X ray findings of noninflammatory degenerative arthritis
What are the radiographic features of noninflammatory, degenerative arthritis (cartilage-based diseases)
- 1. Sclerosis/osteophytes
- 2. Nonuniform loss of cartilage (focal joint space narrowing in area of maximal stress in weight-bearing joints)
- 3. Cysts/geodes
The causes of degenerative arthritis are multifactorial. However, the primary problem and end result is cartilage degeneration. As the cartilage degenerates, the joint space narrows. However, in contrast to uniform, diffuse narrowing seen with inflammatory arthritides, the noninflammatory, degenerative arthritides tend to have nonuniform, focal joint space narrowing, being most pronounced in the area of the joint where stresses are more concentrated (e.g., superolateral aspect of hip, medial compartment of the knee.
Following cartilage loss, subchondral bone becomes sclerotic or eburnated owing to trabecular compression and reactive bone deposition. With denudation of cartilage, synovial fluid can be forced into underlying bone, forming subchondral cysts or geodes with sclerotic margins. As an attempted reparative process, the remaining cartilage undergoes endochondral ossification to develop osteophytes. Such osteophytes commonly occur first at margins or nonstressed aspects of the joint (e.g., medial and lateral aspects of the distal femur and proximal tibia of the knee).