Chêneau Brace Prevents Curve Progression and Improves Sagittal Parameters in Adolescent Idiopathic Scoliosis
Commentary by Baron Lonner, MD
Long-term use of the Chêneau brace in the treatment of adolescent idiopathic scoliosis (AIS) is associated with significant improvements in kyphosis, lordosis, and pelvic tilt in addition to preventing curve progression in the coronal plane, according to a retrospective analysis in the Journal of Neurosurgery: Spine.
The Chêneau brace places pressure on the convexity of the lateral curvature of the spine in people with scoliosis and has wide expansion chambers in the frontal, sagittal, and horizontal planes. While previous studies of this brace have primarily focused on the efficacy of this brace and correcting curvature in the coronal plane, the present study was designed to investigate the effects of this brace on the coronal and sagittal planes as well as pelvic parameters in 32 patients (mean age, 12.9 years) with adolescent idiopathic scoliosis who were at high risk of curve progression.
The patients were instructed to wear the brace 23 hours per day and were evaluated at 4- to 6-month intervals. Follow-up was continued until the patient reached skeletal maturity or the curve had progressed to ≥50 degrees (treatment failure). The average duration of brace therapy was 24.4 months.
High Success Rate Found
The Chêneau brace showed an 81% success rate at stabilizing the spine and preventing curve progression to ≥50 degrees. The brace significantly decreased the degree of kyphosis, lordosis, and pelvic tilt (Table). The authors noted that a high variability in the effects of the brace on sagittal variables as well as pelvic parameters. For example, lumbar lordosis and thoracic kyphosis decrease in 66% and 63% of cases, respectively, and pelvic tilt increased in 38% of cases and was unchanged in 50% of cases.
The study authors noted that future studies are necessary to determine the mechanisms behind the 3 dimensional correction provided by the Chêneau brace.
Baron Lonner, MD
Chief, Division of Spine Surgery
Mount Sinai Beth Israel
Professor of Orthopaedic Surgery
The authors present the outcomes of brace treatment with the Chêneau brace in a small cohort of 32 patients. There are a number of flaws to their analysis and conclusions, which should be pointed out to the reader in order to place into context the conclusions of this study.
The indications for bracing in this AIS cohort are appropriate, including skeletally immature patients over age 10 years, Risser 0-2, premenarchal or less than 1 year post-menarchal. Full time bracing with a recommendation of 23 hours of brace wear per day was instituted until skeletal maturity was achieved or until brace failure occurred defined as Cobb angle of 50 degrees or greater. A fundamental data point missing from this report is the length of follow-up following cessation of bracing. If outcomes were reported several hours after the brace was removed and worn for the final time, the radiographic findings would be very different than if the follow-up period was 2 years, for example. Conclusions cannot be adequately made without this important methodology point. Also missing from this study from a methodological standpoint is the presence of a compliance monitor in the braces.
The authors report an 81% success rate in prevention of Cobb angle progression or an actual decrease in Cobb magnitude, which is in line with results reported in other studies. There is not mention of the mean and standard deviation of curve magnitude improvement in those who had improvement. It would be instructive to understand the nature of the cases in which curve correction occurred. Younger, more skeletally immature, lower BMI, smaller index curvature, thoracolumbar versus thoracic curvature, differences in brace compliance, for example.
Finally, the authors report an “improvement” in kyphosis and lordosis. Both kyphosis and lordosis were decreased. In fact, common wisdom would suggest that losing kyphosis in the typically hypokyphotic spine of the idiopathic scoliosis patient is undesirable for the potential impact on pulmonary function as well as the compensatory regional losses of lordosis in the lumbar and cervical spines. Furthermore, increase in pelvic tilt is not typically desirable as increased pelvic retroversion is associated with disability.
This patient cohort requires more scrutiny before drawing significant conclusions.