Delayed Onset Postoperative Spinal Epidural Hematoma after Lumbar Spinal Surgery: Incidence, Risk Factors, and Clinical Outcomes.

Our study revealed that the overall incidence of delayed-onset PSEH was 0.16% in posterior lumbar spinal surgery and that its risk was different from that of early-onset PSEH. If patients with such risk factors develop neurological deficits 3 days after initial surgery, surgeons should be aware of the possibility of delayed-onset PSEH.