Chondrocalcinosis is also called pyrophosphate crystallite and is characterized by the fact that calcium pyrophosphate forms calcifications in articular cartilage in several joints, menisci in the knees and intervertebral discs in the back. The condition occurs among older people and increases with age. Seizures with arthritis (Arthritis) that reminds of gout is typical. Due to the similarity with gout attacks, the condition was formerly called pseudo gout. However, chondrocalcinosis can also be detected along with Osteoarthrtitis or without symptoms or in chronic joint disease.
The incidence of chondrocalcinosis increases with age and is rarely before the age of 40. Among people over the age of 85, chondrocalcinosis can be detected in more than 20%. However, there is a rare, hereditary form that attacks people as early as 30-40 years of age. Women and men get chondrocalcinosis about as often.
The cause of the disease is precipitation of calcium pyrophosphate dihydrate and calcifications, in contrast to gout where uric acid crystals precipitate. Both conditions are called crystal arthritis or crystal gout. Hyperparathyroidism with too much activity in the bi-thyroid gland also predisposes.
Chondrocalcinosis is frequent at the same time Osteoarthrtitis. Seizures can be triggered by injuries, surgeries and acute illnesses.
It is primarily large and medium-sized joints that are attacked, in particular kneejoints and wrists.
- Acute Arthritis is most common. The symptoms can be acutely swollen, red, hot and tender joints. During such severe attacks, unwellness and mild fever may occur. Blood samples then usually show elevated CRP and Sedimentation rate. Such attacks are similar to gout, but high levels of uric acid in blood and uric acid crystals in joint fluid are not expected in chondrocalcinosis.
- The disease can also occur without symptoms and is then detected randomly by imaging, such as X-rays or ultrasound. In other cases, at the same time, osteoarthritis occurs.
- Osteoarthritis without prior damage or other explanatory causes may be due to chondrocalcinosis, especially where unusual joints such as shoulders and wrists are attacked.
- Arthritis (Rheumatoid Arthritis) Similar disease course occur in that small joints of the fingers, wrists, ankles and toes are attacked on both sides of the body. However, there is no elevated anti-CCP antibody in the blood as is most common in arthritis. In diagnostic imaging and synovial fluid examinations, chondrocalcinosis is detected, which is not expected in arthritis.
- Other forms that are more rare can look like polymyalgia revmatika (PMR) with muscle stiffness and muscle aches especially in the morning. Chronic poop over time can lead to similar misalignments neuropathic joint damage / Charcot joint.
- A rare manifestation is acute arthritis of the neck with pyrophosphate crystals around cervical vertebra C2 which can cause severe pain and neck stiffness, fever and signs of inflammation in blood tests ("crowded its syndrome"). This can be misinterpreted as meningitis.
Medical history includes current symptoms (see above), especially in predisposed people in old age. There is also a demand for signs of infections and gout that may resemble chondrocalcinosis.
Ved clinical examination signs of other disease are excluded. The joints are examined specifically for joint inflammation (arthritis), osteoarthritis and signs of infection.
- In case of acute attacks of chondrocalcinosis, CRP and the Sedimentation rate increase at least as markedly as at a gout attack.
- The number of white blood cells may be elevated, but most often lower than with infection
- Uric acid is not expected to be particularly high
Joint fluid. Pyrophosphate crystals are detected under a phase contrast microscope or polarization filter.
Imaging. X-rays show the storage of pyrophosphate crystals as a tight band along the articular cartilage (see X-ray at the top of the page). The same can be produced by CT examination. Ultrasound can also show changes, while MRI images are less specific.
The diagnosis of chondrocalcinosis is based on typical symptoms, imaging and detecting the typical rhomboidal crystals of calcium pyrophosphate dihydrate in the joint fluid (by microscopy in polarized light).
Similar conditions, differential diagnoses
In case of seizures, relief is necessary and one can supplement with cooling of warm, inflamed joints. Anti-inflammatory drugs can be used and often relieve well. Drainage of synovial fluid and injection of corticosteroids are effective treatments. NSAIDs have palliative effects, but in elderly people, particular attention must be paid to the risk of side effects. Colchicine or prednisolone are alternatives, of which colchicine can also prevent attacks. Experimental treatment with interleukin-1 inhibitors (anakinra)(reference: Ottaviani S, 2013).
The acute attacks are very troublesome, but not dangerous. The chronic form can lead to joint damage such as osteoarthritis or arthritis.
- Zamora EA, 2021
- Rosenthal AK, 2016
- Richette P, 2009
- MacMullan P, 2012
- Grans Compendium in Rheumatology
- Great Norwegian encyclopedia