Dandy-Walker malformations with other complex congenital deformities associated with scoliosis: a case series.

Dandy-Walker malformations (DWM) is a rare condition with an estimated prevalence of 1 in 30 000 cases. Although DWM often complicates scoliosis, its prevalence and the time of onset are unknown because only a few reports have described the association between scoliosis and DWM. This case series describes spinal deformity associated with DWM. The clinical records and spinal radiographs of 23 consecutive patients with DWM at a single centre were reviewed. DWM was clinically diagnosed if patients met the following three conditions: (1) posterior fossa enlargement, (2) cerebellar hypoplasia and (3) cystic dilation of the fourth ventricle on MRI. Radiological assessment records for the presence, prevalence and time of onset of DWM were studied. Twelve of 23 patients (52%) demonstrated a scoliotic deformity, with 3 (13%) having severe deformities exceeding 60°. The average age at diagnosis was 3.6 ± 2.9 years (range: 0.7-9.7) and at radiographic examination during the final follow-up was 8.7 years (range 1.0-22.0). Only two patients were skeletally mature. The coronal angular deformity at the final follow-up was 34.2 ± 32.3° (range: 10.1-125.1°). One patient with moderate deformity >25° died before bracing. In addition, of three patients with severe deformities, only one had undergone posterior spinal fusion. The prevalence of scoliosis in DWM was 52%, and all patients who developed scoliosis reported early-onset scoliosis under 10 years of age. Early diagnosis and screening of spine deformity are required for patients with DWM to prevent disease progression. Evidence level: 4.