Why is the repair response so limited in the articular cartilage of a joint after an injury in the adult athlete?

Why is the repair response so limited in the articular cartilage of a joint after an injury in the adult athlete?

• A. Articular cartilage cells do not undergo mitosis in the mature athlete
• B. There is abundant blood supply to cartilage
• C. Cartilage regenerates rapidly
• D. The joint capsule blocks repair tissues

Answer: (A)

Articular cartilage has limited repair in adults because the resident cells that maintain the tissue divide very little after maturation. Chondrocytes stay largely quiescent, so there isn’t a significant influx of new cells to replace damaged tissue. Compounding this, the cartilage is avascular, so blood vessels don’t bring nutrients or progenitor cells to the injury site. Without a blood supply and with minimal cell proliferation, healing is slow and the repair tissue is typically fibrocartilage rather than the original hyaline cartilage, leading to limited restoration of function. That’s why the idea that articular cartilage cells do not undergo mitosis in the mature athlete best explains the restricted repair. The other statements don’t fit because cartilage isn’t richly vascularized, it doesn’t regenerate rapidly, and the joint capsule isn’t the primary barrier to healing.

Articular cartilage has limited repair in adults because the resident cells that maintain the tissue divide very little after maturation. Chondrocytes stay largely quiescent, so there isn’t a significant influx of new cells to replace damaged tissue. Compounding this, the cartilage is avascular, so blood vessels don’t bring nutrients or progenitor cells to the injury site. Without a blood supply and with minimal cell proliferation, healing is slow and the repair tissue is typically fibrocartilage rather than the original hyaline cartilage, leading to limited restoration of function. That’s why the idea that articular cartilage cells do not undergo mitosis in the mature athlete best explains the restricted repair. The other statements don’t fit because cartilage isn’t richly vascularized, it doesn’t regenerate rapidly, and the joint capsule isn’t the primary barrier to healing.