Role of ligaments and facets in lumbar spinal stability.

摘要: STUDY DESIGN The issue of segmental stability using finite element analysis was studied. Effect ligament and facet (total partial) removal their geometry on segment response were studied from the viewpoint stability. OBJECTIVES To predict factors that may be linked to cause rotational instabilities, spondylolisthesis, retrospondylolisthesis, stenosis. SUMMARY OF BACKGROUND DATA study provides a comprehensive role facets ligaments in preserving No previous biomechanical has explored these issues detail. METHODS Three-dimensional nonlinear performed L3-L4 motion segments, with without posterior elements (ligaments facets), subjected sagittal moments. Effects (partial total) orientations are examined RESULTS Ligaments play an important resisting flexion rotation shear whereas mainly responsible for preventing large extension anterior displacement. Facet loads stresses high under loading. Unlike total facetectomy, selective does not compromise dependent spatial orientation. CONCLUSIONS Rotational instability or displacement (retrospondylolisthesis) is unlikely prior damage ligaments, forward (spondylolisthesis) before degeneration removal. stress distribution predicts osteoarthritis hypertrophy leading spinal stenosis most likely flexion-anterior Selective facetectomy restore canal size compromising segment. A more sagittally oriented less transversely joint instabilities extension.