title: Spinal stenosis frequent in children with multiple hereditary exostoses.
abstract: OBJECTIVE
  Children with multiple hereditary exostoses (MHE) have numerous osteochondromas, with the most prominent lesions typically over the appendicular skeleton. A recent report noted a high rate of intracanal lesions in this patient population and recommended preventative spinal screening with magnetic resonance imaging (MRI) or computed tomography (CT). We sought to evaluate the prevalence of spinal stenosis from intracanal osteochondromas at our pediatric orthopedic center in order to evaluate if routine screening is warranted.
  
  
  METHODS
  All pediatric patients treated for MHE were retrospectively identified. Records were reviewed to determine demographics, previous orthopedic surgery, and indication and results of axial spine imaging (CT or MRI). Imaging studies were reviewed to evaluate the presence of intracanal and compressive spinal lesions.
  
  
  RESULTS
  Between 1990 and 2011, axial imaging was performed in nine patients with MHE due to concerns of pain, weakness, and/or dizziness. These patients had moderate disease involvement, with a mean of 4.9 previous orthopedic surgeries to address skeletal osteochondromas. Two patients with MHE had cervical spinal stenosis secondary to intracanal osteochondromas. Both children successfully underwent spinal decompression. Thus, of our MHE population undergoing axial imaging, 22 % were noted to have intracanal lesions.
  
  
  CONCLUSIONS
  Our experience reveals a >20 % rate of compressive intracanal osteochondromas in MHE patients undergoing spinal imaging. These two patients represent 5 % of the MHE patients treated at our center. These lesions may be slow growing, and significant consequences can occur if not identified promptly. Thus, we confer that routine axial screening of the spinal canal may be warranted in these children.
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, 200 1st St. SW, Rochester, MN 55905 USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Ashraf
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, 200 1st St. SW, Rochester, MN 55905 USA ; Shriners Hospitals for Children-Twin Cities, Minneapolis, MN USA.
authors.forename: A Noelle
authors.initials: AN
authors.lastname: Larson
authors.affiliation: Shriners Hospitals for Children-Twin Cities, Minneapolis, MN USA.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Ferski
authors.affiliation: Shriners Hospitals for Children-Twin Cities, Minneapolis, MN USA.
authors.forename: Cary H
authors.initials: CH
authors.lastname: Mielke
authors.affiliation: Department of Neurosurgery, Mayo Clinic, Rochester, MN USA.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Wetjen
authors.affiliation: Shriners Hospitals for Children-Twin Cities, Minneapolis, MN USA.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Guidera
keywords: CT; Imaging; MRI; Multiple hereditary exostoses; Neurologic symptoms; Pediatric; Spinal impingement