Rheumatology Flashcards
define OA
A progressive disorder of the joints caused by gradual loss of cartilage and resulting in the development of bony spurs and cysts at the margins of the joints.
Commonest form of arthritis
‘Wear & Tear’ or ‘Degenerative Joint Disease’
pathophysiology of OA
Pathophysiology
Loss of cartilage & narrowing of the joint space
Low grade synovial inflammation
Thickening of subchondral bone
Development of bony outgrowths - osteophytes
secondary causes of OA
Primary causes of Osteoarthritis
- Metabolic
- Ochronosis, hemochromatosis, acromegaly, COPD - TRAUMA
- major trauma , fracture, meniscectomy, chronic occupation, repetitive injury / stress - ANATOMICAL
- congenital, slipped epiphysis, AV necrosis, congenital hip - POST ARTHRITIS
- inflam arthritis, RA
Primary causes of OA
Age (4) Obesity Heredity (TWIN STUDY - mutation in type 2 college fibre) Sex (WOMEN) Occupation Predisposing secondary causes Trauma/injury Joint shape Repetitive Use Muscle weakness Joint Laxity
how does increase age put you at risk of OA
- Old cartilage heals less well
- Decrease muscle strength and muscle bulk
- decrease joint propiception
- increase incidence to old age
ddx for OA
- Crystalloid arthritis (gout, pseudo gout)
- inflam arthritis
- SN arthropathies
- Septic arthritis
- Pos-infectious arthropathy
- Fibromyalgia
- tendonitis
important mediators involved in cartilage damage
Cytokines: TNF-a, IL-1, Il-6
collagenases, metalloprotineases, aggrecanases
important mediators in protecting cartilage
IL-4 and TIMP , TGF-b, & IGF-1 protective
Complications of OA
Chondrolysis – Rapid, complete breakdown ofcartilageresulting in loose tissue material in thejoint(Bone death (osteonecrosis). Stressfractures(hairline crack in the bone that develops gradually in response to repeated injury or stress). Heamarthroses – Bleedinginside the joint. Septic arthritis – Infection in the joint. Gout/Pseudogout Joint instability – Deterioration or rupture of the tendons and ligaments around the joint, leading to loss of stability. Pinched nerve (in osteoarthritis of the spine)
strong risk factors for gout
Increasing age Male gender Menopausal state Use of diuretics Iatrogenic Tacrolimus, aspirin High cell turnover Lymphoma’s, chemo Genetic susceptibility Triggers: Alcohol, dehydration
Ddx gout
Pseudogout (calcium pyrophosphate deposition)
Septic arthritis Trauma Rheumatoid arthritis Psoriatic arthritis Reactive arthritis
when do you do uric acid level
Wait > 2 weeks
DO NOT PERFORM in acute attack
x- ray findings in gout
X-Ray of affected joint:
Peri-articular erosions
Punched out appearance
Over hanging edge
3 complication of gout
Nephrolithiasis
Acute uric acid nephropathy
Increased CAD/CVD risk
A 46 year old female patient of Maori heritage presents to her General Practitioner with an acute mono-articular pain, very sudden on onset and 10 out of 10 in severity. She has a history of diabetes mellitus and peptic ulcer disease. The presumptive diagnosis is acute gout. What is the most likely risk factor contributing to her illness?
Maori heritage (family history)