Arthritis of the back, coloured X-ray. Lumbar arthritis caused by chondrocalcinosis, a condition where crystals of calcium pyrophosphate are deposited in soft tissues. In this case, deposits (pink) have formed in the discs of flexible cartilage that separate the bones of the spine or vertebrae (blue). The cartilage has worn away, causing discs in the lower back to collapse. Chondrocalcinosis causes a variety of arthritic conditions. It can produce symptoms similar to gout (this is termed pseudogout), osteoarthritis or rheumatoid arthritis.