Osteoarthititis and crystal arthropathies Flashcards
What is osteoarthiritis
Progressive, degenerative condition affecting joints due to gradual thinning of cartilage, loss of joint space and formation of bony spurs
What is the matrix of the cartilage formed by?
Chondrocytes which are embedded within it
What is the pathogenesis
Loss fo matrice, release of cytokines including IL-1,TNF and mixed metalloproteinases as well as prostaglandins by the chondrocytes
Formation of the cartilage surface and attempted repair with osteophyte formation then occurs
What are the classic symptoms?
Gradual onset ( moths-years)
Mechanical pain- i.e. pain worse on activity, worse end of the day, received by rest
Crepitus- grinding/cracking on movement
Stiffness (<30 mins),inactivity gelling
Bony swellings and deformities of joints
Can get effusions and soft tissue swelling (synovial thickening)
Can lead to loss of function and morbility
What is general varus
A cowboy leg appearance
What may be seen in the hands?
DIP,PIP and 1st CMC joints
Bony enlargements may be seen as DIPs (Heberdens nodes ) and PIPs (Bouchards nodes)
Squaring of the thumb
What can be seen in the knee?
osteophytes, effusion, crepitus and restrictions of movement
Genu varus and valgus deformities
Bakers cyst
What can be seen in the hip?
Restricted movement
the pain felt here may be radiating from the lower back
What can occur with osteophytes?
cervical-may impinge on nerve roots
lumbar-osteocytes can cause spinal stenosis if encroach on spinal canal
What are risk factors for OA
Age (40+)
Gender- F
Genes (e.g. nodal arthritis)
occupation 0 rep stain, heavy lifting
Previous injury/joint abnormality e.g. hypermobiility
Obesity
Other underlying conditions e.g. rheumatoid arthritis, gout, acromegaly
Why are history and examination so important
Exclude primary inflammatory arthiritis
What investigations are usually done?
Bloods- inflammatory markers usually normal
X-rays - typical changes inc joint narrowing, subchondral sclerosis, bony cysts and osteophytes
What are the primary joints affected in RA and OA
RA- MCP, PIP
OA-DIP, CMC
Heberden’s nodes are frequently present in RA T/F
F- they are absent . hebredens nodes are frequently present in OA
What are the joint characteristics of RA and OA
RA- sort, warm,tender
OA-Hard, bony
RA is worse after resting t/f
T
N.B. is present stiffness will be worse in OA after effort, may be described as evening stiffness
Which arthritis has a positive rheumatoid factor, anti CCP antibody and elevated ESR and C reactive protein
RA
What is the non-pharmacological management?
Education Physiotherapy WT loss Footwear Aids
What is the pharmacological management?
Analgesia- paracetamol ect
NSAIDs
Pain modulators - amitriptyline ,gabapentin
Intraarticular steroids-only short term relief
What could be done in terms of surgery?
Arthroscopic washout, loose body, soft tissue trimming
joint replacement
What are the two main conditions of crystal arthopies
Gout
Pseudogout
What is Gout?
Inflammatory arthiritis associated with Monosodium urate crystal deposition
most common inflammatory arthritis in men
What is Pseudogout?
Calcium pyrophosphate sihydrate/CPPD
What is hyperuricaemia?
serum uric acid >7mg/dL
The risk of developing gout is higher the higher the serum uric acid
What is diagnosis of gout based on?
Diagnosis of gout is based on identification of crystals or classic radographical findings, not hyperuricemia alone
When is the best time to check uric acid
2 weeks after the attack
What is acute monoarticular gout
Rapid onset red-hot joint severe pain Duration- up to 2 weeks Site- 1st MTPJ>ankle>knee>upper limb joints>spine
Ddx of gout
Septic arthritis
Trauma
Seronegative arthritis (e.g. psoriatic arthititis, Reiter’s- but need to ask regarding associated symptoms e.g. skin psoriasis, eye symptoms, urethritis
Chronic polyarticular gout
Chronic joint inflammation
Usually after having recurrent acute attacks >10 years
often diuretic associated
What is the gold standard for dignosing gout
joint aspirate
needle-shaped crystals
Negative birefringerence on polarised light microscopy
Management of gout
NSAIDs if no contraindication or colchicine or corticosteroids (oral/IM/IA)
Other analgesia e.g. opiates, paracetamol
What lifestyle modifications- can help with gout
Restrict red meat, offal, beans, shellfish
Reduce alcohol
lose weight
Fluids- 2L/day
What could be included in prophylaxis of gout attacks?
Urate lowering therapy
- Allopurinol/Febuxostat
- start 2-4 weeks after acute attack
- start low dose and titrate
- aimf or target serum rate <0.30mmol/L
What is Pseudogout and how is it diagnosed (also called CPPD)
using a microscope to see small calcium pyrophosphate crystals in joint fluid. They are rhomboid/envelope shaped and there is a weakly positive birefringence
What is the treatment of pseudo gout?
NSAIDs
Colchicine
Steroids
Rehydration
What is hydroxyapatite?
Hydroxyapatite crystal deposition in and around the joint. Females 50-60
Alizarin stain shows red clumps
