Osteoarthritis Flashcards
What is osteoarthritis?
Most common joint condition in the world.
It is usually primary aka generalised, but can also be secondary.
It is a degenerative joint disorder in which there is progressive loss of articular cartilage accompanied by new bone formation and capsular fibrosis.
Definition of OA.
Osteoarthritis (OA) is the result of mechanical and biological events that destabilise the normal process of degradation and synthesis of articular cartilage chondrocytes, extracellular matrix, and subchondral bone.
It involves the entire joint, including the articular cartilage, subchondral bone, pericapsular muscles, capsule, and synovium. The condition leads to loss of cartilage, sclerosis and eburnation of the subchondral bone, osteophytes, and subchondral cysts. It is clinically characterised by joint pain, stiffness, and functional limitation
3 possible aetiologies of OA.
Failure of normal cartilage subject to abnormal or incongruous loading for long periods.
Damaged or defective cartilage failing under normal conditions of loading
Break up of cartilage due to defective stiffened subchondral bone passing more load to it.
Key features of cartilage in OA.
Loss of elasticity with a reduced tensile strength.
Cellularity and proteoglycan content are reduced.
Risk factors of OA.
Age - radiographic OA can be seen in 80% of people of over 65.
Women > Men
Obesity
Trauma
Genetics
Hypermobility
Osteoporosis
Disease
Occupation
Sports
Causes of secondary OA.
RA
Gout
Spondyloarthropathies
Trauma
Septic arthritis
Paget’s
Haemachromatosis
etc…
Symptoms of OA.
Pain and stiffness.
Thre can inactivity gelling and joints “giving way”.
There can be some morning stiffness but this is less than 30 minutes.
Explain the pain in OA.
The pain is usually exacerbated with activity, movement and weight bearing. Pain at rest or at night is unusual.
Early on in the disease the pain might be intermittent but as it progresses it becomes constant.
The pain is often localised to joints affected.
Joints involved in OA.
Knee, hip, hands and lumbar+cervical spine.
1st CMC is commonly affected.
MCPJ are spared but PIPJs and DIPJs can be affected. This is the case in generalised OA.
What are nodular disease of DIPJs called?
Heberden’s nodes
What is nodular disease of the PIPJs called?
Bouchard’s nodes.
What other signs might be seen in the hands?
Squaring at the base of the thumb at the carpo-metacarpal joint
Weak grip
Reduced range of motion
1st line investigations of OA.
X-ray of joints
CRP - should come back normal
ESR - should come back normal
X-ray findings of OA.
LOSS
Loss of joint space
Osteophytes
Subarticular sclerosis
Subchondral cysts.
Diagnostic criteria of OA.
Knee pain plus at least 5 of the following 9 criteria:
age >50 years;
stiffness <30 minutes;
crepitus;
bony tenderness;
bony enlargement;
no palpable warmth;
erythrocyte sedimentation rate (ESR) <40 mm/hour;
rheumatoid factor <1.40;
synovial fluid signs of OA.
+ radiological findings.
