Musc 6 - Reactive Arthritis and Osteoarthritis Flashcards
Which branch of bone disorders does reactive arthritis fall under?
Seronegative spondyloarthropathies
What is reactive arthritis
Sterile inflammation in joints following infection, especially urogenital and GI
What are some extra-articular manifestations of reactive arthritis.
How can reactive arthritis be differentiated from rheumatoid arthritis
- Enthesopathy
- Skin inflammation
- Eye inflammation
Rheumatoid arthritis doesn’t typically present with enthesopathy or eye inflammation.
Also, rheumatoid arthritis tends to be symmetrical whereas reactive arthritis is asymmetrical
Reactive arthritis may be the first manifestation of which 2 diseases
HIV and Hep C infection
Reactive arthritis is AFTER infection. What is infection in joints arthritis form called
Septic arthritis
Describe the differences between arthritis, enthesitis and spondylitis
Arthritis = painful joints
Enthesitis = where ligaments/tendons insert into bones
Spondylitis = back pain
What are the musculoskeletal symptoms of reactive arthritis
Asymmetrical, oligoarthritis (<5 joints)
Lower limbs typically affected
What are some musculoskeletal symptoms of enthesitis (included as part of reactive arthritis)
Heel pain (achilles tendonitis)
Swollen fingers
Painful feet
What are musculoskeletal symptoms of spondylitis (included as part of reactive arthritis)
Sacroiliitis (sacroiliac joint inflammation)
Spondylitis (inflammation of spine)
What are the extra-articular features of Reactive Arthritis
Eye - sterile conjunctivitis
Genito-urinary - sterile urethritis
Skin - psoriasis like rash on hands and feet
How is reactive arthritis diagnosed
- Clinical diagnosis
2. Investigations (e.g. microbiology, immunology, synovial fluid examination) to exclude other arthritis causes
In septic arthritis, synovial fluid culture comes back positive. What about reactive arthritis?
Sterile
How is reactive arthritis treated
There is usually complete resolution within 2-6 months - so symptom management usually
Articular treatment: NSAIDs given, maybe intraarticular corticosteroid
Extra-articular: symptomatic therapy
Oral glucocorticoids given for refractory disease (or steroid sparing agent e.g. sulphasalazine)
What is osteoarthritis
Chronic, slowly progressive disorder - caused by failure of articular cartilage - typically affect joints of the hand, spine, and weight bearing joints (hips and knees)
Which joints of the hand does osteoarthritis typically affect
- DIP
- PIP
- First CMC (thumb)
whereas in Rheumatoid arthritis, DIP is usually spared
Which weight bearing joints of the lower limbs does osteoarthritis typically affect
First MTP joint
What are common signs in the hands of osteoarthritis
Heberdens nodes - DIP (osteophytes present)
Bouchards nodes - PIP (osteophytes present)
Rheumatoid arthritis typically gets better after the patient gets moving. What are the symptoms of osteoarthritis
- Joint pain - worse with activity
- Joint crepitus
- Joint instability
- Joint enlargement
5 Joint stiffness after immobility - Limitation of motion
What are the radiographic features of osteoarthritis
- Joint space narrowing
- Subchondral bony sclerosis
- Osteophytes
- Subchondral cysts
What are some radiographic differences between Rheumatoid arthritis and osteoarthritis
Rheumatoid arthritis - has osteopenia and bone erosions
Osteoarthritis - has subchondral sclerosis and osteophytes
Why does osteoarthritis occur?
What causes it to develop
Occurs due to defective and irreversible articular cartilage and damage to underlying bone
Develops due to:
- Excessive loading on joints
- Abnormal joint components
Articular cartilage has 2 main components, and what type of cell resides in articular cartilage
- Collagen, type 2
- Aggrecan (type of proteoglycan)
Chondrocytes reside
What is the only non-sulphated GAG?
Hyaluronic acid - major component of synovial fluid - has an important role in maintaining synovial fluid viscosity
Describe the composition of aggrecan
100 chondroitin sulphate chains
60 keratin sulphate chains
What are the cartilage changes in osteoarthritis
- Reduced proteoglycan (aggrecan)
- Reduced collagen
- Chondrocyte changes (apoptosis)
What are the bone changes in osteoarthritis
- New bone formation at the joint margins (called osteophytes)
- Changes in the denuded sub-articular bone:
- proliferation of superficial osteoblasts - sclerotic bone production
- focal stress on sclerotic bone = focal superficial necrosis
How is osteoarthritis managed
- Education
- Physio/hydrotherapy
- Occupational therpay
- Weight loss if appropriate
- Exercise
- Analgesia - NSAID / paracetamol / intra-articular corticosteroid injection
- Joint replacement
What are the ECM proteoglycans
Glycoproteins w one or more sulphated GAG chains
GAGs = repeating disaccharide polymers
What are the disaccharides in hyaluronic acid?
Glucuronic acid and N-acetyl glucosamine
There are no disease modifying osteoarthritis drugs
no there are not
