Use of neuropathic pain questionnaires in predicting the development of failed back surgery syndrome following lumbar discectomy for radiculopathy

Abstract

Objective: Failed back surgery syndrome (FBSS) describes neuropathic pain that occurs when extremity symptoms in lumbar disease persist despite structurally corrective spinal surgery. It is unclear whether specific preoperative pain characteristics predict patients prone to such postoperative disabling symptoms. Methods: This prospective study analyzed surgical patients with painful radiculopathy secondary to lumbar degenerative disease. Clinical parameters included general demographic information, preoperative and postoperative clinical examination, self-reported pain and disability scores, and neuropathic pain scoring. The neuropathic pain screening tests used in this study were the Douleur Neuropathique 4 (DN4) and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), with correlation tested for ordinal score and screen positivity. Multiple logistic regression analysis defined predictors of postoperative symptomatology. Results: Among 250 surgical radiculopathy patients, 12% were classified with FBSS. The condition was highly associated with abnormal preoperative screens for neuropathic pain, but not gender, smoking status, or preoperative pain severity (multiple logistic regression, α=0.05). Good correlation was seen between the two screening tests used in this study for absolute ordinal score (Spearman’s ρ=0.84, p<0.001) and thresholding for neuropathic pain features (Spearman’s ρ=0.48, p<0.001). Conclusion: Higher neuropathic pain screening scores correlated with likelihood of postoperative leg pain. Further work will develop more accurate prognostication tools for radiculopathy patients undergoing structural spinal surgery.