1) נזק סחוסי
2) נזק סובחונדרלי
3) שבר סובחונדרלי
Disorders may involve either the:
- cartilage (chondral disorder)
- subchondral bone (subchondral bony disorder)
- both (osteochondral disorder).
Injures:
- נזק סחוסי
- נזק סובחונדרלי
- שבר סובחונדרלי
Pathologic changes
Cartilage
Patterns of cartilage changes
1. Normal cartilage
2. Thickening (softening) with intact surface
3. Blister (пузырек) (arrow)
4. Crabmeat aspect (arrow)
5. Ulceration (arrow)
6. Fissure (arrow)
7. Flap formation (arrow)
8. Diffuse thinning (arrow)
Subchondral bone
Patterns of subchondral changes
1. Focally thickened cortical line (arrow)
2. Focal semilunar subchondral change (arrow)
3. Focal impaction (arrow)
4. “Bowing” (дуговой или арочный перелом) fracture (arrow)
5. Cyst (arrow)
6. Edema (arrow)
7. Diffuse linear branching (ветка дерева) changes (arrow)
8. Osteophyte (arrow)
- Changes are related to aging and chronic stress on cartilage and bone.
- Characteristic changes in cartilage include diffuse chondropathy, whereas changes in bone involve osteophytes, cysts, diffuse edematous patchy subchondral changes, and sclerotic focal areas of semilunar or linear cortical pattern.
Trauma
- Changes are related to acute or subacute trauma and tend to be focal in contrast to degenerative disorder.
- Characteristic changes include focal cartilage defect or fissure, subchondral linearbranching pattern (occult fracture), focal edema (patchy changes, often designated bone bruise), and cortical impaction or bowing.
- Patchy edematous changes can occur in characteristic areas such as with ACL tears.
Inflammatory
Changes are related to inflammatory disorders such as rheumatoid arthritis and joint infection with subsequent cartilage destruction due to extension of pannus and diffuse destruction of joint surfaces.
Typical changes may include diffuse cartilage thinning, erosive cortical changes, and patchy subchondral changes. In a later stage the destruction of cartilage may lead to secondary osteoarthritis.
NM
Links:
1) MRI of cartilage and subchondral bone injury. A pictorial review. De Maeseneer M, Shahabpour M, Van Roy P, Pouders C. JBR-BTR. 2008 Jan-Feb;91(1):6-13.