Long-term results after Boston brace treatment in late-onset juvenile and adolescent idiopathic scoliosis

Background: It is recommended that research in patients with idiopathic scoliosis should focus on short-and long-term patient-centred outcome. The aim of the present study was to evaluate outcome in patients with lateonset juvenile or adolescent idiopathic scoliosis 16 years or more after Boston brace treatment. Methods: 272 (78%) of 360 patients, 251 (92%) women, responded to follow-up examination at a mean of 24.7 (range 16-32) years after Boston brace treatment. Fifty-eight (21%) patients had late-onset juvenile and 214 had adolescent idiopathic scoliosis. All patients had clinical and radiological examination and answered a standardised questionnaire including work status, demographics, General Function Score (GFS) (100 - worst possible) and Oswestry Disability Index (ODI) (100-worst possible), EuroQol (EQ-5D) (1-best possible), EQ-VAS (100-best possible), and Scoliosis Research Society-22 (SRS-22) (5-best possible). Results: The mean age at follow-up was 40.4 (31-48) years. The prebrace major curve was in average 33.2 (20 - 57)degrees. At weaning and at the last follow-up the corresponding values were 28.3 (1 - 58)degrees and 32.5 (7 - 80)degrees, respectively. Curve development was similar in patients with late-onset juvenile and adolescent start. The prebrace curve increased > 5 degrees in 31% and decreased > 5 degrees in 26%. Twenty-five patients had surgery. Those who did not attend follow-up (n = 88) had a lower mean curve at weaning: 25.4 (6-53)degrees. Work status was 76% full-time and 10% part-time. Eighty-seven percent had delivered a baby, 50% had pain in pregnancy. The mean (SD) GFS was 7.4 (10.8), ODI 9.3 (11.0), EQ-5D 0.82 (0.2), EQ-VAS 77.6 (17.8), SRS-22: pain 4.1 (0.8), mental health 4.1 (0.6), self-image 3.7 (0.7), function 4.0 (0.6), satisfaction with treatment 3.7 (1.0). Surgical patients had significantly reduced scores for SRS-physical function and self-image, and patients with curves >= 45 degrees had reduced self-image. Conclusion: Long-term results were satisfactory in most braced patients and similar in late-onset juvenile and idiopathic adolescent scoliosis.