Spine SPINE Volume 38, Number 26, pp 2247-2252 ©2013, Lippincott Williams 8c Wilkins CERVICAL SPINE Anterior Versus Posterior Surgical Approaches to Treat Cervical Spondylotic Myelopathy Outcomes of the Prospective Multicenter AOSpine North America CSM Study in 264 Patients Michael G. Fehlings, MD, PhD,* Sean Barry, MD,* Branko Kopjar, MD,t SangwookTim Yoon, MD,+ Paul Arnold, MD,§ Eric M. Massicotte, MD,* Alexander Vaccaro, MD, PhD,1 Darrel S. Brodke, MD,|| Christopher Shaffrey, MD,** Justin S. Smith, MD,** EricWoodard, MD,+t Robert J. Banco, MD,*i Jens Chapman, MD,t Michael Janssen, DO,§§ Christopher Bono, MD,11I Rick Sasso, MD,|j|| Mark Dekutoski, MD,*** and Ziya L. Gokaslan, M D t t t Study Design. A prospective observational multicenter study. Objective. To help solve the debate regarding whether the anterior or posterior surgical approach is optimal for patients with cervical spondylotic myelopathy (CSM). Summary of Background Data. The optimal surgical approach to treat CSM remains debated with varying opinions favoring anterior versus posterior surgical approaches. We present an analysis of a prospective observational multicenter study examining outcomes of surgical treatment for CSM. Methods. A total of 278 subjects from 12 sites in North America received anterior/posterior or combined surgery at the discretion of the surgeon. This study focused on subjects who had either anterior or posterior surgery (n = 264, follow-up rate, 87%). Outcome measures included the modified Japanese Orthopedic Assessment scale, the Nurick scale, the Neck Disability Index, and the Short- Form 36 (SF-36) Health Survey version 2 Physical and Mental Component Scores. From the 'University of Toronto, Toronto, Ontario, Canada; tUniversity of Wasiiington, Seattle, WA; +Emory University, Atlanta, CA; §University of Kansas, Kansas City, KS; 1 Thomas Jefferson University, Philadelphia, PA; IJUniversity of Utah, Salt Lake City, UT; **University ofVirginia, Charlottesville, VA; ttNew England Baptist Hospital, Boston, MA; ííBoston Spine Croup, Newton, MA; §§Spine Education and Research Institute, Öenver, CO; 11 Brigham and Woman's iHospitai, Boston, MA; |1 ¡indiana Spine Croup, Indianapolis, IN; ***The CORE Institute, Phoenix, AZ; and tttjohn Hopkins University, Baltimore, MD. Acknowledgment date: April 26, 2013. First revision date: June 27, 2013. Second revision date: Septemher 3, 2013. Acceptance date: Septemher 9, 2013. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. Relevant financial activities outside the submitted work: consulting fee or honorarium, board membership, consultancy, grants/grants pending, expert testimony, stock/stock options, royalties, payment for lectures, travel/ accommodations/meeting expenses, patents, payment for development of educational presentations, and support for travel. Address correspondence and reprint requests to Michael C. Fehlings, MD, PhD, Division of Neurosurgery, Toronto Western Hospital, 399 Bathurst St. Ste4WW-449,Toronto, Ontario M.ST2S8, Canada; F-mail: michael.fehlings® uhn.ca DOI: 10.1097/BRS.0000000000000047 Spine Results. One hundred and sixty-nine patients were treated anteriorly and 95 underwent posterior surgery. Anterior surgical cases were younger and had less severe myelopathy as assessed by mJOA and Nurick scores. There were no baseline differences in Neck Disability Index or SF-36 between the anterior and posterior cases. Improvement in the mJOA was significantly lower in the anterior group than posterior group (2.47 vs. 3.62, respectively, P < 0.01 ), although the groups started at different levels of baseline impairment. The extent of improvement in the Nurick Scale, Neck Disability Index, SF-36 version 2 Physical Component Score, and SF-36 version 2 Mental Component Score did not differ between the groups. Conclusion. Patients with CSM show significant improvements in several health-related outcome measures with either anterior or posterior surgery. Importantly, patients treated with anterior techniques were younger, with less severe impairment and more focal pathology. We demonstrate for the first time that, when patient and disease factors are controlled for, anterior and posterior surgical techniques have equivalent efficacy in the treatment of CSM. Key words: surgery, cervical spondylotic myelopathy, CSM, multicenter trial, surgical outcomes. Level of Evidence: 3 Spine 2013;38:2247-2252 C ervical spondylotic myelopathy (CSM) is a progressive, degenerative disease that results in compressioti of the cervical spinal cord, leading to neurological dysfunc- tion.^'^ CSM is the commonest cause of spinal cord impairment in elderly patients worldwide,''^ and yet many controversies exist regarding the optimal management and the outcomes of surgical treatment. Although a number of studies have shown improved neurological outcomes in patients with severe neuro- logical deficits who receive surgical treatment,'^'' the effects of surgery on the full spectrum of CSM cases, ranging from mild to severe, remains in question. Moreover, the relative efficacy of anterior versus posterior approaches to treat CSM remains hotly debated. Several studies have addressed the uncertainty of anterior versus posterior surgical decompression in CSM www.spinejournal.com 2247