Efficacy of the Osaka Medical College (OMC) brace in the treatment of adolescent idiopathic scoliosis following Scoliosis Research Society brace studies criteria

Abstract

Background: The efficacy of brace treatment for patients with adolescent idiopathic scoliosis (AIS) remains controversial. To make comparisons among studies more valid and reliable, the Scoliosis Research Society (SRS) has standardized criteria for brace studies in patients with AIS. The purpose of this study was to evaluate the efficacy of the Osaka Medical College (OMC) brace for AIS in accordance with the modified standardized criteria proposed by the SRS committee on bracing and non-operative management.

Methods: From 1999 through 2010, 31 consecutive patients with AIS who were newly prescribed the OMC brace and met the modified SRS criteria were studied. The study included 2 boys and 29 girls with a mean age of 12 years and 0 month. Patients were instructed to wear the brace for a minimum of 20 hours per day at the beginning of brace treatment. The mean duration of brace treatment was 4 years and 8 months. We examined the initial brace correction rate and the clinical outcomes of main curves evaluated by curve progression and surgical rate, and the compliance evaluated by the instruction adherence rate for all cases. The clinical course of the brace treatment was considered progression if ≥6° curvature increase occurred and improvement if ≥6° curvature decrease occurred according to SRS judgment criteria.

Results: The average initial brace correction rate was 46.8%. In 10 cases the curve progressed, 6 cases the curve improved, and 15 cases the curve remained unchanged (success rate: 67.7%). The mean instruction adherence rate, that was defined the percentage of the visits that patients declared they mostly followed our instruction to total visits, was 53.7%. The success rate was statistically higher in the patient group whose instruction adherence rate was greater than 50% (88.2%) as compared with in those 50% or less (42.8%).

Conclusions: OMC brace treatment for AIS patients could alter the natural history and significantly decreased the progression of curves to the threshold for surgical intervention. Better instruction adherence of brace wear associated with greater success.

Keywords: Adolescent idiopathic scoliosis (AIS); Conservative treatment; Hanging total spine x-ray; Osaka Medical College (OMC) brace; Scoliosis Research Society (SRS); Standardized inclusion and assessment criteria.

Figure 1

Osaka Medical College (OMC) brace. The OMC brace satisfactorily corrects double major curves (a, b) and a standing posture in brace is well balanced (c, d).

Figure 2

Sequential changes of the Cobb angle. The average Cobb angles in upright position before treatment, in hanging position, on initial brace wear, and at final follow-up were 27.3 ± 4.2°, 18.2 ± 4.0°, 14.7 ± 6.7°, and 28.6 ± 11.3°, respectively. The main curves were corrected by wear of the OMC brace better than hanging position. And OMC brace treatment could prevent the progression of curves during periods of growth.

Figure 3

Success rate depend on compliance. The success rate in the patient group whose instruction adherence rate was greater than 50% and 50% or less were 88.2% and 42.8%, respectively. The success rate was statistically higher in the patient group whose instruction adherence rate was greater than 50% as compared with in those 50% or less.

Figure 4

Case 1: 12 years 10 months girl. The patient had a left convex 23° lumbar scoliosis before treatment (a, b). The angles of lumbar curves were corrected to 18° in hanging position and 5° in brace wear, respectively (c, d). Throughout brace treatment for 3 years and 5 months, her instruction adherence rate was maintained at 100%, and the Cobb angle improved to 7° at final follow-up (e, f).

Figure 5

Case 2: 11 years 3 months girl. The patient had a right convex 26° thoracic scoliosis before treatment (a, b). The angles of thoracic curves were corrected to 17° in hanging position and 13° in brace wear, respectively (c, d). Throughout brace treatment for 6 years and 5 months, her instruction adherence rate remained at only 7.7%, and the Cobb angle progressed to 41° at final follow-up (e, f).