Predictive Factors of the Effectiveness of Caudal Epidural Steroid Injections in Managing Patients With Chronic Low Back Pain and Radiculopathy

Study Design: Retrospective clinical outcome analysis. Objective: To evaluate and determine whether demographic, comorbid factors, or physical examination findings may predict the outcome of caudal epidural steroid injections in managing patients with chronic low back pain and radiculopathy Summary of Background Data: The caudal epidural approach is commonly utilized with patients who are on anticoagulation or who have had prior lumbar surgery to treat L5 or S1 radiculopathies. Methods: A retrospective review of 136 patients undergoing an initial caudal epidural steroid injection for radiculopathy from January 1, 2006 to August 30, 2013. The patients were assessed before their injections for their pain levels: visual analog scale, presence of lumbar paraspinal and sciatic notch sensitivity, pain with provocative maneuvers, motor weakness, and sensory loss. The patients were then reassessed following their injection for their visual analog scale pain levels, percentage improvement, and duration of pain relief. Results: Stepwise regression was used to determine whether demographic, comorbid factors, or physical examination signs were predictive of percentage improvement or length of relief following an injection. Among these variables, duration of symptoms was found to be negatively significantly related with a P-value of 0.032 for percentage of improvement. For each week of the duration of symptoms, the percentage of improvement decreased by 0.07%. Regarding physical examination findings, presence of pain with lumbar extension was negatively and significantly related to length of relief duration with a P-value of 0.0124. The mean length of relief duration is 38.37 weeks for individuals without painful lumbar extension and 14.68 weeks for individuals with painful lumbar extension. Conclusions: The mean length of relief following a caudal injection is reduced by 62% in patients who exhibit pain with lumbar extension.