ICD-11 definition : This is a condition characterized by 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 vertebra).;
This is a condition characterized by 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 vertebra).