Outcome following lumbar disc surgery: the role of fibrosis

Failed-back surgery syndrome remains a challenge for spinal surgeons. It can be related to several causes, including poor surgical indication, misdiagnosis, surgical technique failure, spondilodiscitis and fibrosis. Fibrosis has been associated with a poorer outcome in lumbar disc surgery, although its role in the generation of symptoms is not yet clear. In this study, the authors have analyzed any possible correlation between the clinical outcome and the degree of fibrosis. Forty consecutive patients were enrolled in a prospective study. All of them had operations in the lower lumbar disc in a single level for the first time. Three months after the operation they were submitted to clinical outcome evaluations and questionnaires, including Numeric Pain Rating scales (NPR) for lumbar and leg pain, the McGill Pain Questionnaire, The Quebec Back Pain Disability scale (QBPD) and Straight Leg Raising test. These data were correlated with the degree of fibrosis as revealed by Magnetic Resonance Imaging (MRI). After 3 months, the NPR values for lumbar and leg pain ranged from 0 to 8 (mean 2.32 and 1.67 respectively). The values of the post-operative QBPD scale ranged from 1 to 71 (mean 25.9). Every patient showed a varied degree of fibrosis on MRI. However, statistical analysis depicted no significant correlation between fibrosis and a poorer clinical outcome for pain and disability. The authors found no correlation between excessive fibrosis with lumbar and leg pain, disability or straight leg resistance. The role of fibrosis in the generation of symptoms in patients who have had lumbar disc surgery should be reevaluated.