AIS Idiopathic Scoliosis Posterior Spinal Fusion

Isolated Thoracic Fusion for Idiopathic Scoliosis, T2-T12


Above is a 15-year-old female with a right thoracic idiopathic scoliosis measuring 55 degrees. His Risser stage is 4 and Sanders stage is 7, which means there is some, but not a lot, of vertical spinal growth remaining until she reaches skeletal maturity.
From the side there is a lower amount of thoracic kyphosis (25 degrees), which is typical for idiopathic scoliosis

The next step is to determine the flexibility of the curves.
Based on this being a 1B curve pattern we will want to leave a slight amount of tilt of the vertebra at the bottom of the fused area. Why? If we don’t the patient can get a shift of their trunk or body to the left (which causes hips to be uneven) or the disc below the fusion becomes wedged abnormally (which increases risk of this becoming arthritic and painful) or both.
Using the supine image (2nd from left) there is 7 degrees of tilt at the superior endplate of L1 (the first unfused vertebra below the fusion), which is a guide to how much tilt to leave in the fusion.

The next step is to plan the surgery BEFORE we get to the operating room.
Information which help to perform the best surgery possible:
Which should is higher? Right or Left
What is the scoliometer measurement for the thoracic and lumbar curves? These are the “rib humps” we see with scoliosis and want to correct as much as possible. For this patient the thoracic curve is 20 degrees and lumbar is 3 degrees.
Breakdown of which vertebra are in each curve, the proximal thoracic, main thoracic and lumbar curves.
Where and what type of pedicle screws are going to be placed (uniplanar = U; poly or multiaxial = M)
How much tilt do we want to leave for the upper instrumented vertebra (UIV)? Zero for this patient as this will level her shoulders.
How much tilt do we want to leave for the lowest instrumented vertebra (LIV)? 7 degrees as we discussed earlier.

These two radiographs are intraoperative radiographs AFTER correction. Very good scoliosis correction, kyphosis correction and derotation of the spine.

The postoperative radiographs are at discharge 3 days after surgery.

Three years after surgery. Patient is well balanced and back to all activities without limitation and no pain.

Leave a Reply

Your email address will not be published. Required fields are marked *