Blog Topic: Spinal Deformity in Neurofibromatosis Type 1

Surgical Case #2

7-20-2022

The next case is a 14 year old male with NF-1.  There are dystrophic changes to the spine around the thoracolumbar junction, specifically penciling of the ribs and scalloping of the vertebral bodies (red arrows).  This has induced a painful kyphoscoliosis.

The next pictures demonstrate there is some, but not much flexibility of the spine deformity.  The second picture from the left is a supine (laying on one’s back) radiograph.  The third from the left is a push-prone (laying on one’e stomach and radiology technicians pushing to try to improve the spine deformity. Neither of these two do much to change the spine deformity position.

The below two radiographs are performed with the patient actively bending to the left and right.

The below pictures are made from a CT scan, which is then rendered into a 3-dimensional picture which one can rotate around to better understand the deformity.  These particular images were made just prior to the creation of a 3-d model.

The below MRI images demonstrates dural ectasias (red arrows), vertebral scalloping (yellow arrows), and wedging of the vertebra (orange arrow).    The spinal cord (green arrow) is bent around the backside of the L1 vertebra.

The next pictures are intraoperative radiographs (x-rays).  Fixation of the spine can be very difficult (due to dural ectasias and vertebral scalloping) and the quality of the bone to be softer than normal (osteopenia).  Spinal deformity surgery of NF-1 patients requires preoperative CT and MRI evaluations to understand spines and where fixation could be placed and how to correct the spine deformity.  Surgery typically requires use of screws, hooks and sublaminar bands to successfully treat NF-1 spines.

After the L1 vertebra was completely (100%) removed a titanium cage (red arrow) was placed between the vertebra above (T12) and below (L2).  This cage increases the strength of the spine construct.

Below are the before and after surgery pictures.  The surgery nicely improves the spinal alignment on both views.  There was no weakness or sensory changes after surgery.  The patient’s preoperative pain resolved.

Multiple rods across the area where L1 was resected, and the cage was placed, to add more rigidity and durability.