Treatment of Severe Kyphoscoliosis in Children with Mucopolysaccharidosis Type I (Pfaundler-Hurler Syndrome) Using the Growing Rod Technique: A Case Series with Mid-Term Results.

Background: Patients with mucopolysaccharidosis type I (MPS I) have a good life expectancy due to early therapeutic options, such as stem cell therapy. Stem cell therapy can prevent the progression of some skeletal malformations. In contrast, the progression of thoracolumbar kyphoscoliosis, genua vara, and hip dysplasia cannot be influenced. We present 3 cases of children with MPS I with thoracolumbar kyphosis/kyphoscoliosis treated with a growing rod system.

Case Description: The medical records and radiologic imaging of 3 children with a diagnosis of MPS I and kyphosis/kyphoscoliosis of the lumbar spine treated between 2007 and 2019 were retrospectively analyzed. Two children presented with a kyphoscoliosis, and 1 child had a combination of severe anterolisthesis and kyphoscoliosis. Surgery to correct the kyphosis and dorsal stabilization was performed in all patients after exhausted conservative treatment. There were no neurologic complications. Postoperative treatment and aftercare included a corset for 4 months and physical therapy. In all 3 patients, distraction surgery of the lumbar stabilization was done twice at a mean interval of 1 year.

Conclusions: If conservative treatment fails and surgery is necessary, an individual approach is needed. Dorsal stabilization with pedicle screws using a growing rod technique is an option for the correction of thoracolumbar/lumbar kyphosis in children with MPS I. However, fusion should be prevented initially or should be kept as short as possible. We achieved acceptable correction of the spinal deformity using the growing rod technique. Finally, surgery with correction and fusion is necessary after exhausted correction potential.