title: Iatrogenic spondylolysis leading to contralateral pedicular stress fracture and unstable spondylolisthesis: a case report.
abstract: METHODS
  A case report of iatrogenic spondylolysis as a complication of microdiscectomy leading to contralateral pedicular stress fracture and unstable spondylolisthesis.
  
  
  OBJECTIVE
  To improve understanding of this condition by presenting a case history and roentgenographic findings of a patient that differ from those already reported and to propose an effective method of surgical management.
  
  
  METHODS
  A 67-year-old woman with no history of spondylolysis or spondylolisthesis underwent an L4-L5 microdiscectomy for a left herniated nucleus pulposus 1 year before the current consultation. For the preceding 8 months, she had been experiencing low back and bilateral leg pain. Imaging studies revealed a left L4 spondylolytic defect and a right L4 pedicular stress fracture with an unstable Grade I spondylolisthesis.
  
  
  RESULTS
  The patient was treated with posterior spinal fusion, which resulted in complete resolution of her clinical and neurologic symptoms.
  
  
  CONCLUSIONS
  Iatrogenic spondylolysis after microdiscectomy is an uncommon entity. However, it can lead to contralateral pedicular stress fracture and spondylolisthesis, and thus can be a source of persistent back pain after disc surgery. Surgeons caring for these patients should be aware of this potential complication.
authors.affiliation: Department of Orthopaedic Surgery, New York University Medical Center-Hospital for Joint Diseases Orthopaedic Institute, New York, NY 10003, USA. steakmd@aol.com
authors.forename: S G
authors.initials: SG
authors.lastname: Maurer
authors.forename: K E
authors.initials: KE
authors.lastname: Wright
authors.forename: J A
authors.initials: JA
authors.lastname: Bendo
mesh_terms: D000368:Aged; D017586:Diskectomy / Q000009:adverse effects*; D005260:Female; D015775:Fractures, Stress / Q000209:etiology* / Q000601:surgery; D006801:Humans; D007049:Iatrogenic Disease; D007405:Intervertebral Disc Displacement / Q000601:surgery; D008159:Lumbar Vertebrae / Q000293:injuries / Q000601:surgery; D016103:Spinal Fractures / Q000209:etiology* / Q000601:surgery; D013123:Spinal Fusion; D013168:Spondylolisthesis / Q000209:etiology* / Q000601:surgery; D013169:Spondylolysis / Q000150:complications*