Delayed onset of anterior spinal artery syndrome caused by retropulsed bone fragment after kyphoplasty: Case report and literature review.

Background: Percutaneous balloon kyphoplasty is a minimally invasive technique to treat refractory symptomatic osteoporotic vertebral compression fractures. A rare complication called anterior spinal artery syndrome has been documented several times in the literature after the procedure from cement embolism; however, the authors report an unusual case of anterior spinal artery syndrome following kyphoplasty through retropulsion of bone fragmentation. Case presentation: An 83-year-old male was admitted to an acute care hospital for severe low thoracic back pain without neurological symptoms. Computed tomography imaging showed T8 vertebral body compression fracture with 75% height loss. Kyphoplasty was performed four days after the admission without complications. On day nine postoperatively, the patient developed acute onset paraparesis of the lower extremities dissociated sensory deficits involving bilateral loss of temperature and pain, but preserved proprioception and vibratory sense. Magnetic resonance imaging of the spine revealed T2 intramedullary hyperintensity spanning from T7-9 and retropulsion of the bone fragments from a refracture of the T8 vertebral body. Conclusion: This study highlights a rare complication from a standard pain procedure through an unusual mechanism of injury. Clinicians who suspect acute myelopathy following vertebral augmentation procedures should obtain a computed tomography angiogram to identify a potential occluded vessel. If negative, individuals should proceed to magnetic resonance imaging to rule out retropulsion of bone fragmentation into the spinal cord.