What is the initial workup for Calcium Pyrophosphate Dihydrate (CPPD) disease?

From the Guidelines

The initial workup for calcium pyrophosphate deposition disease (CPPD) should include a thorough clinical evaluation, joint fluid analysis, and imaging studies, with a focus on identifying chondrocalcinosis and ruling out metabolic disorders associated with CPPD. According to the American College of Radiology Appropriateness Criteria 1, the most appropriate initial imaging study is a plain radiograph of the affected joint, which can help identify chondrocalcinosis. Joint aspiration with synovial fluid analysis is also essential, looking specifically for weakly positive birefringent rhomboid-shaped crystals under polarized light microscopy. Laboratory tests should include serum calcium, phosphate, magnesium, alkaline phosphatase, and parathyroid hormone levels to rule out metabolic disorders associated with CPPD such as hyperparathyroidism, hemochromatosis, and hypomagnesemia. Complete blood count, erythrocyte sedimentation rate, and C-reactive protein may help differentiate CPPD from other inflammatory conditions.

Some key points to consider in the initial workup include:

• Identifying chondrocalcinosis, which commonly appears in the knee menisci, wrist triangular fibrocartilage, and pubic symphysis
• Ruling out metabolic disorders associated with CPPD, such as hyperparathyroidism, hemochromatosis, and hypomagnesemia
• Using joint aspiration and synovial fluid analysis to confirm the presence of CPPD crystals
• Considering additional imaging studies, such as ultrasound or CT scan, if plain radiographs are inconclusive. The EULAR recommendations for CPPD management 1 also emphasize the importance of a comprehensive approach to diagnosis and management, although they note that the evidence base for CPPD management is limited.

In terms of specific imaging studies, the American College of Radiology Appropriateness Criteria 1 recommend the following:

• X-ray of the affected joint: usually appropriate (rating 9)
• CT scan of the affected joint without IV contrast: may be appropriate (rating 5)
• MRI of the affected joint without IV contrast: may be appropriate (rating 5)
• Ultrasound of the affected joint: may be appropriate (rating 5). Overall, a comprehensive approach to the initial workup for CPPD is necessary to ensure accurate diagnosis and effective management of the condition.

From the Research

Initial Workup for CPPD

The initial workup for Calcium Pyrophosphate Deposition (CPPD) disease involves several steps to diagnose and manage the condition.

• The diagnosis is based on synovial fluid analysis, which involves visualizing positively birefringent CPPD crystals using compensated polarized light microscopy 2.
• X-rays can also be used to identify punctate and linear radiodense areas in fibrocartilage and hyaline cartilage 2.
• Evaluating risk factors and comorbidities, such as prior joint injury, osteoarthritis, hereditary or familial predisposition, and metabolic diseases, is also important in CPPD cases 3.
• In cases where the onset of CPPD occurs before the age of 60, it is essential to examine the patient for metabolic conditions, particularly hemochromatosis 2.
• Imaging techniques, such as identifying crystals in joints, can be used to aid in diagnosis and determine the impact of the disease on patients 4.

Laboratory Tests and Imaging

Laboratory tests and imaging studies are crucial in the initial workup for CPPD.

• Synovial fluid analysis is a key diagnostic tool for CPPD, as it allows for the visualization of CPPD crystals 2, 5.
• X-rays can help identify radiodense areas in fibrocartilage and hyaline cartilage, which are characteristic of CPPD 2.
• Other imaging techniques, such as ultrasound and MRI, may also be used to evaluate the extent of joint damage and inflammation 4.

Clinical Evaluation

A thorough clinical evaluation is necessary to diagnose and manage CPPD.

• Patients should be evaluated for symptoms such as joint pain, swelling, and stiffness, as well as for any underlying metabolic or systemic conditions that may be contributing to the development of CPPD 2, 3.
• A physical examination should be performed to assess joint mobility and tenderness, as well as to evaluate for any signs of inflammation or joint damage 5.
• The patient's medical history should be reviewed to identify any potential risk factors or comorbidities that may be relevant to the diagnosis and management of CPPD 3, 6.