It is not just about the frontal plane: sagittal parameters impact curve progression in AIS patients undergoing brace treatment.
STUDY DESIGN
Retrospective cohort study.


OBJECTIVES
The purpose of this study was to explore the association between pre-brace and in-brace sagittal parameters and curve progression. To date, there has been no published research focused on spinopelvic sagittal parameters and bracing outcomes in AIS. We hypothesize that sagittal spinopelvic parameters are associated with curve progression at 2 years.


METHODS
This study included AIS patients with a pre-brace (PB) major curve between 20° and 45°. The outcome was defined as > 10° curve progression or surgery within 2 years of brace initiation. Spinopelvic parameters included C7-Central Sacral Vertebral Line shift (C7-CSVL), thoracic trunk shift, lumbar lordosis (LL), pelvic incidence (PI), T2-T12 thoracic kyphosis (TK) pelvic incidence-lumbar lordosis (PI-LL) mismatch, sagittal vertical axis (SVA), and pelvic tilt (PT).


RESULTS
Of 50 patients included in this review, [70% Rigo (RCSO) and 30% Boston (BSO)], 16 (32%) patients demonstrated progression (23% of patients with RCSO vs 53% with BSO; p = 0.034). In patients with more than 30% major coronal curve correction (CCC), 23% had progression. 45% of patients progressed when they achieved ≤ 30% correction (p = 0.108). Among PB sagittal parameters and adjusting for coronal curve, patients with an abnormal PB SVA had 3.1 times increased risk of treatment failure compared with patients who had a normal PB SVA. Patients with PB hypo-LL had a 2.8 times increased risk of treatment failure compared with patients who had normal or hyper-LL. Among IB sagittal parameters, patients who had a normal PB PI-LL had a 3.9 times increased risk of treatment failure when they became mismatched in-brace (IB). Patients who had normal pre-brace kyphosis who became hypo-kyphotic IB had an 8.4 times increased risk of treatment failure compared with patients who maintained normal TK or became hyper-kyphotic.


CONCLUSION
These data suggest that we should pay careful attention to sagittal parameters prior to and during brace treatment as braces can control these parameters.


LEVEL OF EVIDENCE
Level III.
['Matsumoto|Hiroko|H|', 'Warren|Shay|S|', 'Simhon|Matthew E|ME|', 'Konigsberg|Matthew W|MW|', 'Fields|Michael W|MW|', 'Roye|Benjamin D|BD|', 'Roye|David P|DP|', 'Vitale|Michael G|MG|']
D000293:Adolescent D001915:Braces D002648:Child D015331:Cohort Studies D000072700:Conservative Treatment D018450:Disease Progression D005260:Female D006801:Humans D008297:Male D012189:Retrospective Studies D012600:Scoliosis D013131:Spine D017211:Treatment Failure
Sagittal Parameters Bracing Spinopelvic Parameters Adolescent Idiopathic Scoliosis