Purpose: Various series have reported successful management of scoliosis after surgical treatment of the associated Chiari malformation, syrinx, or bracing. Multiple factors have been associated with curve progression, but interpretation of outcomes is confounded by the wide range of reported results and size of individual series. We attempted to evaluate the outcomes of Chiari I-associated scoliosis by performing a meta-analysis of currently published data.
Methods: We conducted a systematic review of published articles using Medline, PubMed (from 1950 to January 2010), and reference lists of identified articles for Chiari malformation and scoliosis.
Results: One hundred and twenty patients were identified in 12 studies, of them, 37 % were male. The mean age at the time of surgery was 9.7 ± 4.1 years. The mean curve magnitude at presentation was 34.4 ± 13.0° and progressed to a mean value of 38.9 ± 20.2°, with an average follow-up of 48.3 ± 48.2 months. After surgical intervention, curve magnitude improved in 37 % of patients (n = 42); there was no change in 18 % (n = 20), and curves progressed in 45 % (n = 51). Age (p = 0.0097) and presence of surgical intervention (foramen magnum decompression [p = 0.0099] and syrinx shunting/drainage [p = 0.0039]) were statistically associated with improvement of the scoliotic curve. Surgical decompression of the foramen magnum had the greatest impact on the scoliotic curves.
Conclusions: Data accrued from our analysis suggest that curve magnitude will improve after surgical treatment of the Chiari malformation in one third of patients, and curve progression will stabilize or improve in one half.