Study design: A retrospective study of 1,090 patients undergoing corrective spinal deformity surgery for scoliosis (n = 920), kyphosis (n = 77), or a combination of the two (n = 93) at one institution.
Objectives: To ascertain the etiologies and incidence of neurologic deficits occurring at the time of surgery.
Summary of background data: Potential etiologies of intraoperative neurologic deficits include cord compression, overdistraction, purely vascular, or a combination.
Methods: The study group included only patients with useful function of their lower extremities and normal bowel and bladder control, and patients whose surgeries were in spinal cord territory as opposed to purely cauda equina territory.
Results: There were four major neurologic deficits that occurred during surgery. Three of the four deficits were purely vascular in etiology. The fourth may have had a vascular and mechanical etiology. All four patients had anterior and posterior surgery with harvesting of the unilateral convex segmental vessels, and each had a component of hyperkyphosis, as well as intraoperative controlled hypotension. All four patients showed marked improvement of motor weakness with time.
Conclusions: Significant risk factors were combined anterior and posterior surgery (P = 0.009) and hyperkyphosis (P = 0.0006).