[Congenital anomalies at the emergence of lumbosacral roots]

Thirteen of 45 cases of congenital anomalies of the lumbosacral nerve roots at their site of emergency (ARE) were treated surgically. The most frequently involved roots were L5 and S1, and the commonest anomaly observed was fusion of adjacent roots. The malformations were either bilateral, symmetric or asymmetric, their preoperative diagnosis being by radiculography with metrizamide. Diagnostic criteria and limitations relating to the different varieties of ARE are discussed, confirmation of the presence of the anomaly depending on two peroperative findings. Conventional operative techniques involve wide surgical exploration, but pediculectomy supplies a new approach to the problem, and the advantages of a microsurgical technique are discussed. Improved results can be expected in the future following preoperative recognition of the presence of ARE and advances in operative techniques.