Predictors of radicular pain among adults with lower limb loss and low back pain

BACKGROUND: Low back pain (LBP) affects up to 89% of adults with lower limb loss (LLL). LBP with concurrent radicular pain, ie, pain that radiates into the lower extremity, leads to more significant disability than LBP alone in the general population. OBJECTIVE: The purpose of this study was to identify factors associated with the presence of radicular pain among adults with LLL with comorbid LBP. STUDY DESIGN: Secondary analysis of cross-sectional data. METHODS: Participants, aged ≥18 years who were ≥1-year postunilateral transtibial or transfemoral LLL, were recruited from regional prosthetic clinics and Amputee Coalition National Meetings. Participants completed surveys, including the Patient-Reported Outcome Measurement Information System, 29-item (PROMIS-29). Forward stepwise logistic regression was used to identify factors associated with radicular pain presence. RESULTS: Of the 135 participants [56.0 years (25th, 75th percentile: 47, 64); 56% male, 83% White, 66% transtibial; and 46% traumatic etiology], 46 (34%) reported radicular pain in the preceding 2 weeks. Individuals with greater depressive symptoms (p = 0.012) and greater 7-day average pain intensity (p = 0.034) per the PROMIS-29 were more likely to report radicular pain. CONCLUSIONS: With LLL and comorbid LBP, greater depressive symptoms and higher pain intensity are associated with an increased odds of presenting with radicular pain in the lower extremity, but longitudinal study to evaluate causation is needed. Psychological factors should be considered alongside physical factors when providing care for adults with LLL and comorbid LBP, particularly those presenting with radicular symptoms. Integrating mental health support with traditional pain management strategies may improve outcomes.