Natural History of Adolescent Scoliosis Curve Progression as a Function of Degree of Curvature and Age. Scoliosis Bracing Decision Requires More Information and Dialogue, not simple rule.

Back in 1989 when I was a Junior Resident at the Harvard Combined Orthopaedic Program, I did my first rotation at Boston Children’s Hospital, and learned a very simple rule to use in their busy scoliosis clinic:

If there is any significant growth remaining, consider putting the child/adolescent in a brace if:

Cobb angle 30-39 degrees on initial presentation, or
Cobb angle 25-30 degrees with documented progression, (meaning that you had a previous X-Ray showing Cobb Angle less than 25)

As a resident we loved simple rules, since it made life so much simpler for everyone. Once we knew how to measure the Cobb Angles accurately on the X-Ray using our grease pencils and goniometers, we could successfully determine the treatment:

Observe (Cobb < 25)
Brace (Cobb 25-39)
Surgery (Cobb 40-45 or more)

What could be simpler? Measure Curve. Order Brace. “Next!”

However, after spending two and a half years at Children’s from 1989 through the spring of 1994 off and on as Junior Resident, Senior Resident, Fellow, and then Chief Resident I began to realize that things were not quite so cut and dry as I initially thought. Now, some 13+ years later after finishing up as Chief Resident at Children’s, and having cared for thousands of patients with spinal deformities since then, and also combined with having 2 kids of my own who are now both teenagers, it has become clear that using the simple rule “stamp” to fly through clinic just doesn’t cut it. In addition, after getting additional training in epidemiology at the Harvard School of Public Health, I began to be able to see some of the deeper strengths and weaknesses in the existing scoliosis bracing and other treatment outcomes studies.

Last week at Hey Clinic I saw a very pleasant 9 yo girl with a 28 degree thoracic scoliosis as a second opinion regarding bracing vs. observation vs. other treatment.
We had a good long talk about many of the issues regarding the natural history of scoliosis progression during childhood and adolescence, and also about the long-term effects of scoliosis, including the risk of progression in adulthood.
One of the statistics that I shared with them was that the chance of significant curve progression was very dependent on the size of the curve combined with the number of years remaining for growth. In this child’s case, at age 9 or 10, she has at least 6 more years of growth remaining. Back in 1982, the Scoliosis Research Society (SRS) presented a natural history paper at the Denver SRS Annual meeting which included the Table shown above. In this table, you can see how the younger you are and the bigger your curve, the more likely you will have curve progression. In this girl’s case, she would have over a 90 percent chance of curve progression based on this data. This would be in great contrast to the 16 yo girl who would have a much lower chance of progression.

Attached is a photograph of a data table from Stuart Weinstein’s textbook “The Pediatric Spine” , Chapter 21, “Natural History of Adolescent Idiopathic Scoliosis, page 466, which is:

Table 2. Probability of progression: Magnitude of curve at initial detection
versus age
Curve
Magnitude
at Detection       Age at Detection
                        10-12 y 13-15 y     16 y
< 19 deg.          25%      10%         0%
20-29                60        40              10
30-59                90        70              30
>60                100         90              70

from Weinstein’s "The Pediatric Spine", p 466, Table 2, quoted from reference
78, Nachemson, a, Lonstein J, Weinstein S (1982): Report of the SRS
Prevalance and Natural History Committee 1982, reported at 1982 SRS Denver.

In this chapter, Stu Weinstein outlines 4 growth factors, and 2 curve factors that have big impact on predicting curve progression:

Younger the patient at age of diagnosis
Greater risk of progression before the onset of menarche in females.
The lower the Risser grade at curve detection, the greater the risk of progression. (Your daughter is at lowest Risser grade 0 — ossification of iliac crest growth plate)
Males are at 1/10 of risk progression than females.

2 curve factors:

Double curve patterns have greater tendency to progress than single
Larger magnitude of curve at detection, the greater the risk of progression (11 references quoted)

In this chapter they also report from Univ Iowa study that thoracic curves more than 30 degrees at maturity progressed an average of 19 degrees during the 40 yr f/u period, with the fastest progression being in the curves that were 50-75 degrees at time of maturity, which progressed 0.75 to 1 degree per year (40 degrees over 40 yrs).

This huge variation in expected progression is one of the reasons why it is difficult to interpret many of the bracing studies, in terms of their effectiveness of treatment, since many of these studies included a large percentage of adolescents who were in this low risk of progression group.

However, there have been several recent studies which have called into question the clinical effectiveness of scoliosis bracing, and have strongly suggested the need for new randomized control trials (RCT) to better understand when the Boston Brace or other braces can be useful for preventing curve progression (see below). I can tell you with my own background in epidemiology and outcomes research, it is very difficult to study the effectiveness of bracing for several reasons:

There is tremendous variation among children and adolescents who present with scoliosis in terms of:

   — curve type
    — age at presentation
    — curve size at presentation
    — growth rate
    — curve flexibility
2. Variations in treatment
    — type of brace, if any
    — hours brace worn
    — tightness/fit of brace
    — number of months of treatment
3. Difficulties in getting long-term follow-up data.
  — relatively rare disease.
  — takes MANY YEARS (maybe even 40 or more) to get the outcome you truly care about, which is long-term quality of life THROUGH adulthood, versus the typical short-term measure typically used which is 5 degrees of progression. The current outcome measure of “successful bracing” of 5 degrees or less of progression during a relatively short time period of 2 years after reaching skeletal maturity has more to do with the practical issue of having a measurable outcome variable within the lifespan of many of the investigators that are doing the study, and also while the patients can still be tracked for follow-up. Understanding what the investigators are considering “successful outcome” versus what we would like to know as a life-long “successful outcome” is an important distinction.

— Many patients “cross over” to surgical treatment once their curve shows progression.

In addition, it is important for the child and family to realize the following:

In order for the brace to be effective, it must usually be worn from 16-23 hours per day.
Compliance can often be an issue, and can create tension between child and parents.
The brace must be worn until skeletal growth is completed, which could be 2-6 or so years in most cases.
There may be some psychological / self-image issues around brace wear that could effect the child’s development.
There is no guarantee that the brace will work. Scoliosis surgery may still be necessary as an older adolescent, young adult or older adult. Some adolescents feel “cheated” if they choose the bracing option, and then end up needing surgery anyway. I have had college students weeping wildly in my office, who were treated for years in a brace through middle school and high school who then found out that they needed scoliosis surgery anyway.
The braces can be very expensive (often over $2,000 – $5,000) from most orthotists, although usually covered at least in part by insurance.
Bracing usually multiple trips to orthotist for adjustments, and possibly new braces required as the child grows.
Additional X-Rays needed in the brace to judge the effectiveness of the brace on curve correction.
Bracing does not improve the appearance of the deformity, or the end curve measurement — the hope is to hold the curve at or near the current measurement. Self-image issues have been shown to be a major factor in the long-term effect of scoliosis on the individual.
Scoliosis surgery has changed a lot during the past 40 years, with excellent improvements in postural appearance, much shorter surgical times, hospitalizations, and recovery times, and lower complication rates.
Bracing may be helpful to at least delay surgery until a child is bigger, and has had more axial growth, making surgery less risky. However, this has to be weighed against the potential for severe curve progression despite brace.
Other factors may affect the child/adolescent’s ability to be successfully braced, including body habitus and curve flexibility and location.

Therefore, rather than just applying a simple formula to the decision for bracing a child with scoliosis, we feel that it is better to have a longer dialogue discussing many of the issues above, and then personalizing the treatment based on the particular child/adolescent and their family. This often takes quite a bit of time for me and/or my physician assistants to have an un-rushed encounter or series of encounters to weigh the pros and cons and make the best possible decision for their child/adolescent and family. Like many things in life, there is often no “Black or White” clear answer, but many factors that need to be considered — which should not be too surprising given the complexity of the human body, human spine, and the growing adolescent child in a family and social environment. Hopefully in the future, as we understand the genetic and other etiologies of scoliosis better, and have improved prospective studies we should be able to counsel our patients and families even better. The learning never ends.

Dr. Lloyd Hey
http://www.HeyClinic.Com
Hey Clinic for Scoliosis and Spine Surgery
Raleigh, NC — USA

Some recent abstracts regarding scoliosis bracing are found below, and can also be found by searching http://www.pubmed.org

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A comparison of the thoracolumbosacral orthoses and providence orthosis in the treatment of adolescent idiopathic scoliosis: results using the new SRS inclusion and assessment criteria for bracing studies.
Janicki JA, Poe-Kochert C, Armstrong DG, Thompson GH.

Division of Pediatric Orthopaedics, Rainbow Babies and Children’s Hospital, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, OH 44106, USA.

This is a retrospective cohort study comparing the effectiveness of the thoracolumbosacral orthosis (TLSO) and the Providence orthosis in the treatment of adolescent idiopathic scoliosis (AIS) using the new Scoliosis Research Society (SRS) Committee on Bracing and Nonoperative Management inclusion and assessment criteria for bracing studies. These new criteria will make future studies comparable and more valid and accurate. METHODS: We have used a custom TLSO (duration, 22 hours/day) and the Providence orthosis (duration, 8-10 hours/night) to control progressive AIS curves. Only 83 of 160 patients met the new SRS inclusion criteria: age of 10 years and older at initiation of bracing; initial curve of 25 to 40 degrees; Risser sign 0 to 2; female; premenarcheal or less than 1 year past menarche; and no previous treatment. There were 48 patients in the TLSO group and 35 in the Providence group. The new SRS assessment criteria of effectiveness included the percentage of patients who had 5 degrees or less and 6 degrees or more of curve progression at maturity, the percentage of patients whose curve progressed beyond 45 degrees, the percentage of patients who had surgery recommended or undertaken, and a minimum of 2 years of follow-up beyond maturity in those patients who were thought to have been successfully treated. All patients are evaluated regardless of compliance (intent to treat). RESULTS: There were no significant differences in age at brace initiation, initial primary curve magnitude, sex, or initial Risser sign between the 2 groups. In the TLSO group, only 7 patients (15%) did not progress (<or=5 degrees), whereas 41 patients (85%) progressed by 6 degrees or more, including the 30 patients whose curves exceeded 45 degrees. Thirty-eight patients (79%) required surgery. In the Providence group, 11 patients (31%) did not progress, whereas 24 patients (69%) progressed by 6 degrees or more, including 15 patients whose curves exceeded 45 degrees. Twenty-one patients (60%) required surgery. However, when the initial curve at initiation of bracing was 25 to 35 degrees, the results improved. Five (15%) of 34 patients in the TLSO group and 10 (42%) of 24 patients in the Providence group did not progress, whereas 29 patients (85%) and 14 patients (58%), respectively, progressed by 6 degrees or more, and 26 patients (76%) and 11 patients (46%), respectively, required surgery. CONCLUSIONS: Using the new SRS bracing criteria, the Providence orthosis was more effective for avoiding surgery and preventing curve progression when the primary initial curves at bracing was 35 degrees or less. However, the overall success of orthotic management for AIS in both groups was inferior to previous studies. Our results raise the question of the effectiveness of orthotic management in AIS and support the need for a multicenter, randomized study using these new criteria.

PMID: 17513954 [PubMed – indexed for MEDLINE]