Background: Lateral mass screw fixation with plates or rods has become the standard method of posterior cervical spine fixation and stabilization for a variety of surgical indications. Despite ubiquitous usage, the safety and efficacy of this technique have not yet been established sufficiently to permit “on-label” U.S. Food and Drug Administration approval for lateral mass screw fixation systems. The purpose of this study was to describe the safety profile and effectiveness of such systems when used in stabilizing the posterior cervical spine.
Methods: A systematic search was conducted in MEDLINE and the Cochrane Collaboration Library for articles published from January 1, 1980, to December 1, 2011. We included all articles evaluating safety and/or clinical outcomes in adult patients undergoing posterior cervical subaxial fusion utilizing lateral mass instrumentation with plates or rods for degenerative disease (spondylosis), trauma, deformity, inflammatory disease, and revision surgery that satisfied our a priori inclusion and exclusion criteria.
Results: Twenty articles (two retrospective comparative studies and eighteen case series) satisfied the inclusion and exclusion criteria and were included. Both of the comparative studies involved comparison of lateral mass screw fixation with wiring and indicated that the risk of complications was comparable between treatments (range, 0% to 7.1% compared with 0% to 6.3%, respectively). In one study, the fusion rate reported in the screw fixation group (100%) was similar to that in the wiring group (97%). Complication risks following lateral mass screw fixation were low across the eighteen case series. Nerve root injury attributed to screw placement occurred in 1.0% (95% confidence interval, 0.3% to 1.6%) of patients. No cases of vertebral artery injury were reported. Instrumentation complications such as screw or rod pullout, screw or plate breakage, and screw loosening occurred in <1% of the screws inserted. Fusion was achieved in 97.0% of patients across nine case series.
Conclusions: The risks of complications were low and the fusion rate was high when lateral mass screw fixation was used in patients undergoing posterior cervical subaxial fusion. Nerve root injury attributed to screw placement occurred in only 1% of 1041 patients. No cases of vertebral artery injury were identified in 758 patients. Screw or rod pullout, screw or plate breakage, and screw loosening occurred in <1% of the screws inserted.
Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Investigation performed at the Silicon Valley Spine Institute, Campbell, California; the Rothman Institute, Philadelphia, Pennsylvania; the University of Utah, Salt Lake City, Utah; the Johns Hopkins University School of Medicine, Baltimore, Maryland; the Indiana Spine Group, Carmel, Indiana; the University of Maryland Medical System, Baltimore, Maryland; and Spectrum Research, Tacoma, Washington
Disclosure: One or more of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of an aspect of this work. In addition, one or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
- Copyright © 2013 by The Journal of Bone and Joint Surgery, Incorporated
Enter your JBJS login information below.
Please note that your username is the email address you provided when you registered.