title: Intraspinal canal rod migration causing late-onset paraparesis 8 years after scoliosis surgery.
abstract: Complete intraspinal canal rod migration with posterior bone reconstitution has never been described in the adolescent idiopathic scoliosis (AIS) population. We present an unusual but significant delayed neurological complication after spinal instrumentation surgery.
  
  
  
  A 24-year-old woman presented with lower limb weakness (ASIA D) 8 years after posterior instrumentation from T2 to L4 for AIS. CT scan and MRI demonstrated intra-canal rod migration with complete laminar reconstitution. The C-reactive protein was slightly elevated (fluctuated between 10 and 20 mg/l). Radiographs showed the convex rod had entered the spinal canal. The patient was taken into the operating room for thoracic spinal decompression and removal of the convex rod. This Cotrel-Dubousset rod, which had been placed on the convexity of the thoracic curve had completely entered the canal from T5 to T10 and was totally covered by bone with the eroded laminae entirely healed and closed. There was no pseudarthrosis. Intra-operatively, the fusion mass was opened along the whole length of this rod and the rod carefully removed and the spinal cord decompressed. The bacteriological cultures returned positive for Propionibacterium acnes. The patient recovered fully within 2 months post-operatively.
  
  
  
  We opine that the progressive laminar erosion with intra-canal rod migration resulted from mechanical and infectious-related factors. The very low virulence of the strain of Propionibacterium acnes is probably involved in this particular presentation where the rod was trapped in the canal, owing to the quite extensive laminar reconstitution.
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Obeid
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Vital
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Aurouer
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Steve
authors.initials: S
authors.lastname: Hansen
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gangnet
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pointillart
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Gille
authors.affiliation: Unité de Pathologie Rachidienne, Pôle d'Orthopédie Traumatologie, Hôpital Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076, Bordeaux Cedex, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Boissiere
authors.affiliation: Centre for Spinal Studies and Surgery, Queen's Medical Centre Campus of Nottingham, University Hospitals NHS Trust, West Block, D Floor, Derby Road, Nottingham, NG7 2UH, UK. nasir.quraishi@nuh.nhs.uk.
authors.forename: Nasir A
authors.initials: NA
authors.lastname: Quraishi
mesh_terms: D019299:Decompression, Surgical; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000150:complications / Q000175:diagnosis* / Q000382:microbiology; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D020335:Paraparesis / Q000175:diagnosis* / Q000209:etiology; D011183:Postoperative Complications / Q000175:diagnosis*; D011425:Propionibacterium acnes; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000150:complications / Q000175:diagnosis* / Q000382:microbiology; D011859:Radiography; D012600:Scoliosis / Q000601:surgery*; D013115:Spinal Canal; D013123:Spinal Fusion / Q000379:methods*; D013904:Thoracic Vertebrae / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Adolescent idiopathic scoliosis; Propionibacterium acnes; Rod migration