Osteoarthritis and Reactive Arthritis Flashcards
Define reactive arthritis.
Sterile inflammation in joints following infection, especially urogenital + GI infections
State 1 urogenital and 1 GI infection that can cause reactive arthritis.
Urogenital: Chlamydia trachomatis
GI: Salmonella
What subset of the population does reactive arthritis tend to occur in?
Mainly in young adults with a genetic predisposition + an environmental trigger
How long after the infection does the reactive arthritis tend to appear?
1-4 weeks
Describe the features of the arthritis in reactive arthritis.
Asymmetrical arthritis that occurs in relatively few joints (Oglioarthritis)
Reactive arthritis can cause enthesopathy. Which entheses are likely to get affected and what symptoms will that cause?
Achilles tendonitis (Heel pain)
Dactylitis (swollen fingers)
Metatarsalgia (painful feet because of inflammation of the palmar fascia)
What is a very common feature of sero-negative spondyloarthropathies?
Sacro-iliitis
State 3 extra-articular features of reactive arthritis?
Occular: Sterile conjunctivitis
Genito-urinary: Sterile urethritis
Skin: Circinate balanitis + Keratoderma blennorhagicum
What is the triad of symptoms that can be used to describe reactive arthritis?
Reiter’s syndrome: arthritis + urethritis + conjunctivitis following infection
Where can you get spondylitis in rheumatoid arthritis?
At the atlanto-axial joint– there is synovium here
Describe the main differences between rheumatoid arthritis and reactive arthritis.
Rheumatoid Arthritis F>M All ages (esp. 30-50) Symmetrical, Polyarticular, Small + Large Joints No Enthesopathy No Spondylitis (Except atlanto-axial joint in cervical spine) No Urethritis Subcutaneous nodules Rheumatoid factor HLA-DR4 Reactive Arthritis: M>F 20-40 year olds Asymmetrical, Oligoarticular, Large joints Enthesopathy Spondylitis Urethritis K.blennorhagicum + Circinate balanitis No Rheumatoid factor HLA-B27
What is the main danger in septic arthritis?
Bacteria produce metalloproteinases that can rapidly degrade the articular cartilage
What are the main differences between septic arthritis and reactive arthritis?
Septic arthritis has a positive synovial fluid culture
Treated with antibiotics + may require joint lavage
Describe the treatment of reactive arthritis.
Usually resolves by itself
NSAIDs to control pain + symptomatic treatment of extra-articular manifestations
Use oral glucocorticoids in refractory disease
Define osteoarthritis.
Chronic slowly progressive disorder due to failure of articular cartilage that typically affects the hands (esp. those involved in the pinch grip), spine + weight-bearing joints (hips + knees)
Which 7 joints are most commonly affected in osteoarthritis?
DIP PIP 1st metacarpophalangeal joint Spine Knees Hips 1st metatarsophalangeal joint
What are the names given to the osteophytes found on the hand in osteoarthritis?
Bouchard’s Nodes: PIP
Heberden’s Nodes: DIP
List 6 associations of osteoarthritis
Joint pain (worse with activity, better with rest) Joint crepitus (creaking/ cracking/ grinding) Joint instability Joint enlargement Joint stiffness after immobility Limitation of motion
List 4 radiographic features of osteoarthritis
Joint space narrowing
Osteophytes
Subchondral bony sclerosis
Subchondral cysts
Describe the differences between the radiographic features of rheumatoid arthritis and osteoarthritis.
Both have joint space narrowing
Rheumatoid doesn’t have subchondral sclerosis or osteophytes
Rheumatoid has osteopenia + bone erosions
What can the osteoarthritis be caused by?
Abnormal stress (Excessive loading on joints) Abnormal cartilage
What is the most important component of articular cartilage?
Aggrecan
What makes cartilage robust under compression?
Type 2 Collagen + Aggrecan retain water
What is special about hyaluronic acid?
It’s the only non-sulphated GAG
Maintains synovial viscosity
How is osteoarthritis managed?
Physiotherapy: strengthening muscle around joint improves joint stability
Analgesia: paracetamol, NSAIDs, intra-articular corticosteroid injections
Joint replacement
Weight loss where appropriate
Education
Occupational therapy
What is the distribution of effected joints in septic arthritis? What is the exception to this?
Usually effects just 1 joint
Exception: Gonococcal arthritis effects multiple joints
What characterises the swellings in osteoarthritis?
They are boney + hard on palpation
Which joint is effected by rheumatoid arthritis, but spared by osteoarthritis?
MCP
What is indicated by lack of space in joints in osteoarthritis?
Loss of articular cartilage
Leads to bone in contact with bone
Describe 5 characteristics of an osteoarthritic joint
Breakdown of cartilage Changes to underlying bone Muscular atrophy Boney spur formation Cartilage fragments in synovial fluid
What can cause abnormal stress or cartilage leading to development of osteoarthritis?
Genetic predisposition
Give 2 causes of abnormal stress on cartilage
Trauma + Misalignment
Obesity
What are 3 cartilage changes seen in osteoarthritis?
Reduced proteoglycan
Reduced collagen
Chrondrocyte changes e.g. apoptosis
What are 3 boney changes seen in osteoarthritis?
Proliferation of superficial osteoblasts – Sclerotic bone
Focal stress on sclerotic bone – superficial necrosis
Osteophytes (new bone formation at joint margins)
