osteoarthritis Flashcards
definition of OA
Age-related degenerative synovial joint disease when cartilage destruction exceeds repair, causing pain and disability.
aetiology of OA
classification according distribution of affected joints
primary:
- unknown aetiology
- likely multifactorial
- wear and tear proposed
secondary - Other diseases can cause altered joint architecture and stability.
- Developmental abnormalities (e.g. hip dysplasia, Perthes’ disease, slipped femoral epiphysis).
- trauma - previous fractures
- inflammatory - RA, gout, septic arthritis
- metabolic - alkaptonuria, haemochromatosis, acromegaly
- obesity
- occupational
pathogenesis of OA
Cartilage degeneration
Should be smooth white material over bones so they can slide in a pain free way
synovial joint fissuring and fibrillation of cartilage - get down to bone
loss of joint volume from altered chondrocyte activity, subchondral sclerosis, bone cysts, osteophyte formation, patchy chronic synovial inflammation and fibrotic thickening of the joint capsules
joint effusion in some
new blood comes into bone
epidemiology of OA
Common - most common joint condition world wide
with 25% of those>60 years symptomatic (70% have radiographical changes).
More common in females, Caucasians and Asians.
usually primary
sx of OA
gradual onset
joint pain/discomfort - use related, stiffness (for 10-15mins) or gelling after inactivity
worse with prolongued activity
crepitus on movement
background ache at rest
difficulty with certain movements or feelings of instability
restriction walking, climbing stairs, manual tasks
systemic features typically absent
joints may feel unstable with a percieved lack of power due to pain
signs of OA
local joint tenderness
nodal OA:
- typically DIP, PIP, CMC joints and knees in post-menopausal women
- joint tenderness, derangement and bony swelling
- reduced range of movement
- mild synovitis/small effusions
- bony swellings along margins - Heberden’s nodes - at distal interphalangeal joints
- Bouchard’s nodes - at prox interphalangeal joints
crepitus and pain during movement - joint effusion
restriction of a range of joint movement
assess effect of sx on occupation, family duties, hobbies and lifestyle expectations
Ix for OA
CRP may be elevated
joint XR - The severity of radiological changes is not a good indicator of symptom severity. - LOSS
- loss of cartilage and joint space
- osteophytes
- subchondral cysts
- subchondral sclerosis
synovial fluid analysis
- clear
- viscous with low cell count and cartilage fragments
OA
nodal OA
affects the small joints of the hand
heberden’s nodes - swelling and osteophytes at DIP
bouchard nodes - PIP
thumb IP and base of thumb - internal rotation = squaring of thumb
large joint OA
effects the hips and the knees
joints affected by OA
small joints of the hand
heberden’s nodes - swelling and osteophytes at DIP
bouchard nodes - PIP
thumb IP and base of thumb - internal rotation = squaring of thumb
MTP
facet joints of spine in degenerative spine disease
deformities in OA
from osteophytes/loss of cartilage/joint laxity
- Heberden’s at DIP – osteophytes
- Boucharde = PIP
- Square of thumb
- Varus and valgus deformity of knee
- varus - wear away medial cartilage - lower leg go in
- Valgus – lateral cartilage wear away
OA
DIP of heberden’s node – no joint space.
Subchondral sclerosis around joint.
Osteophyte stick out from joint.
Cysts
OA
Knee medial compartment – loss of space and osteophyte
OA
Hip – lost space and sclerosis
