title: Chronic hypertrophic nonunion of the Type II odontoid fracture causing cervical myelopathy: Case report and review of literature.
abstract: BACKGROUND
  Complications of nonunited Type II odontoid fractures can range from neck pain to progressive neurological deficit from cervical myelopathy. Rarely, the hypertrophic nonunion requires both anterior transoral decompression and posterior decompression with instrumented fusion. We present a case and review literature around this entity.
  
  
  METHODS
  A 68-year-old female presented with rapidly progressive cervical myelopathy (from normal to moderate myelopathy modified Japanese Orthopedic Association [mJOA] 13) over 3 months. Her history was positive for a Type II odontoid fracture managed conservatively and lost to follow-up for 25 years. Spinal imaging studies revealed hypertrophic nonunion and craniocervical kyphotic deformity with significant subaxial stenosis and segmental kyphosis. The patient underwent anterior transoral decompression, followed by posterior occipitothoracic decompression and instrumented fusion. At follow-up, the cervical myelopathy has improved to near normalcy (mJOA 17) with no evidence or implant-related complication.
  
  
  CONCLUSIONS
  Rarely, nonunion of Type II odontoid fractures may be hypertrophic where both instability and compression cause neurological morbidity. Such cases require anterior transoral decompression, posterior cervical decompression, and instrumented fusions.
authors.affiliation: Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada; Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Mohammed F
authors.initials: MF
authors.lastname: Shamji
authors.affiliation: Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Naif
authors.initials: N
authors.lastname: Alotaibi
authors.affiliation: Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Aisha
authors.initials: A
authors.lastname: Ghare
authors.affiliation: Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada; Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fehlings
keywords: Hypertrophic pseudoarthrosis; myelopathy; nonunion; odontoid fracture; transoral surgery