Definition: Deficient development or degeneration of a portion of the VERTEBRA, usually in the pars interarticularis (the bone bridge between the superior and inferior facet joints of the LUMBAR VERTEBRAE) leading to SPONDYLOLISTHESIS.
coordinate with specific vertebra; do not confuse with SPONDYLOSIS or SPONDYLITIS
See AlsoSpondylosis ExamplesSpondylolisthesis