Synovial cysts and the lithotomy position causing cauda equina syndrome

We describe a case of cauda equina syndrome caused by synovial cysts and the lithotomy position. A transurethral resection of the prostate was performed under spinal anesthesia in the lithotomy position. We believe that this is the first case report of facet joint synovial cysts and the lithotomy position causing ischemic neurologic injury to the cauda equina. Other etiologies such as needle trauma, neurotoxicity, hematoma, and abscess were not evident. We believe that positioning the patient in the lithotomy position narrowed the cross-sectional area of the spinal canal in a patient with a coexisting critically stenosed lumbar spinal canal. The resultant mechanical pressure caused an ischemic compression injury to the cauda equina.