ABSTRACT
OBJECTIVE: Redundant nerve roots (RNR) 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. We sought to evaluate a grading scale for RNR, characterize the association with stenosis, and investigate the clinical implications of RNR. METHODS: We conducted a retrospective chart review of 72 patients who underwent lumbar spine surgery from 2016 to 2018 at one institution. Preoperative T2 MRI scans were graded by three reviewers for severity of stenosis (0-4), severity of RNR (0-3), and rostral versus caudal RNR. Spaghetti Sign (SS) was defined as RNR score ≥2 (clear-cut or marked nerve root irregularity). Pre- and post-operative Oswestry Disability Index (ODI) scores were analyzed by stenosis and RNR severity. RESULTS: Seventy-one (98%) patients had severe stenosis (score ≥3) and twenty-five (35%) had a SS. SS was 100% specific for high grade stenosis. If patients had a SS, it was more likely rostral (p = 0.02). Post-operative ODI scores improved significantly, but there were no differences related to RNR score, presence of SS or stenosis severity. CONCLUSION: The study demonstrated that there is a significant association between SS and severe LSS and that presence of RNR is not a negative prognostic indicator for postoperative outcomes.
