The Spaghetti Sign: Nerve Root Redundancy in Lumbar Spinal Stenosis.

Objective: Redundant nerve roots (RNRs) seen in conjunction with lumbar spinal stenosis (LSS) are well-described radiographic findings. Several studies suggest their presence may be a negative prognostic indicator of postoperative outcome. Our hypothesis was that severe RNR (informally known as the spaghetti sign [SS]) can serve as a reliable marker of LSS that would benefit from surgical decompression.

A Comparative Study of Fiducial-Based and Fiducial-Less Registration Utilizing the O-Arm.

Background: Frameless stereotactic surgery utilizing fiducial-based (FB) registration is an established tool in the armamentarium of deep brain stimulation (DBS) surgeons. Fiducial-less (FL) registration via intraoperative CT, such as the O-arm, has been routinely used in spine surgery, but its accuracy for DBS surgery has not been studied in a clinical setting.

Objective: We undertook a study to analyze the accuracy of the FL technique in DBS surgery and compare it to the FB method.