Study Design. A single-center, prospective, consecutive case series of patients undergoing epidural lavage before the treatment of radiculopathy due to lumbar disc herniation.
Objective. To determine whether a novel complex of fibronectin and aggrecan predicts clinical response to epidural steroid injection (ESI) for the indication of radiculopathy from lumbar herniated nucleus pulposus (HNP).
Summary of Background Data. ESI for lumbar radiculopathy due to HNP is widely used despite variable effectiveness for this indication. With increased attention aimed at cost containment, it would be beneficial to identify those in whom ESI may be helpful. There are currently no accurate diagnostic tests to predict response to ESI in back pain and sciatica syndromes. We have previously investigated biomarkers of disc degeneration associated with radiculopathy.
Methods. We embarked to determine whether a molecular complex of fibronectin and aggrecan predicts clinical response to ESI for the indication of radiculopathy from HNP. This prospective study was conducted at a single center and included 26 patients with radiculopathic pain and magnetic resonance imaging positive for HNP, who elected ESI. Epidural lavage with physiologic saline was performed immediately before ESI. The lavage fluid was assayed for the fibronectin–aggrecan complex (FAC) by using a heterogeneous sandwich enzyme-linked immunosorbent assay. The results were compared with the interval improvement in the physical component summary (PCS) score of the Medical Outcomes Study Short Form-36 instrument (SF-36) after injection compared with baseline.
Results. The mean improvement from baseline PCS in patients with the FAC was 22.9 (SD, 12.4) and without the complex was 0.64 (SD, 3.97; P < 0.001). Differences in total SF-36 improvement were also highly significant (P < 0.001). The presence of the FAC predicts a clinically significant increase in PCS after lumbar ESI by receiver-operating-characteristic analysis (area under the curve = 0.97; P < 0.001). There was no significant difference in age (P = 0.25), sex (P = 0.84), laterality (P = 0.06), lumbar spinal level (P = 0.75), or payer type (worker's compensation vs. private insurance; P = 0.90) between groups with and without the marker.
Conclusion. A molecular complex of fibronectin and aggrecan predicts response to lumbar ESI for radiculopathy with HNP. The biomarker is accurate, objective, and not affected by demographic or psychosocial variables in this series.
A fibronectin-aggrecan complex (FAC) in the epidural space was evaluated as a predictor of clinical response to ESI. This prospective study included 26 patients with radiculopathy from HNP. The results were compared with improvement in SF-36 after injection. Significantly greater improvement was observed in patients with the FAC compared to those without.
*Department of Orthopaedic Surgery, Stanford University, Palo Alto, California
†Cytonics Inc, Jupiter, Florida
‡Department of Pathology, University of Pittsburgh, Pennsylvania
§Private Practice, West Palm Beach, Florida.
Address correspondence and reprint requests to Gaetano J. Scuderi, MD, Department of Orthopaedic Surgery, Stanford University, 450 Broadway Street, Redwood City, CA 94063; E-mail: email@example.com
Acknowledgement date: May 5, 2010. Revision date: June 21, 2010. Acceptance date: July 12, 2010.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. One or more of the author(s) has/have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this manuscript: e.g., royalties, stocks, stock options, decision making position.