[Cauda equina hemisyndrome after intradural anesthesia with bupivacaine for hip surgery]

A 68-year-old man underwent hip surgery under subarachnoid anesthesia with bupivacaine and fentanyl to replace an acetabular component. Two days after surgery the patient developed unilateral cauda equina syndrome, affecting five nerve roots (L4 to S3), with no sphincter involvement. Two and a half years later, the lesion had become permanent. We discuss the possible origin of the condition, suggesting differential diagnoses such as mechanical problems (position-mobilization) and anesthetic toxicity.