Calcium pyrophosphate deposition disease
Encyclopedia
Rheumatology
Rheumatology is a sub-specialty in internal medicine and pediatrics, devoted to diagnosis and therapy of rheumatic diseases. Clinicians who specialize in rheumatology are called rheumatologists...
disorder with varied symptoms arising due to the accumulation of crystals of calcium pyrophosphate
Calcium pyrophosphate
Calcium pyrophosphate is a chemical compound that can be formed by the reaction of pyrophosphoric acid and a calcium base or by strongly heating calcium phosphate or calcium ammonium phosphate....
dihydrate in the connective tissues. It is more commonly known by alternative names that specify certain clinical or radiographic findings, although neither is synonymous with CPPD. Pseudogout refers to the acute symptoms of joint inflammation or synovitis
Synovitis
Synovitis is the medical term for inflammation of the synovial membrane. This membrane lines joints which possess cavities, known as synovial joints. The condition is usually painful, particularly when the joint is moved. The joint usually swells due to synovial fluid collection.Synovitis may...
: red, tender, and swollen joints that may resemble gout
Gout
Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
y arthritis (a similar condition in which monosodium urate crystals are deposited within the joints). Chondrocalcinosis, on the other hand, refers to the radiographic evidence of calcification in hyaline and/or fibrocartilage. Pyrophosphate arthropathy is a term that may refer to either of the above. Statistically, the knee joint
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
is the most commonly affected.
General
CPPD crystal deposition disease is a polyarticular arthritis (i.e., it leads to an inflammation of several joints in the body), although it may begin as monoarticular (i.e., confined to just one joint). CPPD crystals tend to form within articular tissues. Although, in theory, any joint may be affected, statistics show that the knees, wrists, and hips are the most commonly attributed areas. In rare cases, pseudogout may affect the spinal canal and cause damage to the spinal cord.The exact cause of CPPD is unknown, although increased breakdown of adenosine triphosphate
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
(the molecule used as energy currency in all animals), which results in increased pyrophosphate levels in joints, is thought to be one reason why crystals may develop. There is some recent evidence suggesting that the gene ANKH
ANKH
Progressive ankylosis protein homolog is a protein that in humans is encoded by the ANKH gene.-External links:*-Further reading:...
is involved in crystal-related inflammatory reactions and inorganic phosphate transport. Excessive calcium (due to hypomagnesemia
Hypomagnesemia
Hypomagnesemia is an electrolyte disturbance in which there is an abnormally low level of magnesium in the blood. Usually a serum level less than 0.7 mmol/L is used as reference. The prefix hypo- means low . The middle 'magnes' refers to magnesium...
) has a potential relationship with chondrocalcinosis, and magnesium supplementation may reduce or alleviate symptoms.
One genetic study found an association between chondrocalcinosis and a region of chromosome 8q.
Signs and symptoms
People with this disorder usually first go to the doctor because inflammation is causing pain in one or more joints. HyperparathyroidismHyperparathyroidism
Hyperparathyroidism is overactivity of the parathyroid glands resulting in excess production of parathyroid hormone . The parathyroid hormone regulates calcium and phosphate levels and helps to maintain these levels...
, hypothyroidism
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
, hemochromatosis, hypophosphatemia
Hypophosphatemia
Hypophosphatemia is an electrolyte disturbance in which there is an abnormally low level of phosphate in the blood. The condition has many causes, but is most commonly seen when malnourished patients are given large amounts of carbohydrates, which creates a high phosphorus demand by cells,...
, hypomagnesemia and renal osteodystrophy
Osteodystrophy
Osteodystrophy is a general term for a dystrophic growth of the bone. It is defective bone development that is usually attributable to renal disease or to disturbances in calcium and phosphorus metabolism.One form is renal osteodystrophy....
are often also associated with chondrocalcinosis. Other diseases associated with chondrocalcinosis are Wilson's disease
Wilson's disease
Wilson's disease or hepatolenticular degeneration is an autosomal recessive genetic disorder in which copper accumulates in tissues; this manifests as neurological or psychiatric symptoms and liver disease...
and osteoarthritis
Osteoarthritis
Osteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
. In some cases, traumatic arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
can cause chondrocalcinosis.
In general, the white blood cell
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...
count is raised. In rare instances, patients may also have signs of carpal tunnel syndrome
Carpal tunnel syndrome
Carpal Tunnel Syndrome is an entrapment idiopathic median neuropathy, causing paresthesia, pain, and other symptoms in the distribution of the median nerve due to its compression at the wrist in the carpal tunnel. The pathophysiology is not completely understood but can be considered compression...
. This condition can also be associated with Milwaukee Shoulder
Milwaukee Shoulder
Milwaukee Shoulder Syndrome is a rheumatological condition similar to Calcium pyrophosphate dihydrate deposition disease , and is the result of periarticular or intraarticular deposition of hydroxyapatite crystals. Crystal deposition in the joint causes the release of collagenases, serine...
. On microscopic investigation with crossed polarizing filters of joint fluid obtained by aspiration, rhombus-shaped, positively birefringent crystals on Congo red stain may be seen.
Diagnosis
Radiography has a large role to play in the diagnosis of chondrocalcinosis, with radiographsRadiography
Radiography is the use of X-rays to view a non-uniformly composed material such as the human body. By using the physical properties of the ray an image can be developed which displays areas of different density and composition....
, CT scans
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
, MRIs
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
, ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
, and nuclear medicine
Nuclear medicine
In nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs...
all having a part. CT scans and MRIs show calcific masses (usually within the ligamentum flavum or joint capsule), however radiography is more successful.
As with most conditions, chondrocalcinosis can present with similarity to other diseases such as ankylosing spondylitis
Ankylosing spondylitis
Ankylosing spondylitis , previously known as Bekhterev's disease, Bekhterev syndrome, and Marie-Strümpell disease is a chronic inflammatory disease of the axial skeleton with variable involvement of peripheral joints and nonarticular structures...
and gout
Gout
Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
.
Arthrocentesis
Arthrocentesis
Arthrocentesis is the clinical procedure of using a syringe to collect synovial fluid from a joint capsule. It is also known as joint aspiration. Arthrocentesis is used in the diagnosis of gout, arthritis, and synovial infections....
, or removing synovial fluid from the affected joint, is performed to test the synovial fluid for the calcium pyrophosphate crystals that are present in CPPD.
Treatment
Because any medication that could reduce the inflammation of chondrocalcinosis bears a risk of causing organ damage, treatment is not advised if the condition is not causing pain.For acute
Acute
Acute may refer to:* Acute accent* Acute angle* Acute * Acute * Acute toxicity...
pseudogout, intra-articular corticosteroid injection, systemic corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs), or, on occasion, high-dose colchicine
Colchicine
Colchicine is a medication used for gout. It is a toxic natural product and secondary metabolite, originally extracted from plants of the genus Colchicum...
. In general, NSAIDs are administered in low doses to help prevent chondrocalcinosis. However, if an acute attack is already occurring, higher doses are administered. If nothing else works, hydroxychloroquine or methotrexate may provide relief.
Research into surgical removal of calcifications is underway, however this still remains an experimental procedure.