Background: Cervical spondylotic myelopathy is the leading cause of spinal cord dysfunction worldwide. The objective of this study was to evaluate the impact of surgical decompression on functional, quality-of-life, and disability outcomes at one year after surgery in a large cohort of patients with this condition.
Methods: Adult patients with symptomatic cervical spondylotic myelopathy and magnetic resonance imaging evidence of spinal cord compression were enrolled at twelve North American centers from 2005 to 2007. At enrollment, the myelopathy was categorized as mild (modified Japanese Orthopaedic Association [mJOA] score ≥ 15), moderate (mJOA = 12 to 14), or severe (mJOA < 12). Patients were followed prospectively for one year, at which point the outcomes of interest included the mJOA score, Nurick grade, Neck Disability Index (NDI), and Short Form-36 version 2 (SF-36v2). All outcomes at one year were compared with the preoperative values with use of univariate paired statistics. Outcomes were also compared among the severity classes with use of one-way analysis of variance. Finally, a multivariate analysis that adjusted for baseline differences among the severity groups was performed. Treatment-related complication data were collected and the overall complication rate was calculated.
Results: Eighty-five (30.6%) of the 278 enrolled patients had mild cervical spondylotic myelopathy, 110 (39.6%) had moderate disease, and 83 (29.9%) had severe disease preoperatively. One-year follow-up data were available for 222 (85.4%) of 260 patients. There was a significant improvement from baseline to one year postoperatively (p < 0.05) in the mJOA score, Nurick grade, NDI score, and all SF-36v2 health dimensions (including the mental and physical health composite scores) except general health. With the exception of the change in the mJOA, the degree of improvement did not depend on the severity of the preoperative symptoms. These results remained unchanged after adjusting for relevant confounders in the multivariate analysis. Fifty-two patients experienced complications (prevalence, 18.7%), with no significant differences among the severity groups.
Conclusions: Surgical decompression for the treatment of cervical spondylotic myelopathy was associated with improvement in functional, disability-related, and quality-of-life outcomes at one year of follow-up for all disease severity categories. Furthermore, complication rates observed in the study were commensurate with those in previously reported cervical spondylotic myelopathy series.
Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
1Division of Neurosurgery, University of Toronto, Toronto Western Hospital, West Wing, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada. E-mail address for M.G. Fehlings: Michael.Fehlings@uhn.on.ca
2Department of Health Sciences, University of Washington, 4333 Brooklyn Avenue N.E., Suite 1400/#315, Seattle, WA 98195
3Emory Orthopaedics & Spine Center, Emory University, 59 Executive Park, South Atlanta, GA 30329
4Department of Neurosurgery, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 3021, Kansas City, KS 66160
5Thomas Jefferson University, 925 Chestnut Street, Philadelphia, PA 19107-4216
6University Orthopedic Center, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108
7University of Virginia, PO Box 800212, Charlottesville, VA 22908
8New England Baptist Hospital, 125 Parker Hill Avenue, Converse 4 Suite 1, Boston, MA 02120
9Boston Spine Group, 299 Washington Street, Newton, MA 02458
10University of Washington Medical Center, Roosevelt II, 4245 Roosevelt Way N.E., 2nd Floor, Box 354740, Seattle, WA 98105
11Spine Education and Research Institute, University of Colorado, 9005 Grant Street, #100, Denver, CO 80229
12Department of Orthopedic Surgery, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115
13Indiana Spine Group, 8040 Clearvista Parkway, Suite 440, Indianapolis, IN 46256
14Department of Orthopedic Surgery, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905
15Department of Neurosurgery, Johns Hopkins University; Johns Hopkins Hospital, Meyer 7-109, 600 North Wolfe Street, Baltimore, MD 21287