The mucopolysaccharidoses (MPS) are genetic lysosomal storage diseases. Peripheral bone dysplasia and spinal involvement are the predominant orthopedic damage. The risk of spinal cord compression due to stenosis of the craniocervical junction is well known in these patients, whereas the thoracolumbar kyphosis is often well tolerated over a long period of time. Thus, signs of spinal cord compression at this level occur later and more insidiously. The authors describe three cases of patients with thoracolumbar kyphosis who suffered from postoperative spinal cord compression in the absence of direct surgical trauma. Analysis of these cases and review of the literature helped identify causal factors resulting in spinal cord ischemia. The risk of perioperative spinal cord complications related to a thoracolumbar kyphosis must be discussed with patients with MPS and their families prior to any surgery, including extra-spinal procedures.