Faculty Collaboration Database

Biomechanics of sequential posterior lumbar surgical alterations. J Neurosurg 1992 May;76(5):805-11

Date

05/01/1992

Pubmed ID

1564543

DOI

10.3171/jns.1992.76.5.0805

Scopus ID

2-s2.0-0026563867 (requires institutional sign-in at Scopus site)   39 Citations

Abstract

Compromise of the functional integrity of the posterior lumbar ligaments and facet joints is a common occurrence after repeated lumbar operative procedures. To evaluate the biomechanical effects of sequential surgical alterations, this investigation analyzed bilateral facetectomies (medial, total, and total with posterior ligament section) in three segments of human cadaveric lumbar spines under increasing compression-flexion. These iatrogenic alterations, designed to replicate common methods of surgical exposure, were created at the lower intervertebral joint (L4-5) while the upper joint (L3-4) remained intact. Overall strength characteristics in the physiological range of 400 N and 600 N demonstrated significant differences (p less than 0.05) in applied compressions for all preparations compared to the intact specimen. Comparison of sequential surgeries, however, did not demonstrate this tendency. Significant changes in the movement of the spinous processes at the upper (unaltered) level occurred only after posterior ligament section, whereas the lower (altered) level showed markedly increasing distraction of both the facets and the spinous processes with sequential operations. Sectioning of the supraspinous/interspinous ligament and associated fascial attachments resulted in a marked transfer of motion to the altered level. This was manifested by the increased anterior displacement of the centrode at the lower level associated with probable posterior migration of the centrode at the upper level. These data suggest that the effects of progressive surgical alterations of the lumbar facet joints are controllable in a preparation undergoing acute compression-flexion loads until the supraspinous/interspinous ligaments, with associated residual tendinous, midline muscle, and fascial attachments, are violated.

Author List

Cusick JF, Yoganandan N, Pintar FA, Reinartz JM

Authors

Joseph F. Cusick MD Adjunct Professor in the Neurosurgery department at Medical College of Wisconsin
Frank A. Pintar PhD Chair, Professor in the Biomedical Engineering 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

Aged
Biomechanical Phenomena
Cadaver
Humans
Lumbar Vertebrae
Male
Middle Aged
Stress, Mechanical