Spine challenges in mucopolysaccharidosis.

PURPOSE: Mucopolysaccharidosis (MPS) are rare inherited metabolic diseases, causing lysosomal storage of mucopolysaccharides; clinical presentation involves skeletal system and particularly the spine. Anomalies include developing kyphosis at thoracolumbar junction, that can causes nervous symptoms, and dens hypoplasia with associated atlantoaxial subluxation that can cause myelopathy. We present our experience in the treatment of spine pathology in MPS.

METHODS: Medical treatments of MPS seem to have little impact on spine disease: treatment of cervical instability often includes surgical decompression and stabilization, as in patient MPS1 that we present, while thoracic lumbar kyphosis is treated by bracing and, in severe cases, with surgery. Bracing is more effective in kyphosis under 40° Cobb. Our surgical cases with thoracic lumbar kyphosis over 40° Cobb, treatment include the first one ever described by only posterior approach with vertebrectomy in MPS and a case of lateral costo-transverse approach instrumented correction.

RESULTS: Surgical patients had no major complications after surgery and CT scan at follow-up showed complete fusion without loss of correction, even if in a cervical case we used an adult rigid instrumentation in a four year-and-six month-old girl (11 years follow-up) and in thoracic lumbar kyphosis case treated by vertebrectomy due to diminutive anatomy we positioned interbody cage in suboptimal position.

CONCLUSIONS: Bracing is a viable treatment strategy in thoracic lumbar kyphosis and can obtain good clinical results at medium terms follow-up even if kyphosis deformity remains in radiographs. Surgical treatment is effective in severe evolving cases both at cervical and thoracic lumbar level, main difficulties arose from unavailability of dedicated instrumentation in very young patient, as even smallest devices available are often too big.