Untreated hypophosphatemic vitamin D-resistant rickets with symptomatic ossification of the ligamentum flavum.

An adult case of untreated hypophosphatemic vitamin D-resistant rickets with symptomatic ossification of the ligamentum flavum in the thoracic region is reported and discussed with regard to the calcium metabolism and the ligamentous ossification. Factors influencing ossification of the ligamentum flavum may be mechanical stress on the spine and an increase in calcium retention.