Calcium crystal deposits are common problems in joint cartilage and synovial fluid. Not much is known about similar deposits in the intervertebral discs. The discs are fluid-filled pads between the vertebrae (bones of the spine).
In this study, disc material removed from 208 patients with disc disease were examined under microscope. The researchers looked for crystal deposits. They counted how many times they found crystal deposits. This is called the incidence. They also studied each component in the disc specimen.
The presence of calcium crystals is important. They can disrupt the natural flow of cells, enzymes, and fluid within any structure, including the discs. Crystals in the disc speed up any degenerative process already going on.
The results of this study showed about a 15 per cent incidence of crystals. The authors report the crystals were all sizes and shapes with various other features. Some crystals looked like scratches on glass. Others were needle- or star-shaped.
The crystals were not unusual in any way. The scientists did see that the more degeneration there was in the disc, the fewer crystal deposits were present. This is called an inverse relationship.
It appears that crystal deposits occur in the discs at about the same rate as occurs in joint fluid and cartilage. The process seems to be age-related and occurs more often after age 60. Crystals may be linked to disc tears and herniation. Future studies to understand how the crystals form may help prevent disc degeneration.