The Shilla Growth Guidance Procedure

My first on this surgical technique was in August of 2018, and I posted yesterday how I compare Shilla Growth Guidance against Traditional Growing Rods and MAGEC Growing Rods.  I will continue to discuss the Shilla Growth Guidance System using a Frequently-Asked-Question format, based on questions parents and caregivers have asked me over the last 10 years.

What size of scoliosis curve can be treated with a Shilla?

The Shilla Growth Guidance System has been used in the treatment of scoliosis 40° or greater (up to 115°, typically 60-80° range).

Can Shilla be used in patients at or near skeletal maturity? 

This Growth Guidance System requires the patient have spinal growth remaining to justify the modulation or guidance of spine growth.  In general, we perform this surgery in patients where spinal growth is anticipated for at least 3 years postoperatively.  If there is less than 3 years of spine growth remaining patients will typically be better treated with a definitive spinal fusion (curves greater than 50 degrees) or other growth modulation techniques such as vertebral body tether or posterior distraction constructs (curve 40-60 degrees).

How is the amount of growth remaining estimated? 

The main factor used in this determination is radiologic evidence of the child’s “bone age”, which can be very different to their chronologic age, based on the date of birth.  Currently the main classification used for determination of “bone age” is the Sanders Classification (reference 1), which uses radiologic evaluation of the growth plates in the hand.  The other method is to judge the amount of ossification (bone development) on the top of the iliac crests (hip bone), and is called the Risser Grade.

                                                          

Which scoliosis curve patterns can be treated with Shilla?

The most common curve pattern treated is the single curve patterns (thoracic or thoracolumbar), and is the easiest to manage.  Double major curves (one thoracic and one lumbar) and single lumbar curves have been treated with Shilla constructs, but there is much less clinical experience in these curve patterns.   

                                           

Thoracic curve

Double Major

Which diagnoses have been treated with Shilla? 

Diagnoses for which the Shilla has been used include: infantile and juvenile idiopathic scoliosis, congenital scoliosis, Beale’s syndrome, myelomeningocele, Marfan’s, neurofibromatosis, spinal muscular atrophy, arthrogryposis, multiple pterygium syndrome, spinal cord tumors, Prune Belly, Dandy-Walker, hypophosphatasia and dwarfism.  In general, all types of early-onset scoliosis (idiopathic, congenital, neuromuscular and syndromic) can be effectively treated by Shilla Growth Modulation System.

What is the age range for patients treated with Shilla? 

Ages at the time of surgery have ranged from 23 months to 11 years with the average patient being around 6-8 years. 

How do you decide when to do a Shilla?

Curve magnitude, documentation of curve progression, and skeletal age have been the key determinants in the decision to operate.

What is the longest follow-up at Wash U?

10 years postop

What does the prototypical construct for look like? 

If you look at the blog post from August 2018 I demonstrated a common spinal construct for Shilla.  What makes Shilla different than growing rod construct is the most curved part of the spine (called the apex) is actively straightened by using multiple pedicle screws, and then creating a solid bony fusion.  By fusing the apex of the scoliosis this most problematic part of the spine will not curve again and will remain in a straightened position.  The apex fusion is usually 2-4 vertebral levels, and the below case has 4 vertebral levels fused T8 through T11, using 8 pedicle screws.  There are 5 screws above and 5 screws below the apical fusion, and these are the Growth Guidance or Shilla screws.  These 10 screws will guide spinal growth along the straightened rods above and below, which is why the rods are left long.  As the spine grows the Growth Guidance or Shilla screws will slide away from the middle of the construct.

                                           

Please send me any questions you may have about this surgical procedure….

References:

1.       Sanders JO, Khoury JG, Kishan S, Browne RH et al. Predicting scoliosis progression from skeletal maturity: a simplified classification during adolescence. J Bone Joint Surg Am 2008; 90(3):540

What is the best surgery for a patient with Early-Onset Scoliosis (EOS) who needs to have surgery?

This is a question parents commonly ask me in the office.  The question is a fair, reasonable question.  So why is it so hard for me to give an answer?  Well.....EOS is a problem which has many facets or things which need to be considered to be able to optimally answer the question.  Every child and every spinal deformity is unique: rib deformities (brown circle), spine/vertebral pathology/problems (purple circle), and differing underlying diagnoses (yellow circle) all need to be considered.  In addition, patient age, location of the deformity, patient height and weight, bone quality, etc…. also comes into play when we consider how to surgically treat a patient.

…and because each patient is unique….….

And for EOS surgery the three surgical “tools” we are going to talk about are:

1.       Traditional Growing Rods (TGR)

2.       Magnetically-Controlled Growing Rods or MAGEC (MCGR)

3.       Growth Guidance Surgery (GGS)

Like many of the decisions we make every day in life, identifying the goals or desired outcome of our actions is important.  For surgery we need to identify what “success” looks like....because if we don’t know what our goals are….we cannot determine if our surgery achieved it goals.  Below is a short list of the “Goals of EOS surgery”. 

So let’s look one-by-one at each one of these goals to see how the three most common surgeries for EOS compare.  Below is study we published comparing Growth Guidance Surgery to Traditional Growing Rods.

So this study reported similar outcomes for scoliosis curve correction, spinal height and surgical complications, with fewer surgeries in the Growth Guidance Surgeries compared to Traditional Growing Rods.

FYI: Distraction-based constructs are Traditional Growing Rods and Magnetically-Controlled Growing Rods

So what are the goals which appear to be equally treated by all three surgeries?

Let’s review how these 3 surgeries compare

When we look at our “Goals of EOS Treatment” you see how favorably Growth Guidance Surgery stacks up against Traditional Growing Rods and Magnetically-Controlled Growing Rods.  When I have a child who needs surgery I consider each of these methods of treatment, but the first one I think of is Growth Guidance, followed by Magnetically-Controlled Growing Rods and if neither of these surgeries can be performed I opt for Traditional Growing Rods.

Below is a typical patient, who at 9 years of age underwent surgery and is shown 3 years after surgery.  He only has had one surgery so far……

The last item I want to comment about is another question I sometimes get asked by parents who have seen other pediatric spine before seeing me: Why haven’t other surgeons offered Growth Guidance as a treatment option for my child?  Growth Guidance surgery has been around since the early 2000s, yet it has not caught on as a popular surgical technique, so it’s not like this is new procedure.  The main issue is Growth Guidance Surgery is a more difficult procedure to perform than Traditional or Magnetically-Controlled Growing Rods and it has been taught to pediatric orthopaedic surgeons at only a couple of medical centers in the U.S. with any frequency (Little Rock, Arkansas and St. Louis, Missouri).

March 30, 2019

At the 2019 Marfans Foundation Heartworks Gala I was awarded the "Hero with a Heart" for my care of patients with Marfans.  It was a wonderful event.  I was truly humbled by the award.

This is the link to the video:
https://youtu.be/8WAOsPsQ1GE

Healthcare Resources for Families: How to be more engaged

A big factor in the outcome of a healthcare treatment, such as surgery, is the concept of Engagement.  Engagement means to interact with something and, in the context of healthcare, means the physician, nursing, support staff and hospital.  It is an active process and implies two-way communication.  It is not just the physician or nurse speaking....it is a discussion, back and forth, about each healthcare topic or issue.  The more engaged the family and patient are in their healthcare the greater the chance is the outcome of treatment will be improved, such as less pain, higher physical function, etc.... 

Below is a hyperlink I recommend looking into, specifically the "For Patients and Families in the Hospital" and "For Patients and Families in the Medical Office".

https://www.ahrq.gov/professionals/quality-patient-safety/patient-family-engagement/index.html

New publication on congenital scoliosis

The Risks of Spinal Deformity Surgery: Occurrence of New Neurologic Deficits

In the blog post from December 17^th, 2018 the operative risks which are common to all surgical procedures done under general anesthesia were presented.  This post will focus on the one of the risks unique to spinal deformity surgery: New neurologic deficits.  This includes paralysis, leg/arm weakness, sensory changes, bowel and bladder incontinence, etc…these are some of the bad things that worry patients, families and surgeons the most.  In 99% of surgeries one main goal is to preserve the patients’ neurologic function that they had before surgery and 1% of the time we are aiming to improve neurologic function (for patients who have problems for which surgery on the spine is being performed).

In 2019, optimal monitoring of spinal cord function during surgery, in the U.S., is to continually assess the motor and sensory tracts of the spinal cord. (3)  This is accomplished with:

1.      Sensory tracts: SSEPs or Somatosensory evoked potentials

2.      Motor tracts

a.      DNEPs or Descending Neurogenic evoked potentials

b.      TcMEPs or Transcranial Motor evoked potentials

There are three noteworthy studies in the area of new neurologic deficits during spinal deformity surgery:

#1: In the largest series of spinal surgeries published to date, Hamilton et al published on 108,419 surgeries (all ages) from the Scoliosis Research Society Morbidity and Mortality database.  There were 1064 new neurologic deficits (1.0%) which were comprised of 662 nerve root deficits, 74 cauda equina deficits and 293 spinal cord deficits, and 35 unknown.  This study reported revision surgery had a 41% higher new neurologic deficit rate than primary surgeries (1.25% vs. 0.89%) and pediatric patients were 59% higher than adults for new neurologic deficit (1.32% vs. 0.83%).

Recovery Rates                                none      partial   complete

               Nerve root                         4.7%      46.8%    47.1%

               Cauda equina                    9.6%      45.2%    45.2%

               Spinal cord                         10.6%    43%       45.7%

#2: From our institution Washington University in St. Louis (Shriners Hospital for Children, St. Louis Children’s Hospital and Barnes-Jewish Hospital), Raynor et al, reported the largest single-center experience with new neurologic deficits after spinal surgery, 12,375 surgeries (all ages) over a 25-year time span.  Neuromonitoring alerts occurred in 3.1% of surgeries and in 93% of those events the corrective interventions during surgery led to data recovery and no new neurologic deficits.  Only 0.12% of all patients had a permanent new neurologic deficit after surgery.

#3: In another study from our center, Thuet et al reported on the largest single-center study on neuromonitoring of pediatric patients (<18 years of age) published to date.   Of the 3436 pediatric patients, there were 74 (2.2%) neuromonitoring alerts for which intraoperative corrective interventions improved 92% to baseline data and function.  Only 6 (0.17%) patients had a new neurologic deficit.

One important finding of this study is neuromonitoring, using sensory and motor tract analysis, is able to predict final neurologic outcome in 99.8% of surgeries. 

In addition, it is important to remember intraoperative alerts happen, and most are not foreseen or predictable.  In this study intraoperative neuromonitoring events occurred once every 42 cases and permanent neurologic deficit every 573 cases.  Hence it is important an action plan is ready to go at all times if a neuromonitoring alert occurs in surgery.

Take-home thoughts about spinal deformity surgery (without vertebral column resections):

1.      Intraoperative neuromonitoring alerts occur in 2.2%-3.6% of cases. (1, 5, 8)

2.      Intraoperative corrective interventions decrease new neurologic deficit rate by 86-92%. (1, 8)

3.      Permanent new neurologic deficits occur in 0.12-0.3% of cases. (1, 5, 6, 8)

4.      New neurologic deficits are more likely in revision surgery (vs. primary) and pediatric patients (vs. adults). (4, 6, 7)

5.      Intraoperative neuromonitoring can predict long-term neurological outcome in 99.8% of cases. (8)

6.      Optimal intraoperative neuromonitoring involves assessing the sensory and motor parts of the spinal cord.

7.      Rates of new neurologic deficit vary by type of spinal deformity: congenital 2.2%, neuromuscular 1.1%, and idiopathic 0.8%. (7)

References:

1.      Buckwalter JA, Yaszay B, Ilgenfritz RM, Bastrom TP, Newton PO.  Analysis of intraoperative neuromonitoring events during spinal corrective surgery for idiopathic scoliosis.  Spine Deformity 2013;1:434-8

2.      Cho SK, Lenke LG, Bolon SM, Pahys JM, Cho W, Kang MM, Zebala LP, Koester LA.  Can intraoperative spinal cord monitoring reliable help prevent paraplegia during posterior vertebral column resection surgery?  Spine Deformity 2015;3:73-81

3.      Fehlings MG, Brodke DS, Norvell DC, Dettori JR.  The evidence for intraoperative neurophysiological monitoring in spine surgery.  Does it make a difference?  Spine 2010;35:s37-46

4.      Hamilton DK, Smith JS, Sansur CA, et al.  Rates of new neurological deficit associated with spine surgery based on 108,419 procedures.  Spine 2011;36:1218-28

5.      Leong JJ, Curtis M, Carter E, Cowan J, Lehovsky J.  Risk of Neurological Injuries in Spinal Deformity Surgery.  Spine 2016;41:1022-7

6.      Raynor BL, Bright JD, Lenke LG, et al.  Significant change or loss of intraoperative monitoring data.  Spine 2013;38:E10-8

7.      Reames DL, Smith JS, Fu K, et al.  Complications in the surgical management of 19,360 cases of pediatric scoliosis: a review of the Scoliosis Research Society Morbidity and Mortality database.  Spine 2011;36:1484-91

8.      Thuet ED, Winscher JC, Padberg AM, et al.  Validity and Reliability of Intraoperative Monitoring in Pediatric Spinal Deformity Surgery.  Spine 2010;35:1880-6

How to maximize the function of your back and minimize back pain:

After a lot of recent office visits on back pain, I think it’s a good idea for me to post some information on how to avoid back pain…at any age.

Three things you can do to optimize the function of your back, and not get back pain:

1.      Maintain your ideal body weight.  The more weight you carry, the higher your body mass index (BMI), the more stress is on your back, its muscles, vertebra and soft tissues.

2.      Be physically fit.  This does not mean running a marathon, riding a century (100 miles on a bike), or swimming the English Channel.  Instead, we recommend participating in aerobic activity in which you raise your heart rate and break a sweat for 20-30 minutes every other day.  This does not have to a competitive or a team sport.  Noncompetitive, individual activities (such as swimming, jogging, etc…) are ideal, as they can be done whenever and wherever you want.  By working on your fitness, you will likely drop unhealthy body weight, strengthen your core musculature, have improved energy and mental outlook.  It is a simple fact: people who are more aerobically fit have less back pain.  There is plenty of scientific data supporting the need for people to be more active and sit less.

3.      Don’t smoke cigarettes or vape.  Both of these activities permit the toxic substance nicotine to enter the body.  The impact of nicotine on the human body is well-documented, and I will not go into it in this blog.  For our topic the impact of nicotine on your back is its effect: severe small blood vessels constriction and inhibition of new blood vessel growth.  This strangulates the tissues, which need continuous supply of oxygen and nutrients, and this especially impacts the intervertebral discs.  These discs are the shock absorbers in the back, and their health is important for the long-term function of the back.  Nicotine accelerates the damage to the discs, causing them to become dehydrated, or lose their water content, which causes secondary collapse and back and possibly leg pain (sciatica).  Once the discs are damaged they can never return to normal…they will only continue to become more worn out.