Osteoarthritis and reactive arthritis Flashcards
What is reactive arthritis?
Sterile inflammation in joints following infection, especially urogenital and gastrointestinal infections
What urogenital infection is associated with reactive arthritis?
Chlamydia trachomatis
What gastrointestinal infections are associated with reactive arthritis?
Salmonella
Shigella
Campylobacter
What important extra-articular manifestations of reactive arthritis are there?
Enthesopathy
Skin inflammation
Eye inflammation
What is a crucial fact about the inflammation in reactive arthritis?
It is sterile, not due to ongoing infection- it happens after the infection has gone
What could reactive arthritis be the first manifestation of?
HIV or Hep C infection
Who does reactive arthritis occur most commonly in?
Young adults with a genetic predisposition (HLA-B27) and an environmental trigger (salmonella infection)
When do symptoms of reactive arthritis tend to appear?
1-4 weeks afrwe infection
What are the musculoskeletal symptoms of reactive arthritis?
It is asymmetrical and occurs in relatively few joints
The entheses can get affected:
- Achilles tendonitis
- Dactylitis
-Metatarsalgia (painful feet because of inflammation of plantar fascia
What is very common in seronegative spondyloarthropathies?
Sacro-iliitis
What extra-articular features are there in reactive arthritis?
Ocular- sterile conjunctivitis
Genito-urinary- sterile urethritis
Skin:
Keratoderma blennorhagicum- psoriasis-like rash appears transiently on hands and feet
Circinate balantis- epithelial inflammation of glans
Reactive arthritis is sometimes called Reiter’s syndrome which refers to what triad of symptoms?
Joint inflammation
Urethritis
Conjunctivitis
What are the differences between rheumatoid and reactive arthritis?
Rh: More common in females Affects all ages Symmetrical, polyarticular and all joints No enthesopathy, spondylitis (except where there is synovium) or urethritis Subcutaneous nodules Rh factor Associated with HLA-DR4
Re: More common in males 20-40 yrs Asymmetrical, oligoarticular and large joints Enthesopathy Spondylitis Urethritis K blennorhagicum and circinate balantis No Rh factor HLA-B27
How is reactive arthritis diagnosis established?
Clinical diagnosis
Investigations to exclude other causes of arthritis like septic arthritis
What is septic arthritis commonly caused by?
Bacterial infections- bacteria release very potent metalloproteinase enzymes that rapidly degrade articular cartilage
Why is septic arthritis a surgical emergency?
Bacteria release very potent metalloproteinase enzymes that rapidly degrade articular cartilage- it requires antibiotics and sometimes lavage of the joints to get rid of the enzymes
Why is there no role for antibiotics in reactive arthritis?
Site of inflammation is sterile
How is reactive arthritis treated?
Articular: NSAIDs to control therapy Intra-articular corticosteroid therapy (oral or IM into the joint) Extra-articular: Typically self limiting Therapy is symptomatic Refractory disease: Oral glucocorticoids Steroid-sparing agents
What is the definition of osteoarthritis?
Chronic slowly progressive disorder due to failure of articular cartilage that typically affects joints of the hands (especially those involved in the pinch grip), spine and weight-bearing joints (hips and knees)
- joints that are most commonly used
Which joints of the hand are commonly affected?
Distal interphalangeal joints
Proximal interphalangeal joints
First carpometacarpal joint
What are osteophytes?
Bony swellings around joints that occur commonly in osteoarthritis
What are osteophytes at the DIP and PIP referred to as?
DIP- Heberden’s nodes
PIP- Bouchard’s nodes
What is osteoarthritis associated with?
Joint pain- worse with activity and better with rest
Joint crepitus- creaking/cracking sound on moving affected joint
Joint instability
Joint enlargement
Joint stiffness after immobility
Limitation of motion
What are the radiographic features of osteoarthritis?
Joint space narrowing
Subchondral bony sclerosis
Osteophytes
Subchondral cysts
What is subchondral bony sclerosis?
Bone underneath failed cartilage tries to react with more bone formation so you get whitening underneath cartilage
What is the problem in osteoarthritis?
Defective and irreversible articular cartilage and damage to underlying bone
What could the abnormal articular cartilage in osteoarthritis be due to?
Abnormal joint components and excessive loading on joints
What is the most important component of articular cartilage?
Proteoglycan called aggrecan
What is aggrecan made up of?
Chondroitin sulphate and keratan sulphate chains
What is aggrecan important for?
Keeping water within the articular cartilage
What do the GAG chains do?
Attract water and are important in integrity of articular cartilage
What is a proteoglycan?
Glycoproteins that contain one or more sulphated glycosaminoglycan chains
What are GAGs?
Repeating polymers of disaccharides
Give some examples of GAGs?
Chondroitin sulphate Keratan sulphate Heparan sulphate Dermatan sulphate Heparin
Why is hyaluronic acid special?
It is the only non-sulfated GAG and is a major component of synovial fluid where it has an important role in maintaining synovial fluid viscosity
What are the disaccharides of hyaluronic acid?
Glucoronic acid
N-acetyl glucosamine
What cartilage changes are there in osteoarthritis?
Reduced proteoglycan
Reduced collagen
How do you manage osteoarthritis?
Education
Physical therapy- physiotherapy, hydrotherapy
Occupational therapy
Weight loss where appropriate
Exercise
Analgesia- paracetamol, NSAIDs and intra articular corticosteroid injection
Joint replacement
