facet tropism
Pronunciation: TROH-pizm
Asymmetric orientation of facet joints between left and right sides at the same spinal level, potentially contributing to instability.
Full Definition
Facet tropism describes the asymmetric orientation or angulation of the bilateral facet joints at a given spinal level, where the left and right facets have significantly different orientations relative to the sagittal plane. This anatomical variation can predispose to rotational instability, asymmetric loading patterns, and degenerative changes. Facet tropism is most commonly observed in the lumbar spine and may contribute to disc degeneration, back pain, and the development of spondylolisthesis. Recognition of facet tropism is important for understanding spinal biomechanics and planning surgical interventions.
Usage
Usage note: Specify the degree of asymmetry and spinal level when documenting facet tropism.
In Context
- "CT imaging revealed significant facet tropism at L4-L5 with 15-degree asymmetry." — radiology report
- "The patient's rotational instability was attributed to congenital facet tropism." — biomechanical analysis