Diseases of musculoskeletal system - joint and bone Flashcards
What are Arthritides?
Pain and stiffness of a joint
Inflammation of the joint
Not one single disease but hundreds of diseases
Acute vs. Chronic arthritis
Acute is pain, heat, redness and swelling
Chronic types include:
Rheumatoid and Osteo
Osteoarthritis
Commonest type of joint disease
- degenerative joint disease
- Progressive erosion of articular cartilage
- formation of bony spurs and cysts at the margins of joints
Epidemiology of OA - Who gets it and why?
Ageing phenomenon
No apparent initiating cause
Secondary OA- knee in basket ball players and elbow in baseball players
Underlying systemic diseases such as diabetes and marked obesity
In men and women, where are most common places of OA seen?
Knees and hands in women and hip in men
Pathogenesis of OA
Chondrocytes-
cellular basis of OA
Chondrocytes produce interleukin-1 – initiates matrix breakdown
Prostaglandin derivatives induces the release of lytic enzymes – prevents matrix synthesis
What is primary OA?
Abnormal stresses in weight bearing joints
Affects fingers, knees and cervical and lumbar spines
Involvement of fingers- Herberden’s or Bouchard’s nodes
What is rheumatoid arthritis?
Chronic systemic disorder-principally affecting the joints
Producing a non suppurative proliferative synovitis- destruction of articular cartilage and ankylosis of joints
Also affects skin, muscles, heart, lungs and blood vessels
Clinical features of RA
Malaise, fatigue and generalised musculoskeletal pain to start off
joints are swollen, warm, painful and stiff in the morning or after activity
slow or rapid disease course over 4-5 years
small joints of the hands and feet are affected - leads to a deformed joint
Pathogenesis of RA
Genetic susceptibility-65-80%-
HLA- DR4 &DR1 or both
Primary exogenous arthritogen- EBV,other viruses, Borrelia
Autoimmune reaction within the synovial membranes- CD4 positive T-cells
Mediators of joint damage: e.g.
Cytokines-
IL-1-6 and TNF
-alpha&beta
Criteria for rheumatoid arthritis diagnosis
Morning stiffness Arthritis in 3 or more joint areas Arthritis of hand joints Symmetric arthritis Rheumatoid nodules Serum Rheumatoid factor
(4 of the above)
What is rheumatoid factor?
Present in most but not all RA patients
In RA diagnosis the analysis of synovial fluid - confirms presence of…
Neutrophils
How does RA present in the skin?
Rheumatoid nodules
Commonest cutaneous manifestation in areas of pressure
RA affects which other organs?
Lung
Spleen
Heart
Which 4 arthritides lack the rheumatoid factor?
Ankylosing spondylitis
Reiter’s syndrome
Psoriatic arthritis
Enteropathic arthritis
What is gout?
A group of disorders producing hyperuricemia
Uric acid is the end product of purine metabolism
Deficiency of the enzymes involved
Clinical features of Gout
Acute arthritis
Chronic arthritis
Tophi in various sites
Gouty nephropathy
Transient attacks of acute arthritis crystallization of urates within and about joints leads to what?
chronic gouty arthritis and deposition of masses of urates in joints and other sites- tophi
What is pyogenic osteomyelitis and how does it present?
Systemic illness-fever Presents: malaise chills marked pain
Diagnosis tools for pyogenic osteomyelitis
X-ray lytic focus of bone destruction surrounded by zone of sclerosis
Blood cultures are positive
Biopsy- if needed shows sheets of neutrophils
What is pyogenic osteomyelitis caused by and how does it spread?
Caused by bacteria
Hematogenous spread
Extension from a contiguous site
Direct implantation
What is infective arthritis?
Acutely painful and swollen joints with restricted movements
What is infective arthritis caused by?
Bacterial-
Staphylococcus, Streptococcus,
Gonococcus,
Mycobacteria
