Postoperative paralysis following the surgery for thoracic ossification of the posterior longitudinal ligament: perioperative and intraoperative management strategies. Illustrative case.

Background: The treatment of thoracic ossification of the posterior longitudinal ligament (OPLL) remains a significant challenge, with a postoperative paralysis rate exceeding 30%. The underlying mechanisms of postoperative paralysis are still unclear, necessitating further investigation into potential risk factors and preventive strategies.

Observations: The authors report the case of a 42-year-old male with diabetes and hypertension who developed complete lower limb paralysis after surgery for thoracic myelopathy due to OPLL. Intraoperative monitoring showed absent motor evoked potentials until the posterior longitudinal ligament was severed, after which they became detectable. The surgery lasted more than 13 hours, with mean arterial pressure maintained between 44 and 91 mm Hg. Postoperative MRI revealed extensive spinal cord edema without severe compression. The exact cause of postoperative paralysis in this case remains unclear; however, possible causes include white cord syndrome or spinal cord ischemia.

Lessons: Postoperative paralysis in thoracic OPLL surgery remains poorly understood. Identifying and addressing risk factors for spinal cord ischemia and reperfusion injury are crucial. The authors propose strategies to reduce risk, including prone and supine position tests, the use of an ultrasonic surgical aspirator to prevent heat-induced spinal cord damage, shortening surgical duration, and meticulous blood pressure management. https://thejns.org/doi/10.3171/CASE25195.