Study design: A descriptive case review.
Objectives: To assess the outcomes of anterior lumbar interbody fusion for painful discs within a solid posterolateral spinal fusion.
Summary of background data: Some patients continue to have pain after posterolateral spinal fusion despite apparently solid arthrodesis. One potential etiology is pain that arises from a disc within the fused levels.
Method: Retrospective review of 176 patients with anterior interbody fusion, which located 20 who had anterior interbody fusion levels of prior posterolateral spinal fusion. All had low back pain, solid posterolateral spinal fusion, and painful disc(s) at the posterolateral spinal fusion level(s) but not elsewhere. Pain was measured by the Numerical Rating Scale, function by Oswestry Disability Questionnaire, and patient satisfaction by the North American Spine Society Outcome Questionnaire.
Results: Follow-up data were available for 18 patients (90%). Mean follow-up was 58 months (25 to 102). There were 10 men and 8 women. Mean age was 45 years (26 to 72). Diagnoses were degenerative discs, herniated nucleus pulposus, spondylolisthesis, and spinal stenosis. Eight patients had injuries after the previous posterolateral spinal fusion that precipitated new symptoms. Two patients had one level fusion, 14 had two levels, and 1 each had three and four levels. Four patients had one prior surgery, 5 had two, and 9 had three or more. All patients had solid anterior interbody fusion by radiograph. Mean Numerical Rating Scale improved from 7.9 before surgery to 4.7 after (P< 0.001). Mean Oswestry Disability Questionnaire improved from 56.3 before surgery to 47.9 after (P = 0.04). Of 15 patients unable to work before anterior interbody fusion, 5 returned to work. Sixteen patients (89%) were satisfied with their results.
Conclusion: Low back pain that continues or recurs after apparently solid posterolateral spinal fusion may be caused by painful disc(s) at motion segment(s) within the fusion. A solid posterolateral spinal fusion may not protect the residual disc(s) from injury. Anterior interbody fusion can provide significant improvements in pain and function and a high degree of patient satisfaction in this clinical setting.