BACKGROUND: In general, the clinical course of acute sciatica is favorable. However, the relationship between morphologic changes in disc herniation and clinical course is not clear.
METHODS: The study population consisted of 283 patients who were included in the Sciatica trial and were randomized to surgery or to prolonged conservative care with surgery if needed. Magnetic resonance imaging (MRI) was performed at baseline and after 1 year. Morphologic changes in disc herniation were correlated to outcomes as assessed by means of the Roland Disability Questionnaire (RDQ), the visual‐analogue scale (VAS) for leg pain, and the patient's report of perceived recovery during the first year according to the intention‐to‐treat and per‐protocol principle using Spearman rank correlation coefficients and logistic regression when appropriate.
RESULTS: The disc herniation reduction after one year was 57% in the prolonged conservative group and 70% in the surgical group (P= 0.003). There was no correlation between the percentage reduction of the herniation and initial size. Low correlations were found between the reduction of the disc herniation and the improvement in the RDQ and the VAS leg pain. No correlation existed between the reduction of the disc herniation and global perceived recovery at one year.
CONCLUSION: Morphologic changes on consecutive MRIs only explain a limited variation in symptom improvement. Therefore, morphologic changes on consecutive MRIs have limited value in the evaluation of patients with a previous confirmed disc herniation.