Can Calcium Pyrophosphate Dihydrate (CPPD) disease cause joint erosions?

Can CPPD Disease Cause Erosions?

Yes, calcium pyrophosphate deposition (CPPD) disease typically does not cause erosions, and the absence of erosions is actually a key distinguishing feature that helps differentiate it from other inflammatory arthritides. 1

Radiographic Features of CPPD

• CPPD is characterized by calcification in cartilage (chondrocalcinosis) and other joint structures, but unlike rheumatoid arthritis or other erosive arthropathies, it generally does not produce true erosive changes 1
• The radiographic features of CPPD typically include joint space narrowing, osteophytes, subchondral sclerosis, and subchondral cysts - similar to osteoarthritis 2
• When CPPD coexists with osteoarthritis, the radiographic changes are extremely similar to those of hand osteoarthritis, making differentiation challenging 2

Differential Diagnosis and Distinguishing Features

• The detection of skeletal erosive changes in a patient with CPPD suggests a coexisting inflammatory arthritis such as rheumatoid arthritis rather than CPPD alone 1
• In a study of patients with CPPD crystal deposition disease, those with true rheumatoid arthritis showed osseous erosions, while those with "pseudo-rheumatoid arthritis" due to CPPD alone did not show erosive changes 1
• The differential diagnosis between CPPD and other arthropathies requires consideration of multiple features including:
  • Age and gender (CPPD more common in older individuals) 2
  • Joint distribution 2
  • Radiographic findings 2
  • Laboratory tests 2

Imaging Modalities for CPPD Diagnosis

• Plain radiographs remain the gold standard for morphological assessment of joint changes in CPPD 2
• Ultrasound can detect CPPD crystal deposition but has limitations in differentiating erosive from non-erosive disease 2
• CT is particularly useful for showing calcification in axial joints, such as in patients with crowned dens syndrome 3
• MRI and ultrasound are superior for detecting soft tissue abnormalities like synovial hypertrophy but are less specific for CPPD 2

Clinical Implications

• When erosions are present in a patient with suspected CPPD, clinicians should consider:
  • Coexisting rheumatoid arthritis 1
  • Psoriatic arthritis (which may target DIP joints) 2
  • Gout (which may superimpose on pre-existing joint disease) 2
• The absence of erosions in a patient with inflammatory arthritis should raise suspicion for CPPD as a potential diagnosis 1

Management Considerations

• No current treatments can dissolve CPP crystals, which explains why control of inflammation is the main focus of therapeutic strategies 3
• Treatment approaches for CPPD focus on symptom management rather than modifying the underlying crystal deposition 4
• Management of any comorbidities associated with CPPD is recommended, though the impact on CPPD outcomes remains unclear 5

The key diagnostic insight is that true uncomplicated CPPD does not typically cause erosions, and when erosions are present, clinicians should suspect either a different diagnosis or a coexisting inflammatory arthropathy alongside CPPD.