Osteoarthritis Flashcards
epidemiology, pathophysiology, presentation, investigation, management and prognosis
Is the onset of OA gradual or rapid, and from what age does OA onset begin?
Gradual onset from age 40
Between what ages does OA incidence increase rapidly?
50-75
What percentage of individuals with OA have limited mobility?
80%
What percentage of individuals with OA have difficulty performing daily lifestyle activities?
25%
Is prevalence and risk of OA higher in men or women?
Women
How does change in composition of the articular cartilage due to OA affect it’s susceptibility to physical forces?
Becomes more susceptible to disruption by physical forces, which is why mechanical stress causes joint degeneration
How much of a joint does OA degenerate?
Entire joint
What cells cause articular cartilage to degrade and reveal underlying bone in OA, and what do they release to cause degradation?
Chondrocytes in areas of stress, that proliferate and release inflammatory mediators that degrade cartilage matrix
After the articular cartilage degrades and underlying subchondral bone is revealed in OA, how does new articular cartilage form?
Underlying subchondral bone becomes the new articular cartilage
In the process of articular cartilage degeneration and underlying subchondral bone becoming the new articular cartilage, how does this affect the joint space in OA?
Causes joint space narrowing
How does subchondral sclerosis occur in OA?
Mechanical stress on underlying subchondral bone (that has become new articular cartilage) grows and hardens
How do osteophytes form from the new articular cartilage in OA?
Local bony areas grow into outgrowths/protrusions
What factors are released in OA that result in pain and inflammation, and how do the factors stimulate this?
Vascular growth factors stimulate neurovascular development, which causes pain and inflammation in the joint
How do bone cysts form in OA?
They form in areas of localised bone necrosis and resorption, which occurs due to stress-induced microfractures in subchondral bone
What is subchondral bone?
Bone beneath articular hyaline cartilage
How does OA affect the synovial lining, and what is the name of this condition?
Synovitis: inflammation and thickening of synovial lining
What is the name of swelling that occurs in OA?
Joint effusion
What is the difference between primary OA and secondary OA?
Primary OA arises from non-specific/idiopathic cause
Secondary OA arises from another specific cause
Give 3 examples of causes that can lead to secondary OA onset?
Trauma, RA, infection
Does OA present in the same way in every joint?
No, presentation of OA depends on type of affected joint
What aspect of the knee is affected by OA, and what is the resulting deformity?
Affects weight-bearing inner aspect which narrows joint space, so results in varus deformity, characterised by bow-legged look
When does pain occur due to knee OA, and how does it change throughout the day?
Activity-related pain that is worst at night and is relieved by morning due to rest
Is elbow OA common in primary or secondary OA?
No, it is rare
What 4 movements are painful due to elbow OA?
Elbow flexion, extension, supination, pronation