Definition

Calcium pyrophosphate deposition disease (CPPD) is sometimes incorrectly referred to as pseudogout or chondrocalcinosis, though these entities are not synonymous with CPPD. Pseudogout refers to the clinical syndrome associated with CPPD, which is characterized by red, tender, and swollen joints and mimics gout. Chondrocalcinosis, on the other hand, is the radiologic or pathologic presence of calcifications in articular or fibrocartilage. This is often caused by calcium pyrophosphate dihydrate crystals, but may also be caused by other forms of calcification.

Clinical Aspects

CPPD crystal deposition disease is a polyarticular arthritis, although it can initially present as monoarticular.

CPPD crystals tend to form within articular tissues. Asymptomatic deposits can form in cartilage, joint capsules, intervertebral discs, tendons, and ligaments. Crystal deposition within cartilage (both hyaline and fibrocartilage) is known as chondrocalcinosis. Chondrocalcinosis initially is only visible microscopically, but if there is enough calcification, we can seen it radiographically as well. Common locations of chondrocalcinosis include the knees, wrists, elbows, and hips.

Crystal-induced synovitis is the result of shedding of crystals in the joint space after rupture of a CPPD deposit. Clinically this presents as an acute inflammatory synovitis very similar to that of an attack of gout, and has been referred to as "pseudogout."

• Other conditions associated with chondrocalcinosis:
  • hyperparathyroidism
  • hemochromatosis

Radiologic Findings

Three main manifestations of CPPD deposition:

1. chondrocalcinosis
2. crystal induced synovitis (pseudogout syndrome)
3. pyrophosphate arthropathy

These manifestations can occur alone or in various combinations, as shown in the Venn diagram below:

Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Fig. 1 CPPD patient with chondrocalcinosis of triangular fibrocartilage complex (TFCC) and scapholunate advanced collapse (SLAC wrist).

Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Fig. 2 Chondrocalcinosis of knee.

Image File history File links Download high resolution version (512x859, 22 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Fig. 3 Extra-articular calcification of the gastrocnemius tendon in a patient with CPPD.

Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Fig. 4 Chondrocalcinosis of the right hip (arrow).

Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Fig. 5 Chondrocalcinosis of the symphysis pubis.

Treatment

Treatment of CPPD is mostly aimed at preventing further crystal formation and reducing symptoms from crystal deposition. CPPD crystal deposition cannot be reversed. If an underlying disease (such as hemochromatosis or hyperparathyroidism) is present, treatment should be aimed specifically at controlling the disease. For symptomatic joints, treatment is similar to treatment of gout. When a single joint is involved, joint aspiration and intra-articular corticosteroid injection is often used, in addition to NSAID's and/or colchicine. When multiple joints are involved, joint injection is often impractical, or limited only to the most severely involved joint, and oral systemic treatment is chosen instead.

References

• Calcium pyrophosphate deposition disease by by Marla Sammer, M.D. and Rob Gutierrez, M.D., University of Washington Department of Radiology
• Steinbach LS, Resnick D. Calcium pyrophosphate dihydrate crystal deposition disease: imaging perspectives. Curr Probl Diagn Radiol. 2000 Nov-Dec;29(6):209-29.
• Chew FS, Maldijian C, Leffler SG. Musculoskeletal Imaging: A Teaching File, Lippincott Williams & Williams, 1999.