Rare Complications of Cervical Spine Surgery: Horner's Syndrome.

Study Design: A multicenter retrospective case series.
Objective: Horner's syndrome is a known complication of anterior cervical spinal surgery, but it is rarely encountered in clinical practice. To better understand the incidence, risks, and neurologic outcomes associated with Horner's syndrome, a multicenter study was performed to review a large collective experience with this rare complication.
Methods: We conducted a retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received subaxial cervical spine surgery from 2005 to 2011 were reviewed to identify occurrence of 21 predefined treatment complications. Descriptive statistics were provided for baseline patient characteristics. Paired t test was used to analyze changes in clinical outcomes at follow-up compared to preoperative status.
Results: In total, 8887 patients who underwent anterior cervical spine surgery at the participating institutions were screened. Postoperative Horner's syndrome was identified in 5 (0.06%) patients. All patients experienced the complication following anterior cervical discectomy and fusion. The sympathetic trunk appeared to be more vulnerable when operating on midcervical levels (C5, C6), and most patients experienced at least a partial recovery without further treatment.
Conclusions: This collective experience suggests that Horner's syndrome is an exceedingly rare complication following anterior cervical spine surgery. Injury to the sympathetic trunk may be limited by maintaining a midline surgical trajectory when possible, and performing careful dissection and retraction of the longus colli muscle when lateral exposure is necessary, especially at caudal cervical levels.
Competing Interests: Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Vincent C. Traynelis reports grants from AOSpine North America during the conduct of the study, and Medtronic - Royalties, Consultant Globus - Institutional Fellowship Support; Zachary A. Smith reports grants from AOSpine North America during the conduct of the study; Wellington K. Hsu reports grants from AOSpine North America during the conduct of the study, personal fees from Medtronic, personal fees from Stryker, personal fees from Bacterin, personal fees from Graftys, personal fees from Ceramtec, personal fees from Relievant, personal fees from Bioventus, personal fees from Globus, personal fees from SpineSmith, outside the submitted work; Sheeraz A. Qureshi reports grants from AOSpine North America during the conduct of the study, and is a consultant and receives royalties from Stryker Spine, Biomet Spine, and RTI; Evan O. Baird reports grants from AOSpine North America during the conduct of the study; Robert E. Isaacs reports grants from AOSpine North America during the conduct of the study, grants and personal fees from NuVasive, Inc., personal fees from Association for Collaborative Spine research, outside the submitted work; Galina Polevaya reports grants from AOSpine North America during the conduct of the study; Justin S. Smith reports grants from AOSpine North America during the conduct of the study, personal fees from Biomet, personal fees from Nuvasive, personal fees from Cerapedics, personal fees from K2M, personal fees and other from DePuy, personal fees from Medtronic, outside the submitted work; Christopher Shaffrey reports grants from AOSpine North America during the conduct of the study, personal fees from Biomet, personal fees from Medtronic, from Nuvasive, personal fees from K2M, personal fees from Stryker, outside the submitted work, and Editorial Board Spine, Spinal Deformity and Neurosurgery; P. Justin Tortolani reports grants from AOSpine North America during the conduct of the study, other from Globus Medical, grants from Spineology, other from Innovasis, outside the submitted work, and in addition, Dr. Tortolani has a patent Globus with royalties paid; D. Alex Stroh reports grants from AOSpine North America during the conduct of the study; Michael G. Fehlings reports grants from AOSpine North America during the conduct of the study; Thomas E. Mroz reports other from AOSpine, grants from AOSpine North America, during the conduct of the study, personal fees from Stryker, personal fees from Ceramtec, other from Pearl Diver, outside the submitted work; and K. Daniel Riew reports personal fees from AOSpine International, other from Global Spine Journal, other from Spine Journal, other from Neurosurgery, personal fees from Multiple Entities for defense, plantiff , grants from AOSpine, grants from Cerapedics, grants from Medtronic, personal fees from AOSpine, personal fees from NASS, personal fees from Biomet, personal fees from Medtronic, nonfinancial support from Broadwater, outside the submitted work; Hani R. Malone reports grants from AOSpine North America during the conduct of the study; Adam S. Kanter reports grants from AOSpine North America during the conduct of the study; Samuel K. Cho reports grants from AOSpine North America during the conduct of the study; grants from OREF, personal fees from Stryker, personal fees from Medtronic, personal fees from DePuy Synthes, outside the submitted work; Ra'Kerry K. Rahman reports grants from AOSpine North America during the conduct of the study; in addition, Dr. Rahman has a patent Deformity System & Pedicle Screws pending. Paul M. Arnold reports grants from AOSpine North America during the conduct of the study; other from Z-Plasty, other from Medtronic Sofamore Danek, other from Stryker Spine, other from FzioMed, other from AOSpine North America, other from Life Spine, other from Integra Life, other from Spine Wave, other from MIEMS, other from Cerapedics, other from AOSpine North America, outside the submitted work.