Joint pathology Flashcards
Osteoarthritis (degenerative joint disease)
- progressive degeneration of articular cartilage, most common type of arthitis
- most often due to wear and tear
- major risk factor is age
- hips, lower lumar spine, knees, DIPs, and PIPs are common sites
presentatio of OA
-joint stiffness in the morning that worsens during the day
pathologic features of OA
- disruption of cartilage that lines the articular surface; fragments of cartilage floating in the joint space (joint mice)
- eburnation of the subchondral bone
- osteophyte formation
what are heberden nodes?
-osteophyte formation in DIP
bouchard nodes
-osteophytes in PIP
What type of collagen is degraded by matrix metalloproteinases?
-type 2
Rheumatoid arthritis
- chronic, systemic autoimmune disease
- women of late childbearing age
- associated with HLA DR4
what is hallmark of RA
- synovitis leading to formation of a pannus
- leads to destruction of cartilage and ankylosis (fusion) of the joint
What is a pannus?
-inflammed granulation tissue
clinical features of RA
- arthiritis with morning stiffness that improves with activity*
- symmetric involvement of PIP joints (swan neck deformity)
- small joints are affected before large ones
- DIP are usually spared
- fever, malaise, weight loss, and myalgia
- Rhematoid nodules
- Vasculitis
- Baker cysts
- pleural effusions
What is a baker cyst?
- swelling of bursa behind the knee
- think of RA when you see this
lab findings for RA
- IgM autoantibody against Fc portion of IgG (rheumatoid factor), marker of tissue damage and disease activity
- neutrophils and high protein in synovial fluid
Complications of RA
- anemia of chronic disease
- secondary amyloidosis
What is the other thing that we have autoantibodies to in RA?
-citrullinated peptides (CCPs)
What is the characteristic finding on the patient’s wrist for RA?
- radial deviation of wrist
- ulnar deviation of the fingers
What can we give RA patients to help with the pain?
-TNF antagonists
Juvenile Idiopathic Arthritis (JIA)
-heterogeneous group of disorders of unkown cause that present with arthritis before age 16 and persist for at least 6 weeks
Seronegative spondyloarthropathies
- group of joint disorders characterized by:
- lack of rheumatoid factor
- axial skeleton involvement
- HLA-B27 association
What does ankylosing spondyloarthritis involve?
- SI joints and spine
- young male adults
- low back pain… bamboo spine
- uveitis and aortitis (leads to aortic regurg)
What is Reiter syndrome?
- triad of arthritis, urethritis, and conjunctivitis
- “can’t see, cant’ pee, can’t climb a tree”
when do we see Reiter syndrome(reactive arthritis)?
-young male adults weeks after a GI or chlamydia infection
What is seen in 10% of cases of psoriasis and involves the axial, and peripheral joints?
- psoriatic arthritis
- gives us sausage fingers or toes
What do 90% of ankylosing spondylitis have?
- HLA-B27
- also HLA-Cw6 alleles
What is reiter syndrome referred to in robbins?
-Reactive Arthritis**
Enteritis associated arthritis
- caused by GI infection
- knees and ankles, abrupt onset
- lasts for about a year, then generally clears up (unlike reactive arthritis)
infectious arthritis
- usually bacterial
- N gonorrhoae most common cause
- S aureus older children and adults
- single joint…. knee
- presents as a warm joint with limited ROM, fever, increased white count and elevated ESR are often present
What kind of suppurative arthritis predominates in children younger than 2?
-H influenza
If someone has sickle cell disease, what infection are they prone to?
-Salmonella
Mycobacterial arthritis
- weight bearing joints
- central caseous necrosis
Lyme Arthritis
- Borrelia burgdorferi
- deer ticks
- arthritis in late stage
- 1 or 2 joints affected at a time
- look for anti-borrelia antibodies
Gout
- monosodium urate
- hyperuricemia
- purine metabolism… excreted by kidney usually excretes uric acid
- prime gout is most common form… etiology of hyperuricemia unkown
secondary gout
- leukemia and myeloproliferative disorders… increased cell turnover
- lesch-Nyhan syndrome: deficiency in HGPRT.. mental retardation and self mutilation
- renal insufficiency: decreased renal excretion of uric acid
How does acute gout present?
- painful arthritis of the great toe
- inflammatory rxn initiated
- alcohol and consumption of meat may precipitate arthritis
What does chronic gout lead to?
- development of tophi- white chalky aggregates of uric acid crystals with fibrosis and giant cell reaction in the soft tissue and joints
- renal failure- urate crystals may deposit in kidney tubules (urate nephropathy)
what will we see in the synovial fluid with gout?
-needle shaped crystals with negative birefringence under polarized light
What is pseudogout?
- resembles gout clinically
- but is due to deposition of calcium pyrophosphate dihydrate (CPPD)
- synovial fluid shows RHOMBOID-SHAPED crystals with weakly positive birefringence under polarized light
what are tophi again?
- pathognomonic hallmark of gout
- large aggregations of urate crystals surrounded by an intense inflammatory rxn of foreign body giant cells
What is a ganglion
- small cyst that is almost always located near a joint capsule or tendon sheath
- no communication with joint space
- popliteal space in the setting of rheumatoid arthritis (Baker cyst)
Tenosynovial giant cell tumor
- term for several closely related benign neoplasms that develop in the synovial lining of joints, tendon sheaths, and bursae
- knee in 80% of cases
- localized variant is the most common mesenchymal neoplasm of the hand
