Orientation and tropism of lumbar facet joints in degenerative spondylolisthesis

The orientation and tropism of the lumbar facet joints at L4-5 level was as sessed by magnetic resonance imaging (MRI) in 53 patients with degenerative L4-5 spondylolisthesis and 53 age- and sex-matched normal control subjects . The degree of disc degeneration at the LA-5 level and of vertebral slip o n lateral radiographs was also evaluated. Patients with degenerative spondy lolisthesis had more sagittally orientated facet joints (P <0.01) and more significant facet joint tropism (P <0.05) than normal control subjects. For patients with degenerative spondylolisthesis, the facet joint tropism was significantly correlated with the degree of disc degeneration (P <0.05). Th e results suggest that morphological abnormalities of the lumbar facet join ts are a predisposing factor in the development of degenerative spondylolis thesis.