Osteoarthritis and Gout Flashcards
What does OA result from
joint integrity, genetics, local inflammation, mechanical forces, metabolic diseases
What happens in OA
Disease of chondrocytes: Cartilage is lost resulting in the degradation of matrix. Cartilage is replaced by bone
What are the RF for OA
Biomechanics: excessive load: knee (8x), hip, hand (3x increase). 25% of UK population obese
Women have 3x increase chance of OA. Menopausal arthritis is a well-recognised phenomenon. Hormonal factors thought to play a role.
Negative correlation between osteoporosis and OA
What are the hand signs for OA
Metacarpal pharyngeal joints tend to be spared
DIJ: Hebeden’s
PIJ: Bouchard
Bony swelling
What are the pain symptoms of OA
Principle symptom is pain: typically exacerbated by activity and relieved by rest. Inactivity gelling is common, although morning stiffness typically lasts less than 30 minutes
What are the examination findings of OA
Predilection for fingers, knees, hips and spine
Rarely affects elbows, wrists (except carpal metacarpal joint)or ankles
Joint tenderness
Bony enlargement
Effusions
Crepitus
What are the radiograph findings of OA
loss of join space, joint line sclerosis, osteophytes, subchondral cysts (white line
What is avascular necrosis in hip
loss of blood supply to femoral head. Can occur in complication of OA.
What is the treatment for OA
Weight loss, physio, pain relief, joint replacement. Start by looking at non-medication based treatment
What is gout
build up on uric acid due to purine metabolism. Xanthine oxidase is key enzyme to turn purine to uric acid.
What are the clinical features of gout
Severe pain of rapid onset
First attack always single joint and never axial skeleton
Great toe MTPJ > 50%
Subsequently any join
What is tophus
Tophus is a deposit of uric acid crystals: can occur in subcutaneous, elbows and ears as well
Bone will be eroded under tophus. Tophus is radio-lucent and will be peri-articular
Scleroderma has similar radiological findings
What do uric crystal deposits in kidneys do
interstitial disease
How is diagnosis confirmed
Diagnosis can be confirmed with arthrocentesis
Crystals are negatively birefringent
Calcium pyrophosphate crystals are positively birefringent
What is the treatment for OA
xanthine oxidase inhibitors. Look out for azathioprine
What is pseduogout
calcium pyrophosphate disease
What are the RF for pseudogout
advancing age, prior joint trauma, familial chrondrocalcinosis, hemochromatosis, hyperparathyroidism hypomagnesemia and hypophosphatasia
What are the signs of pseduogout
Mono or oligoarticular disease seen in 89% of cases
Rapid onset severe joint pain
Peak intensity within 6-24 hours
Fever
Overlying erythema and desquamation
Resolution in 3-4 days
Chondrocalcinosis radiological hallmark of pseudogout
Who should not get gout
Pre-menopausal women should not get gout
What is acute gout caused by
fluctuations in serum urate. Measuring uric acid during an attack is not helpful.
Hyperuricemia in males is over 042, and in females over 0.36
What are the RF for gout
hyperuricemia, persistent alcoholic consumption, diuretic use, high BMI, lipid disorders, older age, male sex, genetics
Fructose has no effect on satiety. Massive RF for gout
What’s the difference in birefrigency between gout and pseudo
Gout negative
Pseduogout positive
What is the distribution of OA
Predilection for fingers, knees, hips, and spine
Rarely affects the elbows, wrists, or ankles
What is the pathway of OA treatment
Topicals->Paracetamol->NSAIDS/COX2->Intra-articular steroid
Co-prescribe PPI with NSAIDS/COX2
Caution with use of NSAIDs alongside low dose aspirin
Do not offer: glucosamine or chondroitin, intra-articular hyaluronan
What is the pathway of purine metabolism
Hypoxanthine->Xanthine->Uric acid
What is purine metabolism catalysed by
Xanthine Oxidase
What are hyperuricaemia levels
Males: >0.42mmol/L
Females: >0.36mmol/L
What are treatment options for gout
NSAIDS: naproxen - avoid in renal, cardiac, or liver disease
Colchicine: 1 mg STAT
Prednisolone: 30 mg od - caution in DM/CCF
Xanthine oxidase inhibitors to prevent recurrence
Allopurinol - rash and risk of DRESS
Fexbuxostat - occur in eGFR, beware theophylline
