Chondrocalcinosis is a type of arthritis that causes sudden episodes of intense pain and swelling in the joints, most commonly affecting the knees, wrists, and other large joints. Also known as calcium pyrophosphate deposition disease or pseudogout, this condition occurs when tiny calcium crystals build up inside the joints and trigger painful inflammation. While the condition shares similarities with gout, it is caused by a different type of crystal and requires its own approach to diagnosis and treatment.

Understanding How Common Chondrocalcinosis Is

Chondrocalcinosis becomes more common as people get older, making it primarily a condition of aging. The disease typically affects individuals over the age of 60, with research showing that almost half of people over 85 have calcium crystal deposits in their joints, though many of them never develop any symptoms.^[1] The condition affects men and women equally, showing no preference for either gender.^[3]

Among younger individuals, chondrocalcinosis is relatively rare. When the disease does appear in people under 65, it often signals the presence of an underlying metabolic or endocrine condition that needs medical attention.^[2] The presence of calcium pyrophosphate crystals increases steadily with age, appearing in nearly half of the population older than 85, although most people with these crystal deposits never experience symptoms or attacks.^[5]

What Causes Chondrocalcinosis to Develop

The exact reason why calcium pyrophosphate crystals form in joints remains unclear to medical experts. What is known is that the condition results from an imbalance in how the body produces and regulates pyrophosphate, a naturally occurring substance in cartilage. When pyrophosphate combines with calcium in the joints, it forms crystals that accumulate in the cartilage (the rubbery tissue that cushions bones) and the fluid-filled membranes surrounding joints.^[3]

Scientists believe that something changes in the joint cartilage of older people that either allows or encourages crystal formation. These crystals first appear in the cartilage itself, but can later spread into the joint fluid and the thin membrane lining the joint space. When crystals release into the joint fluid, the body’s immune system recognizes them as foreign invaders and launches an inflammatory attack, which causes the painful symptoms patients experience.^[8]

Genetics appears to play a role in some cases, as chondrocalcinosis tends to run in families. Some studies suggest that parents can pass the risk of developing the condition to their biological children through inherited genes.^[1] Joint trauma or injury can also trigger crystal formation, with some people developing the condition after experiencing damage to a joint or undergoing joint surgery.^[5]

Risk Factors That Increase Your Chances

While anyone can develop chondrocalcinosis, certain groups of people face higher risks. Age stands out as the most significant factor, with the condition being much more common among individuals older than 65.^[1] Beyond age, several medical conditions create an environment that favors crystal formation in the joints.

Metabolic and endocrine disorders represent important risk factors for developing chondrocalcinosis. Hyperparathyroidism, a condition where the parathyroid glands produce too much hormone, shows the strongest association with the disease.^[3] People with thyroid disease, whether their thyroid is overactive or underactive, also face increased risk. Hemochromatosis, an inherited condition causing the body to absorb and store excessive iron, can lead to calcium crystal deposits in joints.^[1]

Mineral imbalances in the blood contribute to risk as well. Low magnesium levels, known as hypomagnesemia, excess calcium in the blood, and low levels of phosphate all increase the likelihood of developing the condition.^[1] Additionally, people who already have other forms of arthritis, including gout, osteoarthritis, rheumatoid arthritis, or post-traumatic arthritis, may be more likely to develop chondrocalcinosis on top of their existing joint problems.^[1]

Chronic kidney disease also appears on the list of risk factors, as it can affect how the body handles minerals and other substances that might promote crystal formation.^[1] People with hypophosphatasia, a rare inherited disorder affecting bone and teeth mineralization, and those with osteopenia, a condition of reduced bone density, face elevated risks as well.^[1]

Recognizing the Symptoms of Chondrocalcinosis

The symptoms of chondrocalcinosis appear suddenly and can be quite severe. The hallmark of the disease is episodes called flares or attacks, during which joints become intensely painful, swollen, and inflamed. These attacks strike without warning, with patients typically noticing all symptoms at once rather than experiencing a gradual buildup.^[1]

During an acute attack, the affected joint becomes red or shows skin discoloration, feels warm or hot to the touch, and swells noticeably. The pain can be severe enough to interfere with daily activities and limit movement. Stiffness makes it difficult to use the joint normally, and some people experience fever, chills, and overall weakness during severe episodes.^[2]

While chondrocalcinosis can affect any joint in the body, it shows a clear preference for larger joints. The knees are the most commonly affected, but the hands, wrists, shoulders, hips, pelvis, elbows, and ankles can all be involved.^[1] The disease can strike multiple joints simultaneously, adding to the discomfort and disability patients experience.^[2]

The duration of symptoms varies considerably from person to person. A typical attack may last anywhere from a few days to several weeks or even longer.^[1] Between episodes, many people feel completely normal and have no symptoms at all. However, some individuals never experience any discomfort despite having calcium crystals in their joints, a condition detected only when imaging tests are performed for other reasons.^[2]

Over time, repeated attacks and ongoing crystal deposits can lead to chronic problems. The persistent inflammation and accumulation of crystals cause progressive joint damage that mimics the symptoms of osteoarthritis or rheumatoid arthritis. People may develop constant joint pain and stiffness, low-grade inflammation that never fully resolves, swollen joints that appear knobby, decreased range of motion, and morning stiffness accompanied by fatigue.^[2]

Steps You Can Take to Prevent Attacks

Because the exact cause of calcium crystal formation remains unknown, preventing chondrocalcinosis entirely is challenging. However, certain measures can help reduce the risk of joint damage and may lower the frequency of painful attacks. Regular moderate exercise helps strengthen the muscles around joints and can improve overall joint health, though it should be balanced with adequate rest to avoid joint trauma.^[6]

Maintaining a healthy body weight reduces stress on weight-bearing joints like the knees and hips, potentially slowing the progression of joint damage. Unlike gout, chondrocalcinosis does not respond to specific dietary changes, as food intake does not appear to influence calcium pyrophosphate crystal formation. However, if an underlying metabolic or endocrine condition is identified as contributing to the disease, treating that condition becomes crucial for preventing further crystal accumulation.^[2]

For people experiencing frequent attacks, preventive medication may help reduce the number and severity of flares. Healthcare providers sometimes prescribe low-dose colchicine, nonsteroidal anti-inflammatory drugs, or low-dose corticosteroids taken daily to prevent attacks from occurring.^[4] The decision to use preventive medication depends on individual circumstances and should be discussed with a rheumatology specialist who can weigh the benefits against potential side effects.

How the Disease Affects the Body

Understanding what happens inside the joint during chondrocalcinosis helps explain why the symptoms are so painful. In healthy joints, smooth cartilage covers the ends of bones where they meet, acting as a cushion and shock absorber. A thin membrane called the synovial membrane lines the joint space and produces fluid that lubricates the joint, allowing bones to glide smoothly against each other.^[8]

In chondrocalcinosis, calcium pyrophosphate crystals begin forming within the cartilage itself. These crystals, shaped like rhomboids when viewed under a special microscope, accumulate in the cartilage and can later spill into the synovial fluid that fills the joint space.^[3] While crystals sitting quietly in cartilage may cause no symptoms, problems arise when they release into the joint fluid.

When crystals enter the joint fluid, the body’s immune system recognizes them as foreign material and launches a defensive attack. White blood cells called polymorphonuclear neutrophils rush to the scene to fight what they perceive as an infection. These cells release toxic chemicals designed to kill bacteria, but these same chemicals accidentally damage the surrounding cartilage and joint tissues, triggering intense inflammation.^[8]

The inflammatory response involves activation of the NLRP3 inflammasome, a component of the innate immune system that recognizes danger signals. This activation leads to the production of inflammatory molecules that cause pain, swelling, warmth, and redness in the affected joint.^[12] Over time, repeated inflammatory episodes and the physical presence of crystals can alter the mechanical properties of the joint, contributing to cartilage breakdown and permanent joint damage.^[11]

As the disease progresses, chronic inflammation can lead to changes in bone structure. Small pockets filled with fluid called cysts may form, and bone spurs—small projections that stick out from the bones—can develop. The cartilage gradually deteriorates, leading to joint degeneration similar to what occurs in osteoarthritis.^[2] Unlike conditions where crystals can be dissolved or prevented from forming, no current treatment can remove calcium pyrophosphate crystals once they have deposited in joint tissues, making early symptom management crucial to protecting joint function.^[4]