Arthritis and IJD Flashcards
What is arthritis?
Any disorder that affects joints with symptoms of pain and swelling
What is the difference between hyaline, elastic and fibrocartilage?
Hyaline cartilage provides a smooth surface for gliding action at joints
Elastic cartilage is flexible
Fibrocartilage resists strong forces of compression and tension.
What is the superficial zone of the osteochondral unit?
CLosest to the articular cartilage, the superficial zone is made up of type 2 collagen parallel to the joint surface and flattened chondrocytes.
HIgh conc. collagen low conc. protoglycans.
Has the highest water content.
What is the middle zone of the osteochondral unit?
Thickest layer predominantly spheroid cells embedded in the ECM. Large diameter collagen fibres are arranged obliquely.
Higher conc. of protoglycans.
Provides transition between shearing force of superficial layer and compressive force on deeper layers.
What is the deep zone of the osteochondral unit?
Lowest cell density with spheroid chondrocytes perpendicular to the surface.
High largest diameter collagen fibers and highest PG content.
Perpendicular arrangement of collagen fibers distributes the load and resists compression.
What is the tide mark of the osteochondral unit?
Boundary between uncalcified and calcified cartilage, free of cells, that progresses towards the surface with age.
What is the calcified cartilage zone of the osteochondral unit?
Anchored to subchondral bone by hydroxyapatite crystals, provides a barrier to diffusion from blood vessels supplying the bone.
What is the cell and matrix composition of cartilage?
Cells = chondrocytes inside acuna
Matrix = Ground substance and fibres
What are the ground substance and fibres of the cartilage matrix?
ground substance = hyaluronic acid, chondroitin and keratin sulphate
Fibres = types 2 collagen and elastin.
How are cells in the cartilage supplied?
Supplied by diffusion, fluid flow generated by compression or articular and flexion of elastic cartilage.
Explains poor regenerative capacity.
How do superficial articular cartilage lacerations heal?
Little to no ability to heal due to avascularity, so no stem cells available for new cartilage formation. Instead, filling of defect relies on chondrocyte proliferation.
How do deep articular cartilage lacerations heal?
If crosses the tidemark:
Deep enough to involve subchondral bone, which is vascular, hence allows hematoma to form bring influx of cells. No hyaline cartilage formed, new fibrocartilage formed from undifferentiated marrow mesenchymal cells.
What is the clinical relevance of deep articular cartilage laceration healing?
Arthroscopic operation of micro fracture treats small areas of full cartilage loss by creating holes in subchondral bone so that a fibrocartilage scar is produced. Only temporary and for very young patients with bad arthritis.
how does articular cartilage respond to normal physiological stress?
Responds in anabolic way, stimulates matrix synthesis and inhibits chondrolysis.
How does articular cartilage respond to the stress of moderate running?
Increased cartilage thickness and proteoglycan content.
How does articular cartilage respond to excess stress?
Suppressed matrix synthesis and promotes chondrolysis.
How does articular cartilage respond to immobilization?
Cartilage thinning and softening with proteoglycan loss.
how does cartilage change with aging compared to OA?
In aging the water content is decreased making collagen brittle.
In OA water content is increased making cartilage more susceptible to tear and injuries.
What is Erythema?
Swelling and redness around a joint.
What is podagra?
Exacerbation of gout at greater toe MTP joint.
What is cellulitis?
Infection of the skin and subcutaneous fat most commonly by staphylococcal and streptococcal species.
How are chondrocytes affected by infection?
Chondrocytes are fragile with infections as bacterial toxins released cause chondrocyte death which can rapidly destroy the joint.
What is an abscess? How do you treat it?
A confined infection often with puss under pressure causing pain. Does Not respond to abx very well as lack of penetration into joint cavity.
Incision and drainage.
What the timeframe for acute monoarthritis history?
Inflammation of a single joint present for less than 2/52 however acute presentation typically lasting 24/48 hours before presentation.
acronym for differential of acute monoarthritis?
GRASP the differential:
Gout
Reactive
Autoimmune/arthritic
Septic
Pseudogout
Why should acute monoarthritis be treated as septic until proven otherwise?
Time in vital:
- Cartilage injury in less than 48 ours
- Septic shock
- Death
Who are most at risk of septic arthritis
Elderly, IV drug users, Immunosuppressed, Neonates and children.
What are the two most common typical septic arthritis pathogens?
Staph aureus and streptococcus.
What is the most common atypical septic arthritis pathogen
Gonococcal in young sexually active patients.
What is pyrexia?
Temp >38 degrees
What is ESR?
Erythrocyte sedimentation rate.
What is osteomyeitis?
Infective inflammatory condition of the bone.
What does purulent mean?
Containing pus.
What PMH is important for septic arthritis?
Surgical procedures
Immunosuppressants
Existing joint disease
What is the acronym for pain history taking and what does it stand for?
S ite - where
O nset - what doing when pain started
C haracter - what does it feel like?
R adiates - do it?
A associated symptoms e.g. nausea vomiting
T ime - for how long?
E xacerbating/relieving factors - better/worse?
S everity - obtain initial pain score
Important features of an examination for septic arthritis? (4)
- Accurate assessment of joint appearance
- Range of movement
- Pain of movement
- Mark borders of erythema and include date and time.
Investigations required for septic arthritis?
Joint aspiration as early as possible and BEFORE ABX. mark observation of aspirate appearance and send to microbiology.
Bloods: FBC, CRP, ESR, peripheral cultures if pyrexial
Radiographs: identify structural abnormalities or osteomyelitis
What are the 6 steps to septic arthritis management?
- Aspirate - to dryness, before abx, urgent gram stain.
- Antibiotics - empirical abx. 1st line fluclox etc.
- Washout - formal washout in theatre
- Microbiology
- Monitor
- Long term ABX usually 8/52 course
Important features of prosthetic joint infection?
Clinical signs less pronounced
High index of suspicion required
could need revision surgery or long term abx.
What is the difference between the aspiration and blood of gout and psuedogout?
Aspiration:
Gout = monosodium urate crystals
Pseudogout = Calcium pyrophosphate
Bloods:
Gout possible raised serum urate however low serum urate does not exclude gout as cause.
Pharmacokinetics of Colchicine:
Narrow therapeutic index meaning high risk of overdose and gastric upset.
What is the long term management of gout?
Review medication, diet, alcohol, lifestyle and exercise, Allopurinol and refer to rheumatology if no improvement.
What is reactive arthritis?
Aseptic arthritis which occurs 2-6 weeks after a bacterial infection elsewhere in the body e.g. gastroenteritis or a genitourinary infection.
Used to be called reiter’s syndrome but he was a nazi.
What bacteria are common in gastroenteritis?
salmonella and campylobacter
What bacteria are common in genitourinary tract infection?
Chlamydia and gonorrhoea
What is the treatment for reactive arthritis?
NSAIDs physio and occasionally steroid injections.
Typical features of reactive arthritis?
- HLAB27 positive in 85%
- Occur with conjunctivitis and urethritis
- Can’t see, can’t pee, can’t climb a tree
- usually asymmetrical and polyarticular
- Can also present with inflammatory back pain and enthesitis.
What is enthesitis?
Inflammation of a tendon at its insertion onto bone.
What are some chronic joint conditions that can present with an acute flare up?
- OA
- RA
- polymyalgia rheumatica
- seronegative spondyloarthritides
What are seronegative spondyloarthritides?
A group of msk syndromes that test negative or very low rheumatoid factor with common clinical features and immunopathological mechanisms. Most have positive HLAB27 gene.
Name the seronegative spondyloarthritides?(4)
- Psoriatic arthritis
- Enteropathic arthritis
- Ankylosing spondylitis
- Reactive arthritis
PEAR
What is polymyalgia rheumatica and what is it characterised by?
PMR is an autoimmune syndrome characterised by widespread joint and muscles aches with flu-like symptoms including pain and stiffness in limbs, hips and neck, fatigue, fever and weight loss
What is temporal arteritis? What are its symptoms?
Temporal Arteritis. Also known as Giant cell arteritis., It is the most common form of vascular inflammation.
Begins as new headache but can lead to vision changes and blindness.
How can you treat PMR and what are the risk factors?
Treated with exercise, NSAIDs, steroids and physio. Can lead to temporal arteritis.
Most common in caucasian women >50 years
What is psoriasis?
Systemic, immune mediated inflammatory skin disease with a chronic relapse remitting course which may have nail and joint involvement.
What is psoriatic arthritis
Arthritis that develops in people with psoriasis.
How does Psoriatic arthritis present?
Presents with arthritis of the hands, predominantly the DIP joints and also soft tissue changes such as silvery skin plaques, uveitis and dysmorphic nails.
What is uveitis?
Inflammation of the uvea of the eye.
What can psoriatic arthritis progress to?
Can be very severe and progress to rare condition arthritis mutilans where there is destruction and gross deformity of the joints of hand and feet
What is enteropathic arthritis?
Associated with occurrence of IBD, develops in approximately 20% of people with Crohn’s or ulcerative colitis.
What is anti-ccd
Anti-cyclic citrullinated peptides.
What is ankylosing spondylitis?
Systemic inflammatory disease characterised by fusion (ankylosis) of the spine, enthesitis, sacroiliitis and uveitis.
more common in males and symptoms start <45 years old
Also known as axial spondyloarthritis.
what is the treatment for ankylosing spondylitis?
NSAIDs/biologics, dMARDs like sulfasalazine and methotrexate (SSZ and MTX)
