Anomalies and malformations of lumbar spinal nerve roots

In spinal surgery, malformations of lumbar nerve roots and their coverings may result in difficult or even faulty differential diagnoses and intraoperatively in surgical peculiarities and problems. In 5000 operations of the lumbar spine carried out within a ten-year period, 35 cases of malformation of the lumbar nerve roots were observed with 17 conjoined nerve roots emerging from the dural sac and 18 perineurial cysts in the form of cystic anomalies in the transition area of dural and arachnoid root sac into the perineurium of the spinal nerve. Due to the experience gained from these operations carried out to date, radiologic findings as to imaging as well as their interpretation, indications for surgery and intraoperative management are being discussed.