tutorial 2 - bone & joint disease Flashcards
What are the 3 key components of a normal joint?
Cartilage, synovium, supporting ligaments/joint capsule
What are the 4 key causes of painful joints (arthritis)?
- Gout/gouty arthritis
- Osteoarthritis
- Rheumatoid Arthritis
- Septic Arthrtis
What is the most common type of joint disease?
Osteoarthritis
What has the strongest association with OA?
Advancing age
Which joints are most affected by osteoarthritis?
weight bearing joints - knee, hips, lumbar spine, etc.
What is the pathogenesis of osteoarthritis?
Altered chondrocyte homeostasis with overactivity of degrading enzymes. This leads to a decrease in proteoglycans and type II collagen, resulting in degradation of cartilage
What are the effects of OA on the joint space, as seen on xray?
Narrowing of the joint space
What are the 5 key pathological changes seen with osteoarthritis?
- Fibrillation of cartilage
- eburnation (ivory bone)
- sclerosis
- subcondral cysts
- Osteophytes
What is cartilage fibrillation?
Process that occurs in OA where chondrocytes proliferate and then die causing fraying of the cartilage surface
What is eburnation?
In OA, a bone end that is devoid of cartilage getting polished by the grinding action of bone on bone.
What is bone sclerosis in OA?
When bone underneath areas of lost cartilage become more dense, likely to compensate for changes in weight distribution
What are subchondral cysts?
In OA, small cysts that form in the head of the bone when fluid is forces into cracks in the bony surface and become surrounded by a fibrous capsule.
What are osteophytes?
Mushroom shaped bony outgrowths that develop at the margins of articulating bones in OA
What is the name for osteophytes of the distal interphalangeal joints in osteoarthritis?
Heberden nodes
What is the name for osteophytes of the proximal interphalangeal joints in osteoarthritis?
Bouchard nodes
What are the treatments for OA?
Physiotherapy, analgesia, modified activity, joint replacement
Which joints tend to be involved in rheumatoid arthritis?
small joints of hands, feet, wrists, elbows, ankles, knees
What are the 2 most common antibodies present in patients with RA?
Rheumatic Factor (RF), Anti Cyclic Citrullinated Peptides (Anti CCPs)
What gene is related to susceptibility to RA?
HLA (human leukocyte antigen) gene
What environmental factors can exacerbate or initiate the autoimmune response in rheumatoid arthritis?
Smoking, infection
What activates the initial inflammatory synovitis in patients with RA?
Antigen bound to MHC is presented to T helper cells, which produced cytokines to recruit macrophages and plasma cells to the synovium
What are the role of activated and lymphocytes and macrophages in the pathogenesis of RA?
They produce TNF which stimulates proliferation of fibroblasts, synovial cells and chondrocytes which proliferate and secrete proteolytic enzymes that destroy cartilage. Also, T cells activated osteoclasts leading to bone resorption
What is the term for the chronically inflamed, thickened synvovium in RA?
Pannus
What cells activated osteoclasts triggering bone resorption in RA?
T cells
