What is chondrocalcinosis?

Chondrocalcinosis: Definition and Clinical Significance

Chondrocalcinosis is the radiographic finding of calcium pyrophosphate crystal deposition within articular cartilage and fibrocartilage, representing the hallmark imaging feature of calcium pyrophosphate deposition (CPPD) disease, also known as pseudogout. 1

What Chondrocalcinosis Represents

Chondrocalcinosis is caused by deposits of calcium pyrophosphate dihydrate (CPP) microcrystals in joints, and occasionally in tendons and ligaments. 2 The condition results from calcium pyrophosphate crystal deposition within:

• Hyaline cartilage - appearing as linear calcifications along the cartilage surface 3
• Fibrocartilage structures - particularly menisci in the knee, symphysis pubis, and triangular fibrocartilage of the wrist 1, 3
• Synovial membrane and fluid 2
• Joint capsules, tendons, and ligaments in some cases 2

Radiographic Appearance

On plain radiographs, chondrocalcinosis appears as:

• Linear or punctate calcifications in hyaline cartilage, forming a continuous or fragmented opaque border on subchondral bone, separated by a thin radiolucent space 3
• Small irregular clusters with blurred or cloudy margins in fibrocartilaginous structures 3
• Most commonly visible in the knee (both hyaline and fibrocartilage), followed by wrist, symphysis pubis, and other joints 1, 3

Clinical Presentations Associated with Chondrocalcinosis

The presence of chondrocalcinosis can manifest in several distinct clinical patterns:

Asymptomatic Form

• Many patients have radiographic chondrocalcinosis without symptoms and require no treatment 4
• Prevalence increases dramatically with age, reaching 13% across all age groups and much higher over age 70 5

Acute CPP Crystal Arthritis (Pseudogout)

• Sudden onset monoarticular arthritis that can mimic gout or septic arthritis 2, 6
• Represents acute microcrystal synovitis with all typical features of crystal-induced inflammation 3

Chronic Inflammatory Arthritis

• Polyarticular inflammatory pattern that may resemble rheumatoid arthritis 2
• Can progress to chronic arthritis leading to severe disability 6

Osteoarthritis with CPPD

• Most frequently presents as polyarthrosis with degenerative changes 2
• Management objectives are the same as osteoarthritis without CPPD 4

Destructive Arthropathy

• Severe joint destruction capable of seriously damaging one or several joints 2
• Association with osteoarthritis frequently leads to destructive arthropathies 2

Age-Related Considerations and Secondary Causes

If chondrocalcinosis is detected in patients under 60 years of age, evaluation for associated metabolic conditions is essential. 4, 6

Primary metabolic disorders to consider:

• Hereditary hemochromatosis - chondrocalcinosis present in 50% of cases, with radiographs showing degenerative changes, joint space narrowing, osteophytes, and subchondral cysts 5, 6
• Hyperparathyroidism 6, 7
• Hypomagnesemia 6, 7
• Familial predisposition - hereditary forms exist but are less common than sporadic disease 6, 7

Sporadic Form

• Aging is the main risk factor for sporadic chondrocalcinosis 6
• Prevalence ranges from 7-10% in people around 60 years old 6
• Sporadic form is by far the most frequent presentation 6

Diagnostic Approach When Chondrocalcinosis is Suspected

Plain radiography should be the initial imaging method, including anteroposterior, lateral, and tangential patellar views to fully evaluate for chondrocalcinosis and associated arthropathy. 1

Additional imaging modalities:

• Ultrasound outperforms radiography for chondrocalcinosis detection and can demonstrate echogenic synovial hypertrophy and the "double contour sign" 1
• CT can identify chondrocalcinosis and calcification of tendons, ligaments, and joint capsules with informativity nearly equal to conventional radiography 1
• MRI without contrast may be indicated when symptoms persist despite radiographic findings, to evaluate for synovitis, bone marrow lesions, or other soft tissue pathology 1

Definitive diagnosis:

• Joint aspiration with synovial fluid analysis is indicated when effusion is present to confirm crystal disease or exclude infection 1, 7
• Identification of CPP crystals in synovial fluid provides definitive diagnosis 7
• Aspiration can be performed under ultrasound or fluoroscopic guidance 1

Common Pitfalls

• Do not assume all chondrocalcinosis is benign - evaluate for secondary causes in younger patients (<60 years) 4, 6
• Do not confuse with gout - acute CPP crystal arthritis (pseudogout) can clinically mimic gout but requires different long-term management 2, 3
• Do not overlook infection - acute presentations can resemble septic arthritis; joint aspiration is critical when effusion is present 1, 2
• Recognize that chondrocalcinosis represents a spectrum - from asymptomatic radiographic findings to severe destructive arthropathy 2, 6