use patient body height since scoliosis decreases patient height, which would artificially elevate the %-predicted. Our patient, demonstrated above, has FVC 44% of predicted, and FEV1 45% predicted. Again, this should be at 100%. 

Long term our pulmonary function declines, and we lose about 700 cc of our vital capacity when we get into our 60s.  Therefore, if our patient is at 44-45% and is to lose more lung volume, it may put the lung function into a dire situation later in life.  The patient may develop difficulty in walking longer distances, difficulty walking a single flight of stairs, frequent pneumonias, etc…. 

By three-dimensionally correcting the scoliosis, to be as close to normal as possible, can permanently correct the spinal deformity and optimize lung function.

Our treatment plan for this type of patient and spinal deformity is two-fold:

  1. Preoperative Halo-Gravity Traction
  2. Posterior Spinal Fusion

Below is an example of how a spinal deformity can be improved with halo-femoral traction. The spinal deformity was 91 degrees at presentation, decreased to 86 degrees at 17# of traction to 80 degrees at 32# and finished at 78 degrees at 39#, 6 weeks after treatment.

Below are two pictures of, a front and back view, of the 3-d CT scan of the spine.  There are no signs of congenital scoliosis, just a severe idiopathic scoliosis.

After 6 weeks of halo-gravity traction, the patient underwent:

  1. Posterior Spinal fusion from T2-L2
  2. Multiple posterior column osteotomies from 5-T11, to loosen up the spine and get better 3-d correction.

With the preop and 6 week postop radiographs side-by-side it is easy to see how much taller and better aligned the patient is 3-dimensionally.

At 6 weeks after surgery, the patient underwent repeat pulmonary function testing.  Both the FVC and FEV1 improved dramatically. The absolute improvement was 17% for FVC and 18% for FEV1, but the relative improvement from the patient’s preoperative evaluation was 39% for FVC and 40% for FEV1! That is a dramatic improvement and now minimizes the chance lung function will be a problem in the future.

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