Natural history of scoliosis in cerebral palsy and risk factors for progression of scoliosis.

BACKGROUND: Scoliosis in cerebral palsy (CP) often occurs and causes a disturbance in daily life. The purpose of this study was to investigate the natural history of scoliosis in cerebral palsy and determine risk factors for the progression of scoliosis using multivariate analyses.

METHODS: We revised 113 patients with CP (47 males and 66 females) who had scoliosis with a curve of at least 10° were reviewed and retrospectively investigated these cases of scoliosis and analyzed the risk factors for the progression of this condition.

RESULTS: The mean follow-up period was 16.5 years and the mean age at onset of scoliosis was 6.6 years (range: 1-16 years). In 59 patients (52%), the age at onset of scoliosis was under 6 years. On the final radiographs, the mean Cobb angle was 55.1° (range: 10° to 169°). After the age of 20 years, 13 of 40 patients (32.5%) had a progression of over 10° in scoliosis. Multivariate analyses showed the risk factors for the progression of scoliosis to be hip displacement (p = 0.0038), the onset of scoliosis before the age of 6 years (p = 0.0024), and 30° of the Cobb angle before the age of 10 years (p < 0.001). A subtype of CP (spastic quadriplegia) was identified as a potential risk factor.

CONCLUSIONS: After the age of 20 years, 32.5% patients had a progression of over 10° in scoliosis. Risk factors for the progression of scoliosis in CP included hip displacement, early-onset scoliosis, and Cobb angle of 30° before the age of 10 years.

LEVEL OF EVIDENCE: Prognostic level IV - case series.