SpineCor Brace

 

EFFECTIVENESS OF THE SPINECOR BRACE BASED ON THE NEW
STANDARDIZED CRITERIA PROPOSED BY THE S.R.S. FOR
ADOLESCENT IDIOPATHIC SCOLIOSIS

Christine Coillard9 M.D., Valerie VachonM.Sc, Alin CircoM.Sc, Marie Beausijour M.ScA., Charles H. RivardM.D., F.R.C.S.(c), F.A.A.O.S., F.A.C.S.
Study conducted at the 9Research Center, SainteJustine
Hospital and University of Montreal, Canada.

Funded by:
1. Research Center, SteJustine Hospital
3175 ch. Ctte SteCatherine,
Montrial, Quibec, Canada, H3T 1C5

2. SpineCorporation Ltd.

Corresponding author:
Charles H. Rivard, MD, F.R.C.S.(c), F.A.A.O.S., F.A.C.S.
Research Center, SainteJustine
Montrial, Quibec Canada


Abstract

The purpose of this prospective observational study was to evaluate the effectiveness of the Dynamic SpineCor brace for adolescent idiopathic scoliosis following the standardized criteria proposed by the SRS Committee on Bracing and Nonoperative Management. They proposed these guidelines in order to make the comparison among studies more valid and reliable. From 1993 to 2006, 493 patients were treated using the SpineCor brace. 249 patients fitted the criteria for inclusion and 79 patients were still actively being treated. After all, 170 patients have a definitive outcome. All girls where premenarchal or less than one year postmenarchal. Assessment of brace effectiveness included; 1) percentage of patients who have 5: or less curve progression and the percentage of patients who have 6or more progression, 2) percentage of patients who have been recommended/undergone surgery before skeletal maturity, 3) percentage of patients with curves exceeding 45at maturity (end of treatment) and 4) 2years
followup beyond maturity to determine the percentage of patients who subsequently underwent surgery. Successful treatment (correction >5or stabilization 15:) was achieved in 101 patients of the 170 patients (59.4%) from the time of the fitting of the SpineCor brace to the point in which it was discontinued. 39 immature patients (22.9%) required surgical fusion whilst receiving treatment. Two patients out of 170 (1.2%) had curves exceeding 45at maturity. One mature patient (2.1%) required surgery within 2 years followup beyond skeletal maturity. The conclusion drawn from these findings is that the SpineCor brace is effective for the treatment of adolescent idiopathic scoliosis. Moreover, positive outcomes are maintained after years since 45 patients out of 47 (95.7%) stabilized or corrected their end of bracing Cobb angle up to years postbracing. Therapeutic study  investigating the results of treatment: level II.


INTRODUCTION
Many conservative treatments are available for adolescents with idiopathic scoliosis (AIS).
Although there are numerous studies in literature which have tried to summarize the results of
treatment(1-7) , the evidence for their accepted use is still unclear(8). In addition, the lack of
consistency for both inclusion criteria and the definitions of brace effectiveness(9) make many clinicians skeptical about the efficacy of conservative treatments(10,11).

The Scoliosis Research Society (SRS) thought it was necessary to establish parameters for all
future AIS bracing studiesin order to be able to make comparison amongst more valid and reliable studies(9) . Such guidelines will allow promotion of the effectiveness of different braces using different approaches, for instance the three point pressure principle used by rigid braces
and the Corrective Movementused) by the Dynamic SpineCor brace.

The effectiveness of the SpineCor brace has been shown for milder and moderate curves(1). The purpose of the present review is to evaluate the effectiveness of the SpineCor brace for AIS following the new standardized criteria proposed by the SRS Committee on Bracing and Nonoperative Management(9).

METHODS
The studied population
This prospective observational study was carried out on a group of 493 patients (92.7% females) having idiopathic scoliosis treated with the SpineCor brace.

Radiographic analysis
The initial pretherapeutic radiograph used digital technique where the irradiation is half as much as that of standard radiographs(12). The initial evaluation included posteroanterior and lateral Xray
without brace within maximum of one month prior to brace fitting. Control Xrays (erect PA) with the SpineCor brace (and shoe lift when prescribed) were taken on the day of the fitting, at 46 weeks and then every 5 months until weaning. Lateral Xrays were taken once year. At the end of the treatment, the controls were continued at 6 months, one year and once every year. These evaluations were performed without brace.

Inclusion criteria were as follows:

  • Idiopathic scoliosis diagnosis and radiological confirmation of absence of significant pathological malformation of the spine
  • Age over 10 years old and less than 15 when brace is prescribed
  • Risser 0, 1 or 2
  • If female, either premenarchal or less than year postmenarchal.
  • Initial Cobb angle equal to or above 250
  • Initial Cobb angle equal to or less than 400
  • No prior treatment for scoliosis 5

Exclusion criteria were as follows:

  • Presence of a congenital malformation of the spine, spina bifida aperta or spondylolisthesis
  • Neuromuscular scoliosis
  • Postural scoliosis

Skeletal maturity is considered achieved when Risser 4 or more is reached and, in females, when the patient is 2 years after menarche. The United States grading system(13) for Risser sign was used in this study. Taking into account the criteria mentioned above, we needed to exclude some patients from the actual study. Out of 493 patients who accepted the treatment with the SpineCor) brace between 1993-2006, 59 patients were under the age of 10 years at the initial visit, 61 patients had Risser 3 to 5 or were more than 1 year postmenarchal, 112 had an initial Cobb angle below 250 and 12 patients had curvature above 400. From the remaining 249 patients that respected those inclusion criteria, 79 patients were still actively being treated at the time of the analysis for total of 170 patients with an outcome. From this cohort of patients, 47 patients had years follow-up after weaning of the brace.

Description of the bracing system and treatment protocol The Dynamic SpineCor brace, developed in 1992-93, uses specific Corrective Movementdependant of the type of the curve. Curve classification was based on Ponseti and Friedmans 14) classification. The curve specific Corrective Movementis performed, and the brace is applied according to definitions contained the SpineCor Assistant Software. In order to be effective and to obtain neuromuscular integration the brace must maintain and amplify the corrective

movement over time. The brace must be worn 20 hours a day for a minimum of 18 months to
create a neuromuscular integration of the Corrective Movement) through active bio-feedback.
Generally, the brace is stopped at skeletal maturity (at least Risser 4).


Improvement of more than 5o or stabilization of 1 5o of the scoliosis curvature was defined as a
positive outcome. An aggravation of the spinal curvature of more than 5o, progression over 45:,
withdraw and surgery was defined as a negative outcome. The data collected were analyzed in
four outcomes as suggested by the SRS Committee on Bracing and Non-operative Management9.
In order to strengthen the ability to compare and combine results across studies, we stratified our
results by curve type, curve magnitude grouping, and skeletal maturity. Descriptive statistics
were employed to analyze the population.


RESULTS


170 patients (158 girls and 12 males) treated by the SpineCor brace respected the inclusion criteria and were not actively being treated. All girls where premenarchal or less than one year postmenarchal. 39 immature patients required surgery during brace treatment, 12 patients withdraw from the SpineCor treatment and refused any other conservative treatment, 14 patients were weaned before reaching skeletal maturity since they had an authorized end of treatment and
a Cobb angle inferior representing a stable corrective result. 47 patients had 2 years post-brace follow-up.


Assessment of brace effectiveness includes all of the following:


1. Percentage of patients who have 5: or less curve progression and the percentage of
patients who have 6: or more progression
59.4% of patients 101(87+14) patients out of 170 corrected or stabilized their initial Cobb angle,
and 18 patients (10.6%) had 6: or more progression of their initial Cobb angle (without
surgery)47 patients with a successful outcome at the weaning point reached the 2 years follow up.
With post-brace treatment follow-up observation, the treatment success rate at 2 years
was 95.7% (n=47), comparing the end of bracing Cobb angle to the one at 2 years post-bracing.
40 patients out of 47 stabilized their Cobb angle and 5 patients still improved from the time the
brace was discontinued up to 2 years follow-up.


2. Percentage of patient who have had surgery recommendation/undergone before skeletal
maturity 39 immature patients out of 170 (22.9%) required surgical fusion while receiving treatment.The average curve magnitude at bracing in this particular group was 35 15.1: (range:25-40:). General indication for fusion in all patients was progression of primary curve of more than 60: in thoracic region and 45: in thoracolumbar and lumbar region.


3. Percentage of patients with curves exceeding 45: at maturity In addition to patients referred for surgery before maturity, 2 patients out of 170 progressed beyond 45: at maturity (end of bracing Cobb angle).


4. 2-years follow-up beyond maturity to determine the percentage of patients who subsequently undergo surgery Four patients out of 47 (8.5%) had curves exceeding 45: at 2 years follow-up.  However,only two of them had a progression of their Cobb angle after the weaning point, the two others patients had a stabilization of their scoliosis. The Cobb angles of the progressive ones at the end of bracing were 42:and 51: respectively. Their Cobb angles at 2 years follow-up post-bracing visit were 48:and 61:. Regarding this particular sub-group of patients, surgery was required for only one patient, the one who had a Cobb magnitude of 51: at the end of bracing and 61: at the last visit post-bracing. Surgical treatment was not an option for the three other patients.

5. Results stratified by curve type, curve magnitude grouping, and skeletal maturity. The results were analyzed separately by curve type (thoracic, thoracolumbar, lumbar, and double
curves), curve magnitude, and skeletal maturity. Bracing success depending on curve type (table 1) was achieved in 56.8% for thoracic [37+5=42/74], 69.4% for thoraco-lumbar
[29+5=34/49] , 42.9% for double [13+2=15/35] and 83.3% for lumbar curve [8+2=10/12] comparing the initial Cobb angle to the one at maturity. To study the effect of curve magnitude on outcome, the patients were divided into two groups. Group 1 consisted of 67 patients whose curves magnitude at bracing was 25: to 29:, and group 2 consisted of 103 patients with curve magnitude of 30: to 40:. Group 1 had 70.1% of success compared to 52.4% of success for group
2. Comparison of brace success among initial Risser signs  0, 1, and 2 and at skeletal maturity is as followed: 46.4%, 88.9% and 80.6% respectively.


DISCUSSION


The purpose of this prospective observational study was to evaluate the effectiveness of the Dynamic SpineCor brace for adolescent idiopathic scoliosis following the standardized criteria proposed by the SRS Committee on Bracing and Nonoperative Management. In addition, we wanted to compare the effectiveness of the SpineCor brace to rigid braces, particularly; Boston brace2,3, Wilmington brace4, Milwaukee brace5, Charleston brace6,15 and the Rosenberger brace7.


We used these reference articles as an alternative of other since they used very similar inclusion and exclusion criteria as our study. A previous study has been published in 2003 in European Spine Journal1 on the first 195 patients
from the same prospective cohort. This preliminary study in 2003 revealed that on the 29 patients who had a minimum post-treatment follow-up of 2 years, 55% obtained a correction of their initial Cobb angle, 38% stabilized their Cobb angle and only 7% worsened by more than 5:. The
recent results follow a similar trend. Comparing the end of bracing Cobb angle to the one at 2 years post-bracing, our study reveals that the follow-up of orthopedic treatment was a success in 95.7 % of the patients with a mean correction of 8.611.7:. As reported by Montgomery and collaborators16, a follow-up of 2 years is sufficient to foresee progression after weaning from the brace. It seems possible with the SpineCor brace to have sustainable correction or stabilization of
scoliotic curves up to 2 years after discontinuation of brace treatment.


Our results also demonstrated variable positive outcome for patients having a lumbar (83.3%), thoracolumbar (69.4%), thoracic (56.8%) and double curves (42.8%). Double curves were a little bit less successful compared to the other type of curves. This may be explained by the fact that we detected them later compare to the other types of curves because the posture is more often quite normal and they are more rigid. Positive outcome was also achieved for group 1 with 70.1% of success (initial curvature between 25: to 29:) compare to 50.2% for group 2 (initial curvature between 30: to 40:) comparing the beginning of bracing to the weaning point. Those results demonstrate the fact that it is possible to achieved higher rate of correction or stabilization when the conservative treatment is started in the early stage. In spite of this, it was surprising to find out that success was attained in 46.4% of patients having an initial Risser sign of 0
compared to 88.9% and 80.6% for patients having a Risser sign of 1 and 2 respectively.


Although early reports indicated that the Milwaukee brace17 could afford some lasting reduction in the degree of spinal curvature, subsequent studies with longer follow-up demonstrated that, following the cessation of brace treatment, curves that had demonstrated some correction at the end of bracing with traditional rigid braces tended then to continually increased toward the pretreatment angle2,4,5,18. In the study of Noonan and colleagues5, 63% of the 88 patients wearing the Milwaukee brace were classified as a failure. Noonan et al showed that 27 patients (31%) had an arthrodesis; of these 18 patients (67%) had curve progression while they wore the brace, and 9 (33%) had progression of the curve after a trial of intentional weaning. Similar loss of correction over-time was also observed with other braces such as Wilmington and Boston braces.


In the study of Gabos and coworkers4, 22% out of 55 patients demonstrated an increase in the curvature of S5: between the end of bracing with the Wilmington brace to the time of final follow-up (mean of 14.6 years after the completion of treatment). Additionally, 13% demonstrated an increase in the curvature of S5: between the end of bracing and the time of final follow-up that resulted in a curve that was S5: greater than the deformity measured at the time of the initial treatment. Olafsson and colleagues3 studied a population of AIS patients wearing the Boston brace but with smaller curves (22 to 44: curve magnitude). For this cohort of patients,
mean Cobb angle at treatment start was 32 1 6:, after bracing this was 12.1 1 7.6:, after weaning 25.4 1 11.3: and at follow-up 29 1 12:. However, our results show that it is possible to obtain a correction or a stabilization of the pre-treatment Cobb angle (59.4%) and it seems possible to
maintain the brace success for 2 years after the end of the treatment by SpineCor brace since only two patients out of 47 who have completed the 2 years follow up had a curve worsening during this follow-up period.


In summary, the SpineCor Brace is effective for the treatment of AIS. Moreover, the positive outcomes are maintained up to 2-year follow-up beyond skeletal maturity. This particular feature of the SpineCor brace makes it very different to the already published literature on brace in which apparent correction obtained during treatment can be expected to be lost over time4,18. However, future studies that will support and reinforce this finding are necessary. Forthcoming studies using the same standardized criteria for AIS brace studies as used in this study will allow valid and reliable comparison between the SpineCor brace and any others rigid braces.

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