Blog Topic: Talking Points for Early-Onset Scoliosis Patients: Magnetically-Controlled Growing Rods vs. Shilla Growth-Guidance

8-23-2022

 

In the surgical treatment of Early-Onset Scoliosis (EOS) the options boil down to two main constructs:

 

Distraction-Based: this encompasses both Traditional Growing Rods (TGR) and Magnetically-Controlled Growing Rods (MCGR)

            Growth-Guidance: this is also called the “Shilla Procedure”

 

We will not go into detail about these two spine constructs, but ask you go back in this blog to older posts to get the information you are interested in obtaining for you or your child.

The below table is a breakdown of the similarities and differences between Shilla Growth Guidance and Magnetically-Controlled Growing Rods.  This table can be used to stimulate and augment discussions with pediatric spine surgeons about the two constructs, and which is more appropriate for their child.

 

Blog Topic: Blood Management During Spine Deformity Surgery

8-22-2022

 

In 2022, spine deformity surgery usually requires a long incision and temporary retraction of muscles from the spine.  This extensive exposure of the spine helps to loosen up the spine (to get better correction), insert pedicle screws to grip the spine and place the long rods, which moves the spine in space and maintains the correction in its new position (while the spine fusion develops).

 

 

This type of exposure, and the amount of time required for these surgeries (4-6 hours), creates the opportunity to have significant blood loss. Does the amount of blood loss in surgery matter? The answer is “yes”. There is a convincing amount of published research which documents lower complications and better patient outcomes when the blood loss from surgery is low.

 

 

 

During surgical procedures in the operating rooms there are various methods to minimize or stop bleeding, from intravenous medications to topical materials to surgical technique.  In spine deformity surgery, some of these are effective and easy to do, while others are not as effective or require changes in the execution of surgery.   

So how do we minimize blood loss during pediatric spinal deformity surgery? Here are a few of methods we utilize on a daily basis:

Meticulous surgical technique: During surgery it is important to identify any and all bleeding.  Electrocautery is used to stop the bleeding.

Use of tranexamic acid: This medication is given by vein, through an IV, during surgery and has been demonstrated to decrease bleeding.

Topical hemostatic agents: These materials are applied on the surfaces of muscle and bone which coagulates bleeding.

Use of red blood cell scavenging: During surgery we suction blood out of the wound and this type machine collects, filters and spins down to concentrate the blood.  We can then give this concentrated back to the patient.

 

Blog Topic: The Use of Internal Distraction in Severe Scoliosis

8-7-2022

In severe scoliosis, the use of traction has demonstrated an ability to improve the spinal deformity before surgery was actually performed.  There are three main methods:

1.    1. Preoperative halo-gravity traction

2.    2.   Intraoperative halo-femoral traction

3.    3. Intraoperative Internal Dis-Traction

This post will focus on #3: Intraoperative Internal Dis-Traction

To demonstrate this treatment we will use the case of a 13 year old female who has severe scoliosis measuring 105 degrees.  Treatment thus far has been observation.  She had been having daily back pain which prevented her from playing athletics. 

Due to the severe scoliosis a total spine MRI was ordered and a thoracic syrinx was diagnosed (treated nonoperatively).

I call her type of scoliosis: neurogenic.  Many surgeons will call this neuromuscular but I don’t think it is correct to included this type of patient into the same group as cerebral palsy, spina bifida, spinal muscle atrophy, etc….diagnoses.

The image, below far right, is a push prone.  This image demonstrates that when a force is exerted on the spine the scoliosis improves from 105 degrees to 77 degrees.

On the below right sidebender (right side radiograph) the deformity decreases to 82 degrees.

Next are a picture and radiograph taken in surgery, which both demonstrate Intraoperative Internal Dis-Traction.  After exposure of the spine multiple osteotomies (posterior column osteotomies or PCOs) are done to make the spine more flexible, and allow more correction of the scoliosis.

Then a few screws are placed in the lower part of the spine (red circle), then hooks are placed on 4 ribs on the concave side of the scoliosis (yellow circle).  These two foundations are then connected by a rod and then distraction can be done to improve the scoliosis, which you can see it is much better than it was before surgery.

After this rod is placed the remainder of all the pedicle screws are inserted.  Distraction is done multiple times to gradually improve the scoliosis.  It is important to have spinal cord monitoring as the Dis-Traction can make the spinal cord not work normally.

In surgery the right rod is placed, then the Dis-Traction rod is removed, and a new left rod is placed.  During the rod placements more and more and more correction is safely obtained.

The below radiographs demonstrated the postoperative correction, improved from 105 degrees to 38 degrees.

Overall a nice correction in both the front and side views of the spine.

 

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.

 

Blog Topic: Spinal Deformity in Neurofibromatosis Type 1

Surgical Case

7-12-2022

The case presented is a 13 year old male with NF-1 who has a severe, progressive, painful kyphoscoliosis.

There is some inherent spinal flexibility as the thoracic kyphosis of 91 degrees improves when he lays on his back and hyperextends. 

The below selected MRI cuts demonstrates he does not have significant dural ectasias which could complicated surgery.  The axial MRI cut shows the spinal cord very eccentric in the canal, resting against the pedicle.  The spinal cord is slightly out-of-round, which elevates the risk of neurologic issues during surgery.

The below coronal CT scan cuts nicely shows the apex of the scoliosis having very abnormal vertebra.  Instead of being rectangular they are trapezoidal or triangular, which makes the scoliosis have a very tight turn.

The below axial CT scan cuts demonstrates the very abnormal pedicles.  Several of these pedicles (R T7, R T8 and R T9) are very difficult to place straight pedicle screws.  The reason these can be cannulated safely is due to the bone being malleable or bendable, and the pedicles can be bent straight (within reason).

The patients underwent 4 weeks of in-patient halo-gravity traction, with a maximum traction weight of 28 lbs. Despite the spine improving above and below the apex of the scoliosis, and the kyphosis improving, there still was a stiff apex.

Surgical treatment was a T3-L3 posterior spinal fusion and a T10 vertebral column resection, which means the entire T10 vertebra was removed.  This technique disconnects the spine and dramatically increases the flexibility of the spinal deformity.  After the spine was straightened a metal cage was placed in the front to help attain and maintain correction.

The patient is one year out from surgery and his doing well without pain.

 

 

Blog Topic: Spinal Deformity in Neurofibromatosis Type 1

7-10-2022

 

For details on Neurofibromatosis Type 1 (NF-1), I will refer you to Wikipedia:  https://en.wikipedia.org/wiki/Neurofibromatosis_type_I

As this blog focuses on spinal deformity in children and adolescents following is a brief summary as it relates to the musculoskeletal system (spine and extremities):

1.    1.  NF-1 causes tumors along nervous system which can grow anywhere on the body.

2.     2. Musculoskeletal abnormalities:

a.      Spine: Meningocoeles, dural ectasia, scoliosis, kyphosis

b.      Skeletal muscle weakness

c.      Long bones: pseudarthrosis (most commonly tibia), limb hypertrophy

3.      3. Approximately 20% of NF-1 patients will have spinal deformity.

4.     4. There are two types of spinal deformity in NF-1

a.      Idiopathic-like: looks and behaves more like idiopathic scoliosis

b.      Dystrophic

                                                    i.     Sharp, angulated spine deformity (kyphosis, scoliosis and kyphoscoliosis)

                                                   ii.     More common in the thoracic spine

                                                  iii.     Spines can start out having a more idiopathic-like deformity, which can change into a dystrophic type.

                                                  iv.     Causes penciling or thinning of the rib heads which can migrate into the spinal canal

 

 9 year old female

 

 

5.      5. Dural Ectasia: Circumferential enlargement or ballooning of the thecal sac, nerve root sleeves and spinal canal.

a.      More common in lumbar spine

b.      Causes vertebral body scalloping

c.      Also thins the pedicles

 

 

6.      6. Treatment

a.      For the idiopathic-like deformities, lower magnitude deformities are amenable to bracing. Surgical treatment mirrors guidelines for idiopathic scoliosis.

b.      For the dystrophic deformities:

                                                    i.     Bracing is limited in effectiveness

                                                   ii.     Surgery is performed for lower magnitude deformities due to the sharper-angulated deformities, increasing difficulty in achieving necessary spinal fixation and the risk of neurologic changes (such as weakness, sensory changes, bowel/bladder dysfunction).

Next several blog posts actual surgical cases of NF-1 will be presented.

 

Blog Topic: Recent Publication in The Spine Journal

6-14-2022