[Mineral changes occurring with age in the intervertebral disks of L4-L5 vertebrae].

The results of mineralogical examination of 26 L4-L5 intervertebral discs taken from cadavers has been presented. Radiology did not reveal marked osteoarthritic changes at this level. The age of the individuals at the fatal accident ranged from 4 to 87 years (mean 41.2). -- Scanning microscopy, atom absorbtion spectroscopy and roentgen microscopy was used in the examination. Two age related phenomena were discovered; demineralisation of the nucleus pulposus and mineralisation of the anulus fibrosus. Two types of mineralisation were found; the microscopic one visible as granules of different shape and size consisting of crystalline hydroxyapatite aggregates and the one detectable exclusively by sensitive chemical methods as an increase of Ca and P content and disturbance of the remaining elements content in biological structures.