What does fibrillation of the articular cartilage posteriorly at the level of the lateral plateau, abnormal posterior horn of lateral meniscus mean?

Arthitic process: When arthritis start in the joint, start with the articular cartilage(surface usually very smooth) start having roughness in it, also the same thing for the meniscus which a cartilage. The image attached resemble fibrillation advance.Thank you.

Arthitis: Arthritis at metacarpo-phlangeal joint in the most common type of arthritis we see in middle age people causing pain in the base of the thumb.