Iatrogenic spondylolysis leading to contralateral pedicular stress fracture and unstable spondylolisthesis: a case report.

STUDY
DESIGN: 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.