According to the NIH:
Osteoarthritis (OA) is the most common type of arthritis. It occurs most often in the hands, knees, hips, and spine.
OA affects cartilage—the slippery tissue that covers the ends of bones in a joint. Cartilage allows bones to glide over each other and absorbs the shock of movement. In OA, the top layer of cartilage breaks down and wears away, allowing the bones under it to rub against each other. This can cause pain, swelling, and difficulty in moving the joint.
OA is most common in older people, but younger people can have it too, especially in joints that have been injured.
For more information, see:
- Osteoarthritis - causes, symptoms, diagnosis, treatment & pathology
- Stages of Knee Osteoarthritis
- Osteoarthritis 2020
I first started seriously learning about osteoarthritis when my 83-yo father started experiencing pain in his daily walks. His latest radiology report stated:
83-year-old male, non-traumatic swelling of the left knee reducing ability to walk over long distances OA changes?
September 30, 2016.
Tricompartmental spurring. Mild narrowing of the medial tibiofemoral compartment joint space. Mild patellofemoral compartment joint space narrowing. There is calcification projecting over the expected location of the distal quadriceps tendon. In retrospect, this finding is also present on the prior study. There is an effusion in the suprapatellar recess, larger impaired to previous. No intraarticular loose bodies are identified. No aggressive bone lesions or periosteal reaction. No fracture. Moderately severe vascular calcification.
Mild degenerative changes. See above for other findings.
To maintain his metabolic health, my father needs to stay active but the knee pain severely slowed him down. It often caused a pronounced limp and the need to walk with a cane. It is common to treat this pain with analgesics but there are side effects. However, while articular cartilage grows slowly and there is a belief that osteoarthritis is progressive, there is some evidence and annecdotes that articular cartilage regeneration is possible.
DISCLAIMER: My background is engineering and what I have written here is from my personal interest in staying healthy. If you disagree with any of it, let know what you feel is inaccurate and include some references so I can make corrections. This is a work in progress so check back often for updates as I continue to learn. CONSULT WITH YOUR DOCTOR BEFORE MAKING DIET AND LIFESTYLE CHANGES.