intro to rheumatology Flashcards
- What are the structural and functional classification of fibrous joints?
Structural - No space between bones. E.g. sutures in skull, syndesmosis (sheet of connective tissues) in tibia and fibula.
Functional classification - Synarthroses (generally allow no movement) and amphiarthroses (allow very limited movement)
- What are the structural and functional classification of cartilaginous joints?
Structural - Joints in which bone are connected by cartilage. E.g. joints between spinal vertebrae
Functional classification - Synarthroses (generally allow no movement) and amphiarthroses (allow very limited movement)
- What are the structural and functional classification of synovial joints?
Structural classification - Have a space between the adjoining bones (synovial cavity) filled with synovial fluid.
Functional classification - Diarthroses (Allow for free movement)
- What are the components of a synovial joint and describe each of them?
Synovium - 1-3 cell deep lining containing macrophage-like phagocytic cells (type A synoviocyte)
- fibroblast-like cells that produce hyaluronic acid (type B synoviocyte). - Type I collage also present. Synovial fluid - Hyaluronic acid-rich viscous fluid. Articular cartilage - Type II collagen + Proteoglycan (aggrecan)
- What is cartilage composed of?
- Describe the blood supply of cartilage and why is this important?
Specialised cells → Chondrocytes
ECM: Water, collagen and proteoglycans (mainly aggrecan)
Avascular (no blood supply)
Means that cartilage heals poorly after injury.
- What is aggrecan and what is it characterised by?
Proteoglycan possessing many chondroitan sulphate and keratin sulphate chains
Characterised by ability to interact with hyaluronan (HA) to form large proteoglycans
- What is arthritis broadly speaking?
- What are the 2 major divisions of arthritis?
Disease of joints
Osteoarthritis (Degenerative arthritis) Inflammatory arthritis (main type is rheumatoid arthritis)
- What are the pathological changes of osteoarthritis?
Cartilage being worn out and bony remodelling
- Outline the epidemiology and onset of osteoarthritis.
Epidemiology - more prevalent as age increases
- more likely if you've had previous joint trauma - people who have jobs involving heavy manual labour are more prone to it. Onset - Gradual, slowly progressive disorder.
- Which joints are affected typically in osteoarthritis?
Joints of hand - DIP, PIP, first CMC
Spine Weight-bearing joints of lower limbs - especially knees and hips, first MTP (metatarsophalangeal joint)
- What signs and symptoms are associated with osteoarthritis?
Joint pain - worse with activity, better with rest
Joint crepitus - creaking, cracking grinding sound on moving affected joint. Joint instability (giving way) Joint enlargement (e.g. Heberden's and Bouchard's Nodes) Joint stiffness after immobility Limitations of range of motion
What is the difference between Heberden’s and Bouchard’s nodes
- Heberden’s Nodes → Osteophytes at DIP joints.
2. Bouchard’s Nodes → Osteophytes at PIP joints.
- List the radiographic features of osteoarthritis.
Joint space narrowing
Subchondral bony sclerosis (increased white appearances on xray) Osteophytes (bone spurs) Subchondral cysts
- What are the physiological, cellular and molecular changes that occur in inflammation?
Increased blood flow
Migration of WBCs (leucocytes) into tissues Activation/differentiation of leucocytes Cytokine production (E.g. TNF-alpha, IL-1,16 and 17 - Important ones for joint disease)
- What are the causes of joint inflammation?
Infection - Septic arthritis, TB
Crystal arthritis - Gout and pseudo-gout Immune-mediated (autoimmune) - Rheumatoid arthritis, psoriatic arthritis, reactive arthritis, SLE
- What are the causes of joint inflammation?
Infection - Septic arthritis, TB
Crystal arthritis - Gout and pseudo-gout Immune-mediated (autoimmune) - Rheumatoid arthritis, psoriatic arthritis, reactive arthritis, SLE
- What causes septic arthritis?
- What are the risk factors of septic arthritis?
Bacterial infection of a joint (usually caused by haematogenous spread)
Immunosuppressed, pre-existing joint damage, intravenous drug use (IVDU)
- Why is septic arthritis classified as a medical emergency?
Untreated, septic arthritis can rapidly destroy a joint.
- How many joints are usually affected in septic arthritis?
- What is the main exception?
1 (mono-arthritis)
Gonococcal septic arthritis - often affects multiple joints (polyarthritis); it is less likely to cause joint destruction.
- When should you consider septic arthritis for a patient?
Any patient with an acute painful, red, hot swelling of a joint, especially if there is a fever.
- What technique can you use to diagnose septic arthritis?
Joint aspiration (then send sample for urgent gram stain and culture)