Comparison of contemporary occipitocervical instrumentation techniques with and without C1 lateral mass screws. Neurosurgery 2007 Sep;61(3 Suppl):87-93; discussion 93
Date
10/03/2007Pubmed ID
17876237DOI
10.1227/01.neu.0000289720.04836.fdScopus ID
2-s2.0-34548663708 (requires institutional sign-in at Scopus site) 15 CitationsAbstract
OBJECTIVE: This study was designed to test the kinematic properties of three occiput-C2 instrumentation constructs with and without supplemental rigid C1 fixation. The results are compared with intact specimens and with constructs incorporating contemporary cabling techniques.
METHODS: Five unembalmed human cadaver specimens underwent range of motion (ROM) testing in the intact condition, followed by destabilization with odontoid osteotomy. Destabilized specimens then underwent ROM testing with each of seven occipitocervical instrumentation constructs, all incorporating occipital screws: C1 and C2 sublaminar cables with cable connectors, C2 pars screws +/- C1 lateral mass screws, C2 lamina screws +/- C1 lateral mass screws, and C1-C2 transarticular screws +/- C1 lateral mass screws.
RESULTS: All seven constructs demonstrated significantly lower ROM in all loading modes than intact specimens (P < 0.05). With a single exception, the addition of C1 lateral mass screws to the screw-based constructs produced no significant change in ROM in any of the loading modes. Compared with intact specimens, constructs anchored by C1-C2 transarticular screws demonstrated the greatest decrease in ROM, and those anchored by sublaminar cables demonstrated the least decrease in ROM.
CONCLUSION: Any of the tested screw-based constructs are likely to provide adequate support for the patient with an unstable craniocervical junction. Therefore, the choice of construct should be based on anatomic considerations. The routine incorporation of C1 lateral mass screws into occipitocervical instrumentation constructs does not seem necessary.
Author List
Wolfla CE, Salerno SA, Yoganandan N, Pintar FAAuthors
Frank A. Pintar PhD Chair, Professor in the Biomedical Engineering department at Medical College of WisconsinChristopher E. Wolfla MD Professor in the Neurosurgery department at Medical College of Wisconsin
Narayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Atlanto-Axial JointAtlanto-Occipital Joint
Bone Screws
Cadaver
Humans
Internal Fixators
Joint Instability
Range of Motion, Articular
Spinal Fusion
Technology Assessment, Biomedical