Scientific Articles

Surgical Compared with Nonoperative Treatment for Lumbar Degenerative Spondylolisthesis

Four-Year Results in the Spine Patient Outcomes Research Trial (SPORT) Randomized and Observational Cohorts

Weinstein, James N. DO, MS¹; Lurie, Jon D. MD, MS¹; Tosteson, Tor D. ScD¹; Zhao, Wenyan MS¹; Blood, Emily A. MS¹; Tosteson, Anna N.A. ScD¹; Birkmeyer, Nancy PhD²; Herkowitz, Harry MD³; Longley, Michael MD⁴; Lenke, Lawrence MD⁵; Emery, Sanford MD⁶; Hu, Serena S. MD⁷

Author Information

¹Departments of Orthopaedics (J.N.W., W.Z., and E.A.B.), Medicine (J.D.L. and A.N.A.T.), and Community and Family Medicine (T.D.T. and A.N.A.T.), Dartmouth Medical School, One Medical Center Drive, Lebanon, NH 03756. E-mail address for J.N. Weinstein: [email protected]

²University of Michigan Health System, 2101 Taubman Center, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0346

³Department of Orthopaedic Surgery, William Beaumont Hospital, 3535 West 13 Mile Road, #744, Royal Oak, MI 48073

⁴Nebraska Foundation for Spinal Research, 11819 Miracle Hills Drive, Suite 102, Omaha, NE 68154

⁵Department of Orthopaedic Surgery, Washington University School of Medicine, One Barnes-Jewish Hospital Plaza, Suite 11300 West Pavilion, St. Louis, MO 63110

⁶Department of Orthopaedics, West Virginia University, 3700 Robert C. Byrd Health Science Center South, Morgantown, WV 26506

⁷University of California Medical Center, 400 Parnassus Avenue, Third Floor, San Francisco, CA 94143

The Journal of Bone & Joint Surgery 91(6):p 1295-1304, June 01, 2009. | DOI: 10.2106/JBJS.H.00913

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Abstract

Background: The management of degenerative spondylolisthesis associated with spinal stenosis remains controversial. Surgery is widely used and has recently been shown to be more effective than nonoperative treatment when the results were followed over two years. Questions remain regarding the long-term effects of surgical treatment compared with those of nonoperative treatment.

Methods: Surgical candidates from thirteen centers with symptoms of at least twelve weeks' duration as well as confirmatory imaging showing degenerative spondylolisthesis with spinal stenosis were offered enrollment in a randomized cohort or observational cohort. Treatment consisted of standard decompressive laminectomy (with or without fusion) or usual nonoperative care. Primary outcome measures were the Short Form-36 (SF-36) bodily pain and physical function scores and the modified Oswestry Disability Index at six weeks, three months, six months, and yearly up to four years.

Results: In the randomized cohort (304 patients enrolled), 66% of those randomized to receive surgery received it by four years whereas 54% of those randomized to receive nonoperative care received surgery by four years. In the observational cohort (303 patients enrolled), 97% of those who chose surgery received it whereas 33% of those who chose nonoperative care eventually received surgery. The intent-to-treat analysis of the randomized cohort, which was limited by nonadherence to the assigned treatment, showed no significant differences in treatment outcomes between the operative and nonoperative groups at three or four years. An as-treated analysis combining the randomized and observational cohorts that adjusted for potential confounders demonstrated that the clinically relevant advantages of surgery that had been previously reported through two years were maintained at four years, with treatment effects of 15.3 (95% confidence interval, 11 to 19.7) for bodily pain, 18.9 (95% confidence interval, 14.8 to 23) for physical function, and −14.3 (95% confidence interval, −17.5 to −11.1) for the Oswestry Disability Index. Early advantages (at two years) of surgical treatment in terms of the secondary measures of bothersomeness of back and leg symptoms, overall satisfaction with current symptoms, and self-rated progress were also maintained at four years.

Conclusions: Compared with patients who are treated nonoperatively, patients in whom degenerative spondylolisthesis and associated spinal stenosis are treated surgically maintain substantially greater pain relief and improvement in function for four years.

Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.