Fact-sheet: Osteoarthritis
- Osteoarthritis / chondropathy
- Degenerative arthropathy
- Degenerative chondropathy
Updated on 06/13/2025 at 4:15 PM
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Definition
Degenerative chondropathy related to cartilage degeneration, associated with subchondral remodeling, osteophyte production, ligamentous laxity, and synovitis.
Osteoarthritis may be:
- Primary, with no identified cause, with a genetic component.
- Secondary to abnormal mechanical stress (excess weight, joint overload)
- Post-traumatic
- Post-surgical
- to a crystal-induced arthropathy (gout, CPPD)
- to an inflammatory arthritis
- Hemochromatosis
Radiography
Basic radiographic semiology:
- Joint space narrowing (nonspecific)
- Subchondral osteosclerosis
- Marginal and/or subchondral osteophytosis
- Subchondral cysts, possible erosions
Focus on hip radiography:
- Normal and pathological values of coxometry
- Definition of acetabular protrusion and coxa profunda
CT
Finer and more sensitive analysis than standard radiography.
CT arthrography allows visualization of the cartilaginous surfaces and detection of intra-articular loose bodies.
MRI
Direct visualization of cartilage with grading of chondropathy
Visualization of subchondral edema as T2 or PD FatSat hyperintensity
Better assessment of subchondral bone (geodes, erosions)
Assessment of associated ligamentous injuries (and of the Knee menisci)
Assessment for an inflammatory flare: intra-articular effusion, Synovitis.
Classification
Kellgren and Lawrence classification:
- grade 0 (none): no radiographic sign of Osteoarthritis
- grade 1 (doubtful): doubtful joint space narrowing and possible osteophyte
- grade 2 (minimal): osteophytes and early joint space narrowing
- grade 3 (moderate): moderate osteophytes, definite joint space narrowing, subchondral sclerosis and possible bone deformity
- grade 4 (severe): large osteophytes, complete joint space narrowing, severe subchondral sclerosis and bone deformities