3DCT scan in a 7-year-old girl with MPS type IV A showed laminectomy of C1 was done at the II stage of surgical treatment (occipitospondylodesis). Correction and posterior instrumentation of the cervical spine at the C0–C5 level in conjunction with posterior spinal fusion with costal autograft was performed. Few months after decompression at C1 level, occipitospondylodesis (i.e., fixation of the upper 2 or 3 cervical vertebrae to the occipital bone) was performed. 3D-CT = three-dimensional computer tomography, MPS = mucopolysaccharidosis.