Angle-meter to indicate the proper angle of insertion in anterior percutaneous cervical cordotomy. Technical note

An angle meter has been devised to facilitate the anterior approach to lower cervical percutaneous cordotomy and to afford the operator increased accuracy in placing the needle electrode. A method is described which allows the operator to set the trajectory of the needle electrode accurately at the stage when only the tip of the needle is inserted into the disc. The procedure requires no mathematical calculations and has proved accurate in 40 cases.