Rheumatology Flashcards
What is rheumatology
The medical speciality dealing with diseases of the musculoskeletal system including Joints Tendons Ligaments Muscles Bones
What is a joint
Where two bones meets
Tendons
Cords of strong fibrous collagen tissue attaching muscle to bone
Ligaments
Flexible fibrous connective tissue which connects two bones
Which joint allows free movement ( diarthroses)
Synovial joints ( have a space between adjoining bones called the synovial cavity) and this space is filled with synovial fluid
Fibrous joint structural classification
No space between the bones
E.g. sutures in the skull, syndesmosis ( sheet of connective tissue) in the tibia and fibula joint ( ankle)
What kind of movement does the fibrous joint allow for
Synarthroses ( generally allow no movement)
Amohiarthroses ( allows very limited movement)
What kind of movement does the cartilaginous joint allow
Synarthroses
Amphiarthroses
Cartilaginous joint
Joints in which the bones are connected by cartilage
E.g. joints between the spinal vertebrae
What is the synovium made up of
1-3 cell deep lining containing macrophage like phagocytic cells ( type A synoviocyte) and fibroblast like cells that produce hyaluronic acid ( type B synoviocyte)
Type 1 collagen
What does synovial fluid contain
Hyaluronic acid rich viscous fluid
What is articulate cartilage made up of
Type II collagen
Proteoglycan ( aggrecan )
What is cartilage composed of
Specialised cells called chondrocytes
Extra cellular matrix - water, collagen and proteoglycans ( mainly aggrecan) . Cartilage is a vascular - has no blood supply so cartilage heals poorly after injuries
Aggrecan is a proteoglycan that possesses many chondrites sulfate and keratin sulfate chains
Characterised by its ability to interact with hyaluronan to form large proteoglycan aggregates
What is arthritis
Disease of the joints
Two types of arthritis
Osteoarthritis ( degenerative arthroscopic where the cartilage is worn out)
Inflammatory arthritis ( main type is rheumatoid arthritis - main problem is inflammation )
Pathological changes in osteoarthritis
Cartilage is worn out and there is bony remodelling leading to bone Spurs
Epidemiology of osteoarthritis
More prevalent as age increases
Previous joint trauma ( e.g. footballers knees)
Jobs involving heavy manual labour
Gradual onset and slowly progressive disorder
Joints of the hand affected by osteoarthritis
Distal inter phalanges joints ( DIP)
Proximal inter phalangeal joints ( DIP)
First carpometacarpal joint ( CMC)
Other joints affected by osteoarthritis
Spine
Weight bearing joints of lower limbs
esp knees and hips
First metarsophalangeal joint (MTP)
What can osteoarthritis be associated with
Joint pain ( worse with activity but better with rest) Joint crepitus - creaking, cracking , grinding sound on moving affected joint Joint instability ( giving way) Joint enlargement - herberdens nodes Joint stiffness after immobility - gelling Limited partition of range of motion
How can you tell from an x ray that there are subchondral bony sclerosis
Increased white appearance
What is inflammation
A physiological response to deal with injury or infection . But excessive / inappropriate inflammatory reactions can damage the host tissues
What are the manifestations of inflammation
Red ( rub or) Pain ( donor) Hot ( calor) Swelling ( tumor) Loss of function
There is an increased blood flow
Migration of white blood cells ( leukocytes) into tissues
Activation / differentiation of leucocytes
Cytokine production - TNF alpha, IL1 , IL6 , IL17
Causes of joint inflammation
Infection
Crystal arthritis
Immune mediated ( autoimmune)
Infection related joint inflammation
Septic arthritis - acute presentation such as acute bacterial infection
Tuberculosis - chronic presentation
Crystal arthritis joint inflammation
Gout
Pseudogout
Immune mediated joint inflammation( autoimmune)
Rheumatoid arthritis
Psoriasis arthritis
Reactive arthritis
Systemic lupus erythematosus ( SLE)
Septic arthritis
Bacterial infection of a joint
Risk factors ; immunosuppressed, pre existing joint damage , IVDU
Untreated, it can eventually destroy a joint
How many joints are affected in sceptic arthritis
1 ( mono arthritis)
Gonococcal sceptic arthritis is an exception : it often affects multiple joints ( poly arthritis ) it is also less likely to cause joint destruction
Sceptic arthritis presentation
Acute painful, red, hot, swelling of a joint, especially if there is fever
Diagnosis is by joint aspiration , send sample for urgent gram stain and culture
Treatment is with surgical wash out ( lavage) and IV antibiotics ( but antibiotics by itself won’t work well)
Common organisms which cause sceptic arthritis
Staphylococcus aureus, streptococci , gonococcus
Gout
Gout is the syndrome caused by deposition of Urate crystals leading to inflammation
Hyperuricaemia
High Uris acid levels
Causes of hyperuricaemia
Genetic tendency Increased intake of purine rich foods Reduced excretion ( kidney failure)
Pseudogout
A syndrome caused by deposition of calcium pyrophosphate dihedral ( CPDD) Crystal deposition crystals - inflammation
Risk factors for pseudogout
Background osteoarthritis
Elderly patients
Inter current infection
Clinical features of gout
Acute mono arthritis of rapid onset ( first metatarsophalangeal joint is the most commonly affected joint - podagra)
Gout also affects other joints ; joints in foot, ankle, knee, wrist, finger, and elbow are the most frequently affected
Crystal deposits ( to phi) may develop around hands, feet, elbows and ears
What are shown on the X days of gout
Juxta articulate ‘rat bite’ erosions at the MTPJ of the great toe
Crystal arthritis synovial fluid analysis
Use polarised light to see it
Gout ; needle shapes crystals with negative birefringence
Pseudogout ; rhomboid shaped crystals with positive birefringence
RA
Chronic autoimmune disease characterised by pain , stiffness and symmetric synovitis ( inflammation of the synovial membrane ) of synovial ( diarthrodial) joints
Overview of RA
Chronic arthritis - poly arthritis : swelling of small joints of the hand and wrists is common
Symmetrical
Early morning stiffness in and around joints
May lead to joint damage and destruction - joint erosions
Extra artcular diseases can occur
Rheumatoid nodules - others such as vasculitiw and epsicoeritis
Rheumatoid factor may be detected in blood - autoantibody agains IgG
Rheumatoid arthritis ; pattern of joint involvement
Symmetrical
Poly arthritis
Affects small and large joints, but particularly hands and feet
Common affected joints; MCP PIP Wrists Knees A led MTP
Primary site of pathology in RA
Synovial arthritis
Common extra articulate features of RA
Fever
Weight loss
Subcutaneous nodules
Generally not feeling well
What are subcutaneous nodules
Nodules are classically found just below elbows but also on the fingers
Associated with severe disease of RA so may act as a prognostic factor
What cytokine is the most predominant in RA
TNF alpha
Primary clinical treatment of RA
TNFalpha inhibition
Rheumatoid arthritis autoantibodies
Rheumatoid factor ( typically IgM antibodies - IgM anti IgG antibody)
Antibodies to citrullinated protein antigens - mediated by enzymes termed as peptidyl arginine deiminases
Drug treatment of anti rheumatic drugs
1 st line treatment
Methotrexate in combination with hydroxyxhloroquine or sukfasalazine
2nd line ;
Biological therapies offer potent and targeted treatment strategies
Biological therapies of RA
Inhibition of TNF alpha
B cell depletion
Modulation of T cell co stimulation
Inhibition of IL6 signalling
RA Randi graphical changes
Joint space narrowing - Y Subchondral sclerosis - N Osteophytes - N Osteopenia- Y Bony erosions - Y
Osteoarthritis radio graphical changes
Joint space narrowing - Y Subchondral sclerosis - Y Osteophytes - Y Osteopenia - N Bony erosions - N
Psoriatic arthritis
Psoriasis is an autoimmune disease affecting the skin
Rheumatoid factors are not present
Reactive arthritis
Sterile inflammation in joint FOLLOWING infection especially urogenital and gastrointestinal
Reactive arthritis is the first manifestation of HIV or HepC infection
Systemic Lupus Erythematous ( SLE)
Can affect any organ
Clinical tests for SLE
Antinuclear antibodies ( ANA) - high sensitivity for SLE but not specific so a negative test rules out SLE but positive tests does not mean SLE
Antidouble stranded DNA antibodies ( anti -ddDNA Abs)
High specificity for SLE in the context of the appropriate clinical signs
