Abstract
The morphological changes in bone and articular cartilage destruction have been described in sixteen consecutive cases of rheumatoid arthritis in which biopsy material was obtained during synovectomy of the knee. The following observations were made.
1. Bone and cartilage is replaced by fibrous granulation tissue which proliferates from periosteal and perichondrial fibroblasts.
2. These proliferative changes are distinct from the chronic synovitis of rheumatoid disease, but a chronic synovitis is necessary for them to appear.
3. Synovectomy does not remove the cells replacing bone and cartilage but its performance in some ways leads to their regression.