Surgical management of thoracolumbar kyphosis in mucopolysaccharidosis type 1 in a reference center

Purpose Mucopolysaccharidosis (MPS) I is a rare autosomalrecessive lysosomal storage disease. Thoracolumbar kyphosisis an early characteristic feature of the disease. Ossificationfailure in the anterosuperior quadrant of the vertebral bodyresults in anterior dislocation. This study describes the surgicalmanagement of thoracolumbar kyphosis in MPS IH (Hurlersyndrome) in a national reference center.Methods Among 72 MPS I patients followed in our institution,we treated surgically 14 MPS IH patients with severethoracolumbar kyphosis. The decision was made after documenteddeformity progression. Mean age at surgery was8 (3.5–15) years. Sagittal imbalance of the trunk was constant.One patient underwent extended fusion for associated scoliosis.We retrospectively reviewed 13 patients who underwentselective circumferential fusion at the thoracolumbar level.Results Average preoperative kyphosis was +57.5°(+30°;+90°). Surgical correction of the kyphosis was about 66 %and maintained at final follow-up. Fusion was obtained in allpatients. Two patients required revision surgery consecutivelyto a previous posterior-only fusion, as a significant loss ofcorrection occurred. One patient presented delayed neurologicdeficit secondarily to cardiac embolism. One patient died postoperativelyfrom cardiorespiratory failure.Conclusion Surgery is necessary when kyphosis is progressivedespite orthopedic management, aggravating the multifactorialtrunk imbalance. Regarding our experience, circumferentialarthrodesis should be recommended to achievestable correction. Surgical management requires a multidisciplinaryapproach due to multisystemic failure and neurologicalrisks specific to metabolic disorders.