Quantitative anatomy of subaxial cervical lateral mass: an analysis of safe screw lengths for Roy-Camille and magerl techniques. Spine (Phila Pa 1976) 2008 Apr 15;33(8):893-7
Date
04/12/2008Pubmed ID
18404109DOI
10.1097/BRS.0b013e31816b4666Scopus ID
2-s2.0-42149176012 (requires institutional sign-in at Scopus site) 62 CitationsAbstract
STUDY DESIGN: Determination of lateral mass screw lengths with Roy-Camille and Magerl techniques of screw insertion using computerized tomography in 98 young, asymptomatic North American volunteers.
OBJECTIVE: To provide reliable and normative data on safe screw lengths using the Roy-Camille and Magerl techniques of lateral mass fixation in the subaxial cervical spine.
SUMMARY OF BACKGROUND DATA: Lateral mass screw lengths have been studied in the past using differing subject and measurement characteristics and small sample sizes. Results demonstrated considerable variation in screw length and influencing factors. Inappropriate screw lengths can result in neurovascular injury during screw insertion, facet joint damage, or inadequate fixation.
METHODS: Bicortical screw lengths were bilaterally measured at each spinal level from C3-C7 in 98 young volunteers using computed tomography reconstructions through the lateral masses obtained in the plane of the screw in Roy-Camille and Magerl techniques.
RESULTS: With both techniques, trajectories were longest at C4-C6, shorter at C3, and shortest at C7. Screw lengths were greater in males when compared with females at all levels. Average Magerl screw lengths were approximately 2.6 mm longer at C3-C6 levels, and approximately 1.3 mm longer at the C7 level when compared with Roy-Camille technique. There was minimal correlation between screw lengths and anthropometric measurements including stature, body weight, and neck length.
CONCLUSION: Significant variations exist at each subaxial level with either technique. We recommend the surgeon determine screw lengths for fixation at each level using preoperative sagittal oblique computed tomography scans, which provide the most accurate technique of preoperative templating for screw length.
Author List
Stemper BD, Marawar SV, Yoganandan N, Shender BS, Rao RDAuthors
Brian Stemper PhD Professor in the Biomedical Engineering department at Medical College of WisconsinNarayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdultBone Screws
Cervical Vertebrae
Equipment Safety
Female
Humans
Internal Fixators
Male
Neck
Neurosurgical Procedures
Prosthesis Design
Tomography, X-Ray Computed
