Chondrocalcinosis Consistent with CPPD
Chondrocalcinosis is the radiographic or pathologic finding of calcium deposits in cartilage, and when consistent with CPPD, it represents the deposition of calcium pyrophosphate dihydrate crystals in both hyaline articular cartilage and fibrocartilage of joints. 1
Definition and Pathologic Basis
Chondrocalcinosis refers specifically to calcification visible within cartilage structures, appearing as punctate and linear radiodense areas on imaging. 2 When these deposits are composed of calcium pyrophosphate dihydrate (CPPD) crystals rather than other calcium-containing crystals, this constitutes CPPD disease. 3
The key distinction is that chondrocalcinosis is a descriptive imaging/pathologic term, while CPPD is the specific disease entity causing it. 3 Not all chondrocalcinosis is due to CPPD—other conditions can cause cartilage calcification—but CPPD is the most common cause. 3
Clinical Spectrum and Presentations
CPPD presents with highly variable clinical manifestations, ranging from completely asymptomatic radiographic findings to severe inflammatory and destructive arthropathy. 1
The clinical phenotypes include:
- Asymptomatic chondrocalcinosis: Radiographic findings without symptoms, common in elderly patients and requiring no treatment 1
- Acute CPP crystal arthritis (pseudogout): Sudden, severe inflammatory attacks mimicking gout or septic arthritis 2, 4
- Chronic CPP crystal inflammatory arthritis: Persistent inflammatory arthritis that can mimic rheumatoid arthritis 5, 6
- Osteoarthritis with CPPD: Degenerative changes with superimposed crystal deposition, potentially accelerating joint destruction 1
- Destructive arthropathy: Severe, rapidly progressive joint destruction resembling neuropathic joints 2, 4
Epidemiology and Age-Related Prevalence
The prevalence of radiographic chondrocalcinosis increases dramatically with age, affecting approximately 13% across all age groups but rising substantially after age 70. 1 Specifically, prevalence reaches 10-15% in patients aged 65-75 years and exceeds 40% in those over 80 years old. 2
Diagnostic Approach
Definitive diagnosis requires demonstration of positively birefringent CPPD crystals in synovial fluid using compensated polarized light microscopy, combined with characteristic radiographic findings. 2, 5
The radiographic hallmark is punctate and linear calcifications in fibrocartilage (menisci, triangular fibrocartilage of wrist) and hyaline cartilage. 2 The 2023 EULAR imaging recommendations emphasize that conventional radiography remains a key diagnostic modality for identifying chondrocalcinosis, though ultrasound and CT can also detect crystal deposits. 1
Associated Metabolic Conditions
For patients presenting with CPPD before age 60, screening for underlying metabolic disorders is mandatory. 2 CPPD is three times more likely in patients with primary hyperparathyroidism (OR=3.03,95% CI 1.15 to 8.02), and is also associated with hemochromatosis, hypomagnesemia, and hypophosphatasia. 1, 2, 5
Early-onset disease particularly requires evaluation for hemochromatosis. 2 However, most cases are idiopathic and sporadic, occurring in elderly patients without identifiable metabolic abnormalities. 2, 6
Pathophysiologic Distinction from Gout
Unlike gout, there is currently no treatment to prevent CPP crystal formation or enhance their dissolution. 1 Elevated inorganic pyrophosphate levels drive crystal formation, but no pharmacologic agents are available to modulate this process in clinical practice. 1 This fundamental difference means CPPD management is restricted to symptomatic control rather than disease modification. 1
Common Pitfalls
The term "chondrocalcinosis" is often incorrectly used interchangeably with CPPD disease, but chondrocalcinosis is merely a radiographic finding that can be asymptomatic. 3 Additionally, the presence of chondrocalcinosis does not automatically indicate that current joint symptoms are caused by CPPD—concomitant osteoarthritis or other conditions may be responsible. 1