Upper cervical fusion in children with Morquio syndrome: intermediate to long-term results

Background: Paraplegia or death secondary to upper cervical spine instability and spinal cord compression are known consequences of Morquio syndrome. Decompression and fusion of the upper cervical spine are indicated to treat spinal cord compression. The purpose of this study was to report the intermediate to long-term results of upper cervical spine fusion in children with Morquio syndrome. Methods: Twenty patients (nine female and eleven male) with Morquio syndrome who underwent upper cervical spine fusion at a mean age of sixty-three months were retrospectively analyzed with use of hospital records. Radiographic and clinical results were reported. Results: The average follow-up period was eight years and ten months. Fusion was achieved in all patients except one; this patient underwent a revision with transarticular C1-C2 screw fixation. Seven patients developed symptomatic instability below the fusion mass that required extension of fusion to lower levels at a mean of ninety-one months after the initial operation. Two patients required decompression and fusion of a site other than the upper cervical spine. Asymptomatic cervicothoracic and thoracolumbar kyphosis was prevalent among our patients. All patients were neurologically stable at the time of the latest follow-up visit. Conclusions: Upper cervical spine fusion provides reliable fusion and a stable neural outcome in patients with Morquio syndrome. However, distal junctional instability is a major problem at long-term follow-up. Kyphotic deformity of the cervicothoracic and thoracolumbar junction may be present in a large number of patients with Morquio syndrome and evaluation for spinal stenosis at these levels should also be considered. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.