Complete Paraplegia Due to Anterior Spinal Artery Syndrome Following Total Knee Arthroplasty under Epidural Anaesthesia: A Case Report

Abstract

Anterior Spinal Artery Syndrome (ASAS) is an uncommon devastating neurological condition caused by ischemia in the spinal cord. We present a rare case of complete paraplegia due to ASAS following a total knee arthroplasty under lumbar epidural anaesthesia. The patient was a 78-year-old woman with mild hypertension. Epidural anaesthesia was performed at the L3-L4 interspace after a single uneventful attempt. Twenty hours postoperatively, the patient developed a flaccid paralysis of both legs, with complete loss of motor function, rectal tone and tendon reflexes, but no Babinski reflexes. Pinprick and temperature sensation were both absent bilaterally from T11 down. Proprioception and vibration sensation were intact in the ankle joint only. An immediate MRI of the spine and a second one, 48 hours postoperatively, demonstrated only a central disc herniation at T10-T11 with concomitant spinal canal stenosis. Based on neurological and MRI findings, the diagnosis of ASAS was made. The epidural catheter was removed immediately. Methylprednisolone 30 mg/kg iv bolus over 15 minutes, followed by a 5.4 mg/kg/h iv infusion for the next 23 hours was given. The patient was transferred to a rehabilitation center but no improvement was noticed and one year later the deficit was considered permanent and 2 years later the patient died. The present case alerts the orthopaedic surgeons and anaesthesiologists for the risk of ASAS in patients having predisposing factors for blood flow restriction to the spinal cord, such as elderly patients with degenerative spine disorders. The guidelines of ASAS management are analysed on a case-based approach.

Keywords

• knee arthroplasty complications
• regional anaesthesia complications
• spinal cord infraction