Presentations

Abstract

Introduction: LEARNING OBJECTIVES: (1) To review the imaging findings of chondrocalcinosis (CC) on radiographs. (2) Explore the spectrum of diseases associated with chondrocalcinosis.

Case Information: BACKGROUND: Chondrocalcinosis (CC) is a term used to describe visualization of gross calcium deposition in hyaline and fibrocartilage. CC is commonly and mistakenly used interchangeably with calcium pyrophosphate deposition (CPPD), however, these two are not synonymous. For some familial CC cases, mutations have been identified in the ANKH gene affecting pyrophosphate metabolism; however, the exact underlying pathogenic mechanism of calcium deposition in cartilage remains not entirely understood6. CC is often seen with advanced osteoarthritis but is also associated with a wide variety of diseases. While most commonly associated with CPPD, CC is also associated with Addison's disease, Wilson's disease, alkaptonuria (ochronosis), hypothyroidism, hyperparathyroidism, hypomagnesemia, and hereditary hemochromatosis (HH) largely due to abnormal calcium/pyrophosphate metabolism. Management of CC generally involves anti-inflammatory medications and control of the underlying etiology.

Discussion/Clinical Findings: IMAGING FINDINGS: Often demonstrated on radiographs, CC appears as hazy punctate and linear densities in hyaline and fibrocartilage. These findings remain similar despite differences in the underlying cause of the CC. Typical locations involve the knee, wrist, hip, and symphysis pubis, areas often affected by degenerative changes4. CC in the knees tend to affect the menisci more commonly than the articular cartilage. In the wrist, the most common site of calcification is the triangular fibrocartilage complex. While unusual, it is possible to also see CC in areas such as the acromioclavicular joints, external ear, and ankle cartilage as well.

Conclusion: CONCLUSION AND/OR TEACHING POINTS: 1. CC is associated with a wide variety of disease processes. 2. CC is more commonly found in elderly patients with advanced osteoarthritis. 3. One must consider an underlying metabolic process for patients under 60 years old presenting with CC on radiographs. 4. Associated diseases include CPPD, Addison's disease, Wilson's disease, alkaptonuria (ochronosis), hypothyroidism, hyperparathyroidism, hypomagnesemia, and hereditary hemochromatosis (HH).