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The Association Between Preoperative Spinal Cord Rotation and Postoperative C5 Nerve Palsy

Eskander, Mark S. MD; Balsis, Steve M. PhD; Balinger, Chris MD; Howard, Caitlin M. MD; Lewing, Nicholas W. MD; Eskander, Jonathan P. MD; Aubin, Michelle E. MD; Lange, Jeffrey MD; Eck, Jason DO, MS; Connolly, Patrick J. MD; Jenis, Louis G. MD

Journal of Bone & Joint Surgery - American Volume: 5 September 2012 - Volume 94 - Issue 17 - p 1605–1609
doi: 10.2106/JBJS.K.00664
Scientific Articles

Background: C5 nerve palsy is a known complication of cervical spine surgery. The development and etiology of this complication are not completely understood. The purpose of the present study was to determine whether rotation of the cervical spinal cord predicts the development of a C5 palsy.

Methods: We performed a retrospective review of prospectively collected spine registry data as well as magnetic resonance images. We reviewed the records for 176 patients with degenerative disorders of the cervical spine who underwent anterior cervical decompression or corpectomy within the C4 to C6 levels. Our measurements included area for the spinal cord, space available for the cord, and rotation of the cord with respect to the vertebral body.

Results: There was a 6.8% prevalence of postoperative C5 nerve palsy as defined by deltoid motor strength of ≤3 of 5. The average rotation of the spinal cord (and standard deviation) was 2.8° ± 3.0°. A significant association was detected between the degree of rotation (0° to 5° versus 6° to 10° versus ≥11°) and palsy (point-biserial correlation = 0.94; p < 0.001). A diagnostic criterion of 6° of rotation could identify patients who had a C5 palsy (sensitivity = 1.00 [95% confidence interval, 0.70 to 1.00], specificity = 0.97 [95% confidence interval, 0.93 to 0.99], positive predictive value = 0.71 [95% confidence interval, 0.44 to 0.89], negative predictive value = 1.00 [95% confidence interval, 0.97 to 1.00]).

Conclusions: Our evidence suggests that spinal cord rotation is a strong and significant predictor of C5 palsy postoperatively. Patients can be classified into three types, with Type 1 representing mild rotation (0° to 5°), Type 2 representing moderate rotation (6° to 10°), and Type 3 representing severe rotation (≥11°). The rate of C5 palsy was zero of 159 in the Type-1 group, eight of thirteen in the Type-2 group, and four of four in the Type-3 group. This information may be valuable for surgeons and patients considering anterior surgery in the C4 to C6 levels.

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

1Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, 3471 Fifth Avenue, Pittsburgh, PA 15213. E-mail address:

2Department of Psychology, Office 286 Psychology Building, Texas A&M University, College Station, TX 77843

3Department of Orthopedic Surgery, University of Massachusetts Medical School, 55 Lake Avenue, Worcester, MA 01655

4Tulane University Medical School, 1430 Tulane Avenue, New Orleans, LA 70112

5The Boston Spine Group, 299 Washington Street, Newton, MA 02458

Copyright 2012 by The Journal of Bone and Joint Surgery, Incorporated
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